project: chesser house sustainability project · sustainable practice approaches ... 6 phase change...

Project No: SSE1307D Date: May 2010 Revision: 0

Project:

CHESSER HOUSE SUSTAINABILITY PROJECT

Prepared For:

Harmony Corporation Pty Ltd

Level 8, 26 Flinders Street Adelaide SA 5000 Prepared by:

System Solutions Engineering Level 1, 75 Fullarton Road Kent Town SA 5067

SYSTEM SOLUTIONS ENGINEERING PTY LTD

SSE1307D Final Report 1 Chesser House Sustainability Report

TABLE OF CONTENTS

TABLE OF CONTENTS .............................................................................................................................. 1

Executive Summary .............................................................................................................................. 3

Acknowledgements ............................................................................................................................. 4

Disclaimer .............................................................................................................................................. 5

Introduction ............................................................................................................................................ 6

1 Aim ................................................................................................................................................ 6

2 Scope ............................................................................................................................................ 6

3 Description of Chesser House .................................................................................................... 7

4 Overview of report ....................................................................................................................... 7

Observations .......................................................................................................................................... 8

1 Energy analysis of Chesser House ............................................................................................. 8

Business As Usual Approaches ............................................................................................................ 9

1 Overview ...................................................................................................................................... 9

2 Re-Commissioning and Re-Tuning ............................................................................................ 9

3 Heat Recovery Ventilation ....................................................................................................... 10

4 High Efficiency Lighting ............................................................................................................. 12

5 Outdoor air Economy Cycle Systems ..................................................................................... 14

6 Part Load Performance ............................................................................................................. 15

7 Metering ..................................................................................................................................... 17

8 Gas Fired Technologies ............................................................................................................ 19

9 PICCV .......................................................................................................................................... 20

10 Summary..................................................................................................................................... 21

Sustainable Practice Approaches .................................................................................................... 22

1 Overview .................................................................................................................................... 22

2 High Efficiency Thermal Insulation ........................................................................................... 22

3 Lighting Control .......................................................................................................................... 24

4 Chilled Beams ............................................................................................................................ 25

5 Glass Coatings ........................................................................................................................... 26

6 Cogeneration ............................................................................................................................. 28

7 Regenerative Lift Braking Systems ........................................................................................... 32

8 Occupant Comfort Control ...................................................................................................... 33

9 Shaw Method of Air Conditioning ............................................................................................ 36

10 Fuel Cells .................................................................................................................................... 38

11 Absorption Chillers .................................................................................................................... 40

12 Indirect Evaporative Cooling ................................................................................................... 41

13 Natural Ventilation ..................................................................................................................... 44

14 Induction VAV Technology ...................................................................................................... 46

15 Summary..................................................................................................................................... 48

Stretch Objectives ............................................................................................................................... 49

1 Overview .................................................................................................................................... 49

2 Geothermal Systems ................................................................................................................. 49

3 Innovative Shading ................................................................................................................... 51

4 Air Engines .................................................................................................................................. 53

5 Green Walls/Roofs ..................................................................................................................... 55

6 Phase Change Materials .......................................................................................................... 62

7 Building Integrated Photo Voltaic............................................................................................ 64

8 Solar Air Conditioning ............................................................................................................... 67

9 Energy Enhanced Gas .............................................................................................................. 69

10 Fibre Optic Solar Lighting .......................................................................................................... 71

11 Wind Energy ............................................................................................................................... 74



12 Summary..................................................................................................................................... 76

Recommendations and Conclusions ............................................................................................... 77

1 Concept Comparisons .............................................................................................................. 77

2 Recommendations for Chesser House ................................................................................... 81

3 Recommendations for Similar Buildings ................................................................................. 81

4 Conclusion ................................................................................................................................. 82

References ........................................................................................................................................... 83

1 Internet Resources Used ........................................................................................................... 83

2 Text Resources Used.................................................................................................................. 83

3 Modelling Programs Used ........................................................................................................ 84



EXECUTIVE SUMMARY

This report is written to investigate and compare the feasibility of implementing a number of energy saving techniques at Chesser House, ranging from common practice approaches to innovative stretch objectives. Consideration is also given to the suitability of each technique in existing and new commercial office buildings.

The methodology used was to introduce each concept, describe how it can be applied, estimate costs and energy savings and provide views on the level of demonstration available in implementing the concept. A detailed comparative analysis utilising weighted parameters was then used to give each concept a score, such that conclusions and recommendations could be made.

Results of the analysis indicated that the best course of action for Chesser House included undertaking a re-commissioning and re-tuning plan, improving metering, upgrading base building lighting, implementing a daylight control strategy, installing fuel cells and installing building integrated photovoltaic panels. For other commercial office buildings (new or existing) a number of concepts were identified as potentially being worthy of further consideration, including concepts such as glass coatings, high efficiency lighting, building integrated photovoltaic panels, improvements in metering, occupant comfort control, lighting control, the Shaw Method of Air Conditioning, fuel cells, re-commissioning and re-tuning and economy cycle systems.

It was found that the proposed system for Chesser House reduced base building greenhouse gas emissions by 8.6% and base building electricity consumption by 12.5%. These results show a significant level of energy and greenhouse gases can potentially be saved. This resulted in an increase in the unofficial NABERS energy estimation from the current 3.5 stars to 4 stars, representing best practice.

The report was limited primarily by both time constraints and sensitivity of information. The report was set a time period for which to be completed, as such all investigation, modelling and reporting were limited in a sense. This also affected the quantity of concepts considered, as the report did not consider every applicable concept available. Sensitivity of information limited the report by reducing the availability of technical data for some of the more innovative concepts. Due mainly to the prototype nature of many concepts, technical data was difficult to source, leading to manufacturer’s claims being unverifiable.



ACKNOWLEDGEMENTS

This report received funding support through the Government of South Australia's Building Innovation Fund. The Fund aims to establish South Australia as the nation’s leader in demonstrating innovative and leading edge approaches to reducing the carbon footprint of existing commercial office buildings, and is delivered under the climate change sector agreement between the South Australian Government and the Property Council of Australia (South Australian Division).



DISCLAIMER

This report is prepared to assess the suitability for further investigation/implementation of several technologies/concepts at Chesser House. The report also provides views on potential application of technologies/concepts to other commercial office buildings. Detailed investigation should be completed before proceeding with any of the concepts/technologies presented in the case of other commercial office buildings, as suitability of the concept/technology may vary significantly.

Quoted energy savings and costs are based on information sourced from manufacturers and are estimates only. Accurate energy savings and budget prices should be sourced directly from manufacturers, due to variations in technology and market conditions.

All information collected and used to compose this report is considered to be ‘freely available’; as such there is no intention to expose sensitive information associated with technologies/concepts.

Due to the nature of some concepts/technologies presented in this report, no guarantees can be made regarding the availability, reliability and outcomes associated with the concepts/technologies.

Energy savings and GHG abatement potential were calculated using energy consumption data sourced from investigating the systems currently operating in Chesser House, such that whole building consumption could be estimated. For each technology, where possible, the resulting energy savings were calculated by modelling the effects on Chesser House, such that a new total building consumption could be determined. This allowed reductions in GHGs and energy to be quantified and formed the basis for the NABERS estimation. During the reporting phase, several upgrades were taking place which affected consumption, as such; minor differences in whole building consumption may be present.



INTRODUCTION

1 AIM

This report is completed with the intent of studying possible commercial office building energy saving techniques for potential future application to Chesser House, 91-97 Grenfell Street, Adelaide. Main aims include identifying suitable methods of reducing building energy consumption, investigating innovative sustainable concepts and promoting or demonstrating sustainable practice within the industry and general public.

Whilst identifying energy saving techniques suitable to Chesser House is a main aim of the report, there will also be considerable focus on other situations where a particular concept may be suitable. This is intended to allow other buildings to incorporate concepts investigated within this study, such that the report is not limited only to Chesser House. This allows a wider range of concepts to be studied (some which may not be directly applicable to Chesser House) and also provides a means of promoting the concepts within the industry.

Innovation is included as a main aim of the report as ‘pushing the boundaries’ of common office building energy saving practice was deemed necessary to produce more significant results. For several years, there has been considerable push to find new sustainable practices, which this report aims to respond to, whilst also comparing what can be considered common with more innovative concepts.

Demonstration potential of concepts studied is also included as a main aim, as furthering awareness of the possible applications of the technologies is important to provide education and encouragement for other industry members and the general public.

2 SCOPE

The scope for the report is as follows:

- Site inspections and familiarisation. Regular inspections were made to gain a complete understanding of the building itself and the systems operating within it.

- Collection of site metering Data, drawings and any other relevant technical data available.

- Detailed research and evaluation of potentially appropriate concepts, including decision making on the necessary detail of investigation required for each concept. The basis for selecting the concepts is focused on energy savings and innovation; however such factors as water consumption and indoor environment quality were taken into account. The report is primarily concerned with refurbishments, however new buildings are also considered.

- Detailed modelling and calculations of both the current state of operation of Chesser House and the expected outcomes after implementation of each concept. Availability of information and applicability to commercial office buildings dictated the level of modelling undertaken for each concept. Technologies which were expected to return insignificant savings or had little to no available technical data necessary to perform modelling, were not modelled in detail.

- Review of current systems within Chesser House, including noting observations.

- Preparation of this report, including detailed comparisons of potential sustainable and innovative upgrades to Chesser House and recommendations of future works.



3 DESCRIPTION OF CHESSER HOUSE

Chesser House is a 12 story commercial office building located on Grenfell Street, within the central business district of Adelaide, South Australia. Adelaide experiences a climate consisting of hot, dry summers and cold, wet winters. The climate is such that heating and cooling requirements are a 50% split, with approximately half of the year dedicated to providing heating or cooling. Adelaide’s summers are however quite extreme, with temperatures putting large amounts of stress on building’s air conditioning systems, and in turn, the electricity grid.

Chesser House is identifiable by its vast expanses of highly tinted, glazed facade, which covers floors 2 through to 11. The glazed floors sit upon a base (ground and first floor), which is a different structure composed of red brick and having a larger floor plan. Essentially, the ground and first floor have a much large area associated with them, with floors 2 through to 11 being considered as ‘typical floors’. The 12th floor is a rooftop plant room.

4 OVERVIEW OF REPORT

This feasibility report is written with the intent of describing and comparing a broad range of energy saving techniques available, from basic practices to more innovative methods. To assist in clarifying how each concept should be viewed, the report is split into three main categories; Business as usual approaches, sustainable practice approaches and stretch objectives. This was deemed necessary to gain an understanding of what approaches to energy savings should already be in place and which approaches should be considered sustainable or innovative. Each concept will be described individually such that relevant comparisons between concepts can be made.

Business as usual approaches is essentially energy saving techniques which should be considered as standard practice within a commercial office building. The techniques are generally not technically intensive or particularly expensive to implement, rather they are a simple and effective way to save energy with little need for significant changes throughout the building or its systems. Most of the techniques described in this section are quite versatile and may be applicable to almost any new or existing building.

Sustainable practice approaches are considered to be more recognisable sustainable or ‘green’ practices which are applied to buildings seeking to reduce their energy consumption and promote a sustainable image. The concepts involved in this section are considered less common methods of energy reduction, however may be more widely known for their sustainable characteristics and as such have a good level of demonstrative potential. The complexity of the concepts presented varies however generally they are more costly and difficult to implement to existing buildings than those presented in the ‘business as usual section’.

Stretch objectives, as the name suggests, covers the more innovative and ambitious energy saving techniques which are not commonly applied to buildings due mainly to the large capital investments required and the ambiguity of the results surrounding many of the concepts. Typically these concepts would be more applicable to new buildings with fewer design constraints; however they have the potential to be applied in existing buildings given the appropriate circumstances. These concepts are objectively studied for application at Chesser House to gain an insight into how they perform competitively with more widely used approaches to energy saving.

Each topic to be presented is done so firstly by introducing the concept and its typical applications and providing an overview of the inherent strengths and weaknesses. The concept is then described in detail, to provide an understanding of its operation and the results it can achieve. The energy saving potential is then qualitatively and for most concepts, quantitatively described for application at Chesser House. There is also discussion of potential savings available for application to other typical office buildings, where the concept may be more suited. Concepts which fall under the ‘Sustainable Practice’ and ‘Stretch Objectives’ sections also include discussion regarding the demonstrative potential available.



The concepts are then compared using such metrics as expected costs, potential energy savings and demonstrative potential. Recommendations are then made for which concepts may be best suited to Chesser House; there are also recommendations as to what other situations the concepts may be applicable.

OBSERVATIONS

1 ENERGY ANALYSIS OF CHESSER HOUSE

In terms of energy consumption, Chesser House is performing slightly above average; there is however significant potential for reducing energy consumption further – making the building represent a standard of excellence, in terms of energy efficiency. Chesser House was built in the late 1980s, as such the levels of energy efficiency are not at the standard of newer buildings. This leads to the potential of considerably reducing energy consumption though simple measures due to the introduction of new technology over the years.

Air conditioning systems within commercial office buildings are accountable for a large portion of the total energy consumption, with Chesser House being no different. Chesser House’s air conditioning strategy includes a rooftop chilled water plant with floor by floor air handling units. The floor by floor air handling units are very inefficient in their mode of operation as they incorporate both reheat and VAVs, which wastes both fan and cooling energy. Another significant energy waste is present on the ground floor, with a single, small retail tenancy operating outside usual office hours and being air conditioned by a water cooled package unit, which serves half of the ground floor. The operation of this package unit also causes the respective rooftop cooling tower to operate.

Another issue which is present at Chesser House, which effects Chesser House’s base building NABERS rating is metering. There are cases within the building where energy is being attributed towards base building consumption, when the consumption should actually be under tenant consumption. This adds to the base building’s energy consumption, and in turn, reduces the NABERS rating.

Correcting the above two issues has the potential to raise the NABERS rating significantly, as such allowing Chesser House to operate at a much higher level of energy efficiency.



BUSINESS AS USUAL APPROACHES

1 OVERVIEW

The phrase ‘business as usual’ refers to the normal course of action undertaken during what can be considered as business. The decision in using the phrase as the title for this section is based upon the fact that the concepts presented within this section should be viewed as just that; actions which should be considered standard during operation of a building. Luckily, there are many individuals within the industry who would consider the list of concepts presented in this section as part of their business as usual approaches in design, costs however can frequently lead to some concepts being neglected.

This section discusses the potential application of the Re-commissioning/Re-tuning of a building, heat recovery ventilation, high efficiency lighting, outdoor air economy cycles, part load performance, improved energy metering, gas fired technologies and pressure independent constant characterised valves. This list represents commonly known approaches which focus on reducing wasted energy throughout buildings; the concepts themselves are usually applied in most designs, however frequently buildings can be seen without them place.

2 RE-COMMISSIONING AND RE-TUNING

2.1 INTRODUCTION

Re-commissioning and building re-tuning involves both regular inspections of building services operations such that they conform to their original design and also repairing/replacing systems or installing new systems such that the building can operate more efficiently. The motive for this is simply to identify which systems are not performing as originally intended or which systems are redundant and could be replaced. These systems can be applied both to new or existing buildings, in the form of a detailed re-commissioning plan.

Various systems within buildings deteriorate over time from their optimal operating condition, due to ageing or outdated equipment, changing occupant requirements and deferred maintenance. All of these factors can steadily accumulate into inefficiencies which may go un-noticed during standard operation and maintenance. The levels of which these inefficiencies are present depend on both the age of the building and the nature of the systems operating within; however for any new or existing building a re-commissioning plan has the potential to identify and save significant quantities of wasted energy.

Re-tuning of a building refers to the actions taken after determining which systems within an existing building require maintenance or updating. The extent of this works can vary significantly, depending on the nature of the defects or redundancies present. Generally, replacing an existing system within a building which has been in operation for a significant period of time with a new version of the technology will return savings, due to advances in technology leading to increased levels of efficiencies.

The only real disadvantage associated with a re-commissioning and re-tuning plan is the disruption to occupants caused by the surveying and works. This can be resolved however, if the possibility of out of business hours work is feasible.

2.2 SYSTEM DESCRIPTION

A typical system for Chesser House could include an independent team consisting of relevant professionals working with maintenance staff to thoroughly re-commission and re-tune the building where required. Generally a re-commissioning strategy will include an initial design/investigation phase, followed by a measuring/recording phase, followed by a correcting phase and concluding with a recommendation for future works phase.

The initial design and investigation phase will include a thorough assessment of the requirements of the building occupants and the current mechanical, electrical and hydraulic



systems operating within Chesser House. This phase primarily focuses on giving the re-commissioning team an understanding of how the building is currently operating.

The measuring and recording phase involves physically measuring or testing all or a random selection of building services during operation, these tests could include measuring air quantities leaving diffusers or measuring chilled and heating water flows. Completing this will show which systems are still working close to their design set-point and which systems will require modifying or updating.

The correcting phase will include such actions as balancing the air conditioning systems and calibrating sensors as per requirements. This phase will resolve issues which have become apparent through the measuring and recording phases, and will also provide minor modifications to respond to changing occupant requirements.

After completing the re-commissioning phase, recommendations can be made of systems which have been identified as requiring replacement/updating.

2.3 ENERGY SAVING POTENTIAL

The energy saving potential of re-commissioning and re-tuning is relatively high, as it provides a systematic approach to identify and solve inefficiencies and problems, with little immediate investment on equipment or systems. Essentially, the age of the building, the amount of occupant changes and the standard of the original design and construction will determine the amount of energy available to be saved.

3 HEAT RECOVERY VENTILATION

3.1 INTRODUCTION

Heat recovery ventilation refers to the use of air as a heat transfer medium to recover or reject heat while ventilating a space. The process of ventilating a building during periods of extreme ambient conditions and maintaining an interior set point temperature through air conditioning requires significant amounts of energy. Using a heat recovery ventilator, it’s possible to reduce the energy used to condition the outdoor air by approximately 75%. The effectiveness of heat recovery ventilation relies on the proportion of outdoor air relative to return or recycled air, with the potential savings increasing with the greater amounts of outdoor air required. Section J of the Building Code of Australia stipulates requirements for new buildings regarding heat recovery systems; such that for outdoor air flow rates of greater than 1000L/s, heat recovery must be used (CO2 monitoring can be used as an alternative). Recently, increased awareness of the relation between indoor air quality and occupant comfort has driven a demand for large quantities of outdoor air (Green Star points are awarded for surpassing Australian standards), making heat recovery a standard feature in buildings which aim to achieve sustainability.

Typically heat recovery ventilators are enclosed units which include two fan powered air paths driving air through a heat exchanging medium, with pre-filtration. Heat recovery ventilators also completely separate each stream of air; such that mixing does not occur (this is necessary to ensure no cross-contamination occurs). The units require little energy input, with the fans being sized to account for the increased static pressure. Efficiencies vary depending on the unit, however currently most units range between 70-80%, which (minus the fan energy required for the unit) directly equates to the achievable reduction in cooling/heating power requirements.

Heat recovery ventilation is best suited to situations where a large amount of outdoor air is required relative to supply air. Such situations exist in special cases such as operating theatres and commercial kitchens or also in highly populated rooms such as meeting rooms and classrooms.


Chesser House is primarily comprised of general offices, waiting areas/customer service areas and some meeting/board rooms. Therefore, a majority of the building does not require a



large proportion of outdoor air. The building however exhausts 6400L/s of semi conditioned air through a toilet exhaust fan riser and general tenant exhaust fan riser (both located in the 12th floor plant room), which could potentially be used through a large heat recovery ventilator and ducted down through penetrations to each floor’s AHU. However the cost and structural considerations involved in providing penetrations and the associated ductwork would make it an infeasible concept, indicating that heat recovery ventilators are not a suitable solution for Chesser House.

The Australian standard for outdoor air requirements in an office space is to allow for 10L/s of outdoor air per person per, with 1 person per 10m2 of floor area. Using the thermal simulation program, Camel, to model a typical floor of Chesser House, an estimate of the conditioned supply air is approximately 10,000L/s. A calculation of the outdoor air requirements results in 880L/s per floor, which shows less than 10% outdoor air is required. This ratio is too low to achieve any significant savings and would take some time to offset the embodied energy required in manufacturing the unit and modifying the ductwork within the building. Also the associated fan energy required to operate any heat recovery system will most likely outweigh the savings achieved through reductions in heating/cooling energy.

Temperature occurrences for Adelaide show that for a vast majority of the time the ambient air temperature is close to room design conditions, as can be seen on the chart below. This indicates that as the temperature difference is low, the potential for saving energy with heat recovery is also low.

Figure 3.1 Temperature Occurrence for a 12 hour day (9am-9pm)

Currently, Chesser House has a high proportion of recycled (or return) air, meaning that the small amount of outdoor air is being mixed with the large amount of return air, before being conditioned. This mixing is effectively a better form of heat recovery than using a ventilator, as such, the current system utilising return air should be maintained to Chesser House. A worthwhile exercise however would be to survey each floor to determine outdoor air requirements and re-commission each air handling unit such that it delivers the minimum outdoor air quantity. Also, the installation of CO2 sensors on each floor to control the amount of outdoor air could reduce the required amount of outdoor air, hence saving energy.

A possible alternative to heat recovery ventilation is to implement a heat recovery system utilising water, where water becomes the mode of heat transfer. Again this isn’t deemed feasible for application at Chesser House, as the costs of installing such a system would greatly outweigh the benefits.




As discussed above, heat recovery technology frequently does not provide high levels of energy savings unless a large quantity of outdoor air is required. As such the annual energy savings achievable through the use of heat recovery at Chesser House is negligible. An important factor worth mentioning however is the ability to reduce peak load requirements, and in turn, reduce air conditioning capacities.

The above toilet exhaust heat recovery system would be expected to provide savings of approximately 5,000 to 10,000kWhrs per annum, resulting in cost savings of approximately $750 to $1,500. This would result in approximately 1 tonne of CO2 being saved per year. As can be seen the savings are significantly low, this is due to the both the fan energy required to power such a system and the low occurrence of days in which heat recovery has a substantial effect. The cost of implementing such a system at Chesser House would far exceed the savings, making it an infeasible option. This system however does hold potential in new buildings where there may be more flexibility in the locations in which ducting can be installed.

On a 40°C day, a total of 22.4kW of refrigerated energy per floor can be saved through the use of heat exchangers. This saving can assist to greatly reduce the peak load requirements of Chesser House, whilst also reducing the stress exerted on the electricity grid which occurs during such periods. Another beneficial factor is that the floor by floor air handling units can now be reselected to a lower capacity when an air conditioning upgrade is required, reducing the capital cost of the upgrade. These factors, although beneficial, do not warrant the installation of a heat recovery system.

