cibse - carbon 60 challenge

CIBSE CARBON 60 CHALLENGE HOARE LEA LONDON OFFICE TEAM Daniel Birks Mark Doughty Iain Fraser Devanthi Gunawardena Minesh Varia Ola Yussuf Neil Delgaty

HOARE LEA Consulting Engineers

Glen House 200 - 208 Tottenham Court Road London W1T 7PL Tel: 020 7890 2560 Fax: 020 7436 8466

CARBON 60 CHALLENGE

HOARE LEA LONDON OFFICE

March 2004 MD/LEO/0240121 X:eng/enquiries/2004 enquiries/0240121/london office entry 280504 Rev A Page 1

AUDIT HISTORY

REVISION

DESCRIPTION

DATE

ISSUED BY

REVIEWED BY

‘0’ First Issue 30 March 2004 DB, MD, IF, DG,

MV, OY ND

A Second Issue 28 May 2004 DB, MD, IF, DG, MV, OY

ND

This report is provided for the stated purposes and for the sole use of the named Client. It will be confidential to the Client and the client’s professional advisers. Hoare Lea accepts responsibility to the Client alone that the report has been prepared with the skill, care and diligence of a competent engineer, but accepts no responsibility whatsoever to any parties other than the Client. Any such parties rely upon the report at their own risk. Neither the whole nor any part of the report nor reference to it may be included in any published document, circular or statement nor published in any way without Hoare Lea’s written approval of the form and content in which it may appear.

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CONTENTS EXECUTIVE SUMMARY 1.0 APPLICATION ENTRY FORM 2.0 INTRODUCTION 3.0 OVERVIEW OF PROPOSALS, PROJECTED PERFORMANCE AND COSTS 4.0 PROPOSED CHANGES 5.0 PROPOSALS FOR FUNDING AND MANAGEMENT 6.0 SUMMARY OF KEY RESULTS 7.0 INITIAL AND FINAL VALUES AND PERCENTAGE CHANGE 8.0 IMPLEMENTATION PLAN 9.0 SUMMAY OF TECHNICAL PROPOSALS APPENDIX A– HEATING ENERGY CALCULATIONS

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EXECUTIVE SUMARY INTRODUCTION Our analysis shows that it is not mere hyperbole to seek to reduce CIBSE HQ’s carbon emissions by over 60% nor to use the result to reset goals for a range of UK’s building stock that are currently considered ‘stretch targets’. Our proposals focus on doing ‘the basics’ well and using proven technologies to reach the goal. While the combined effect of our measures is to exceed the carbon reduction target, they still leave opportunity for further carbon cutting measures to be implemented in the future – in line with our view that an exemplar project should demonstrate that the route to carbon neutrality (and beyond) is better thought of as a journey rather than a single leap. Our proposals are also designed to improve the comfort and ‘work experience’ of the building’s users. We believe that the strides needed in building energy performance cannot gain widespread support for so long as ‘energy efficiency’ continues to be thought to involve privation or loss of enjoyment to users or to demand significant behavioural change by them. The aim of CIBSE C60 must be to demonstrate that it is perfectly reasonable to contemplate swingeing cuts in emissions alongside user benefits. Hence our proposals and carbon cutting forecasts involve little demand on users to change their behaviour. However, we do propose measures to engage users in the goal and which show them the individual and collective opportunities to influence their workplace’s carbon outcomes. Further, by improving the building’s indoor climate, enhanced staff productivity can be anticipated. Achieving ‘more with less’ is part of exactly the same continuum as energy efficiency, because, at the limit, it means that GDP growth would not demand growth in space use, construction and all that is entailed. It is a critical message that economic growth is sustainable in a low energy economy. We propose to reduce the carbon emissions by over 60% by the following means:

• Improving the building fabric • Decreasing small power usage • Enhancing efficient lighting design • Reducing hot and cold water use • Providing mechanical ventilation • Enhancing energy management, and • Modernising the heating system and changing the fuel type.

One key factor in achieving the savings is obtaining the (realistic) support of the building’s occupants. PRACTICALITY OF PROPOSALS Our proposals have been weighed against the practicalities of implementation. Established techniques for carbon reduction are utilised, each of proven effectiveness. None presents unusual project risk. The optimisation of the building includes an improvement in the working conditions for CIBSE staff –particularly through enhanced ventilation and lighting. Operational management and training has been addressed in the proposals for improved energy management. In the ever-changing working environment it is more important than ever that staff have an awareness of their relationship with their immediate surroundings and the broader environment beyond. The dynamic Carbon Monitor label is designed to assist in this engagement.