For other typical commercial office buildings, heat recovery ventilators are only really effective if large proportions of outdoor or exhaust air is present, and the ability to deliver the heat exchanged air to the appropriate locations is feasible. In these situations, heat recovery ventilators should be viewed as a compulsory feature to the air conditioning design.

4 HIGH EFFICIENCY LIGHTING

4.1 INTRODUCTION

Lighting is one of the biggest energy consumers in the commercial office building environment. Tenant lighting commonly only operates during a typical work day, whereas base building lighting in some cases operates continuously, resulting in a continuous use of energy. The potential to reduce energy consumption through the use of higher efficiency light fittings is considerable, and can result in short pay back periods.

Possibly the most energy efficient form of lighting is light emitting diodes (LEDs). LED fittings have significantly less power consumption associated with them than conventional fittings; however there are issues with lighting quality, as LED fittings produce a more direct beam of light, which may not be desirable. Fluorescent lighting has also recently improved in its energy efficiency, with newer fittings having considerably reduced wattage. Fluorescent lighting is often a much more cost effective option that LEDs, and can commonly provide better levels of lighting. The choice to use LED or fluorescent is often case dependent, as some situations may not be suitable for an LED instalment. However generally LED fittings are characterised by their very low wattage, and can provide good savings in the correct application.


Chesser House recently underwent a lighting upgrade to T5 fittings throughout the tenanted offices on most floors. These fittings represent a good level of energy efficiency and lighting quality and as such do not require an upgrade. The foyer and car park area however would benefit from a lighting upgrade incorporating LEDs and high efficiency fluorescents.

The foyer lighting arrangement currently consists of 17 metal halide lamps located on the high ceiling area and 28 halogen lamps located on the lower ceiling near the lifts. The ceiling heights are 8m for the high area and approximately 4m for the lower area, making both ceilings difficult to reach for maintenance purposes. It is proposed to replace the 17 metal



halide lamps with 17 x 2x26W compact fluorescent downlights and the 28 halogen lamps with 28 x 12W LED fittings. The approximate cost of this upgrade would be in the range of $18,000 to $20,000. This cost is relatively high due to the fact that allowances were made for working at heights and afterhours work, which would be necessary in Chesser House’s foyer.

Figure 4.1 2x26W Compact fluorescent fitting (http://www.pierlite.com.au/

Figure 4.2 12W LED fitting (LedLogik – in house technical information)

The car park lighting arrangement consists of 4 high bay lamps and 18 x T8 fluorescent tubes; there are also 2 high bay lamps not functioning. Currently the high bay lamps are very over designed, in terms of lighting density and are mounted below their recommended height, providing a low quality lighting level. The current fittings also consume a large amount of power, with each fitting being 1.5kW. It’s proposed to replace the existing fittings with 3 x 400W Stellar fittings and 1 x 100W Parkwatt fitting. The approximate cost for the car park upgrade would be $3,000.

Figure 4.3 Stellar fitting (http://www.pierlite.com.au/

Figure 4.4 Parkwatt fitting (http://www.pierlite.com.au/



The above works represents a cost effective method of providing high levels of lighting energy efficiency, through the use of both low power fluorescents and LED fitting.


The existing lighting arrangement at Chesser House consumes approximately 3.3kW, with the above proposed works reducing the consumption to 1.8kW. This returns an annual saving of approximately $1,000. The car park area currently consumes approximately 5.34kW with the proposed upgrade providing a reduction to 2.9kW. The annual savings for the car park works would be approximately $1,905. As can be seen, the energy savings are considerable, with consumption effectively halved through implementation of the new fittings. The estimated payback period for the car park area would be 1.5 years, whereas for the foyer area works the payback period would be much longer, at approximately 18 to 20 years. The high payback period associated with the foyer area is due to the increase in installation costs, as afterhours work and work at high level would be required. As for the car park lighting, the short payback period is due to the existing fittings being unnecessarily high powered, leading to the potential to achieve high savings. Implementing this upgrade will return an approximate greenhouse gas emission abatement of 17.8 tonnes of CO2 per annum.

High efficiency lighting provides a reliable option to achieve energy savings, for new or existing buildings. Existing buildings with older lighting systems are good examples of where a highly efficient lighting upgrade would return high savings, due to the improvements in lighting technology. New buildings hold a slightly higher potential to reduce energy consumption though the use of high efficiency lighting, as the systems can be better incorporated with the architectural design of the building. As such there may be more instances where LEDs can provide a good lighting level.

5 OUTDOOR AIR ECONOMY CYCLE SYSTEMS

5.1 INTRODUCTION

An outdoor air economy cycle system refers to the use of outdoor air of a particular temperature range to provide free cooling within a building. Due to such factors as internal heat gain (due to people, computers, lighting etc.) and solar heat gain through windows, it’s quite common for a building to become warmer than ambient conditions. When this occurs, a greater quantity of outdoor air can be introduced into the space to assist in cooling while in turn reducing the load on the air conditioning system. During economy cycle mode, only the air conditioners fan motor is running, which compared to the compressor, consumes considerably less energy.

An economy cycle works by closing the return air path from the space back to the air conditioner and opening a relief path for that air to escape, while also opening an outdoor air path which supplies the cooler outdoor air to the space via the air conditioners fan. The process can be seen in the diagram below. When the cycle is not in operation, the outdoor air path partially closes, to allow the minimum required outdoor air for ventilation purposes to enter the space and the return air path re-opens, to allow re-circulation. The relief air path usually completely closes, however if a large minimum quantity of outdoor air is required, the relief path may remain partially open to reduce unwanted pressure build-up.

Economy cycles can either have a simple on/off style operation, or can modulate as required. A modulating system works by varying the quantity of outside air depending on room and ambient conditions, whereas on/off operation simply switches the cycle on during a certain temperature range (usually 16-21°C). The modulating system is more effective as it can operate over a wider range of temperatures (< 21°C), as during situations of cold ambient air the system can introduce a smaller proportion of outdoor air so as not to overcool the room.

If implemented in the design phase, the cost of installing an economy cycle systems is quite small, as the system only requires extra ductwork, dampers and controls. Retrofitting an economy cycle system is highly dependent on available space, but is still possible.




Chesser House currently has outdoor air economy cycle systems present with modulating control over the quantities of exhaust and outdoor air. This system will provide energy savings where ever it is applied and is a suitable option for large commercial office buildings.


The energy saving potential associated with utilising economy cycles depends on the likelihood of the building requiring cooling or heating during a period of low or high ambient conditions respectively. If this case is likely to occur more often, there is a potential for more energy to be saved. Therefore energy savings are highly case dependent, however a reasonable estimate would be approximately 5% of the air conditioning load, for a typical large office building. Regardless, a degree of energy saving will be achieved for little investment, therefore outdoor air economy cycle systems should be viewed as a building as usual approach to reducing energy consumption.

6 PART LOAD PERFORMANCE

6.1 INTRODUCTION

Part load performance refers to systems acting in a way such that input energy is varied, either continuously or over several stages, directly in relation to that of the required output. Part load performance can be well described using the example of a car’s accelerator. When taking off from a standing start, the most efficient way to accelerate to the desired speed is to gradually depress the accelerator, then when the required speed is met, maintain a degree of acceleration such that the car does not lose speed. This represents the concept of part load performance quite well. If the same example is used for a situation where no part load performance exists, the procedure for accelerating the car up to speed and maintaining that speed would be: accelerate flat footed until the speed is met, upon reaching the desired speed, stop accelerating completely, once the speed begins to fall, accelerate flat footed again, and so forth. Clearly the first example exhibits a much more energy efficient scenario, however, in commercial office buildings; part load was overlooked in the past.

Part load performance has the potential to be applied to a wide range of systems throughout a commercial office building, including: air conditioning compressors, chillers, pumps and fans. Generally any system where the demand for the system’s output varies can incorporate some form of part load performance. Commonly, part load performance is applied to fans and air conditioners, in the form of variable speed drives and inverter compressors respectively. Typically, fan energy within commercial office buildings is accountable for that vast majority or base building consumption, as such, this section focuses on the application of part load performance to fans, in particular-variable speed drives.

Fans within buildings are responsible for providing air movement by supplying or exhausting desired air quantities, dependent on building code requirements and intended use of the building. The desired air quantities arise during the design phase, and are typically based upon some form of peak operating condition. This peak condition is then used to size and select appropriate fans, such that the design conditions can be met. Due to efforts in reducing costs, it’s common for fans to be single-speed in operation (such as to meet the peak conditions), however to actively respond to changing space requirements, fans with a variable speed motor can be used.

In many situations, peak exhaust or supply air quantities are not always required, and if no fan speed control is available, energy is wasted as the space can be unnecessarily over-supplied or over-exhausted. Additionally, speed control of fans can reduce generated noise, as noise levels decrease with a reduction in fan speed. Generally, variable speed fans assist in providing a greater level of control over mechanical services within a building, which allows a greater level of control over the amount of energy used.



Fan speed control can be achieved through various methods; auto-transformers, star/delta switches and triacs are the most common, whereas frequency inverters, capacitance control and multi-speed motors can be used. Each method of speed control has its advantages in particular applications, and investigation into which method is most suitable is required. A point worth mentioning is depending on the current fan motor, a variable speed system may not be suitable, as the system can impose efficiency losses on unsuitable motors, reducing the energy savings.


The original design at Chesser House has a single fixed speed air handling unit per typical floor with VAVs providing zone airflow control. There is also exhaust fans located on the 12th floor plant room, serving the whole building. This system is quite wasteful in its current operating state, and is well suited to be upgraded. Works are currently being completed to fit variable speed drives to each air handling unit, such that fan energy consumption can be reduced.

Aside from the current upgrades proceeding, a good course of action to take would be to fit booster fans on typical floors and upgrading the toilet exhaust fan to incorporate a variable speed motor.

The typical floor AHUs currently run at a fixed speed supplying a constant amount of air such that each zone’s maximum air requirement is met. When a zone requires less air, the zone’s VAV starts closing, controlling the air flow at the zone by increasing the static pressure. This mechanism reduces the supply air to the zone; however the energy used by the fan remains the same.

On each typical floor, several smaller VSD booster fans could be installed to boost pressure to each zone. The large fan (or primary air fan) will be set to run at speeds such that the minimum pressure requirement of a zone is met, while the booster fans will modulate and the boost the pressure of the other zones as required. Therefore, instead of running the primary air fan at full capacity constantly, the fan will run at a significantly slower speed (as to account for the lowest pressure requirement) with the smaller booster fans providing the necessary extra air flow. A diagram of the proposed system is shown below. Note that there is a booster fan assisting each zone except for the south zone, which is expected to be the zone with the lowest associated system resistance, as such requiring no boosting.

Figure 6.1 Diagram of VSD fan control strategy

The toilet exhaust fan serving Chesser House runs at a fixed speed which is based upon exhausting an amount air set by Australian Standards. The operation of the fan is constant, however when a toilet is not in use for a period of time, there is little need for the fan to be consistently running. This constant operation results in constant energy usage, which gives a potential to provide savings. The proposed system will not achieve the same level of savings as the fan control strategy mentioned above; however the intent of the report makes the concept worth considering.

The proposed upgrade to the toilet exhaust system includes fitting a VSD motor to the fan and installing dampers at each floor take-off, such that a particular floor’s toilet exhaust



system can be closed off from the common exhaust duct. The dampers are controlled by motion sensors, when someone enters the toilets, the damper will open and the fan exhausts the required air, when the toilet is unoccupied for a certain period of time (10 minutes or more would be suitable) the damper closes and the fan will exhaust less air. The intent of this system is to reduce the energy used during normal operation of the fan, which involves exhausting air from each floor’s toilet, to a new control strategy which involves exhausting only from the toilets being used.

Retro-fitting variable speed drives will provide savings in any commercial office building if used appropriately. The main issue to consider is whether there will be instances where the fan can operate below its design speed, whilst still satisfying the requirements of the space. An investigation specific to the building should be completed to identify situations where variable speed fans would be appropriate solutions.


The energy saving potential of applying the floor by floor air handling unit and booster fan part load performance upgrade to each generic floor in Chesser House was determined to be approximately 200,000kWhr per year. This equates to an approximate 10% reduction of the electrical power requirements of the entire building. This represents a significant energy saving, which occurs due to the inefficient operating strategy associated with the current system. The cost of such an upgrade would be approximately $1,045,000, or $95,000 per floor, which would return a payback period of around 23 years.

The energy saving potential of fitting a variable speed motor to the toilet exhaust system is dependent on the amount of people per floor, as this would affect the frequency of usage of the toilets. Assuming that a person enters the bathroom at least once every half hour, the exhaust from the floor will be shut off for approximately 1.3 hours per day, which represents a 15% decrease in running time. Including a safety factor a reasonable estimate of the savings achievable is 624kWhrs per year. This is a low energy saving which would not justify the cost of completing the upgrade, especially considering the savings achievable with the floor by floor system.

Greenhouse gas emissions would be reduced by approximately 185 tonnes if the floor by floor AHUs and the toilet exhaust systems were upgraded to include part load performance, which represents a considerable saving.

The energy saving potential for other buildings depends entirely on the particular application, however savings as high as 70% can be expected.

The proposed floor by floor system would work well with Induction Variable Air Volume (IVAV) units replacing the current standard VAVs, which will be described in detail in a later section of this report.

7 METERING

7.1 INTRODUCTION

In today’s resource climate, providing in-depth metering within commercial buildings is gaining importance due to its potential to reduce base building energy usage, track energy usage within buildings, plot consumption trends and give an understanding of how much energy certain everyday processes use. In depth metering can act as a basis for determining which systems are excessive consumers and would be suitable for upgrading, allowing easy identification of potential retrofits as necessary. This section will focus on metering and producing real time data of energy (gas and electricity); however principles can be applied to water metering.

Metering can frequently contain small errors in labelling and organisation, which can lead to energy consumption being categorised incorrectly. This can lead to incorrect tenancy billing, leading to tenant and base building consumption being incorrectly measured. A common occurrence involves energy consumption within a building being attributed incorrectly



towards base building consumption, resulting in the base building being seen as consuming more energy, when in reality the energy should be covered by the tenant(s).

Generally the more intensively a building is metered, the better the understanding of how each system within a building is using energy. For example it would be beneficial to see comparatively how much energy air handling units on each floor of a building are using. Such a system can allow building owners and tenants to better understand where their energy is going. Typically, a certain power level is selected based on how much metering is feasible, with every system within the building drawing more power having its own separate meter.

Real time metering (also known as smart metering) or displaying power as its being drawn from the grid instantaneously is also a useful way of giving building owners and tenants a clearer understanding of the energy certain processes use. This method allows building users to track their energy usage throughout the day, allowing for data to be used to compare against other typical days or even against other tenant’s usage. This method allows for a quicker indication of when a fault has occurred or when a system is drawing power when it shouldn’t, compared to usual metering which may only give an indication monthly, resulting in large amounts of kWhrs wasted.

Real time power usage can also be used to display consumption on a larger scale. For example placing large display screens showing actual power usage of an entire building in its foyer will indicate the overall performance of the building, which can allow easy comparisons between the efficiencies of various buildings. This concept can also lead to the display screens showing savings achieved since performing upgrades, allowing for demonstration of works.


Chesser House currently has a smart metering system with a fairly extensive array of meters. The system however does have some issues regarding accounting for all power consumption, as it appears that some tenant power is being attributed incorrectly to the base building. An in depth audit could be undertaken to ensure that energy consumption within the building is being properly accounted for. A noted example of where this issue is occurring in Chesser House is in a server room, which is air conditioned on a 24 hour basis, with the consumption being attributed to base building when it should be included in the tenant’s bill.

To improve the current system at Chesser House, sub-metering could be further implemented to span systems which draw more than a certain power level. A more detailed investigation is recommended to determine an appropriate energy usage size in which metering would be required.

The use of real time displays of consumption is recommended to assist in creating an understanding for tenants in how their usage is comparing to previous periods. This concept could also allow tenants to compare their usage against the average tenant consumption. Also providing a screen displaying base building consumption in the foyer, showing savings achieved since previous upgrades, would greatly promote the building’s ‘green image’. Clearly real time metering and visual displays can be as intensively applied as desired; the concept’s intent is however to provide a means for an understanding of how buildings are performing and how certain processes are effecting the buildings efficiency. Therefore the level of real time metering and displays should be minimised, for a cost benefit, but as such to still give the level of understanding.


The energy saving potential involved with improving metering is associated with shifting base building consumption to tenant consumption where appropriate (saving base building energy, which will lead to improvements in the buildings NABERS rating), identifying faults or large consumers early and promoting an awareness of energy consumption, encouraging a culture of reducing energy consumption.

For commercial office buildings located In Adelaide, base building consumption is attributed to, on average, approximately 40 to 50% of the whole building consumption. Currently



Chesser House’s base building is consuming approximately 62% of the entire building’s consumption. This represents an unusually high proportion, indicating the potential for a considerable amount of energy to be transferred to tenant consumption. This would in effect reduce energy consumption attributed to the base building, increasing the base buildings NABERS rating. An in depth audit should be completed to investigate accurately the energy savings available to confirm this estimate.

Through the use of real time metering, faults or high energy consuming systems can be identified immediately, rather than at the next billing period. For example if a control system is working incorrectly due to a fault, switching a large portion of lights on during the night, the fault can be identified almost immediately, in effect saving consumption which would have been wasted had the fault continued un-checked.

Utilising real time metering won’t directly save energy, however it is a useful way of demonstrating energy savings achieved and also encouraging energy saving actions. A useful phrase to consider is ‘if you can’t measure it, you can’t manage it’, this can be applied to real time energy metering as providing better measurement of consumption allows greater management of consumption. As such this concept focuses on creating an opportunity to see clearly how much energy is being used, encouraging implementation of energy saving techniques.

8 GAS FIRED TECHNOLOGIES

8.1 INTRODUCTION

This section is based upon the use of gas fired technologies for systems which would more conventionally be powered by electricity. For a commercial office building, a large consumer of electricity is air conditioning. Gas fired air conditioning technology is quite commonly used as an alternative option in situations where available electrical power is low; however there are other inherent features which are beneficial, such as reducing energy consumption and greenhouse gas emissions. Other gas fired technologies, such as co-generation plants are covered later in this report.

One of the most common gas fired air conditioning system is gas VRV. VRV refers to a Variable Refrigerant Volume condenser (located either outdoor or in a plant room), with associated electric powered fan coil units (located within the air conditioned space, providing the heating/cooling). This system differs from conventional direct expansion air conditioning which has one condenser unit per indoor unit. VRV technology allows the use of one high capacity condenser unit to serve a number of indoor units (wall mounted, cassette, ducted etc.), with the condenser unit varying the flow of refrigerant to match the requirements of the indoor units. VRV can be either electrically powered or gas fired, and is a suitable technology for commercial office buildings as one or more VRV condensers can be placed in the plant room to serve the entire building.

The benefits of using gas fired technology are associated with the cost of gas consumption, the reduction in greenhouse gas emissions, the reduction in peak electrical load and the improved efficiency of gas compared to grid based electricity. Disadvantages include potentially higher capital costs and more specialised servicing requirements.


The use of gas VRV technology has little feasible application to Chesser House, with the building designed to provide air conditioning through chillers and cooling towers. Essentially, the cost of swapping the current systems with gas VRV and its associated indoor units would be too high to justify the energy savings achievable.

Gas VRV is best applied in a new building or when an electrically powered VRV system requires replacement in an existing building. A good example of the potential use in a new building would be to provide a gas VRV on each floor (or more if required), with several ducted fan coil units serving the floor in a zoned arrangement. The system has benefits over



the single AHU per floor system, as greater control over zoned conditioning requirements is achievable.


The energy saving potential of using gas fired VRV systems comes from the lack of inefficiencies associated with conventional electrical power. As the gas is burned closer to the required location of the power, the efficiency is higher compared to conventional electricity which travels through the grid. This energy saving can be considered a ‘bigger picture’ energy saving, as the saving is compared to the conventional power grid, not another system within the building. Also, natural gas technologies assist in reducing the peak load on the grid. This relieves the demand on the grid and hence does not contribute to the growing need for larger capacity power stations. Reductions in peak demand are recognised by Greenstar, and are awarded points.

As stated earlier, gas also has a lower greenhouse gas emission coefficient, as the emissions associated with combusting gas are less attributable to global warming. This is beneficial when rating the building under NABERS, which rewards the use of natural gas over conventional power. Natural gas is still a limited resource however; as such the use of it isn’t particularly sustainable.

Gas is also cheaper than electricity in South Australia; as such a gas fired VAV system will reduce overall running costs.

Natural gas is clearly a good solution to providing a means for running a building in a more ‘green’ fashion. Gas fired VRV is just one potential use of the fuel, with other highly efficient systems running on gas considered later in this report.

9 PICCV

9.1 INTRODUCTION

PICCV is an acronym used for pressure independent characterised control valves. PICCVs are an effective solution for a chilled/heating hot water valve arrangement, providing significant benefits over other valve systems. The PICCVs function is to control the flow of water travelling through an air conditioning coil. As the flow is dependent on space temperature, means to adjust the flow of water with an effective method required. PICCVs are comprised of two valves: the pressure self-regulating valve (PI) and characterised control valve (CCV).

Typically, controllable flow through a coil is achieved using either a two pipe or three pipe system. A two pipe system consists of an upstream bypass, with an isolator and modulator before the coil, and a balancing valve after the coil. This system works by balancing the flow at the balancing valve, with the modulator adjusting the flow to maintain a constant space temperature. The modulator is adjusted by the building management system (BMS), which reads temperature sensors in the space to adjust the flow as required. Three pipe systems work in a similar fashion; however the bypass is at the modulator with an additional balancing valve which replicates the pressure drop of the coil. This system has benefits over a two pipe system, as the balancing valve always receives the same pressure drop. Balancing valves in two pipe systems experience varying pressures when the flow is modulated, this can sometimes cause the modulator and balancing valve to fight each other, causing ‘hunting’ to occur.

PICCVs use a modified two pipe system, with a PICCV used to replace the modulator and balancing valve. A PICCV system contains an upstream bypass, with an isolator followed by a PICCV before the coil, and a single isolator located after the coil. The PICCV acts to both modulate the flow and maintain a constant pressure, in effect providing the required modulating and balancing in a single device before the coil. The PICCV is linked with the BMS, allowing the BMS to know exactly what flow is going through the coil, a feature not available with the other systems described.

The benefits involved with a PICCV system includes reductions in pressure drop (reducing pumping energy required), accurate knowledge of flow through the coil and the ability for



the BMS to communicate directly with the valve to determine valve flow rates. The most significant of the benefits is the ability for the BMS to actively know what flow is travelling through the coils, as the level of control flexibility is greatly increased, allowing such control strategies as staging to be achieved.

Figure 9.1 Pressure Independent Characterised Control Valve (http://www.belimo.com/)


Chesser House’s floor by floor AHUs currently have a two pipe system; as such a PICCV system would perform better. However the cost of retrofitting PICCVs rules this option as infeasible, unless valve replacements are required. However this system does provide benefits in comfort and controllability, as such if complaints exist, or more in-depth control is desired, further consideration would be beneficial.

For a new building utilising chilled and heating hot water, PICCVs are a good option and should be considered for installation. Utilising PICCV technology will provide the benefits discussed in the introduction section without a significant cost difference to typical valve setups. Initial costs are likely to be slightly higher for PICCVs; however as less valves are required in a PICCV system, installation costs are reduced which will reduce the initial cost difference.


As discussed, PICCVs reduce energy consumption directly through reducing the load on the pumps. This is due to the PICCV system having fewer valves compared to a typical system, leading to less system resistance for the pump to overcome. There is also the potential to save energy indirectly by allowing greater control over the flow of chilled water, as the BMS can read the flow directly from the PICCV.

10 SUMMARY

Clearly, concepts such as commissioning and re-tuning, high efficiency lighting, part load performance (in particular, VSD fans) and in depth metering are all suitable for further consideration for implementation at Chesser House. For new commercial office buildings, the application of these concepts should be considered business as usual; however, at a building such as Chesser House, they can be typically overlooked.

Improved metering, variable speed drives and high efficiency lighting can be considered as the most applicable business as usual concepts to Chesser House. Improved metering will assist in fixing incorrectly allocated energy consumption (which is recognised to be a problem at Chesser House), therefore reducing base building energy consumption. Upgrades to include variable speed drives and new foyer lighting will assist in reducing energy consumption by removing inefficiencies associated with the existing systems.



SUSTAINABLE PRACTICE APPROACHES

1 OVERVIEW

The concepts presented in this section act to promote sustainability, rather than provide a sustainable solution true to the meaning of the term ‘sustainable’. The interpretation of what can be considered sustainable has widened during recent times, as the word has gained marketing appeal since rising energy costs and the threat of global warming have been frequenting the media. Sustainable practice is considered to be a method of promoting sustainability, by providing solutions which act to reduce energy consumption and greenhouse gas emissions whilst providing a level of demonstration. This level of demonstration generates awareness of the concept’s intent to reduce energy consumption, and also allows for similar projects to follow suit.

The topics presented in this section are high efficiency insulation, innovative lighting control, chilled beams, glass coatings, cogeneration, temperature offset and humidity control, regenerative braking, Shaw method of air conditioning, fuel cells, absorption chillers, indirect evaporative cooling, natural ventilation and induction technology.

2 HIGH EFFICIENCY THERMAL INSULATION

2.1 INTRODUCTION

Insulation assists in reducing unwanted heat flow within a building. This can occur through walls, roofs, floors, partitions or HVAC ductwork. Unwanted heat flow is a clear waste of energy, as without adequate insulation air conditioning systems are required to increase their capacity to account for losses. Insulation is typically measured using R values, which describe the thermal resistance of the insulation; a higher R value indicates a more effective insulator.

Minimum R values for insulation within new commercial office buildings are outlined for the various climate zones in the Building Code of Australia (BCA) in the energy efficiency chapter. R values are given for roofs, walls and ductwork. Although the BCA applies only to new buildings and significant refurbishments, if existing buildings are not meeting the requirements for energy efficiency then there is indication that energy consumption can be reduced.

Generally, cost, thickness and materials used limits the R value in which insulation can achieve. Detailed investigation looking at the available space and budgetary requirements should be completed before selecting insulation.


Chesser House’s external walls are made up almost entirely of windows, making the use of insulation unsuitable. The top (12th) floor houses the plant room and as such also does not require a high level of insulation. The areas in which high R value insulation will prove to be most effective would be the ground and first floor structure, the floor by floor ceiling space windows and the air conditioning ductwork throughout the building.

In terms of retrofitting the insulation in Chesser House, the ground and first floor’s roof and walls and air conditioning ductwork are deemed infeasible options. Although they would benefit from higher efficiency insulation, the costs and works involved in supplying and especially installing the insulation would outweigh any potential gains. The ceiling space in each typical floor provides the only feasible location for an insulation retrofit, around the perimeter. Although insulation in this location would primarily reduce heat transfer between the outside and the ceiling space (which is obviously less preferable than between the outside and the room space), this would still reduce the unwanted heat flow to a small degree to the room space and air conditioning ductwork without drastically modifying the wall structure. Insulation in this location will be discussed in this section.



The typical floor ceiling space is assumed to be 600mm in height, with the perimeter of each typical floor being approximately 112m, this results in the total ceiling space perimeter area being 67.2m2 per floor. For the purpose of this report, it is assumed that the ceiling space perimeter wall is comprised only of the glazing. Aerogels Australia makes an insulation product named ‘Spaceloft’ which can provide a very high R-value. Spaceloft can provide a thermal conductivity of 0.011-0.013 W/m.K at 38°C, which represents a highly effective thermal insulator. Aerogels Australia claims that their product is two to eight times more effective than traditional insulation, and it also lightweight and durable. For Spaceloft with a thickness of 10mm, an approximate cost of $44.50 + GST per m2 should be allowed.

Figure 2.1 Spaceloft insulation (http://www.aerogel.com/)

High efficiency insulation, such as Aerogel, is a suitable option for other existing buildings in any location where reduced heat flow is desirable and relatively easy access is provided. For new buildings, providing the highest R value permitted by cost and spatial requirements is highly recommended, and should be seen as a reliable opportunity to save energy.

Another technology worth mentioning, although not applicable to Chesser House unless an entire ductwork refurbishment is required, is Kingspan’s Koolduct. The Koolduct product replaces conventional metal ductwork with rigid phenolic insulation to provide the required air distribution. The product can provide a good solution to ductwork insulation with a light, highly efficient material with low embodied energy. It is recommended to consider this product if ductwork requires replacing.


The energy saving potential of this concept would be low, due to the fact that insulation cannot be applied at Chesser House where it is most suitable, due to the walls being composed almost entirely of glazing. To accurately predict the energy saving potential, information regarding the existing insulation at Chesser House is required. The investigation required to determine this was deemed outside of the scope of the report, due to the expectation that the concept will not achieve significant energy savings.

Generally, in new or existing commercial office buildings, energy savings attributed to insulation are dependent on both the quantity of the insulation used and the efficiency of the air conditioning systems. For new commercial office buildings a combination of both highly efficient air conditioning plant and highly efficient insulation is desirable, due to the savings being considerable. However, for an existing building with a highly efficient air conditioner, installing higher efficiency insulation may not be worthwhile, as the savings will be lower. Therefore the case where the feasibility will be the highest will be in situations where existing air conditioning plant has a relatively low efficiency, as this situation will provide the quickest payback.



2.4 DEMONSTRATIVE POTENTIAL

The demonstrative potential of this concept is moderate, as although the technology is not visible to building occupants and the general public, the concept of high efficiency insulation is quite well known as being sustainable. Due to recent public awareness facilitated by government grants for insulation, the concept is quite well known. As such if the concept is advertised through the appropriate forums, then demonstration would be achieved as the concept would assist in promoting the building’s green image.

3 LIGHTING CONTROL

3.1 INTRODUCTION

This section discusses the intelligent control of lighting throughout commercial office buildings such that energy consumption is reduced by temporarily dimming or switching off lighting when not required. It is common occurrence within buildings for areas which are frequently not in use or are well lit by natural daylight to have constant lighting. A combination of effectively placed daylight and motion sensors provides a good opportunity for saving energy by using artificial light in a more efficient way.

Daylight sensors simply maintain a desired lighting level (lux) within a zone which during the day has a natural light contribution. As the daylight levels increase, the system dims or switches off the artificial light such that the desired lux is maintained, therefore reducing the artificial light’s power consumption. The effectiveness of a daylight sensor relies on the introduction of natural light to the space, as the higher the level of daylight entering the space the higher the potential savings achievable. As such, buildings with large areas of glazed facade, atriums or skylights have the potential to benefit from the installation of daylight sensors.

Motion sensors can also be connected to lighting systems such that in unoccupied areas lighting can be switched off. Using motion sensor control also ensures that lights are not left on overnight or during non business days. Motion sensor lighting can only be applied in certain zones, as some areas require constant lighting for security reasons.

The use of motion and daylight sensor controlled lighting should be viewed as a necessary part of highly efficient lighting systems, due to their ability to ensure lighting is only used when required.


Chesser House currently has motion sensor technology installed throughout the building; however there is significant potential to benefit from the use of daylight sensors, in both perimeter zones on typical floors and the foyer area. To maximise the reduction in energy consumption, daylight sensors should be applied wherever their use would be effective, in determining this, an investigative procedure should be completed. Generally, software modelling is required to determine which lights will be able to be dimmed or switched off during daylight hours.

For other commercial office buildings, daylight and motion sensors can be an effective solution. Typically new buildings designed to incorporate high levels of daylight can benefit greatly from the use of daylight sensors, whereas existing buildings may experience more limitations.


On a typical floor at Chesser House there are approximately 40 fittings which can potentially be daylight sensor controlled. Approximately 7 daylight sensors would be required to appropriately zone the system. This results in approximately 2kW of lighting power used per floor on perimeter zones. With the use of daylight sensors throughout each typical floor, savings in the range of $6,855 or 45,700kWhrs per annum can be expected. The cost of installing such a system would be approximately $16,000 as such a 3 year payback period would be expected. The foyer area also provides a good opportunity for the use of daylight



sensors, with the raised ceiling area being relatively close to large areas of glazing. Savings for the foyer area would approximately be 1330kWhrs per year amounting to savings of $200, for a cost of $200. As such, the savings for the foyer area is quite small, however if considering using sensors throughout the whole building, the savings become more significant, increasing the feasibility.

Greenhouse gas abatement potential of implementing the above lighting control strategy would be approximately 42 tonnes of CO2 per annum.

For other commercial office buildings, new or existing, savings would depend on the number of fittings which are located near areas lit by daylight and the power consumption of those fittings.


The demonstrative potential of intelligent lighting is moderate, as the technology can be viewed to be working by building users and visitors. Also as daylight sensors are frequently incorporated with areas which have high levels of natural light, occupant comfort will increase as will the perception that the building is energy efficient in its use of natural light.

4 CHILLED BEAMS

4.1 INTRODUCTION

Chilled beams offer an alternative option for cooling a building; using chilled water pipes arranged in modular units mounted on ceilings compared to traditional air conditioning delivering cooled air over large lengths of ductwork to diffusers. Chilled beams currently are available in two distinct versions, passive chilled beams and active chilled beams.

Passive chilled beams are somewhat simpler in construction, consisting of a cooling coil with fins and housing typically suspended from the ceiling. The cooling coil contains a flow of chilled water (typically in the range of 13°C to 17°C), which acts to cool the surrounding air, causing it to drop to the floor. Due to the buoyancy of the warmer air closer to floor level, air is continuously cooled.

Active chilled beams have a slightly more complex construction. In addition to the finned cooling coil, they have a means of delivering an outdoor air supply. Essentially the outdoor air is introduced above the coil, through nozzles, and mixes with the return air from the space, before passing over the coil and cooling. Due to the forced convection associated with active chilled beams, much higher cooling capacities are available than that of passive chilled beams. Passive chilled beams struggle to meet the cooling load requirements of most buildings, as such; active chilled beams will be the focus of this section.

Chilled beams are not suitable for situations with high latent loads (heat coming from people, humid air, steam, etc.), therefore hot, dry climates can benefit from the use of chilled beams. Chilled beam systems, without supplementary latent heat control, may have condensation issues, causing them to sweat. To overcome this issue, management of indoor moisture levels is required to keep the dew point of the indoor air below that of the chilled water temperature.

The benefits of chilled beam technology include reduced fan energy, reduced noise, providing cooling closer to the source of heat (the space) and improvement in chiller performance (as the chilled water temperature in chilled beams are higher than that for conventional air conditioning, allowing the chiller to run at a higher CoP). Potentially the most significant advantage of chilled beams is the reduction in ceiling space required, compared to typical air conditioning systems. In large multi-storey buildings, this can sometimes equate to an extra floor.

Disadvantages include the requirement for humidity control to ensure no condensation occurs, reduction in supply airflow below that of acceptable levels, limited economy cycle potential and the difficulties in providing heating. There is also a disadvantage associated with the ‘dumping of cold air’ effect, as frequently velocities cannot be achieved to



adequately diffuse the air off the chilled beams, making the cold air fall straight to the floor. This leads to cold areas directly below the beams, which may become uncomfortable.


Chilled beams aren’t suitable for a retrofit, as such are not feasible for application to Chesser House. The use of Chilled beams is primarily based on reducing ceiling space requirements, allowing for new buildings to squeeze more floors in. As such, an existing building cannot feasibly modify the amount of floors, meaning the most substantial benefit is not achievable.

Also, chilled beams are somewhat limited in their ability to meet the cooling requirements of a typical office building. This results in Chilled Beams only really being suitable to well designed, energy efficient newer buildings.


The energy saving potential of chilled beams can become difficult to quantify when comparing to a well designed, typical air conditioning system. Although the use of chilled beams has the potential to increase chiller efficiency and reduce associated fan energy, it has higher inherent pumping energy required and still requires energy for outdoor air introduction and treatment. Energy savings have been claimed to be in the range of 10% to 20% of the total cooling HVAC requirements, however detailed investigation should be completed to assess the suitability and the potential benefits of a chilled beam system for any new building considering this technology.


Chilled beams do have quite a high level of demonstrative potential, as a chilled beam ceiling is significantly visually different to that of a common ceiling. An issue with this however is that due to the special ceiling requirements of chilled beams, other services which are usually hidden from view become visible (chilled beam ceilings require air to easily reach the coils, as such ceilings are commonly porous, with numerous small holes). This can be overcome by painting the in-ceiling services black to reduce their visibility.

5 GLASS COATINGS

5.1 INTRODUCTION

Un-shaded, exterior glazing exposed to direct sunlight is accountable for large quantities of solar energy being transmitted to interior building spaces. Newer, well designed buildings incorporate either shading from external sources (shades, reveals, etc.) or high efficiency glass with solar reflecting properties, whereas existing buildings with clear glass having a degree of solar exposure experience large heat gains due to solar energy, causing increased cooling costs. High efficiency glass coatings can be retrofitted to reduce the transmission of the radiant solar heat incident on an existing building, reducing the heat load to the space and thus saving energy. Glass coatings can also assist in reducing glare, further improving occupant comfort (glare levels are a factor recognised by Greenstar).

Glass coatings can easily be applied to existing buildings, with energy savings being present on all clear glass surfaces exposed to direct sunlight. Glass coatings cannot outperform complete shading from overhangs or revels, however if an existing building is without shading, high efficiency glass coatings will return significant energy savings.


Chesser House currently has two different forms of shaded glazing on its typical floors, TS30 on grey and SS22 on clear with shade coefficients of 0.33 and 0.32 respectively. This represents high performance glass (clear glass has a shade factor of 0.9, with a lower shade factor allowing less transmission of energy) and as such, there is no need for glass coatings to be applied on typical floors.

There is a potential for application to the ground and first floors however, particularly on the horizontal glazing located above the basement shown in the below image. Both the



horizontal and the arched glazing above the entrance (also shown below) are constructed with clear glass, giving a potential for use of the glass film.

The horizontal glazing is on the northern side of Chesser house and is partially shaded by a semi-opaque green sail, with approximately 40% of the glass area covered. There is also shading from the adjacent buildings on the western and eastern sides. The arch has no shading and faces north.

Figure 5.1 Foyer horizontal glazing

Figure 5.2 Entrance circular arch


The foyer was modelled using Camel and Beaver, to simulate the thermal load on the area with and without the glass film. Removing the semi-opaque green sails and applying R20 film



supplied by MEP Films to both the arch and the horizontal glazing, approximately 1.4% of the building’s entire energy consumption can be saved. This results in a saving of approximately $1,320 per annum. The cost of the upgrade would be approximately $4,500, returning a payback period of 3.5 years. Greenhouse gas emissions will be reduced by approximately 8 tonnes.

Although the resulting energy savings are relatively low, the price of the upgrade is also quite low and the associated works would not significantly interrupt operation of the building. Applying the film could also lead to a smaller capacity air conditioning unit being selected to serve the foyer during the next plant upgrade, leading to energy savings and cost savings which would come close to paying off the cost of the coating upgrade.

The energy saving potential associated with using the R20 film on other existing buildings located in Adelaide with un-shaded, clear glazing with solar exposure is approximately 200-300W/m2 (depending on orientation). Due to the low price and resulting energy savings, installing the film (or any other equivalent film) is an effective solution to reduce the cooling demand in any building with the above conditions.


The small scale nature of the proposed upgrade results in there being essentially no demonstrative potential. The upgrade can really only be advertised with the idea being that it is ‘part of a larger picture’ in terms of reducing energy usage throughout Chesser House.

For other existing office buildings with more significant areas of glazing the upgrade could provide a high degree of demonstration, as the films can give a tinted or one-way mirror style look, which can be quite eye-catching. There is a general awareness that tinted windows reduce solar energy transmission, as such, vast expanses of tinted windows would create awareness that efforts to save energy have been made.

6 COGENERATION

6.1 INTRODUCTION

Cogeneration, also known as cogen, is the capturing and reusing of waste energy from a process. Every process which involves usage of energy has associated waste, whether it is in the form of heat, sound, or light. With cogen it is necessary to determine which process is required and what waste products can be captured and effectively used.

In most applications, heat is a common form of waste energy which can be effectively captured in a cogen system. Electricity generation has large amounts of inherent waste heat associated with it, making the recapturing in a cogen process a highly useful option. The process of generating electricity and capturing the waste heat is known as combined heat and power (CHP), which will be the focus of this section.

Within a large commercial building, CHP could potentially provide the necessary heat energy for absorption chillers, heating hot water or domestic hot water, with the electricity being utilised for non critical applications or sold back to the grid. Typically, large CHP plant would be best applicable to new buildings, where it is possible to strategically plan the positioning and function of the plant within the building, whereas for a refurbishment difficulties arise is finding an appropriate situation. As a result, small scale CHP, or micro-CHP, would typically be a more effective solution for an existing building.

It is worth noting that cogeneration, as the name suggests, refers to two output forms of energy usage, as such the term trigeneration is used to describe three output forms of energy usage. The three typical outputs of trigeneration include heat, electricity and cooling. Trigeneration is effectively a subsection of cogeneration, as the principle of energy reuse is the same, therefore it was decided that no separate section was warranted, as its possible applications will be covered in this section.




The proposed CHP system for Chesser House includes micro-CHP to serve domestic hot water and specific lighting loads throughout the building. The selected unit is the Dachs micro CHP unit (shown in below), a natural gas fired micro-CHP plant with a single cylinder 580 cc four stroke engine. The unit has a maximum efficiency of 88%; however with the addition of an external heat exchanger or “condenser”, the efficiency can be raised to 99%.

As can be seen in the technical data (also show below), for a natural gas fuel input of 20.5kW, 5.5kW of electrical energy and 12.5kW of thermal energy (without the addition of the condenser) is produced, resulting in an efficiency of approximately 88% (including auxiliary load). With the addition of the condenser, the thermal output increases to 14.8kW, pushing the efficiency to 99%. The maximum water temperature at rated efficiency is approximately 83°C. The unit produces 56dB (A) at 1m, which is reasonably low if located appropriately away from workstations or other noise sensitive areas.

The foyer lighting load is approximately 3.3kW and a typical floor is approximately 8kW, therefore one unit could potentially serve the ground floor and two could serve a typical floor. The remaining electrical power could then be sold back to the grid.

An estimation using Rheem’s selection guide of the required domestic heating hot water thermal load for the whole of Chesser House is 60kW, which allows for 1 person per 10m2 of lettable area, each using 4L of hot water per 8 hour period. This equates to approximately 5kW of thermal load per floor.

To meet the required loading domestic hot water loading, four Dachs units could be used with the addition of a buffer tank. The units would produce enough thermal energy to satisfy the required thermal loading of the domestic hot water required for the entire building, whilst also producing electrical energy to service lighting on two typical floors and the foyer.

The buffer tank will include temperature sensing valves and will be sized to meet the hot water requirements of the building which is approximately 4600L of hot water per 8 hour period.



Figure 6.1 Dachs micro-CHP plant (Image received from supplier)



Figure 6.2 Technical data (Image received from supplier)


Micro CHP, if used appropriately, provides an effective option for saving energy. With the particular system described for Chesser House, the main consideration is to size for the minimum domestic heating hot water load while treating the electrical output from the cogeneration process as a bonus.

Currently, Chesser House has two Rheem 65/270N domestic hot water heaters installed, capable of delivering 10,490L of hot water over an eight hour peak period. The units require 105kW of thermal input, which using Rheem’s selection guide indicates the system is oversized. With four micro CHP units running, the required fuel input would be 82kW.

The total electrical power generated by four Dachs CHP units running is 22kW, which would be enough to provide lighting energy to the foyer and two other floors, with Chesser House’s the current lighting system.



Therefore a potential of 45kW of energy can be saved with the replacement of the current heating hot water system with the micro CHP and buffer tank system. This would result in a cost saving of $14,040 per annum. Savings in this order would reduce greenhouse gas emissions by approximately 123 tonnes of CO2, which represents a considerable saving.

The budget price of a Dachs unit with included condenser is $31,698.00 AUD. The total budget price for the proposed system for Chesser house including buffer tank, pumps, installation and all associated wiring and piping would be approximately $175,000. Assuming 8 hour per day operation this would lead to a payback period of 12 years.

For other typical commercial office buildings, this system could effectively be retrofitted in a similar manner. The proposed system requires the availability of a gas hot water system to be replaced, or a similar heating demand which is relatively constant. The electrical energy can either be sold back to the grid or utilised for non critical plant.