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INNOVATION While most of the proposals involve well known, modern and proven, carbon reduction techniques, their uniqueness lies in their assemble - as a collective – an holistic strategy that produces UK’s first ‘normal’ Carbon 60 building - unadorned by PV, wind-turbine, turrets or any of the ‘green stripes’ of popular environmental architecture. Of course a view might be that the building displays nothing that hints at its carbon performance credentials. Another view would be that ‘green stripes’ are not mandatory in great carbon outcomes. Architecture needs to understand this. The proposal for a Dynamic Carbon Monitor is a new idea to maintain the interest of the occupiers and visitors in relation to carbon use and reduction. LEVEL OF CARBON REDUCTION This proposal predicts a 67% reduction in existing emissions. Our only ‘shortcut’ involves the use of (largely) renewable wood pellet fuel for heating. However, this ‘fix’ is applied only after significant reductions in heat energy have been achieved. We believe it is legitimate (and economic) to turn to renewables once reasonable measures to reduce energy use have been put in place. We consider that, by switching to lap-top PCs, it will be possible to extend the reduction to over 70%. However, as this measure maps onto work styles, we took this change to be outside the scope of the competition. COST We recognise that the capital costs of our proposals are high. Each measure has been costed, as realistically as we can, alongside its expected ‘opex’ savings (at current energy tariffs) and carbon reductions. Collectively they achieve the C60 goals at a long pay-back. However, much of this investment is enduring – it ‘fixes’ elements of the energy equation that should never need to be revisited in the HQ’s residual life and provides a platform to contemplate future enhancements when they become cost viable. With the prospect of the $60 barrel looming, we believe normal investment return paradigms need rethinking. EVIDENCE FOR CARBON REDUCTION Carbon reductions arising from the proposals have generally been estimated using simple techniques. They have been aggregated recognising the laws of diminishing returns apply. We have allowed a margin of error – and we have sought not to overstate the case. Most of the calculations and assumptions are described in the report or its appendix. CONCLUSION We believe our proposal answers the CIBSE C60 competition brief, and the underlying ambitions of the Meacher Challenge that inspired it, as something:

• grounded in reality, • widely applicable to the nation’s building stock • which balances the needs of workplace users with the imperatives of climate change mitigation

that shows it is possible “to have your cake and eat it”

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1.0 APPLICATION FORM

First Name Neil Surname Delgaty On behalf of Hoare Lea London Office C60 Challenge Team

Age and course (required for student entrants)

N/A

Organisation Hoare Lea London

Address Glen House, 200 – 208 Tottenham Court Road

London

Postcode

W1T 7PL

Tel 020 7890 2500 Fax 020 7436 8466 e-mail [email protected]

Are you a member of CIBSE?

Yes

If so, what is your membership number? 6612

Other professional affiliations, if any Member of Energy Institute

Do you wish to enter as a full-time student? No

If, so, can you provide proof of this status N/A I have read and understood the competition rules and intend to submit entry by closing date 30/3/04 Signature Neil Delgaty Date 30 March 2004

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2.0 INTRODUCTION

This proposal has been issued as an entry into the CIBSE Carbon 60 Competition. It has been put together by a team of young engineers, with between one and four years post graduate experience, in their own time. The team was chaired and co-ordinated by Neil Delgaty an Executive Engineer. The team are from the London Office of Hoare Lea Consulting Engineers.

The submission has been compiled based on the information available within the CIBSE/competition website and from the site visit on 18 May 2004.

The submission proposes to reduce the carbon emissions by 67%, based on the energy consumption set out in the September 2002 Action Energy report.

Based on the information available we have estimated the existing buildings energy use split amongst the various systems as follows:

System

Annual Electrical Energy (kWh)

Annual Gas Energy (kWh)

Carbon Emissions (kgC)

% Carbon Emissions

Heating

0

217,500

11,310

51.8

Hot Water

7,980

0

934

4.3

Cooling

1,764

0

206

0.9

Fans, Pumps Controls

11,032

0

1,291

5.9

Catering (gas)

0

2,500

130

0.6

Lighting

34,800

0

4,072

18.7

Small Power

33,150

0

3,879

17.8

TOTAL

88,726

220,000

21,822

100

It is proposed to reduce the carbon emissions by undertaking the following modifications:

• Enhancing the building fabric • Providing mechanical ventilation • Changes to the heating system • Reducing hot & cold water consumption • Changes to the lighting systems • Reducing small power use

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• Enhancing Energy Management

The effects of these changes can be seen in the following chart: EXISTING AND PROPOSED CARBON EMISSIONS

0

5

10

15

20

25

Existing Proposed

Car

bon

Emis

sion

s kg

C Small power LightingCatering gasFans,pumps,controlsCoolingHotwaterHeating

67.6% Carbon reduction

It should be noted that some changes proposed are affected by other changes (e.g. improvements in heating efficiency are affected by reduction in heat loss). The results identified in this report relate to the combined effect of making all the changes and recognise that compound effects produce diminishing returns. Where this occurs, the measures are viewed compositely and their respective contributions to the overall energy savings proportioned. The proposed changes have been design considering Health & Safety of the installers and operators. Further risk assessments will need to be undertaken during the detail design to eliminate reduce risk.

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3.0 OVERVIEW OF PROPOSALS, PROJECTED PERFORMANCE AND COSTS

PROPOSAL

CAPITAL COST

(£k)

REDUCTION IN

CARBON EMISSIONS (%)

Changes to building fabric

86.1

41.4

Changes to means of ventilation

22.5

-0.9

Changes to Heating Systems

20.0

10.3

Changes to Hot & Cold Water Systems

0.8

0.9

Changes to lighting systems

25.0

7.5

Changes to small power use

0

4.4

Changes to energy management

0

4.0

Design & Project Management

10

0

TOTAL

164.4

67.6%

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4.0 PROPOSED CHANGES 4.1 CHANGES TO BUILDING FABRIC 4.1.1 Description of Action/Measure

Introduction

It is proposed to enhance the thermal performance of the building to reduce heat loss and therefore carbon emissions. We intend to reduce heat loss using the following means; external insulation, high performance glazing and improving air-tightness to reduce infiltration

Currently Delta house is a Victorian building and includes a solid brick façade with single glazed windows except at basement level where they are double-glazed. The Conference Centre is of later construction (1985), the building façade has a cavity wall and double-glazed windows. The building envelope thermal properties have been estimated (see table 4.1.1) from building construction information, energy bills and by reference to the time of construction (see appendix A for calculations)

Thermal Transmittance ‘U’ Value (W/m2 K) Envelope Element

Delta house

Conference centre Wall 2.0 0.6 Roof 0.6 0.6

Exposed Floor 2.0 1.7 Windows 5.6 3.3

Building leakage ‘ACH’ (Average) Building 1.0 0.6

Table 4.1.1-Estimated building thermal properties.

From the estimate made we where able to produce a winter energy balance graph (see figure 4.1.1) to determine level of heating required to offset heat losses due to building leakage and fabric losses.

-120.0

-100.0

-80.0

-60.0

-40.0

-20.0

0.0

20.0

40.0

1 2 3 4 5 6 7

Delta house

Conference centre

Build fabric loss through windows

Net heat balance

Figure 4.1.1 – Current winter heat balance for Delta House and Conference centre at -1°C

kg/C/annum 10,906 (Utilising gas)

Carbon emissions

kWh/annum 209,724 Heating Energy usage

Building Leakage

Build fabric losses through walls, roof and basement floor

People gains

Lighting gains

Small power gains

Heat flow KW

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Poor thermal properties of the Delta House building has meant the heating load is almost double the typical rule of thumb value of 60W/m², while the later built Conference Centre falls in line with this value. The heating system of the two buildings accounts for about 50% of the building’s carbon emissions.

After reviewing the estimates made for both the building heating load, we feel there is significant scope to improve the building thermal performance for Delta House as this is currently greatly above typical heating requirement. The Conference Centre has typical heating loads hence any improvement in the thermal performance would have less returns in terms of payback and carbon reduction.

Insulating of exposed walls

Heat loss through the exposed single leaf wall is currently 35% of the total heat loss. We feel the most cost and thermal effective solution is to externally insulate the building. By having the insulation on the outside, there are significant advantages over the inside: � The internal floor area is not reduced � Possibility of cold bridging is reduced. � Thermal mass of the building is still exposed to the

heated room air. � Building structure is enclosed within a waterproof envelope. � The work can be done with the building occupied. Currently we feel a U-value in the order of 0.3 W/m2K is achievable, utilising a Sto Ltd product. Figure 4.3 is a picture of Stanhope Gardens in London; it shows that external insulation with rendering can be utilised while maintaining the aesthetic appearance of the building. We intend to externally insulate the building, while maintaining the aesthetic appearance of the façade; this mainly includes the decorative window framing. Further detailing would be needed at a later stage with the external insulation installer, the building services consultant and the architect. This would produce a balanced solution that would maintain the aesthetic appearance of the facade and the requirement to reduce heat loss.