The demonstrative potential of CHP plant is relatively low, although if the electricity or heating is being used in a way such that it can be singled out and is appropriately advertised, exhibition is possible. For the case of Chesser House, the foyer lighting would be a good opportunity to provide advertisement of the technology, as the lighting is in an area with a high level of exposure. To make people aware that the technology is present within the building, small plaques placed within the building or even an electronic display showing energy savings could be used.

7 REGENERATIVE LIFT BRAKING SYSTEMS

7.1 INTRODUCTION

Regenerative lift braking systems are a simple and yet effective way of improving the efficiency of how a lift operates. Regenerative braking is a technology which has become well established, with examples being seen in the automotive industry, as the potential to capture braking energy in a useful form for any moving vehicle can improve efficiency greatly. Applying the concept to lifts allows reliable energy savings to be made, as the energy dissipated in braking a lift is considerable.

Regenerative lift braking simply works by converting the lift’s kinetic energy as it descends into usable electricity, which can be applied within the building or fed back to the grid. As a lift descends and the brakes are applied, conventional lift brakes dissipate the lift’s kinetic energy through heat via a set of resistors. During braking, regenerative systems use the lift car, counterweight and brakes as the motor, with the lift motor becoming a generator to generate electricity. Regenerative braking can occur on a lightly loaded ascent, and all descents.

This technology is widely applicable throughout any building with lifts, and represents an effective method of reducing wastage associated with everyday power consumption. New lift systems incorporating regenerative drives also include several other energy efficient techniques such as sleep mode (lift switches off after a short period of idle time) and an algorithmic control of people management (where lift users must press a button indicating the floor they require before entering the lift, such that the control system can manage the number of users requiring that floor, as such less trips are completed).


Chesser House currently has four lifts serving the entire building, with a small degree of regenerative braking. The current lift system is not suitable for a retrofit, with the only option for utilising this concept being to replace the entire system. The cost of doing such an upgrade would be approximately $800,000, as such is only really feasible when the current lifts reach the end of their service life.

Regenerative braking is a concept which is applicable wherever lifts are required. As such for new or existing buildings, application of the concept is warranted. The concept is particularly



applicable to new commercial office buildings (due to the potential difficulties in retrofitting the system being non-existent) and should be viewed as a simple way to improve the energy efficiency of the lifting system.


The energy saving potential of this concept is quite good, wherever it’s applied, as the energy dissipated by the lift braking system is considerable. Manufacturers claim savings in the range of 25 to 40% with the use of new lift systems incorporating regenerative drives. The overall savings however are dependent on factors such as the current lift system, building height and frequency of use. When considering an upgrade, an investigation into the current lift operating system is required to determine the feasibility for retrofitting, and also the expected energy savings. Manufacturers claim savings of up to 70% are possible comparing new energy efficient motors with regenerative drives to geared system induction motors, as such considerable savings are achievable if existing systems are relatively inefficient.

At Chesser House, a saving of 40% of the total lift energy consumed returns a yearly savings of 27,636kWhrs. This results in a cost savings of $4,145 per annum and a reduction in greenhouse gas emissions of 25 tonnes per year. As mentioned, the cost of implementing such a system leads to the concept only being feasible in the case of an upgrade due to the current system reaching the end of its service life.


The demonstrative potential of this concept is low, as publishing or advertising would be required to call attention to the use of it. However the use of regenerative braking is a concept which is quite well understood and known as an energy saving measure, ensuring that with appropriate advertising, a green energy efficient image of the building would be portrayed.

8 OCCUPANT COMFORT CONTROL

8.1 INTRODUCTION

Commercial office buildings are accountable for large portions of energy consumption. Although some of this energy can be attributed to services which allow the building and occupants to function, a significant amount of energy is consumed directly to provide occupant comfort. The primary basis for providing a comfortable environment is to encourage tenants to occupy the building by providing a workspace which promotes productivity. Occupant productivity is based on numerous factors, one of which is comfort, as such a building with a high level of comfort is attractive for prospective tenants, and is also effective at retaining existing tenants, due to the potentially more productive workspaces available.

Comfort is affected by various factors, with thermal conditioning, ventilation rates and lighting levels providing comfort while also consuming significant degrees of energy.

Thermal conditioning within a building provides comfort by attempting to maintain a ‘set point’, which is done by controlling both temperature and humidity. Conditions within a space are allowed to depart from the set point to a certain degree, with the intention being that conditions are maintained within a ‘comfort zone’.

Ventilation rates act to disperse indoor pollutants and odours, increase oxygen levels and manage carbon dioxide levels, such as to provide a comfortable and safe indoor environment. Outdoor air flow rates are based on standards; however carbon dioxide monitoring within the space is also used to indicate when outdoor air is required.

Lighting levels are designed to meet a certain luminance level (Lux level) such that visibility is not hampered and the space is not too bright/not too dark. Lux levels are based on Australian standards, with different spaces requiring different levels.

Of the three factors mentioned above, thermal comfort can be described as the most difficult to standardise. Thermal comfort is reliant on a varying degree of factors and



perception can differ from person to person. Set point conditions are based on surveys conducted by the American Society of Heating, Ventilation and Air-Conditioning Engineers (ASHRAE) several decades ago, and are not found in Australian Standards or the BCA. High powered air conditioning systems are designed to maintain a space within the comfort zone, however little work has been done on measuring thermal comfort with intent to reduce energy consumption.

When a building’s air conditioning system is underperforming and providing uncomfortable thermal conditions, there frequently is an associated waste of energy. Also there may be certain situations where energy can be saved by moving the set point within the comfort zone. Both of these factors indicate that a method of measuring and monitoring comfort and set point conditions would be highly beneficial.

The intent of measuring and monitoring set point is to both ensure that comfort conditions are met whilst ensuring that the air conditioning systems are working appropriately. Comfort issues are usually identified after occupant complaints, whereas issues can be resolved almost immediately if appropriate monitoring is conducted. Appropriate monitoring can include measuring temperature and humidity, and trending the results to compare with energy consumption. Again, as discussed earlier with improving metering, the phrase ‘if you can’t measure it, you can’t manage it’ holds relevance with this concept.


A useful technology which could easily be applied to Chesser House is Automated Logic’s Environmental Index (EI) program. EI uses a series of key metrics to return a percentage score of the building’s comfort levels. Sensors monitoring temperature, humidity and carbon dioxide levels within a zone communicate with the EI program to display the data. Each metric can be given a weighting, allowing for customisation, to attribute to the final score. The score can be plotted over time periods to allow trending.

With the system installed, issues can be identified and re-commissioning or re-tuning can be completed. Also control strategies and set points can be investigated and adjusted to reduce energy consumption whilst still maintaining acceptable comfort levels. Essentially the system assists in allowing for greater control over services within the building, rating the comfort levels achieved.

Figure 8.1 Example of the EI program (Image received from supplier)



Figure 8.2 Example of trending data using EI, the top graph and analogue gauge show comfort and EI %, the bottom shows the energy consumption (Image received from supplier)

This system is highly applicable to other buildings, existing or new. The ability to measure comfort levels is a significant benefit, as high indoor occupant comfort levels are rewarded under Green Star.


The energy saving potential of using this concept to assist in modifying the set point temperature is large. Small temperature or humidity set point changes throughout Chesser House can result in overall large energy savings. Utilising this technology allows set point modifications to occur whilst real time monitoring of comfort conditions is occurring, ensuring that energy savings can be made without compromising on comfort levels.

For example, modifying the cooling set point temperature by 0.5˚C, such that it would be 24.5˚C, would achieve an energy saving of 0.7% of the entire building. This set point temperature is still well within a ‘safe’ comfort range, and would most likely not be noticeable to building occupants. Therefore there is a potential to save approximately $659 and 4 tonnes of CO2 per annum, which represents a moderate saving. To implement this, initial costs are essentially negligible; as such it’s clear that on a large scale, small set point changes can achieve highly beneficial results.

To implement this concept however, the ability to measure and track comfort is critical. Therefore, although there is nothing stopping set point modifications being completed without the use of EI software, a high quality building environment would require some form of comfort tracking (such as EI software) to ensure that the indoor environment remains comfortable, and occupants do not notice the changes taking place.


The demonstrative potential of this concept is quite low, as the technology is intended to be used by the appropriate personnel as a basis for understanding comfort levels within the space. The only means for demonstration is through publishing the use of the technology within industry forums.



9 SHAW METHOD OF AIR CONDITIONING

9.1 INTRODUCTION

The Shaw Method of Air Conditioning (SMAC) is a simple yet effective method applied to chilled water systems to control humidity within a conditioned space whilst providing considerable energy savings. The concept utilises both outdoor air pre treatment and chilled water temperature optimisation, such that chiller energy consumption is reduced through improvements in coefficient of performance (COP) and energy efficiency ratio (EER). The system itself is quite simple to apply, with the concept providing excellent opportunities in a retrofit situation.

Humidity control is based upon human comfort and specialised requirements (e.g. art galleries). Generally, as humidity increases, comfort decreases. As ambient humidity increases, space humidity increases, due to the introduction of outdoor air to the space required for ventilation. To achieve comfort, some form of humidity control is required to produce supply air which is comfortable.

Conventional humidity control is achieved by ‘over-cooling’. In dropping the chilled water temperature, humid air loses significant amounts of moisture as it passes cooling coils, as condensation occurs. The condensation which occurs on the coils is moisture directly from the air; as such the air becomes ‘dry’. This process is effective in controlling humidity levels, however a result of this over-cooling is, quite obviously, very cold air, which is unsuitable to be supplied to the conditioned space. In order to bring the air back to comfortable conditions, re-heat is required, where further energy is exerted to heat the air using coils downstream of the AHU. This process is wasteful in two ways, firstly and more intuitively, it is wasteful as it requires re-heat. Secondly, the process requires the chiller to work harder, which causes it to run less efficiently. The SMAC resolves both of these inefficiencies, providing for the opportunity to achieve considerable savings.

The SMAC system differs from the above as it has a dedicated outdoor air pre cooling coil upstream of the AHU’s coil. This allows the humid outdoor air to be targeted separately, which is much easier (from an energy consumption perspective) than mixing the humid outdoor air with the relatively dry return air, and then attempting to dehumidify. This process allows the chilled water temperature to be run higher, allowing the chiller to operate in a much higher efficiency range. After providing the pre cooling, the chilled water is then passed through the AHU’s coils where a mixture of the pre cooled outdoor air and return air pass through it. This process removes the need for reheat, allowing for energy savings to be realised.



Figure 9.1 Diagram of the operation (http://www.brite.crcci.info/case_studies/pdfs/casestudy-10_graphics-version.pdf)

The SMAC represents a system which corrects the inefficiencies present within conventional chilled water strategies, by providing simple changes to process. The system can work effectively in all climates and is well suited to large commercial office buildings. Its ability to be simply retrofitted (relative to a number of other new technologies) ensures that it is a concept well worth consideration for application when energy savings are desired in existing commercial office buildings. It should also be noted that through the use of the SMAC, water consumption can actually be reduced, which is a major benefit in dry climates.


Chesser House is currently undergoing an upgrade which includes the SMAC, coupled with a high efficiency chiller.

For other commercial office buildings, new or existing, which incorporate chilled water plant, the SMAC should be considered for application. The fact that the system can be installed quite simply to a broad range of projects further increases the basis for implementing the concept. The cost of SMAC systems is also quite low, allowing for relatively fast payback periods to occur.

SMAC has also demonstrated its complimentary application with induction variable air volume (IVAV) systems, due to the reductions in fan energy throughout the system. A combination of both IVAV and the SMAC can a highly effective, energy efficient retrofit option to a chilled water system, with results comparable with chilled ceiling or underfloor displacement.


Generally, modelling the energy saving results solely associated with the SMAC is difficult, as the system depends highly on the operation of the associated chilled water plant. Savings occur due to the reduced need of over cooling and over dehumidifying (set points can be set to exactly 24˚C and 60% relative humidity, as the SMAC system can effectively maintain them), eliminates the need for reheat and increases chiller CoP (as the chilled water temperatures can be set closer to the chiller’s range of best efficiency).




The demonstrative potential of this concept is relatively low to moderate, with demonstration only significant throughout the industry. Also the simplicity and effectiveness coupled with the potential to reduce energy consumption is generating interest.

10 FUEL CELLS

10.1 INTRODUCTION

Fuel cells provide a mechanism for generating electricity by utilising the energy released during electro-chemical reactions. Fuel cells use a ‘reactant fuel’ and air to force the passage of electrons across a circuit, leading to a current being produced. A useful analogy is to liken fuel cells to batteries, as they produce a continuous DC current through a chemical reaction. Also, similar to batteries, fuel cells have an anode, cathode and electrolyte. Batteries are characterised by having an associated capacity of suppliable power, and require recharging or replacing once it ‘runs flat’, whereas fuel cells provide power so long as a supply of oxygen and fuel are maintained.

Fuel cells can be categorised into two general groups: low temperature fuel cells and high temperature fuel cells. Low temperature fuel cells, as the name suggests, produce electricity via a low temperature chemical reaction. The reaction is possible at low temperatures only if the fuel is purified into a very rich hydrogen gas, which typically involves energy intensive processes. High temperature fuel cells can produce electricity using a less hydrogen rich fuel (e.g. natural gas) by heating the fuel and air mixture internally. High temperature fuel cells are currently a more feasible option, due to the ease of only connecting the unit directly to a natural gas feed, however in the future if hydrogen can be produced and stored on a large scale, low temperature fuel cells may take over as an effective method of generating electricity.

Fuel cells can be further categorised into different types of electrolyte, with different applications or situations potentially more suited to a particular electrolyte. Generally fuel cells can be designed to operate at different temperatures, with different fuel types, with different output power ranges and with different heat up and cool down periods. Different electrolytes also have different associated efficiencies achievable. For the commercial office building application, where a highly efficient, constant power fuel cell is required, a solid-oxide electrolyte provides an effective solution. Solid oxide fuel cells are a high temperature fuel cell; as such they can produce electricity whilst making use of a range of fuels, making the fuel cell an appropriate solution in situations where natural gas is readily available.

Benefits of solid oxide fuel cells include their associated high efficiency, their ability to be flexible in terms of fuel usage, the low level of emissions, low noise and vibration, the potential for utilising the waste heat and their lower cost relative to other types of fuel cells. Disadvantages are the long start up/cool down times, stability issues associated with high temperatures. Solid oxide fuel cells do require grid connection for heat up and cool down, as the gas (natural gas) requires energy in the form of heat to produce hydrogen. Whereas low temperature fuel cells can be grid independent.


As solid oxide fuel cells are more suited to continuous operation, and require long heat up and cool down periods which further consume electricity, when applying the technology to office buildings, systems which require 24 hour electricity should be considered as the most feasible options. 24 hour systems include security lighting and server rooms (including associated server room air conditioning). Solid oxide fuel cells can operate in a self sustain mode, where the unit runs without exporting any power, however this mode of operation is inefficient in the sense that it still consumes gas. It is possible to continue running the fuel cell, while feeding electricity back into the grid, in situations where systems don’t require constant 24 hour power, although further investigation should be completed to determine the cost effectiveness of this type of scenario. Systems which require power for the entire 24 hours (or



close to) could be considered as possible candidates for solid oxide fuel cells, with excess power produced fed back into the grid.

Chesser House has security lighting and a 24 hour auxiliary cooling loop; as such there is the potential to apply fuel cell technology throughout the building. A survey should be undertaken to determine the required load of all the 24 hour systems (or systems with similar operating hours), such that the fuel cell(s) can be sized. Backup grid connections should still be used in the event of unit shutdown due to maintenance or failure.

Ceramic Fuel Cells Limited manufactures a solid oxide fuel cell, called BlueGen MG 2.0, which would be applicable to a situation such as Chesser House’s. The unit is capable of producing 2kW of electrical power whilst consuming 12.6MJ of natural gas. The unit is 970 x 660 x 600mm, and requires electrical, natural gas and water inputs. Depending on the load requirements, a number of units can be used within a building. The price of a BlueGen unit is expected to be within the range of $6,000 to $8,000.

Figure 10.1 BlueGen fuel cell unit (http://www.cfcl.com.au/)

BlueGen units would be applicable in any commercial office building where systems require constant, 24 hour electricity. The units are relatively small and can be relatively easily retrofitted to buildings. For the case of a new building, a worthwhile option would be to investigate a larger scale fuel cell, to provide power to all or most of the building.


The energy saving potential of this concept is really dependent on the amount of units installed. Each BlueGen unit has a claimed efficiency of 60% at 1.5kW of output power, which is considerable compared to conventional grid based electricity which is generated at an overall efficiency of approximately 20 to 30%. This represents a significant energy saving and greenhouse gas emissions reduction. From a cost perspective, the unit requires 12.6MJ/hr of gas to produce 2kW of electricity, resulting in a cost of approximately $1100.74 per annum, whereas 2kW of electricity purchased from the grid would cost approximately $2620.80 per annum (assuming gas price of 1.4c/MJ and electricity price of $0.15/kW, with 24 hour operation).

A good example of the possible use of this technology at Chesser House would be the stairs, which have 24 hour security lighting, and the auxiliary cooling loop. There are approximately 50 T8 fittings in the stairwell, which equates to approximately 1.8kW of power usage. The auxiliary cooling loop draws approximately 8kW of power. 5 BlueGen units located in the rooftop plant room could meet the power requirements of the stair lighting and the auxiliary



cooling loop, saving approximately $7,604 per annum. The CO2 savings are approximately 51.6 tonnes, with 85.6 tonnes saved through electricity and 34.03 tonnes emitted due to the natural gas usage. This represents a considerable saving relative to the initial cost, as such provides a suitable option. A payback period for the above system would be 5.3 years assuming a cost of $40,000 for five units.

Worth mentioning is that as fuel cells don’t incorporate the combustion of hydrocarbons, emissions are considerably more environmentally friendly. This leads to lower greenhouse gas emissions than if power were to be drawn from the grid.

The energy saving potential for other existing commercial office buildings would be similar to that shown above, with the limitation on the potential savings being the amount of systems which would be suitable (24 hour systems). For new buildings, if a large scale fuel cell is to be used, savings would be due to the efficiency of the fuel cell being greater than that of conventional power generation.


The demonstrative potential of this concept is low, with the units being suited to installation in plant rooms. The concept of fuel cells is quite well known as a sustainable option for electricity generation, as such using advertising pathways with the intent of promoting the technology’s use within the building would help to provide demonstration.

11 ABSORPTION CHILLERS

11.1 INTRODUCTION

Absorption chillers use heat as an energy source to provide the necessary heating and cooling within a building. The chillers can work either by capturing waste heat from other processes (e.g. the waste heat from a cogeneration process is usable, leading to a process called trigeneration) or by being directly fed fuels such as natural gas, biogas, diesel or recycled oils. Absorption chillers provide a non electric solution to heating and cooling requirements, whilst also providing for an opportunity to easily transition to various types of fuels. The concept can also assist in achieving a completely sustainable building, as it is possible for the system to run off such heat sources as solar energy.

Absorption chillers work quite differently in heating and cooling mode, with newer models utilising ‘separate heating’. In cooling mode, the chiller works by inputting energy to heat a lithium bromide water solution (LiBr), using the LiBr as the absorber and water as the refrigerant. The refrigerant water then enters the evaporator (under a vacuum), causing its temperature to drop rapidly, and is sprayed over copper tubing to provide cooling. After absorbing heat from the air conditioning system, the water evaporates and is then absorbed by the LiBr solution leading to the process repeating itself. Heating mode is somewhat simpler, with the system working as a vacuum boiler. Heat energy is used to raise the temperature of the LiBr solution, producing a vapour which heats the heating hot water in the copper tubing.

The primary benefits associated with absorption chillers arise from the use of alternative fuels, leading to the reduction in peak electricity demands. Benefits such as cheaper running costs and higher overall energy efficiency are also associated with gas systems. Another significant benefit is, as mentioned, the ability to use a range of fuels or energy sources, including such sources as solar or geothermal. There are also several advantages of absorption chillers not directly relating to energy consumption, including noise and vibration reductions, no large moving components and lower maintenance requirements.

Disadvantages lie primarily in the cost, with the systems requiring a more significant initial investment than conventional electric systems. Also abruption chillers may or may not be an efficient option in certain situations, as such a detailed investigation would be required to determine the conditions in which the chiller would be running. Absorption chillers also have a greater pumping energy requirement and cooling tower capacity compared with electric chillers. Also there are potential difficulties in maintaining the vacuum conditions required.




Chesser House currently has a new highly efficient electric chiller; as such it would be infeasible to consider installing an absorption chiller at this stage. Also a well designed and selected electric chiller can be a more suitable solution in certain cases. Consideration of installing an absorption chiller may be worthwhile at the end of the current electric chiller’s service life, as after a period of time initial costs may be lower relative to electric chillers due to technological development.

Absorption chillers provide an option for creating a sustainable cooling solution, as the technology allows heat generated from any source to work to provide cooling. As such, in designing a system incorporating an absorption chiller, other technologies such as solar, geothermal or cogeneration plants should be considered as sustainable options. In situations where the above technologies aren’t feasible, running the absorption chiller of gas or a similar fuel may be more feasible whilst still providing energy savings. Further feasibility analysis is required on a site by site basis to determine which option would provide the best solution.


The energy saving potential of absorption chillers depends on a wide range of factors. Manufacturers claim achievable efficiencies to be 2 times greater for absorption chillers than that of electric chillers, with associated CO2 emissions being 4 times lower. Energy savings, however, are really dependent on the existing plant (in a retrofit) and the heat source used. For example, if an existing building currently operates with an electric chiller of low efficiency, then the savings achievable through an absorption chiller retrofit would be significant. Also, if a waste heat source can be supplied to an absorption chiller (from a cogeneration process or similar), then the overall savings would increased. For Chesser House, this could approximately result in savings in the order 70,000kWhrs to 130,000kWhrs per year, returning a cost saving of $10,000 to $20,000 per year and a greenhouse gas emissions reduction of 50 to 75 tonnes. The claimed efficiencies and associated savings would vary significantly depending on several factors, in addition to the factors mentioned above, however, the potential to consume no grid based energy (including gas) exists if a well designed solar or geothermal system is used with the chiller.


The demonstrative potential of the concept is low due to the technology being enclosed within a plant room. If the technology is combined with such concepts as geothermal or solar, then the potential to promote the building as having sustainable geothermal or solar air conditioning could provide an avenue for demonstration and creating awareness.

12 INDIRECT EVAPORATIVE COOLING

12.1 INTRODUCTION

Indirect evaporative cooling (IEC) is a concept which utilises the features of an evaporative cooling process, coupled with a heat exchanging process, such that air can be cooled without the addition of moisture. Conventional evaporative cooling works by adding moisture to air to drive it towards saturation, the process can be effective at reducing temperature in dry climates however the added moisture content in the space raises the humidity significantly, which can result in conditions within the space being out of the range of human comfort. IEC has the ability to achieve the temperature reductions similar to evaporative (or greater, if several stages are used), whilst maintaining a constant level of moisture in the supply air stream.

IEC works by driving air through an evaporative cooling process, such that the air’s temperature drops and humidity rises. This cooler air (which can be referred to as the indirect stream) then passes through a sensible heat exchanger, such that its temperature is exchanged with another stream of air (the direct air), before being exhausted to the atmosphere. The direct air is therefore cooled due to the heat exchange process without gaining any moisture, as the air streams do not come in contact. The direct air can then be



fed to the space to provide cooling or put through another evaporative cooler, repeating the process. The below diagram shows an overview of the IEC process:

Figure 12.1 IEC process, note that the cool air to room with no added moisture can then be run through another evaporative cooler (making that air the indirect air), such that the process repeats itself and becomes 2 stage.

IECs have similar traits to that of typical evaporative coolers, as their performance highly relies on the ambient air conditions. Generally the hotter and drier the ambient conditions, the greater the cooling effect. Performance is significantly reduced however, when ambient humidity increases or ambient temperature reduces. For example a hot dry day of 40˚C at 20% relative humidity (typical of an Adelaide summer) will result in an IEC system performing well, whereas a warm humid day of 28˚C at 70% relative humidity typical of a tropical climate will result in a the system providing close to insignificant cooling. Therefore unless the ambient conditions are known to be consistently hot and dry, IEC should only be used to supplement refrigerated air conditioning. Also similar to evaporative coolers, IECs require a supply of water to operate; as such if water consumption is a concern then IEC may not be suitable.

IEC systems typically have been used in specialised applications, requiring designing to suit the particular application, leading to the technology not commonly being applied. Seeley International manufactures a packaged indirect evaporative cooler, which has only recently come onto the market, called the Climate Wizard. The Climate Wizard utilises several stages of indirect evaporative cooling, resulting in lower achievable temperatures. This concept allows for easier and cheaper implementation of IEC technology, increasing its feasibility. As such, this section will focus on the use of the packaged Climate Wizard technology, as it is considered unnecessary to have a tailored IEC system in a commercial office environment.



Figure 12.2 Seeley’s Climate Wizard (http://www.seeley.com.au/)

Seeley’s Climate Wizard is available in two sizes, CW-H10 and CW-H15, with each model supplying a different quantity of air. Input fan energy is rated at 3.0kW and 3.5kW for each system respectively. The units are large (1828x1610x1985mm for the CW-H15) and should be located in a plant room or rooftop.

Application of Climate Wizard technology in commercial office buildings can either be supplementary cooling, outdoor air pre-cooling or condenser air pre-cooling. Supplementary cooling is simply utilising the Climate Wizard as an extra air conditioner on hot days, supplying the cool air directly to the space to assist the refrigerated air conditioning. This technique provides significant benefits as the Climate Wizard’s efficiency during hot ambient temperatures is much higher than that of refrigerated air conditioning, as such power consumption during these periods can be greatly reduced. Outdoor air pre-cooling involves using the Climate Wizard to cool the required quantity of outdoor air before it enters the building’s air conditioner, subsequently reducing its cooling load. Condenser air pre-cooling involves cooling the air fed to the condenser units (the ‘outdoor units’) of air conditioning systems, such that they experience a cooler ambient temperature, allowing them to run much more efficiently. Each application requires adequate control such that the Climate Wizard only runs when necessary, as the units fan energy is considerable.


For Chesser House, The most effective usage of Climate Wizard technology would be supplementary cooling. Outdoor air pre-cooing systems are considered infeasible due to insufficient space. Condenser air pre-cooling was also not considered as Chesser House operates primarily on a water cooled system, as such does not benefit from the technology (only an air cooled system would benefit from condenser air pre-cooling).

To provide supplementary cooling in Chesser House, a single Climate Wizard could be installed on the first floor roof area and in each typical floor’s plant room (plant room installations are subject to space requirements). For the foyer area installation, the cool air can be ducted directly into the raised ceiling area, whereas for the typical floor installations, the cool air can be fed into the supply air ductwork just after the AHU’s fan (at a distance such that only a small pressure loss is incurred). Temperature and humidity sensors should control the Climate Wizards to run only in periods where it will reduce the air conditioning load by an amount greater than that of the Climate Wizard’s fan energy. A safe estimate of when this will occur is during temperatures greater than 30˚C and a relative humidity less than 50%, which occurs quit frequently during the summer months.

In terms of air distribution this system should work quite effectively. Supplying the air from the Climate Wizard at high level in the foyer and in typical floor duct work ensures that the cold air from the unit has time to mix with the warmer air, resulting in a well distributed air temperature at floor level. This solves the potential issue with the Climate Wizard supplying air that is too cold at a location which is too close to building occupants, causing discomfort.

For other commercial office buildings, any of the application techniques previously mentioned are worthy of consideration and should be seen as potential options. Essentially, the Climate Wizard technology applied to buildings will both provide energy savings and act to reduce peak load requirements significantly. The technology is best suited to new commercial office buildings, as this allows the system to be better integrated with the air conditioning system. However application to existing commercial office buildings is still just as feasible, albeit with deign challenges.


The energy saving potential of using the Climate Wizard technology at Chesser House lies in the reduction of peak period energy consumed and the reduction in air conditioner load. The foyer area at Chesser House is served by relatively inefficient air conditioners; as such the potential to reduce energy consumption through the use of the Climate Wizard is present, due to its significantly higher efficiency.



The reduction in peak energy period consumption is due to the very high level of efficiency achievable by the Climate Wizard at high ambient temperatures. During these periods, refrigerated air conditioners suffer from efficiency losses and consume large amounts of power. This results in severe stress being placed on the electricity grid, resulting in higher costs. The Climate Wizard can assist in addressing this issue by providing an alternative for meeting the extreme cooling required.

Reduction in air conditioner load comes about due to the Climate Wizards ability to supplement the cooling provided by the refrigerated air conditioner system. When operating with a climate wizard in a supplementary cooling situation, the refrigerated air conditioning should be seen as being a secondary system, with the climate wizard providing as much of the cooling requirement as possible. Only in situations when ambient conditions are too low or too humid should the refrigerated air conditioner take over, and the Climate Wizard be switched off.

Seeley claim savings of up to 35% are achievable when comparing the cooling costs of utilising Climate Wizard technology to standard refrigerated air conditioning. These savings will vary significantly on a number of factors, including resulting ambient conditions and efficiencies of refrigerated plant. Estimates of energy savings per annum, per Climate Wizard unit at Chesser House would be approximately 10,000kWhrs returning a saving of approximately 9 tonnes of CO2 and $1,500. This would result in total savings of approximately 120,000kWhrs, 110.4 tonnes of CO2 and $18,000 per annum if each floor was to be served by a Climate Wizard. Note that these savings do not include extra costs associated with the increase in water usage. An approximate cost for an installed climate wizard would be $20,000, making the total cost being approximately $240,000 for installing Climate Wizards on each floor at Chesser House. Although the actual savings compared to initial costs seem low, the benefit of a Climate Wizard system is that when it is at its most efficient is at the same time that electricity grid will experience its most stress. As such it assists in peak reductions, which is extremely beneficial.

The energy saving potential for new commercial office buildings is considerable, as the potential to supplement a large portion of the total air conditioning with Climate Wizards is feasible. For existing commercial office buildings, the energy savings are highly cased dependent and should be considered individually.


The demonstrative potential of indirect evaporative cooling is relatively low, due to the concealed nature of the technology. The unit is typically located within plant rooms or on roof top plant areas, as such is out of view of the building users and general public. Demonstration is likely to be within the air conditioning industry, due to the concepts potential to reduce peak cooling load requirements.

13 NATURAL VENTILATION

13.1 INTRODUCTION

Natural ventilation is the process of delivering outdoor air through a building utilising the natural forces induced by air pressure or temperature differences. The basic principle is air moves from a high pressure zone to a low pressure zone; as such features of a building can be designed to maximize this airflow for the purpose of ventilation. Natural ventilation is a concept which is best applicable to new buildings, as the use of a natural ventilations system is most effective when integrated with building design. Natural ventilation’s main advantage is the fact that its operation utilises no fan energy. The main disadvantages are associated with the variability and difficulties in controlling the system. There are two fundamental methods of ventilating a building naturally, using cross ventilation, driven by wind power, or using stack ventilation, taking advantage of buoyancy forces of hot air.

Cross ventilation utilises wind to allow air to flow through a building, by providing openings on opposite walls to create a direct path for wind to travel through. The simple fact that wind is extremely variable and fickle in nature, especially in urban environments, makes cross



ventilation a difficult concept to apply efficiently. Cross ventilation works by taking advantage of the high pressure zone on the windward side of a building and the resulting low pressure zone on the sheltered side of the building. This difference in pressure allows air to make a path through the building, providing ventilation. This system can be made possible using automatically opening louvers controlled by pressure sensors, as to sense where the wind is blowing from.

Stack ventilation relies on hot air rising and being directed upwards out of a building, whilst being replenished at low level by cooler air. To ensure this system works effectively, consideration must be given as to how assistance can be provided in heating and cooling the air. Air within a space can be effectively warmed and exhausted utilising a solar chimney, which works by using solar energy to heat up a chimney, in effect heating up the air inside the chimney allowing it to rise. Cooler air can be sourced low down from shaded areas or from areas near a body of water.

Natural ventilation, as a standalone system, is only really suitable in situations where no air conditioning is required, for example in large storage warehouses. In situations where air conditioning is required, such as office spaces, natural ventilation can only really be efficiently applied as a supplement to mechanical systems. Minimum outdoor air quantities introduced to an office space are governed by Australian standards which are required to be complied with as stated in the Building Code of Australia. Australian standards do make reference to natural ventilation as an option for providing outdoor air, however for the situation of a commercial office building this is deemed unsuitable, as natural ventilation provides little control over the conditions of the incoming air. Natural ventilation can only really be applied to assist economy cycle systems or to provide a night purge. Both options will be discussed in the next section.


Chesser House has been designed to incorporate a standalone mechanical ventilation system, with a mechanical fan driven economy cycle system. Due to the fact that the building hasn’t been designed to incorporate natural ventilation systems, there is no feasible or beneficial option in applying the concept.

As stated above, naturally assisted economy cycle systems and night purge are the most suited options for naturally ventilating an office building. Naturally assisted economy cycle systems involve providing controllable openings allowing outdoor air into the space to act as an air conditioning economy cycle system (see earlier section for explanation of an economy cycle system). Night purge is the method of flooding the building with cooler night air during the summer months, by allowing air to naturally flow into the building. Night purge can be mechanically driven or natural utilising the stack effect or cross ventilation. Night purge assists in pre-cooling the building before the start of the usual cooling schedule, as such reducing cooling energy consumption.

For a commercial office building, natural ventilation should be considered early in the conceptual design of the building, as a passive energy saving technique. As such using night purge or a naturally assisted economy cycle should be considered for an option to save energy in a proposed new building. Natural ventilation used as a mixed mode system can also be quite suited to a chilled beam system, providing humidity control is put in place.


Fan energy can account for the majority of air conditioning energy consumption within commercial office buildings. Natural ventilation is a method of reducing the requirement of fan energy, and to a lesser extent, heating and cooling energy. This can result in a large potential to save energy. Studies have shown that energy savings of up to 25-33% are achievable with the use of natural ventilation; however this result would vary considerably depending on the location of the building and how extensive the system is.

A commercial office building located in Adelaide would benefit from the use of natural ventilation for night purge or naturally ventilated economy cycles. The savings would be



highly dependent on the magnitude of the system, however as Adelaide has high solar loads and frequent cooler nights; a fair degree of energy savings would be available.


The demonstrative potential of natural ventilation is quite high, as a well designed natural ventilation system incorporating passive features may include fins and louvers. Also well designed naturally ventilated buildings are typically thinner. Features such as these will be clearly noticeable to building users and members of the public.

Also natural ventilation is can be associated with indoor environment quality; as such building users may notice the building being more comfortable.

14 INDUCTION VAV TECHNOLOGY

14.1 INTRODUCTION

Induction variable air volume (IVAV) technology refers to VAV units (or ‘boxes’) with an induction process. The conventional VAV box is used in a ducted air conditioning system to regulate airflow to certain zones within a building. The VAV box is located downstream of the air conditioning unit’s fan on the duct run, and contains a damper which can be controlled to deliver certain flows. Although the system can work effectively if designed appropriately, conventional VAVs can only reduce the airflow to approximately 50% before occupant comfort is sacrificed due to reduced air movement. IVAVs can overcome this issue by recycling air from within the ceiling space, increasing air movement.

IVAVs work by mixing primary air, from the air conditioner, with secondary air, induced into the IVAV box from the space, to increase the overall airflow to a particular zone. This process is highly beneficial as it ensures that an air conditioning system can modify its supply air quantity without compromising air movement in the space. Providing a good level of flow within the space is crucial in ensuring that the space does experience stagnant air, leading to the perception that it’s ‘stuffy’. Essentially, IVAV systems can allow the primary air to be reduced to 20%, whilst still providing adequate air movement within the space, compared to a typical VAVs ability to achieve 50%.

Conventional VAVs also have issues associated with’dumping’ of cold air, which is a comfort issue. Frequently when high levels of cooling are required, the cold supply air falls to the floor which can cause issues due to lack of air distribution and a ‘waterfall’ effect of cold air dropping directly from the diffuser. IVAV resolves this problem through creating a greater air flow.



Figure 14.1 Typical VAV system

Figure 14.2 IVAV system

IVAV systems work very effectively with fans incorporating variable speed drives (VSD). An air handling unit equipped with a VSD fan serving multiple zones (each with IVAVs) can slow down to supply enough air to meet the lowest pressure requirement of the system, with the IVAVs ensuring comfort is not lost in each zone by maintaining air movement. This method can accommodate the large savings available by reducing the fans running speed whilst maintaining the indoor environment quality.


As discussed in the Part Load Performance section, Chesser House’s current setup of a single AHU per floor serving all zones, with VAVs and reheat coils controlling the air supplied to each zone is both inefficient and ineffective in terms of energy consumption and comfort. It is proposed to replace the existing VAVs with IVAVs, combined with the VSDs and secondary fans discussed earlier in this report. The current system at Chesser House also incorporates electric reheat coils, it is proposed to remove the coils and utilising gas fired reheat coils in-built in the IVAV boxes.

The system will be controlled such that the IVAVs will maintain air velocities through the diffusers into the room, whilst the primary air fan drops in speed to meet the minimum required pressure of the entire system. Therefore the energy savings will be made possible without compromising the movement of air, which is recognised and rewarded under Greenstar’s indoor environment quality section under air change effectiveness.

For other existing commercial offices buildings, this concept would be suitable in similar situations to Chesser House (single AHU serving multiple zones). Generally in air conditioning systems with large duct runs and energy hungry fans, IVAVs and VSDs are an option worth considering. This system is also highly applicable to new buildings, due to the ability for the system to provide greater levels of control, reduce fan energy and maintain comfort.


The potential to reduce energy consumption associated with IVAV technology lies in its ability to maintain air flows while allowing the supply air fan to run at a lower speed. Therefore, IVAVs facilitate a solution for maintaining comfort while reducing energy consumption, so in a sense, they don’t save energy but rather provide means for maintaining a high quality indoor environment with less required fan energy. For Chesser House, the energy savings presented



with the variable speed driven fans would be descriptive of the potential savings this concept can assist in achieving. This system is highly recommended to be considered for implementation due to its attributes.


The demonstrative potential of IVAV technology is quite low. The technology will maintain comfort levels which could allow minor demonstration to building occupants, however as the technology is concealed from view demonstration must come through advertising in the appropriate forums.

15 SUMMARY

Concepts such as lighting control, glass coatings, regenerative braking, occupant comfort control, fuel cells, indirect evaporative cooling and induction VAV all hold a degree of applicability to Chesser House. Lighting control and glass coatings represent simple and effective methods to reduce energy consumption. Glass coatings also provide an opportunity to improve occupant comfort in the foyer area, which is an issue. Regenerative braking potentially holds the biggest reduction in energy consumption, due to the lifts currently consuming a large portion of the buildings entire energy consumption.

Concepts such as absorption chillers, chilled beams and natural ventilation are not particularly applicable to Chesser House, although may be worth consideration for other existing or new commercial office buildings.



STRETCH OBJECTIVES

1 OVERVIEW

The concepts presented in this section generally are characterised by high capital costs, high levels of demonstration, high energy savings and innovation. They are referred to as stretch objectives as essentially these are all concepts which should be considered as long term goals for achieving an environmentally friendly building. Compared to the concepts presented in other sections of this report, these concepts are in their infancy, in terms of development and testing. As such a level of risk is involved with the reliability of the results expected to be achieved; however as mentioned with this risk comes greater potential to reduce energy consumption. There is also a higher degree of innovation associated with each concept, as the implementation of these concepts is not common practice.

Topics presented include geothermal systems, innovative shading, air engines, green walls/roofs, phase change materials, building integrated photo voltaic, solar air conditioning, solar gas, solar lighting and wind powered systems.

2 GEOTHERMAL SYSTEMS

2.1 INTRODUCTION

Geothermal energy is the natural source of heat existing within the earth’s crust. This heat source is available in abundance for harvesting, creating an opportunity to supply clean energy in a sustainable fashion. Geothermal systems, for the purpose of this report, can be split into two categories, small scale and large scale. Both systems have the potential to be applied to assist in powering a building.

Small scale geothermal systems refers to utilising the relatively constant temperatures present just below the earth’s surface to exchange heat, providing assistance in heating and cooling processes. This process is more applicable to buildings, as generally the depths required to be reached are quite low. Both ambient air and the earth’s surface fluctuate greatly in temperature, whereas the temperature at shallow depths below the surface stays relatively constant at around 10°C to 25°C, this provides the ability for exchanging heat to and from a building.

Small scale geothermal systems operate by passing a liquid (commonly a refrigerant or water) through an underground pipe network, allowing it to heat or cool. The liquid can then be used in a heating or cooling process where applicable. The process requires energy input only for the pumping of the liquid, making a high level of efficiency possible.

Large scale geothermal systems, as the name suggests, refers to larger systems which penetrate deeper into the earth’s surface, primarily for the purpose of electricity generation. These systems capture the heat, or geothermal energy, trapped deep in the earth’s crust. There are four main types of geothermal energy – hydrothermal, geo-pressured, magma and hot rocks. These systems have the potential to produce substantial quantities of electricity, however are considerably more difficult to implement, particularly in the case of buildings.

Hydrothermal refers to hot water or steam formed in fractured or porous rock, usually caused by heat from molten magma or the circulation of water through a deep fracture or fault. Hydrothermal resources typically can be found at depths of 100m to 5km. Geo-pressured resources are high pressure gases found in large aquifers, deep underground. Magma is the most plentiful of the geothermal resources, and is found at depths greater than 3-4km. Magma reaches temperatures of over 1000°C, as such there is a large amount of energy which could be potentially harvested, however little research has been undertaken in the use of this resource. Hot rocks are dry rock heated in a similar way to the hydrothermal resource, but contain no water due to aquifers or fractures not being present for water to be located. Hot rocks are comparably easily accessible and are abundant throughout the earth’s crust.



Generally large scale systems can produce a much wider range of temperatures, and as such can be used for heating, cooling and electricity generation. Below is a map of Australia showing the earth’s crust temperature distribution at a depth of 5km. As can be seen central Australia has a vast majority of the higher temperature zones, although areas around most cities are still quite high.

Figure 2.1 Temperature distribution at a depth of 5km (http://www.renewbl.com/)

The benefits of geothermal systems are its potential to produce clean energy which is essentially free (not including initial infrastructure costs) and its abundance. This represents a significant benefit as few other natural resources can reliably match this.

The disadvantages associated with geothermal systems are its performance being highly dependent on location (temperatures may vary greatly depending on location), temperatures cannot be guaranteed to remain constant throughout the life of the project, upfront costs can be very high and the plant area required can become extremely large, with deep underground penetrations.

For a commercial office building, located within a CBD, geothermal systems are really only potentially feasibly incorporated in a new building. This is due to the required drilling commonly being too expensive and inappropriate within city infrastructure. Also, knowledge of Australia’s geothermal resource distribution has focused almost entirely on the higher temperatures available, with little research and mapping completed for lower temperatures. These lower temperatures (around 100°C) would have significant potential for application within buildings, and would be found closer to the surface. Unfortunately, due to the lack of research it is difficult to estimate what temperatures would be available for use.


The use of this technology, both on a small scale and a large scale, is deemed infeasible to Chesser House, due to the capital cost required to perform drilling in or around the building. Also, unless testing is completed, exact temperatures achievable are not known, and as such the performance of the system would be unclear.

Retrofitting a geothermal system is highly dependent on available space, and the feasibility of drilling into the ground (coordination is required such that other underground services are not damaged). Generally, small scale systems used for heat exchanging are more feasible for use in existing buildings, as the capital costs are lower and the systems are less intrusive. Various manufacturers can provide geothermal systems to supplement systems throughout a building, and could be considered for this situation.



Geothermal systems are best applied for wide scale power generation, and are less suitably applied to serve single buildings. A large scale system located in a site where geothermal energy is high and drilling deep into the ground poses no issues is a much more efficient and cost effective option than attempting to apply the technology to a building. There is however still the potential for its application in a building, as with its use energy consumption can be reduced.


The energy saving potential of geothermal systems can vary, depending on the scale. Large scale systems which have been sited appropriately can produce vast amounts of energy for the purpose of electricity generation; as such the energy saving potential is considerable. Small scale systems used for the exchanging of heat reduce energy consumption to a lesser extent, with manufacturer’s claiming 30% to 70% savings in heating and cooling costs.

Small scale systems are most effective when a relatively small heating or cooling process is required close to the ground, as pumping energy can start to outweigh savings if refrigerant is required to be pumped over large height differences.


Geothermal energy is quite well known as an alternative and sustainable energy source; as such the demonstrative potential is quite good. Although the system may not be in clear view of building occupants or members of the public, the fact that the technology applied to buildings is quite innovative will ensure that demonstrative potential exists.