Fig 4.3 (Courtesy of STO Ltd)

As the Columns would only require external rendering, the aesthetic appearance of the decorative window framing is maintained

Façade to be externally insulated and rendered to minimise heat loss.

Columns have a better thermal performance, as this comprises of thicker brickwork.

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High Performance Glazing

The section looks at realistic U-values achievable from current glazing technology and how this can assist to reduce heat losses and to minimise local discomfort at the perimeter. The overall U-value of the window is a function of glazing and frame used, the high conductivity of the frame relative to the glazing can lead to high overall U-value, however research has shown that framing that utilise thermal breaks within the framing system can achieve U-values in the order of 1.5W/m2K. Scandinavian Practices commonly use a “2+1” window, where a single pane thermally isolate a double-glazed sealed inner layer (see figure 4.1.2). Whole window U-value achievable is in the order of 1.15 W/m2K (0.95 W/m2K centre pane)

Building air leakage

The building air leakage contributes to almost 50% (equating to an average of 1 ACH) of the total heat loss through the building. Publications such as CIBSE TM29 have shown this value can be reduced to 0.15 ACH. It is likely that much of the excess infiltration is at or around the existing doors and windows. Replacing windows and additional insulation should help to seal most gaps.

Proposed thermal performance of envelope In summary it is proposed to change the thermal performance of the façade to achieve the following parameters.

Thermal Transmittance ‘U’ Value (W/m2 K) Envelope Element

Delta house

Conference centre

Wall 0.3 0.6 Roof 0.2 0.6

Exposed Floor 1.5 1.7 Windows 1.15 3.3

Building leakage ‘ACH’ Building 0.2 0.6

Table 4.1.6-Proposed building thermal properties.

Composite U Value of window including frame to be 1.15W/m2K (meaning mid pane U value likely to be 0.95W/m2K)

Wall ‘U’ value = 0.3W/m2K

Highly insulated/thermally broken framing system

Single pane

Sealed double pane unit Argon filled with E = 0.1

Figure 4.1.2- 2+1 window

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4.1.2 Implications for CIBSE

The implications of this proposal to CIBSE are:

� Improved local comfort from cold radiation. We have reduced the whole glazing U value to

1.15W/m²K and the glazed area is less than 10%. McIntyre[1] demonstrates that a 50% glazed facade with a whole window U-value of 2.0W/m²K produced a radiant asymmetry well within the criteria recommended in CISBE guide A .

� Improve local comfort from downdraught. We have reduced the centre glazed pane U value

to 0.95W/m²K, Heiselberg [2] work presents a simple relation between U-Value (centre pane) and glazing height to avoid downdraughts. From this relationship a centre pane U-value of 0.95W/m2K (2+1 window) implies a maximum height of 2.2m to avoid downdraught; Delta house meets this requirement comfortably.

� Addition insulation will reduce pre-heat times.

� Summer time temperatures will improve since the façade attenuates solar gains more

effectively.

� It maybe necessary to obtain Planning consent to undertake the proposed work.

4.1.3 Total Effect on Performance and the Basis of this

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

20.0

30.0

40.0

1 2 3 4 5 6 7

Delta houseConference centre

Figure 4.4- Proposed winter heat balance for Delta house and Conference centre at –1°C It can be seen that during external temperatures of –1°C, the net heat flow has dropped relative to the existing construction, the additional external insulation, 2+1 window and integration of air barrier seals would lead to reduction in operating hours of perimeter heating system. Steady state calculation shows a 68% reduction in the annual heating bill/carbon emissions (assuming no changes to the heating system).

kg/C/annum 3,490

Carbon emissions

kWh/annum 67,112

Heating Energy usage

Building Leakage

Build fabric losses through walls, roof and basement floor

People gains

Lighting gains

Small power gains

Build fabric loss through windows

Net heat balance

Heat flow KW

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4.1.4 Total Effect on Cost and the Basis for this

Building element

Note/ Budget cost per m² Cost

2+1 Window £350 supply and install (As provided by Sampson

windows)

£26,700

External insulation and rendering

£80 (As provided by Sto Ltd) £58,400

Reduced infiltration

£1000 (labour) This is mostly included in

the above cost

Total Cost

£86,100

Associated saving with installing new envelope.