3 INNOVATIVE SHADING

3.1 INTRODUCTION

Solar energy is accountable for a significant portion of the heat which dictates a building’s maximum cooling load. The Australian sun is quite strong, and allowing the radiated energy to be transferred to an air conditioned space with little or no attempt to reduce it is extremely wasteful. Generally, buildings are designed to incorporate large amounts of glazing for exterior visual appeal, introduction of natural light and to provide building occupants with views. These requirements lead to building designs which require either highly efficient glass (with low shading factor and U value) or large amounts of shading. Glass with low shading factors will significantly reduce the solar load transmitted to the space, however not to the same degree as if the glass is completely shaded. Shading also can reduce transmission of heat through non glass surfaces, as an un-shaded wall’s surface rises above ambient temperature as the sun’s energy is exerted on it. Shading a wall can remove this issue. The shading can become an innovative and quite attractive feature of the building, with dramatic fins and louvers creating a striking image.

The design challenge associated with the use of innovative shading is achieving the balance between the quantity of shading achieved and the quantity of material used. If positioned correctly, adequate shading can be achieved with a relatively small amount of material. Consideration needs to be given to determine the locations on the building’s exterior surface which will require the most shading, and at what times of the day the sun will direct the most energy to that particular area. A well designed shading system can reduce the solar heat load through glass through proper placement, whether the shading is extravagant or minimalistic.

Shading through the use of louvers and fins is primarily incorporated early in the design phase of the building; however retrofitting shading to buildings which are deemed to require it is frequently done. Retrofitting can prove to be an expensive option, but if it is a justifiable action it can provide a wealth of benefits.


Chesser House’s main structure is basically entirely composed of glazing with a shading factor of approximately 0.33. There is no shading via louvers, reveals or fins; however adjacent



buildings on the east and west would provide some shading on the respective sides of Chesser House. Regardless of the shading factor, due to the vastness of exposed glazing, providing extra shading will reduce energy consumption, and will be investigated in this section.

The eastern, northern and western glazed walls of Chesser House would all benefit from extra shading. The orientation and positioning of Chesser House is quite good, with the eastern side primarily covered by the concrete structure that houses the stairwell/lifts/toilets and the western wall largely shaded by a taller building. The north-western and north-eastern corners are however quite exposed, and would receive significant solar load.

Essentially, the more shading provided the bigger the reduction in energy consumption. Therefore, rather than propose a new design for shading the building, this section will focus more on quantifying what can potentially be saved.

Hunter Douglas Commercial supply products to control the amount of sunlight entering a space, and are worth consideration if a shading upgrade is desirable. A product which would be suitable in a retrofit situation for Chesser House is Quadroclad, a sun control fin system. This product is light, rigid, and has a quick installation time. This product would also be suitable for consideration in any other building, new or existing, where a shading solution is required.

Figure 3.1 Quadroclad fin system (http://www.hunterdouglascontract.com/)


Due to the existence of the efficient, shaded glazing, the use of further shading using fins or similar can only provide small energy saving. Providing 600mm shading at slab level for each floor provides a saving of only 0.7%, or approximately $660 and 4 tonnes of CO2 per year. Clearly this saving is insignificant and would not justify the expected high capital cost. Another likely cause of the low energy savings achieved is due to the relatively high frequency of mild or heating ambient conditions, as in these conditions shading will provide no added benefit.

Existing commercial office buildings which do not have shaded glass will benefit considerably from increased shading, however capital costs may rule out most upgrades. For new commercial office buildings the concept is quite applicable, as the shading can be well integrated with the architectural design of the building.




The demonstrative potential of this concept is large, due to the ability to design shades such that they become an attractive feature of the building. Numerous new buildings use innovative and visually striking shades as one of their main attractions, with some designs being the defining feature of the building. There is also a clear understanding as to how shading can assist in reducing cooling costs; as such the concept assists in promoting sustainability.

The concept also allows for a large degree of innovation, as designs can be quite unique and tailored to suit particular buildings.

4 AIR ENGINES

4.1 INTRODUCTION

Air engines, also known as compressed air engines, make use of compressed air to supply energy. Compressed air has been harnessed for several decades, being used in pneumatic tools or engines, utilising pistons or turbines to deliver power. Essentially compressed air is a well established way of storing energy for mechanical use. Recently, an awareness of the use of compressed air as an energy transfer medium has created an opportunity for several prototype air engines to be presented to the industry, with their selling point being the achievable high efficiency. These air engines have a wide range of applications, from being used to power vehicles to wide scale power supply; this section will focus on the potential use of air engines in the building services sector.

Air engines can be used to replace conventional on site power generators, utilising some form of combustion (diesel, gas, bio-fuels etc.) to compress air and as such provide work to the generator to create electricity. The motivation for investigating the concept lies in the claimed efficiencies (useful energy out divided by energy in). Typical generators have efficiencies in the range of 20% to 30%, whereas air engines used for generators have claimed efficiencies of 45% to 70% (without any cogeneration component). These high efficiencies can lead to on site electricity generation (using gas or a similar combusting fuel) replacing the need for grid power supply. Clearly if power can be generated on site at such high efficiencies, then the potential to reduce overall energy consumption is significant.

It must be stressed that the efficiencies stated are claimed by manufacturers with no verification. Due to the prototype nature of the technology, manufacturers and designers are not willing to provide technical information. As such the energy saving claims given in this report are based upon non-verified the manufacturer’s claims.

Moteur Development International (MDI) is one of the few organisations developing the technology, and promoting its use for power generation. They focus extensively on the use of air engines in automobiles, stating that air engines are a more suitable replacement for internal combustion driven cars than electric powered. They also focus on the use of air engines for residential, commercial and industrial power generation, ranging from as small as 6kW to over 1MW.

The use of air engines for electricity generation within buildings is still very much in a prototype or development phase, however the innovation related to this concept and its potential to revolutionise power usage and delivery make it a concept worth discussing. Generally the benefits of this technology are its high efficiencies and its potential to easily transition between fuels. The disadvantages however at this stage aren’t very clear, as the technology is yet to be put into production and tested. Disadvantages are likely to lie in cost and potential mechanical or maintenance issues associated with newer technologies.


To implement this technology at Chesser House, a single air engine, located in the building’s plant room, could be used to serve the entire building’s electrical requirements. The dimensions of the unit and available plant room space would need consideration, as a rearrangement may be necessary. The air engine would be sized to meet the peak load



required, which is approximately 800kW for Chesser House. The most suitable currently available fuel would be natural gas, although the air engine would provide usefulness in the long term with its ability to transition to other fuels with ease.

Using this system, Chesser House would become completely independent of grid electricity (which is produced and delivered relatively inefficiently) and would run efficiently off a small amount of natural gas. This system would also potentially greatly improve the buildings NABERS rating, due to the use of natural gas, which has a lower CO2 coefficient associated with it. There is also a potential to use the waste heat from the combustion in a cogeneration process, which would further reduce energy consumption.

Air engines, as a concept, can potentially provide an important step in solving the issues of climate change and the looming peak in conventional energy. With this in mind, utilising air engines in buildings (both new and old) could be a method in providing a highly efficient “close to the source” energy solution which could facilitate the shift towards renewable energy sources. Therefore air engines deserve consideration for both new and old buildings, as the more interest shown in this technology will begin to drive it from a prototype phase to a concept which can become commonly applied.


The energy saving potential of air engines is considerable, with the claimed efficiency of the MDI engine being up to 70%. Assuming conventional electricity is produced at an approximate efficiency of 20%, this actually returns a saving of approximately 70%.

To quantify the potential savings more accurately, Chesser House consumes approximately 630,000kWhrs of electricity per year, which at a rate of 15c per kilowatt costs approximately $94,500 per year. If the whole building was to be powered by an air engine, approximately 3,240,000MJ of natural gas would be required to power it (at 70% efficiency), resulting in a yearly cost of $35,640. Therefore a saving of over $55,000 per year is achievable with the claimed data. This is a considerably large saving, which is due to the relatively low current cost of natural gas. This option also returns a saving of approximately 190 tonnes of greenhouse gas emissions per year.

On a larger scale, the energy savings are even more significant, as the onsite power generated by the air engine would be a much higher efficiency that the process of getting power off the grid from the power station. As such a much smaller energy input would be required to power Chesser House, which would both assist in reducing peak demand on the power station and benefit the natural environment with the associated reductions in emissions and natural resource depletion.

Due to the substantial savings available and the resulting positive impact on the environment, it would be beneficial to further consider the option of retrofitting an air engine. The associated energy savings available for other new/existing buildings would be quite similar to that of Chesser House, with reliance on grid electricity being the driving factor for the available savings. Therefore this technology has the potential to be widely applicable throughout the commercial building industry.


The use of air engines would provide a high level of demonstrative potential, due to the innovative nature of the technology, the associated energy savings possible and the potential to move towards 100% sustainability through the use of renewable fuels (e.g. biofuels). Also due to the technology being relatively unique, powering an entire building using compressed air is demonstrative in itself.

The air engine itself would be hidden from public and building user’s view, therefore a degree of promoting the use of the technology within the building would be beneficial.



5 GREEN WALLS/ROOFS

5.1 INTRODUCTION

Green walls and green roofs are terms used to describe the use of vegetation integrated into a building’s structure. Typical styles of flora used can range from simpler grass or vine systems to more architecturally colour coordinated floral displays. Green walls/roofs have several attributes which may make them an appealing option for a new building or retrofit, including; architectural or aesthetic benefits, reduced heating/cooling load requirements, improved surrounding air quality and improved sound insulation.

Green walls can be best described as a vertical garden, with vegetation covering a portion or all of a wall. The vegetation is attached to the wall using specialised modules which allow adequate space for roots, soil and hydration. Watering is usually done via drip irrigation systems, with collection trays situated as to ensure water can be collected and re-used as necessary. Green roofs are simply vegetation planted on the roof of a building, providing a rooftop garden type landscape. Green roofs include a membrane which encapsulates and seals the system, with drainage points situated such as to allow easy recycling or reticulation through the building.

Generally Green walls and roofs can be installed in either complete systems, modular systems or blanketed systems. Complete systems are only really suitable for green roofs however allow a large degree of freedom in the use of vegetation. Such a system is more suited to a new building, such that it could be incorporated in the initial design. Modular systems are simply trays or modules of vegetation which are fixed to the building such as to achieve the desired coverage. Modules can support a moderate degree of vegetation and usually range in depth from 75mm to 300mm. Blanket systems are considerably thinner than modular systems, and as such cannot support a diverse range of vegetation. Both modular and blanket systems are more suited to a retrofit.

Green walls and roofs can be described as being intensive or extensive, with intensive requiring a higher degree of attention and maintenance whereas extensive indicates a more passive approach. Generally intensive walls and roofs require a more complex mounting structure and usually are composed or more diverse and detailed plants. Thus intensive green walls and roofs lead to generally higher costs.

Figure 5.1 A green wall, located in Tokyo, Japan



Figure 5.2 Singapore’s Nanyang University’s School of Art, Design & Media’s green roof (http://www.greenroofs.com/)

The benefits associated with green walls and roofs cover a wide variety of categories, some of which are listed below.

- Primarily, green walls and roofs act as a link between the ‘natural’ environment and the urban environment, which holds significance due to the increasing vastness of cities causing urban inhabitants to feel isolated from nature.

- Internal green walls can also improve occupant comfort by improving indoor air quality through filtering the air and replacing carbon dioxide with oxygen during photosynthesis. The production of oxygen can also assist in reducing the required ventilation rates, which in turn will reduce air conditioning energy.

- Green walls and roofs, if positioned correctly, can also improve thermal and noise insulation, however the size of the wall dictates the achievable results in this situation. Thermal insulation is however, further enhanced by the plants transpiration process, which ensures the plant’s surfaces do not exceed ± 5°C from ambient, compared to a metal deck roof which can greatly exceed ambient due to solar radiation.

- Green walls and roofs can also assist in reducing the ‘urban heat island effect’, which occurs due to solar radiation being well absorbed by materials used in the urban environment.

- Also, depending on the flora used, the surrounding air quality can be improved, through the removal of carbon dioxide and volatile organic compounds.

- Both green walls and roofs can also act as a water filtration system, by capturing and filtering storm water.

- An appropriately designed and located green wall or roof can provide all the above advantages, making them an attractive option for providing an innovative and beneficial feature of the building.

Green walls and roofs have various design challenges associated with them. Significant difficulties can arise in maintaining the vegetation, especially in the case of green walls due to the possible difficulties in providing safe access. Supplying adequate hydration can also become a difficulty, as pumps and a source of water are required. Also significant modifications to infrastructure are required to house green walls/roofs.

The primary intent of this report is to investigate options which reduce energy consumption; therefore other potential benefits of green walls/roofs will be given secondary consideration when deciding which concepts are most applicable. However due to the benefits of green



walls/roofs being so diverse, if benefits other than only reducing energy are sought after further detailed investigation should be completed as to how the concept will perform.


Floors three to eleven of Chesser House are comprised largely of glazed façade, with a relatively small roof area. There is also a pre-cast concrete structure which houses services, toilets, stairs and lifts. Installing a green wall or roof in this section of the building would be either infeasible or without any particularly benefit in terms of energy savings. Floor’s ground to one are of a different nature in terms of design and structure, and would be a more suitable location to consider the installation of such a concept. In determining where to locate the green walls/roofs, primary consideration was given to the reduction in heat transmission into the building due to ambient temperature and solar load. Consideration was also given to the demonstrative potential of the location.

Internal green walls were neglected as it was deemed that the energy saving potential was insignificant, and as such, was not suitable for inclusion in this report. Internal green walls do have several benefits associated with them, primarily in the category of indoor environment quality, and should be further investigated if required.

The ground and first floor have a larger footprint than the higher floors and are red brick in construction. There is also a first floor roof area with a section of glazed roof as discussed in previous sections. With the focus being on both energy savings and demonstrative potential, the most suitable locations for a green wall would be the northern and western walls of the ground and first floors and the most suitable location for a green roof would be on the first floor roof area.

As can be seen in the below image, the northern wall has a large shade at first floor level. The area below the shading is primarily comprised of glazing and as such wouldn’t be as suitable for a green wall. The wall area above the shading is well exposed to sunlight and would provide a good mounting location, as the shade could assist in providing a base. The proposed location for mounting the green wall on the northern wall would be in this location.

Figure 5.3 Ground and first floor northern wall

The western wall is quite well shaded and features a pergola which supports a dense vine structure, as seen in the image below. The north-western corner of the building is un-shaded and receives a fair degree of solar load; as such it would be possible to reduce that load with the use of a green wall. The pergola extends for approximately 25m down the side street next to the building, with only one half of that length being covered in vines. It is proposed to install a green wall which will extend from the north wall around to the western wall, to the end of the pergola. As with the northern wall’s proposed location, the green wall on the western roof shall stay at first floor level, above the pergola.



Figure 5.4 Ground and first floor north western corner, viewed from the north

Figure 5.5 Ground and first floor western wall (Chesser House is the right side building), viewed from the south

Elmich Australia supply a vertical green wall module with stainless steel supports, a drip irrigation system and collection trays which can be retrofitted to existing walls. A selection of plants are available and are shown in the table below, it is recommended to select plants on a water requirement basis, with plants requiring the least amount of water the most favourable. The fully saturated weight of 1m3 of green wall is less than 500kg; therefore appropriate structural considerations should be made before proceeding with the design. For a fully planted and installed green wall in the proposed location on Chesser House (supplied by Elmich), the estimated total cost would be approximately $500,000 (approximately $1,500 to $1,700 per m2).



Figure 5.6 A fully planted Elmich green wall module ready for installation (www.elmich.com.au/)

Figure 5.7 Table of available plants for a green wall system (www.elmich.com.au/)

The first floor roof area would be the most suitable location for a green roof, provided adequate access is possible and structural requirements can be met. Covering the entire first floor roof area with the green roof system will effectively reduce heat transmission through the roof and could also possibly provide a location for storm water filtration/capture. Elmich Australia also can provide the necessary water proofing membrane and drainage modules for a fully planted price of approximately $240 per m2. The proposed green roof option at Chesser house using the Elmich system would cost approximately $70,000. A more extensive selection of plants are available for green roofs, as shown in the below table, and again should be selected with water consumption in mind.



Figure 5.8 Elmich’s green roof system (www.elmich.com.au/)



Figure 5.9 Table of available plants for a green roof system (www.elmich.com.au/)

For other new or existing buildings, external green walls and roofs are most suitably applied in situations where large, easily accessible areas of structurally suitable façade or roofing are available. To maximise energy savings, areas which are exposed to direct sunlight and have internal conditioned space directly on the other side of the wall/roof should be focused upon. Consideration should also be made regarding the potential storm water management benefits associated with green walls/roofs when selecting locations. Generally, green walls and roofs are much more suited for use in new buildings, as the system can be better integrated into the overall operation of the building, whereas in the case of a retrofit, it becomes difficult to completely take advantage of the range of benefits available.


The energy saving potential of installing a green wall and roof system for Chesser House lies in the opportunity to reduce air conditioning load to the foyer area and first floor. A fully planted green wall will greatly reduce heat transmission to and from the space, and can also reduce outside wall surface temperatures due to the transpiration process discussed previously.

Using the modelling programs Camel and beaver, it was calculated that approximately 2% of the building’s overall energy consumption can be reduced through the use of the green



wall/roof system described above. This would result in a saving of approximately $1,885 per annum. These savings do not take into account any pump energy associated with an irrigation system, as such actual savings would be slightly lower.

Greenhouse gas emissions would be reduced by approximately 12 tonnes of CO2 per year, with a marginal increase in this value due to the transpiration process.

Focusing solely on the energy and greenhouse gas savings, it’s difficult to justify the installation of the green wall/roof system at Chesser House, or any other existing building for that matter. As discussed however, the potential energy savings are only a small part of the available benefits. Generally, installing a green wall/roof is most feasible when all the benefits are taken advantage of.

As mentioned, the intent of this report is to investigate options for reducing energy consumption and in turn, greenhouse gas emissions. However a significant issue with green walls/roofs is water consumption. This concept is much better suited to climates which experience above average rainfall, as in such situations pumping energy can be reduced significantly. Adelaide’s climate is characterised by hot, dry summers, which would put considerable stress on a green wall/roof system. Also Adelaide frequently experiences drought conditions. Therefore, in terms of water usage, this concept may not be applicable at Chesser House.

Energy savings for other commercial office building is moderate to low, with the concept’s ability to almost completely reduce heat transmission to zero being the only avenue of savings. For existing commercial office buildings, the issue is finding a suitable location to install the green wall or roof. If this can be done, savings can be reasonable, as the efficiency of the existing air conditioning may be relatively low, as a result returning high levels of savings. New commercial office buildings have the potential to incorporate the concept with the building’s design. As such the green walls or roofs can be placed allowing for better demonstration, more effective water usage and storm water capture and in locations where a greater insulation effect is achieved.


The potential for demonstrating a green or sustainable image with the use of green walls or roofs is high, as the systems themselves are easily recognisable as a ‘natural’ feature of the building. Both external and internal green walls have a very high level of demonstrative potential, especially when positioned such that they can easily be viewed by building users or members of the public. Green roofs, depending on their location, can still provide high levels of demonstration; however can sometimes be secluded from street level view.

The system at Chesser House is well positioned to be easily viewed from street level, with the green wall facing towards Grenfell Street. The green roof will also be easily viewable from other buildings and from Chesser House above first floor level.

6 PHASE CHANGE MATERIALS

6.1 INTRODUCTION

Phase change materials (PCMs) are materials which use the change in phase from liquid to solid or gas to liquid in order to store energy in a convenient form. Typically, phase change materials are in the form of a wax, with a high heat capacity and a melting point close to a desired temperature (depending on the application). The technique of using PCMs for energy storage has been well established in the space industry, by providing a method of better insulating space suits, however the potential application in buildings is yet to be appreciated.

The mechanism for how a PCM works is quite simply described by use of an example. Consider a PCM with a melting point of 23°C, used to assist in maintaining a set point temperature of 24°C in the space adjacent to the PCM. During a period of high temperature, the wax begins to melt and draw energy from the surroundings, in effect cooling the area. Once the temperature begins to fall, the liquid wax begins to solidify, a process which slowly



releases heat to the surroundings. The effectiveness of a PCM energy storage system depends on both the heat capacity and the mass of material used, as such if a suitable selection is made, the cost of maintaining the set point of 24°C can be greatly reduced.

Within buildings, PCMs can be stored in small capsules and strategically positioned such that less energy is required to condition the space. PCMs can either be positioned in and around walls/roofs/floors, to provide an insulating effect, or efficiently positioned in large quantities to provide a thermal mass for energy storage or peak shifting. Using PCMs to insulate and provide thermal mass is a widely applicable enhancement and if used appropriately can provide energy savings in most situations.

Currently, PCMs for applications in buildings are commercially available but are quite uncommon. Published material on the results of installing PCMs in buildings is essentially non-existent and as such the use is still in a semi prototype phase. PCMs for the use as thermal reservoirs are more commonly used, typically during lower or higher temperature processes or to shift the peak load of air conditioning systems. The potential application to assist in insulating buildings is much less commonly applied.


For Chesser House, the most suitable solution to reduce energy consumption by the use of PCMs would be to install small panels of encapsulated PCMs to assist in insulating the building. The PCMs panels shall be positioned in the perimeter zone, either at roof level or mounted vertically on the columns. The panels can be purchased with the PCMs pre-installed in small capsules from specialised chemical companies or manufactured to suit with the PCM purchased elsewhere.

The PCM panels are only intended to assist in insulating the building by reducing internal temperature swings, as such sizing of the quantity of material is based on what’s feasible, rather than what could completely meet the load. From modelling the heat load of a typical floor in Chesser House, the perimeter zones receive approximately 100kW of load. Using this value to size the amount of PCM required, a total of 18 tonnes of PCM with a latent heat of fusion of 209kJ/kg would be required to store all the energy. Therefore, it can be seen that matching the load is not a feasible solution, as the quantity is too high, and a selection based on price and structural issues is required. The below chart shows the linear relationship between the mass of PCM and the corresponding energy storage capacity (PCM estimated to change phase between 20-30°C with latent heat of fusion 209kJ/kg). As can be seen, the energy storage capacity is still significant even in small amounts, with 1tonne capable of storing approximately 60kW. Generally, the PCM should be spread as much as possible, to distribute the load safely. As such, structural analysis is required to determine how much mass can safely be applied.



Figure 6.1 Energy storage capacity with relation to mass for PCM with latent heat of fusion of 209kJ/kg


The energy saving potential of PCM insulation is difficult to accurately predict theoretically, with the best option for gaining an insight into savings being independent testing. Currently, PCM insulation manufacturers claim energy savings within the 20-30% range are possible (of the total heating/cooling energy used). However the conditions in which the savings were achieved are not specified, as such the claim cannot be verified. Also, due to the prototype nature of PCMs, technical data is difficult to obtain, as such no reliable heat transmission coefficient equivalent (U value) can be obtained and used for calculating the insulating effect of the material.

As mentioned earlier, using PCMs to assist insulation is a widely applicable concept, as reducing the heat flow in and out of a building will always reduce air conditioning load. Therefore, for other commercial office buildings, the installation of PCMs will reduce energy consumption; however the concept will be particularly beneficial if used in buildings with poor insulation.

For buildings with air-cooled chillers, the option of using large quantities of PCMs as thermal reservoirs is worth noting. With a PCM thermal reservoir, the chiller could operate overnight to cool (and freeze) a specific quantity of PCM and switch off during the day to allow the PCM to melt and provide cooling throughout the building. The benefits of this system include the energy saving caused by running the chiller at night when ambient conditions are cooler and as such the air on the compressor is lower and also the savings involved with using off-peak electricity.


The benefits of improved insulation is well known, and an understanding that a well insulated building will be more comfortable to occupy and will lead to energy savings is widely accepted. As PCMs can be used to assist insulation, the performance of PCMs can be related to that of better insulation. This could allow PCMs to be described as an innovative form of insulation, which does provide some opportunity for demonstration. The PCM panels are however usually hidden from view; therefore unless an effort is made to create awareness of their existence within the building, the demonstrative potential is quite low.

7 BUILDING INTEGRATED PHOTO VOLTAIC

7.1 INTRODUCTION

Harnessing solar energy through the use of photovoltaic (PV) cells is a well established and popular method of generating electricity in a renewable method. PV cells are playing an important role in allowing for the gradual transition from conventional energy resources, by providing one of the many options for achieving sustainability. In commercial office buildings, the feasibility of solar PV is relatively low, when looked at from a cost vs. energy savings perspective; however integrating the PV technology into the building itself can potentially lead to a feasible solution.

Building integrated photovoltaic (BIPV) is a term used to describe PV cells integrated into a building such that they become part of the facade, or the building material itself. The benefit of this method is that the BIPV replaces the conventional building material in a section of facade, therefore decreasing the overall cost. BIPV can be used to replace areas of facade or glazing, or can be used to act as shades or louvers. As conventional PV can be difficult to justify in terms of cost versus energy savings, BIPV can be a worthwhile alternative which can prove to be cost effective whilst also leading to a sustainable solution. BIPV basically provides a different way of viewing solar PV technology, as instead of solely looking at the power generated by the PV as the way of payback, it instead includes the reduction in cooling costs, the replacement of building material costs (with the BIPVs) and also the expected increase in value of the building.



Figure 7.1 BIPV used as louvers (http://www.solarshop.com.au/)

A useful technique for utilising BIPV involves incorporating transparent PV panels to act as glazed facade or shades, similar to tinted glass. By doing this, areas where glazed facade is present can benefit from reductions in air conditioning load, as the transparent BIPV panels can be manufactured such as to reduce heat transmission. Also, transparent BIPVs can assist in reducing glare.

Figure 7.2 Potential locations for installation of BIPV (http://www.solarshop.com.au/)



Figure 7.3 Transparent BIPV (http://www.solarshop.com.au/)

Transparent BIPV is composed of a semi amorphous thin film silicon core sandwiched between two sheets of glass. Therefore the PV cell is protected by the glazing, ensuring that damage to the cell does not occur. Electrical wiring is concealed within a metal framing around the edge of the panels. Different levels of tint are available leading to different shading coefficients, with the darker the tint resulting in reductions in cooling costs.

Essentially BIPV is a stretch objective as it promotes the concept of ‘capturing solar energy wherever possible’. If all new buildings were to incorporate BIPV on a large scale, significant amounts of energy would be generated, greatly assisting in creating sustainability.


For application to Chesser House, the most feasible option for applying this technology would be the foyer’s glazed roof area. The basis for selecting this location is due to the horizontal orientation of the glazing, the lack of shading and the current issues associated with glare. The horizontal orientation and lack of shading ensures that the BIPV is well exposed to sunlight, as such can operate at a high efficiency, whereas the glare issues (as indicated earlier in this report, regarding glass coatings) can be resolved by utilising the highly tinted option. The added benefit of reducing cooling costs will also be of significance due to the relatively low efficiency of the air conditioning system which serves the foyer. Using a transparent BIPV to replace the glazing will produce electricity and solve the glare issues, whilst still maintaining aesthetics and natural light within the space. The glazing on the other typical floors of Chesser House do provide a possible location for the transparent BIPV, however a retrofit this large would be infeasible due to the large costs and extensive works required.

There is approximately 55m2 of glazing available for the use of transparent BIPV in the foyer area. The Solar Shop Australia can provide Suntech’s SeeThru cells, which can fit 52m2 of the available foyer roof space (due to the size and shape of the panels). It is recommended that a relatively low transparency is selected, 5% would be appropriate, such that glare issues are resolved.

BIPV is best suited to new commercial office buildings, as the concept can be incorporated into the overall design at an early stage. This allows for planning to occur such that areas with the BIPV cells can act to reduce heat transmission to the space and still be well exposed to sunlight. For existing commercial office buildings, BIPV is only really feasible in situations where solar PV is desired and a part of the building would benefit from replacement.




The energy saving potential of the proposed BIPV works at Chesser House are reasonable, with a 4.2kW rated installation possible with the given space. The cells have the capability of producing approximately 18.2kWhrs per day, leading to a total of approximately 6643kWhrs per year. This results in a yearly saving of $996.45. The energy consumption reduction associated with the shading effect of the cells would increase this value. Annual savings including the reduction in air conditioning load should be approximately $2,316. This returns a reduction in CO2 emissions of 14 tonnes per year. The cost of such system would be approximately $27,000. Although the initial price is quite high, this concept should be viewed minus the cost of installing glazing which would solve the glare issues. Utilising this method of considering the concept, the feasibility is increased.

For other commercial office buildings the driving factors for the energy savings are the available space, the exposure to sunlight and the shading/reduction in heat transmitted to the internal space. If all of these factors are present, and a need or desire to replace an area of the building or facade exists, then BIPV would be a good option to consider.


The demonstrative potential of this concept is high, as the technology is easily viewable from the building’s exterior. Also solar PV cells are quite popular and well known for their ability to generate ‘green power’, adding to the high level of demonstration.

8 SOLAR AIR CONDITIONING

8.1 INTRODUCTION

Solar air conditioning refers to the use of solar energy to provide either all of, or a portion of the required power to heat and cool a building. Solar air conditioning can be considered as a sustainable technology, due to the potential for it to run completely grid independent. There are several different configurations in which solar air conditioning systems can operate, each with a basic set of key stages: heat collection, thermally driven cooling/heating and delivery.

Heat collection is the first step in providing solar air conditioning; as the name suggests it involves harvesting the heat available from the sun such that it can be used in the system. Heat collection is achieved through the use of collectors, in the form of air collectors, flat plate collectors, evacuated tubes, trough reflectors or solar towers. Each technique has its own particular benefits or disadvantages, depending on the application. Trough reflectors and solar towers are able to achieve the highest temperatures, due to their ability to focus a large amount of light. Trough reflectors are effectively parabolic troughs which work to focus sunlight onto a tube of liquid, the troughs can move to track the sunlight, such that as much energy as possible is captured. Solar Towers operate in a similar manner, with the difference being the tube is located on top of a tower, and a field of reflectors aim sunlight directly at the tube. Images of both trough collectors and a solar tower are shown below.

Figure 8.1 Solar Trough Collectors (NEP Solar, www.nep-solar.com)



Figure 8.2 Solar Tower (lisas.de/projects/alt_energy/sol_thermal/powertower.html)

Thermally driven cooling can be completed using various techniques, including: desiccant cooling, adsorption chillers, absorption chillers and ejector refrigeration. Absorption chillers are quite common and can help to provide a more efficient process than the other thermal cooling systems presented. Absorption chillers are covered earlier in this report, and are considered as the most feasible option if a solar air conditioning system is desired for a commercial office building. Heating requirements can also be achieved using absorption chillers, in a simpler process.

Delivery simply refers to the method of delivering the heating/cooling capacity to the space, with an absorption chiller this refers to the chilled/heating hot water loop and the air handling units or fan coil units.

As mentioned, solar air conditioning has the potential to be completely grid independent. The above techniques however only include the use of solar energy to provide the heating/cooling load, as the system as a whole would still require significant pumping and fan energy (to deliver the chilled/heating water and the air). As such to be completely grid independent, some form of onsite power generation is required, such that the pumps and fans can be powered. It is recommended however to have a backup gas line such that during periods where solar energy can not sufficiently provide enough energy for cooling, gas can be used.

Solar air conditioning has been applied in various locations around the world; as such the viability of the technology has been verified. However the technology is highly dependent on various factors which directly effect is feasibility. For example the cooling capacity achievable is dependent on the solar energy which is harvestable; as such a large unshaded area is required for heat collection. Also solar energy has a degree of variability associated with it, leading to the potential for temperatures not being high enough. Therefore the feasibility of solar air conditioning is very case dependent, and frequently would only be suitable in a supplementary form (providing cooling when sufficient solar energy is available).


As discussed earlier in this report, Chesser House recently underwent an upgrade to a highly efficient electric chiller. As such a solar air conditioning system, which would require an absorption chiller, is not feasible at this stage, and would be best considered at the end of



the current chiller’s service life. Solar air conditioning also currently represents a significant initial investment, which would also decrease its feasibility at Chesser House, considering the investment already made for the current chiller.

For a commercial office building with a centralised chilled water plant, a typical solar air conditioning setup would include a solar tower or trough collector system, with an absorption chiller serving several air handling units. The cooling capacity of this system depends upon the available space for heat collection, with the roof space at Chesser House expected to be unsatisfactory for a suitable capacity to be achieved. As such solar air conditioning is best suited to a building which has access to a vast expanse of unshaded area (either on the roof or nearby vacant land) and has many passive design features such that the buildings air conditioning load is low.

For existing commercial office buildings, the use of solar air conditioning would rarely be feasible, due to the fact that insufficient space would frequently not be available to meet the capacity and the cost of retrofitting such a system would be too high. New commercial office buildings have more of a potential for implementing such technology, as the system can be integrated within the building’s design such that it can perform at its best.


The energy saving potential of utilising solar air conditioning is reasonably high, however a large portion of energy consumed to condition a building is associated with fan and pump energy. Generally a large commercial office building would see approximately 60% of its energy consumption go towards air conditioning, with approximately half of that associated with fan and pumping energy. Solar air conditioning has the potential to entirely account for condenser energy (the energy required to provide the heating and cooling effects), which can be approximately 20-30% of the entire buildings power consumption. These values assume that the solar heat collection system is large enough to produce a level of heat such that the absorption chiller system can work uninterrupted, whereas in most cases this would be unachievable, and the energy savings would be less.


A solar air conditioning system holds a high level of demonstrative potential, due to the innovation associated with the concept and the fact that the system can be visible to occupants/members of the public (particularly in the case of a solar tower). The concept of solar air conditioning can be considered as innovative, as the technology is still in its infancy in terms of application. The technology may also be viewable from the exterior of the building, which will further the demonstrative potential.

9 ENERGY ENHANCED GAS

9.1 INTRODUCTION

Energy Enhanced gas refers to the concept of using solar energy to drive a chemical reaction, using natural gas to form hydrogen, which is capable of producing higher levels of energy. The process involves a solar tower, concentrating solar energy and heating a gas mixture to cause a chemical reaction, in effect producing a hydrogen gas with a higher level of potential energy.

The CSIRO have developed and are testing a solar enhanced gas – named SolarGasTM – which can produce approximately 26% more energy than natural gas. The hydrogen gas can be formed at temperatures of approximately 600˚C to 800˚C, which are achievable in solar towers. Essentially the gas is primarily being used as a method of storage for the solar energy, rather than conventionally converting solar energy directly into electricity. As such, the primary use of this technology is its ability to generate the gas on a large scale and transport it without incurring large scale losses. The gas can also be used to release the solar energy in a reversed chemical reaction process, as such providing a more sustainable solution.

For de-centralised use, if sufficient roof space is available, using a gas similar to SolarGasTM would provide an effective option for a more efficient building. As long as natural gas is



available at the building then the concept can be used. Also, some form of hydrogen generator would be required to produce electricity.

Enhancing the energy potential of gas is still in its infancy, with significant research and development underway due to its potential to be a solution to the requirement for sustainable energy. As for applying the concept in de-centralised situations on inner city building roofs the potential is available, and with further research could prove as a suitable option for reducing building energy consumption.

Figure 9.1 National Solar Centre’s solar tower (http://www.csiro.au/)


As the system’s effectiveness relies on the amount of reflectors used to achieve temperatures such that the gas can react, the important factor in determining whether this option is feasible is the available unshaded space. Chesser House’s roof space is quite small and is expected to be insufficient to provide space for the reflectors to achieve the temperatures required. As such, it’s unlikely that this option would be feasible. Generally a large, unshaded roof space would be more suitable for this concept to work effectively. Approximately 700m2 of unshaded roof has the potential to yield 100kW of electrical energy generated using solargas.

Also, as using solar energy to enhance gas is still in the process of being researched and developed, a detailed investigation is required to assess and test the concept. There are several health and safety issues associated with the high temperatures reached during the processes involved, which will also require consideration.


The energy saving potential of this concept is quite large, due to the opportunity to increase the energy content of natural gas to 26%. The hydrogen gas produced could be used to power a cogeneration plant, generator or air engine. As mentioned, 100kW is achievable with approximately 700m2, with capacity increasing with available space. Due to the nature of the technology, prices of the system would be quite high, with estimates for a 100kW system being over $1,000,000; however with time and further development this price should reduce.

Essentially, for a large scale commercial office building, the concept should be viewed as an option for significantly increasing the energy content of gas to be used in a large plant (cogeneration, air engine etc.). If sufficient roof space is available and an innovative solution



for reducing energy consumption is sought after, then this option should be considered and further investigated.


As discussed in the solar tower section, this concept would also hold a high degree of demonstrative potential, as the system would be clearly visible. Demonstrative potential would also increase significantly due to the opportunity to significantly revolutionise energy consumption and storage, and the level of innovation associated with this concept.

10 FIBRE OPTIC SOLAR LIGHTING

10.1 INTRODUCTION

Fibre optic solar lighting utilises sunlight to provide natural light, capturing the sunlight from an outdoor solar collector and transporting it through fibre optics to luminaries inside a building. Solar lighting provides an effective solution for introducing natural light into spaces in situations where windows, light shafts and atriums are infeasible; leading to the solution being effective for existing buildings. A vast proportion of the energy used in electrical lighting is consumed during daylight hours, when high quality, full spectrum light is available from the sun. This concept can completely relieve the need of electrical lighting during times of daylight, which is highly useful in situations where daylight is not achievable or increased levels are desired.

Solar lighting works by collecting sunlight using an outdoor collector panel which is comprised of numerous optical lenses. The lenses track the sun throughout the day, ensuring they directly face the incident sunlight. Connected to the panel are the flexible optical cables, which are capable of transporting light over a certain distance. The cables themselves include a degree of lux loss which is proportional to cable length, as such the longer the cable length the less sunlight is transmitted into the space. At the end of the optical cable run are the controllable luminaries, which can be switched on and off. The solar lighting system blocks any ultra-violet radiation, which can be harmful to tissues and textiles. Therefore, there are no health and safety risks associated with being exposed to the light.

Figure 10.1 An example of how the sunlight can be transferred to interior rooms or zones using solar lighting (http://www.parans.com/)

The benefits of solar lighting includes both the energy saving potential of reducing electrical lighting levels and also the improvement in occupant comfort associated with the increase in daylight levels.



Fibre optic solar lighting can be effectively combined with daylight sensor-controlled electric lighting throughout the building, resulting in significant energy savings. This concept extends the potential use of daylight sensor controlled light to rooms or areas within buildings far away from natural light sources. Essentially, the more electrical lighting controlled by daylight sensors, the higher the energy savings achievable. Solar lighting also produces no heat during operation, reducing cooling load requirements. Electric lighting levels and other sources of natural light (windows, atriums etc.) all contribute significantly towards the heat load of the building, resulting in less air conditioning energy being consumed when using solar lighting.

The increase in daylight levels throughout an indoor space can assist in improving occupant comfort, leading to improvements in productivity. There have been numerous studies on the relationship between natural light levels and human health, with natural light being important for maintaining sleeping patterns and general health. Low levels of natural light can lead to decreased productivity and more frequent sick leave amongst employees; as such the importance of supplying natural light to workspaces is high. Providing adequate natural light levels is recognised by Green Star.

The limitations of solar lighting are due to the technology requiring direct sunlight to operate. As such shading, clouds and more obviously, night time, all cause the solar lighting system to produce no light. Also currently the technology cannot store the sunlight in any form; as such the sunlight is only transmitted into the space as it is available outdoors.


Chesser House provides quite good levels of daylight, due to its glass facade, resulting in the concept of fibre optic solar lighting being an unnecessary option. The interior zones on typical floors at Chesser House receive lower levels of natural light, however the technology is inapplicable to these situations as the cable length required to serve these zones will result in significant losses to the natural lighting levels achievable from the luminaries. Daylight sensors for the purpose of reducing lighting energy consumption are however recommended, as discussed earlier in the report.

For other existing commercial office buildings, solar lighting should be considered in situations where: natural light levels are low, the potential cable run from the exterior to the interior is short and the current electric lights can be controlled by daylight sensors. In such situations, fitting solar lighting with daylight sensors wherever possible would provide an effective option for reducing energy consumption and increasing occupant comfort.

For new commercial office buildings, solar lighting should be implemented to as high a degree as possible, combining the concept with daylight sensors. Solar lighting can be seen as an alternative to providing daylight to internal zones through atriums or light shafts; however they provide a benefit over these two concepts as they don’t contribute to the heat load of the building. Providing sufficient external views are still an important point to consider, as such solar lighting should be seen as an option for providing light to internal zones, with external zones expected to receive sufficient light from windows.

Parans manufactures fibre optic solar lighting systems for buildings, providing collectors, luminaries and cabling. Various types of luminaries are available for different applications, some of which are shown below. Currently the cost of the Parans lighting system is too high to be considered as a cost effective solution, due to its infancy, however cost is expected to fall after product and manufacturing developments.



Figure 10.2 A Parans Luminary (http://www.parans.com/)

Figure 10.3 The Parans outdoor solar collector panels (http://www.parans.com/)


The energy saving potential of a fibre optic solar light system with daylight sensors is based upon the amount of luminaries used and the power usage of the current electrical light fittings. Generally, light fittings surrounding the solar light luminaries can expect power consumption reductions in the range of 10 to 20%. This represents a relatively small degree of savings considering the capital cost of solar lighting systems; as such the system will be ruled infeasible for most applications. As stated above, the cost of the systems is expected to fall, which may lead to feasibility in the future. Currently the system would only feasibly be considered if daylight is greatly sought after, in an area which without solar lighting would have none.


The demonstrative potential of this concept is high, due to both its innovative nature and its exposure to building users. Building users will most likely find the extra levels of daylight aesthetically pleasing, as it will add to their level of comfort. Also as the luminaries are quite



distinctive in terms of their physical appearance and the light they emit, as such building users will easily be able to identify them.

11 WIND ENERGY

11.1 INTRODUCTION

Wind is a plentiful source of renewable energy which has been harnessed for many years. The concept of capturing the kinetic energy in wind and converting it into usable electricity is well established and is prevalent all around the world, with large wind farms increasingly becoming a renewable source of base load electricity. Wind turbines are most effectively sited in areas which are consistently subjected to steady, laminar winds, with coastal areas or areas with vast expanses of flat land surrounding the most suitable. Wind turbines installed in these remote areas are usually of a large scale, producing electrical loads in the megawatt range, there is however the potential to use small scale wind turbines in built up urban areas, with potential to install on the roof of tall buildings. This section will focus on the use of wind turbines to produce electricity within urban areas on building rooftops.

Installing wind turbines on building rooftops is a challenging exercise, with many inherent problems to overcome. In a vast amount of cases, roof mounted wind turbines in urban environments are infeasible due to local sheltering effects and turbulent airflows caused by surrounding buildings. Most wind turbines require at least 10km/hr winds to begin generating power, which may not be achievable on a regular basis if the building is protected from the wind. Also there are significant issues involved with the dynamic loading exerted on the turbines during operation, which get transmitted to the building, causing structural and vibration issues. Generally, wind turbines are best suited to either very tall buildings (such that they extend above surrounding buildings) or to buildings which are surrounded by areas of flat land. In both cases adequate structural supporting for the turbines is required; as such it’s commonly more feasible to consider wind turbines early in the building’s conceptual design.

Small scale wind turbines can be categorised as either being vertical axis or horizontal axis in orientation, with the axis being the line the turbine’s blades rotates around. Horizontal axis turbines are the configuration used in large scale wind farms and are the most easily recognisable, they are characterised by their likeness to propellers. Vertical axis wind turbines most commonly are used in either a Darrieus or Savonius configuration. Each turbine has certain advantages and disadvantages associated with it, with the proposed wind turbine’s site being a deciding factor when selecting a configuration. Typically Savonius wind turbines are better suited to more built up areas with less steady wind flow, as they can consistently produce power at a low level in variable wind speeds and directions. Traditional horizontal axis wind turbines are more suited to situations where a more steady laminar wind is prevalent (e.g. on a taller building’s roof) as they can work extremely effectively in consistent winds of reasonable strength. Images of the three configurations are shown below.

Figure 11.1 Horizontal axis wind turbine (http://www.clean-energy-ideas.com/)



Figure 11.2 Savonius wind turbine (http://www.energybeta.com/)

Figure 11.3 Darrieus Wind Turbine (http://www.reuk.co.uk/)

Aside from the various design challenges mentioned above, wind energy has several benefits and disadvantages associated with it. Benefits include the potential to generate energy in a sustainable manner, relative low cost when compared to other forms of renewable energy and the high level of demonstrative potential associated with turbines. Disadvantages include the fact that turbines only generate power when adequate wind is blowing, potential visual impacts, the potential noise and vibration issues if not correctly designed and possible safety concerns with having large rapidly moving blades on a building’s rooftop.


Chesser House is located near the centre of Adelaide’s central business district, and is well sheltered by surrounding buildings. Therefore it is very likely that wind quality on Chesser House’s rooftop is of an insufficient standard to warrant installing wind turbines. Also the roof plan at Chesser House is likely to be unsuitable for the use of wind turbines, as the roof space is split between the 11th floor and the 12th floor plant room (12th floor plant room has a smaller area than the 11th floor). Therefore the use of wind turbines would not be a feasible option for reducing energy consumption at Chesser House.



The use of wind turbines in a commercial office building setting is most appropriately applied as part of a solar/wind hybrid system. This is due to both technologies being reliant on resources which have an inherent variability associated with them, as wind and solar energy may occur at different periods of time. In doing this, there is a greater opportunity for the hybrid system to feed power at a constant rate, compared to if either technology was used exclusively. Therefore the use of wind turbine technology should be considered for new or existing buildings (with suitable roof space), which have a sufficient level of wind quality (e.g. it is tall, not shaded by nearby buildings, in an area which has a high wind rating) and which have sufficient structural strength to overcome the resulting loads.

To gain perspective on the potential use of wind turbine systems, to achieve a rated output of 6kW, a turbine’s rotor size would be of approximately 5m. A rotor of this size would be feasible in very few instances; therefore it is clear that a relatively low level of power is achievable. It is possible to use several smaller turbines rather than a single large turbine; however consideration must be given to turbulence effects associated with placing wind turbines in close proximity of each other.


A useful factor which can be applied to wind turbines to determine their predicted energy output is the capacity factor, which is a ratio of the mean power output of a turbine installation to the rated power output. Mean output power is the average power produced by the turbine over a period of time, rated power is the power rating claimed (usually by the manufacturer) at a certain wind speed (for example a turbine may be rated to 5kW at 8m/s, meaning it produces 5kW in winds of 8m/s). Therefore the higher the capacity factor, the more effective the wind turbine installation. Commercial wind farms in Australia usually have a capacity factor in the range of 30 to 40 percent, which represents a good level of output. Well sited and well designed small scale wind turbine installations on building rooftops can range from 10 to 20 percent in capacity factor. Using the 6kW example noted above, applying a capacity factor of 20% returns an average output of 1.2kW, or 10,483.2kWhrs and 9.5 tonnes of CO2 per year, which is a reasonable saving.

Essentially the capacity factor and the available space dictate the level of energy savings achievable with the use of wind powered systems, both of which require in depth investigation if considering the use of wind turbines.


The demonstrative potential of wind turbines is high, due to the technology being easily visible to the public. Wind turbines are well known as being a sustainable technology; as such the use within a building will promote a green image.

There is debate on the attractiveness of wind turbines; however most of this is centred on large scale wind turbine sites, as frequently these farms are near coastal areas which may be quite scenic. Therefore in an urban environment the issue of wind turbines being visually negative is essentially nonexistent.

12 SUMMARY

This section of the report represented the more innovative and challenging concepts which reduce energy consumption within buildings. A number of the concepts investigated were not particularly feasible to Chesser House, or other existing typical commercial office buildings, due to the magnitude and complexity of the systems. The concepts hold more relevance to new commercial office buildings, due to the potential to integrate the systems at an early stage of the building’s design.

The concepts which did indicate a potential for application to Chesser House are air engines and building integrated photovoltaic. Air engines have the potential to reduce energy consumption significantly; however there is a degree of risk involved with the concept due to its prototype nature. Building integrated photo voltaic has the potential to provide moderate energy savings whilst also resolving issues present relating to glare in the foyer area.



RECOMMENDATIONS AND CONCLUSIONS

1 CONCEPT COMPARISONS

To determine which concept is most applicable to Chesser House, relevant comparisons are necessary. It is within the intent of the report to both provide a level of investigation and a level of comparison for each concept, as to create an understanding of which concept should be viewed as the best option. The technique used for comparison and the results achieved are related to the concept’s performance at Chesser House, however this section can still hold relevance to other commercial office buildings, as the results still can assist in providing a basis for decision making, regarding which concepts to apply.

1.1 METHODOLOGY

To obtain meaningful results, comparisons are completed based upon several weighted parameters, using a point basis with the concept achieving the highest score being the most applicable. Parameters were selected with the intent to facilitate a broad comparison, allowing each concept to be given a representation as to how well suited it is for application. The concepts were scored as to how well they performed under each parameter; concepts which performed highly received a higher score, whereas concepts which performed poorly received a lower score. Each concept’s parameter score was then weighted using a percentage style system, with parameters of high importance given 100% and parameters of low importance given 10%. The sum of all weighted parameter scores for each concept determines how the concepts rank against each other, as such allowing for a relevant comparison to be made.

1.2 PARAMETERS

Each parameter is sorted into five general categories; sustainability, functionality, demonstration, costs and risk. The parameters and categories are shown below:

Sustainability:

- Energy Consumption (level of energy consumption)

- Green House Gas Emissions (level of GHG emissions)

- Peak Energy Demand (peak demand reduction)

- Other pollutants (level of other pollutants emitted e.g. NOx)

- Embodied energy (energy associated with manufacture etc.)

- Resource Consumption (consumption of water, gas, electricity)

- Functionality

- Ease of installation and maintenance

- Building Occupant Disturbance (disruption during installation, operating noise, vibration etc.)

- Future Considerations (design for disassembly, ease of upgrade)

- Resource Reliability (e.g. gas is reliable, wind is not)

Demonstration

- Aesthetic Appeal

- Public Awareness (public gains sustainability awareness due to project)

- Industry Awareness (industry gains sustainability awareness due to project)

Costs

- Capital costs (initial cost of the upgrade)



- On-Going Costs (cost of maintenance etc.)

- Cost of Upgrade (cost once service life is finished)

- Return on Investment (payback periods)

Risk

- Level of Development (technology is well tested or researched, or in prototype phase)

Concepts are given a score of 1 to 5 as to how well they perform within the given parameter, with a higher score showing a better result. For example a concept which has a very low level of development will score 1, whereas a well established concept will score 5. The scores given are based on in-house knowledge and are comparatively assigned.

1.3 WEIGHTINGS

Weightings are crucial in providing results which hold relevance to the case in question. Appropriate and well formulated weightings allow for comparisons to be personalised, such that parameters which are of higher importance hold a greater significance to the final result.

Weighting factors were determined using resulting averages from a variety of sources. The resulting weighting factors, rounded to the nearest 0.5%, are shown below:

Energy Consumption

Green House Gas Emissions

Peak Demand

Other Pollutants

Embodied Energy

Resource Consumption

Installation and maintenance

Occupant disturbance

Future Considerations

Resource Reliability

Aesthetic appeal

Public awareness

Industry awareness

Capital Costs

On going costs

Cost of Upgrade

Return on Investment

Level of Development

Category:

SUSTAINABILITY

FUNCTIONALITY

DEMONSTRATION

Weighting factor

(%)

92.5

92.5

92.5

Parameter:

COSTS

RISK

55

70

100

75

77.5

75

82.5

62.5

75

72.5

75

82.5

72.5

75

80

Figure 1.1 Weighting factors

The weighting factors shown above are only really applicable to Chesser House, as the sources used to obtain the factors were aware that the comparisons are based primarily on that building. If using a similar technique for another commercial office building, weighting factors should be re-determined for that case using another set of key personnel related to that building.

1.4 RESULTS

The results of the comparative analysis are summarised on the following page. Note that the scores given for each concept represent the applicability to Chesser House, as such; the results should only be viewed as a guide for other commercial office buildings.



The highest ranking concepts were glass coatings, high efficiency lighting, building integrated photovoltaic, improvements in metering, occupant comfort control, lighting control, the Shaw Method of Air Conditioning, fuel cells, re-commissioning and re-tuning and economy cycle systems. Chesser House is currently undergoing an upgrade to implement the Shaw Method of Air Conditioning and economy cycle systems; as such these systems will not be included in recommendations.

Improvements in metering, occupant comfort control and re-commissioning and re-tuning all represent simple systems with relatively low initial costs. Metering and re-commissioning and re-tuning are more corrective measures, whereas occupant comfort control acts to modify the operation of the HVAC plant such that energy consumption is reduced. Re-commissioning and Re-tuning may expose other issues present with the building’s operation; as such it should be seen as the first step in improving Chesser House.

High efficiency lighting and lighting control both provide good options for reduced energy consumption, although the proposed lighting control won’t benefit the base building. The proposed systems are both relatively low cost solutions which will improve the building’s operation.

Building Integrated photovoltaic systems and fuel cells are the more innovative concepts which scored highly. Both concepts can provide reliable energy savings and are not excessively expensive. Glass coatings scored well due to its ability to simply reduce energy consumption and its short payback period. This concept however is not needed as the area where glass coatings is proposed is the same area where BIPV is proposed (BIPV has the same effect as glass coatings, with the addition of electricity generation).

As expected, the stretch objectives scored low due to the low levels of functionality and the high level of costs and risks involved. This makes it difficult to justify the installation of such concepts; however the intent to implement such technologies would require an acceptance of the risk and a desire to ‘break the boundaries’ of what’s commonly applied in buildings. It may be sometime before these concepts are viewed as business as usual (some may never be), hoverer if the intent is to be innovative and market a sustainable image, consideration of these technologies is worthwhile.



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Weighting Factor (%) 92.5 92.5 92.5 55 70 100 75 77.5 75 82.5 62.5 75 72.5 75 82.5 72.5 75 80

Re-Commissioning and Re-Tuning 4 4 2 5 5 5 4 2 5 5 1 1 2 3 3 5 3 5 64 50 9

Heat Recovery Ventilation 1 1 3 5 4 3 2 4 5 5 1 1 1 3 5 5 2 5 56 43 16

High Efficiency Lighting 4 4 2 5 4 4 4 5 4 5 4 3 2 5 5 4 5 5 74 58 2

Economy Cycle Systems 2 2 1 5 5 5 5 3 5 5 1 1 1 4 5 5 3 5 63 49 10

Part Load Performance 3 3 1 5 4 5 3 3 4 5 1 1 2 3 3 3 2 5 56 44 15

Metering 4 4 1 5 5 5 5 5 5 5 1 1 2 5 5 4 5 5 72 57 3

Gas Fired Technologies 2 4 4 3 3 4 3 3 4 5 1 2 3 2 3 2 3 5 56 45 14

PICCV 2 2 1 5 4 4 2 2 3 5 1 1 1 3 3 2 2 5 48 37 20

High Efficiency Insulation 1 1 1 5 2 5 3 3 2 5 1 2 2 2 4 4 2 4 49 38 19

Lighting Control 4 4 1 5 5 5 4 4 4 5 1 2 2 4 5 4 4 5 68 54 6

Chilled Beams 3 3 1 5 2 3 1 1 2 5 4 2 3 2 3 1 2 4 47 36 21

Glass Coatings 4 4 3 5 4 5 4 5 5 5 3 3 3 5 5 5 4 5 77 60 1

Cogeneration 4 3 1 3 3 4 2 3 2 5 1 2 4 3 2 3 2 4 51 41 18

Regenerative Braking 4 4 1 5 4 5 3 4 4 5 1 2 4 3 4 1 3 4 61 48 11

Occupant Comfort Control 3 3 3 5 5 5 5 5 5 5 1 1 4 5 5 3 5 3 71 56 4

Shaw Method oF Air Conditioning 4 4 2 5 4 5 4 5 4 5 1 1 3 4 4 4 4 4 67 53 8

Fuel Cells 4 4 1 4 3 5 4 5 4 5 2 3 4 3 4 4 3 2 64 50 9

Absorption Chillers 2 3 3 4 3 5 2 3 5 5 1 1 3 2 4 4 3 4 57 45 14Indirect Evaporative Cooling 2 2 4 5 3 3 3 4 4 5 1 1 2 3 4 4 2 3 55 43 16

Natural Ventilation 3 3 1 5 3 5 2 4 4 5 3 3 3 3 5 4 2 4 62 48 11

Induction Technology 1 1 1 5 2 5 2 4 3 5 1 2 3 2 5 1 1 5 49 38 19

Geothermal Systems 3 3 2 5 2 4 1 2 5 4 1 4 5 1 2 1 1 2 48 38 19

Innovative Shading 1 1 3 5 3 5 2 4 3 5 4 3 3 1 4 1 1 4 53 41 18

Air Engines 5 5 5 4 2 4 1 4 5 5 1 3 5 1 2 2 2 1 57 46 13

Green Walls/Roofs 2 3 3 5 3 2 1 5 4 3 5 5 5 1 2 2 1 2 54 41 18

Phase Change Materials 2 2 4 5 2 5 2 5 4 5 1 2 4 2 4 2 1 1 53 42 17

BIPV 4 4 3 5 3 5 4 5 4 5 4 4 4 2 5 3 3 3 70 55 5

Solar Air Conditioning 3 3 4 5 2 5 2 2 4 2 2 3 4 1 3 3 2 2 52 41 18

Energy Enhanced Gas 4 5 4 4 2 4 2 2 5 3 2 3 4 1 2 2 2 1 52 42 17

Solar Lighting 1 1 1 5 4 5 3 4 4 5 5 4 5 3 5 3 1 2 61 47 12Wind Powered Systems 3 3 2 5 2 5 2 2 3 1 3 4 3 2 2 2 1 4 49 38 19

Figure 1.2 Comparative Analyses



2 RECOMMENDATIONS FOR CHESSER HOUSE

From the above analysis, the most suitable course of action to take at Chesser House would be to implement a re-commissioning and re-tuning plan, improve metering by ensuring all loads are correctly accounted for, upgrade base building lighting, implement a lighting control strategy throughout the entire building, install fuel cells to account for 24 hour loading and install a BIPV system on the glazed areas of the foyer. These works represent the best options for improving the energy efficiency of Chesser House, whilst still providing a level of demonstration and innovation.

Completing the above works has the following effects on building energy consumption and greenhouse gas emissions (all per year):

Total Reduction in Electricity Consumption: 168,110kWhr

Total Reduction in Greenhouse Gas Emissions: 125.66t

Focusing on base building consumption varies the result, as the lighting control strategy only effects tenant consumption. The below results show changes in base building consumption:

Total Reduction in Electricity Consumption: 122,410kWhr

Total Reduction in Greenhouse Gas Emissions: 84.01t

Percentage Reduction in Electricity Consumption: 12.5%

Percentage Reduction in Greenhouse Gas Emissions: 8.6%

As can be seen the results are considerable, with significant reductions in both base building and tenant consumption. It would be a reasonable estimate that the above base building works would translate into an improvement in the building’s NABERS rating by approximately half a star, from an estimated 4 stars to 4.5 stars.

If a more innovative result is desired, with a higher potential to reduce energy consumption, air engines could be considered. The manufacturer’s claims are significant; however the prototype nature of the technology results in there being large risks. Allowing some time to pass for further development of the technology would be worthwhile.

3 RECOMMENDATIONS FOR SIMILAR BUILDINGS

Due to the independence of each building, the applicability of the concepts presented in this report would be based upon each building’s individual traits. As such, some concepts may be applicable in some cases, whereas some may not be. A good example of this is the BIPV concept at Chesser House; typically this concept is more suited to new buildings, such that it can be designed into the facade, however in this case there was a good option to apply the technology in a retrofit.

Generally for new commercial office buildings, a wide range of the concepts presented in this report could be applied and may be suitable in certain cases. An example of a highly performing system would include some form of energy harvesting (e.g. energy enhanced gas, BIPV, geothermal systems), a usable power energy generator system (e.g. air engines, cogeneration with absorption chillers) and a number of systems throughout the building to improve general energy efficiency.

For existing commercial office buildings, first step measures such as re-commissioning and re-tuning provide an excellent option to identify systems which may be in need of an upgrade. This should then narrow down the potential options significantly, allowing a better solution to be achieved. In most cases, simple systems such as lighting control, occupant comfort control, small scale cogeneration, fuel cells, Shaw Method of Air Conditioning and indirect evaporative cooling are likely to be the best options for existing buildings. Other concepts investigated may be applicable in certain cases, depending on the building.

Clearly providing recommendations regarding actions to take to reduce energy consumption in typical commercial office buildings is somewhat invalid, as it’s difficult to identify a building as being typical. However an indication as to what is likely to be a



worthwhile concept for consideration, which is what is presented in this report, is of a much higher relevance. It is intended that the concepts presented give an indication as to how they may be applied and how well they perform in a given situation (in this case, the situation is Chesser House). Therefore, this allows a more informed decision to be made when investigating options for reducing energy consumption in an innovative way.

4 CONCLUSION

The concepts presented in this report offer a wide range of options which provide various levels of risk, innovation and energy savings. Most concepts demonstrated that they are applicable in certain situations and are effective solutions in providing a degree of sustainability. The final recommendations for Chesser House returned a good result, as they fulfilled the reports intention, which is to find innovative concepts which save energy and promote sustainability. Recommendations were also given regarding options for consideration in other commercial office buildings, existing or new.

The commercial building sector is responsible for a significant amount of greenhouse gas emissions and resource consumption, during both construction and operation. It is clear that currently only a certain degree of energy savings in commercial office buildings can be feasibly achieved, with stretch objectives having high associated savings falling outside of the limits of feasibility, primarily due to costs. Unfortunately, these stretch objectives do not become feasible without someone taking a risk, therefore the future of a majority of these technologies is not only based upon how well they can perform, but also how many private or government bodies are willing to accept the risks and trial them. This is occurring however, at seemingly an increasing rate.

Global warming and resource depletion cannot be completely addressed by the building sector alone, as even if every building is carbon neutral and capable of generating its own electricity, other sectors would still be responsible for their portions of emissions and consumption. However, the building sector is well positioned to act as a leader in sustainable operation, due to the large amounts of funding available and technological developments occurring. Therefore, there should be a feeling of responsibility within the industry to take advantage of the situation and begin to future-proof buildings, such that not only can the sector reduce its effect on the environment, but can also set an excellent example of how it is possible to achieve sustainability. The crises which will face us in the future can be significantly reduced in severity, and possibly even completely overcome, if action is taken early. Everyone will need to accept a degree of uncertainty and trial methods less commonly used to achieve sustainability, in this lies the potential for significant reward. It is in the best interest of everyone in the building sector to reach for achieving sustainability, as the negative implications of doing nothing is simply too vast.



REFERENCES

References used for this report is comprised of technical data sourced directly from manufacturers, in house technical data, in house knowledge and experience, internet resources and various texts.

1 INTERNET RESOURCES USED

- http://www.energystar.gov/ia/business/BUM_recommissioning.pdf

- http://solar-thermal.anu.edu.au/low_temp/phase_change/index.php

- http://www2.basf.us/corporate/080204_micronal.htm

- http://www.entropysolutionsinc.com/default.htm

- http://www2.dupont.com/Consumer/en_US/

- http://www.mep.com.au/

- http://www.infolink.com.au/c/Kone-Elevators-228196/Introducing-KONE-Eco-Efficient-Regenerative-Drives-n851050

- http://www.seav.vic.gov.au/manufacturing/sustainable_manufacturing/resource.asp?action=show_resource&resourcetype=2&resourceid=34

- http://www.ces.uoguelph.ca/research/envweb/

- http://www.csiro.au/

- http://www.ecospecifier.org/products/public/vim_sustainability_monodraught_wind_catcher_blp

- http://www.cyclopicenergy.com/

- http://www.building.co.uk/story.asp?storycode=3054640

- http://www.climatewizard.com.au/

- http://www.solarshop.com.au/

- www.pierlite.com.au/

- www.belimo.com/

- www.cfcl.com.au/

- www.dadanco.com.au/

- www.smactec.com/

- www.clipsal.com.au/

- www.broad.com/english/news/read.asp?id=49

- www.parans.com/

- www.itmdi-energy.com/

2 TEXT RESOURCES USED

- John Wiley & Sons, Wind Energy Handbook, Burton, Tony, 1947

- U.S. Geological Survey Information Services, Geothermal energy : clean power from the Earth’s heat, Duffield, Wendell A, 2003

- John Wiley & Sons, Fuel cell systems explained, Larminie, James, 2003



3 MODELLING PROGRAMS USED

- ACADS-BSG – Camel (building heat load estimations)

- ACADS-BSG – Beaver (building energy consumption estimations)

- Lighting Analysts Inc. – AGI32 (lighting design)

4 NABERS ASSESSMENT

NABERS Office Rating Results (Before implementing recommendations)

Date

23 Mar 2010 Site

Chesser House 91-97 Grenfell Street Adelaide 5000 South Australia Climate zone

Central Rating type

Base Building Rated area

11377 Hours of occupancy

50

Energy rating

Energy/Greenhouse Rating 3.5 stars

Your building offers good systems and management practices and reflects an awareness of the financial and environmental benefits of optimising energy use. Other Results Normalised emissions 105 kgCO2/m2 per annum Raw emissions 978774 kgCO2 per annum Energy consumption 382 MJ/m2 per annum Green power fraction 0% Energy rating Details

Electricity 979567 kWh 0% GP (Emissions: 930,589 kgCO2) Gas 826044 MJ (Emissions: 48,186 kgCO2) Disclaimer This report alone is not an accredited assessment. It does not give you any right to use any associated logo or to publicise your result. An accredited rating can only be obtained from an Accredited Assessor who follows a strict protocol.



NABERS Office Rating Results (After implementing recommendations)

Date

23 Mar 2010 Site

Chesser House 91-97 Grenfell Street Adelaide 5000 South Australia Climate zone

Central Rating type

Base Building Rated area

11377 Hours of occupancy

50

Energy rating

Energy/Greenhouse Rating 4 stars

Your building demonstrates excellent greenhouse performance reflecting good design and management practices, high-efficiency systems and equipment, and/or energy sources characterised by low greenhouse emissions. Other Results Normalised emissions 98 kgCO2/m2 per annum Raw emissions 894678 kgCO2 per annum Energy consumption 392 MJ/m2 per annum Green power fraction 0% Energy rating Details

Electricity 857157 kWh 0% GP (Emissions: 814,299 kgCO2) Gas 1377924 MJ (Emissions: 80,379 kgCO2) Disclaimer This report alone is not an accredited assessment. It does not give you any right to use any associated logo or to publicise your result. An accredited rating can only be obtained from an Accredited Assessor who follows a strict protocol.

project: chesser house sustainability project · sustainable practice approaches ... 6 phase change...

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