Reduced capacity of boiler plant.

Plant is near to end of its life and will need to be replaced.

£20,000 Capital cost

Reduced heating energy bill At 1.8p/kWh £2,548 per annum

Reduced heating pumping energy bill

At 7.0p/kWh £320 per annum

Payback

Simple payback

23 years

Table 4.1.5-Budget costing and payback

Using simple payback it has been calculated that the number of years for the proposed envelope design to pay for itself is approximately 23 years. Whilst this payback is high by conventional commercial standards, the improvements will generally last more than the payback period.

References

1. McIntyre D A Radiation draughts Building Services Engineer, 43 136-139 (October 1975) 2. Heiselberg P Draught risk from cold vertical surfaces Building and Environment 29 (3) 297-301

(1994)

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4.2 CHANGES TO MEANS OF VENTILATION 4.2.1 Description of Action/Measure

The building’s present ventilation strategy generally relies upon opening the windows, apart from the air-handling unit which serves the council chamber which is manually controlled at the reception. The air-handling unit, when in use is often on at low speed with the cooling disabled. The toilets are provided with local mechanical extract ventilation systems that are discharged through windows. Measures to improve the air-tightness of the building are central to the energy saving strategy. However, this in turn eliminates gratuitous ventilation so occupants would then be forced to use opening windows for ventilation – even in the depths of winter. Apart from the risk of draughts, it is likely that uncontrolled natural ventilation would eliminate much of the benefits of the building improvement works. Hence, it is proposed to provide a mechanical displacement ventilation system for ventilation (and some cooling potential) to each of the occupied rooms. The ventilation system would provide a controlled rate of ventilation (16 litres per second per person) whilst enabling heat recovery from the exhaust air when appropriate. Refer to the system schematic of the ventilation strategy below and the typical floor plate arrangement overleaf. Based on the results of thermal modelling we suggest a mixed mode ventilation strategy incorporating openable windows during the summer, and a displacement ventilation system during the winter (and during the summer if the user decides it is better than natural ventilation, particularly as a means of nocturnal cooling).

Earth at 10 deg

Delta House

Conference Centre

Heating Coil Thermal Wheel

VVeennttiillaattiioonn sscchheemmaattiicc

Fan

Fan

Supply air

Exhaust air

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Ventilation Control Strategy Outside air temp

Supply air temp

Temperature control strategy Number of hours1

-5 to 4 19/20 Outside air is pre-heated by the underground ducts. The thermal wheel recovers some more heat energy from the extract air supply. The heater coil is then used to provide the remaining heat required to achieve the desired supply air temperature

360

5 to 18 19 Outside air is supplied through the underground ducts and uses the thermal wheel as required. Generally the re-heat coil is not required.

1100

19 to 26 19 Openable windows are relied upon for ventilation. 990 26 + 18/19 Outside air is pre-cooled by the underground ducts to the

desired supply air temperature. The thermal wheel is used to reheat if necessary. The heater coil is not in operation

150

The system will comprise a supply fan, filter and attenuator located in the conference centre plant room connected to an underground ductwork linked to Delta House. A thermal wheel (linked with the extract air path) and a heating coil will be located within the plant room of Delta House. The current plant room may need to be slightly extended to accommodate this. Supply ductwork will run up Delta House in a new riser as indicated on the typical floor arrangement overleaf. At each level, ductwork will distribute to each occupied room to a displacement ventilation terminal. An extract fan, located within the Delta House plant room will discharge vitiated air collected from each of the occupied rooms to outside. The supply fan could be suspended at high level within the ground floor delivery room in the conference centre, subject to final design. Some design issues such as acoustics, support of air-handling unit and access would also need to be finalised during detailed design. The air-handling unit serving the conference centre appears to be in reasonable condition. We would estimate that it has 5-15 years economic life. We would therefore suggest retaining this air-handling unit. The control for this is within reception and appears to be simple and effective since it is only used when required.

4.2.2 Implications for CIBSE

The building will be provided with a good rate of outside supply air that is filtered and tempered to 18/19°C to enhance the environmental conditions and providing a healthier workplace. One likely consequence will be to reduce respiratory sickness absenteeism and create a productive and pleasant workplace. The economics of providing such a ventilation system can be offset with the reduction in absenteeism. Generally a 1% increase in productivity as a result of reduced absenteeism would offset the annual energy bill.

4.2.3 Total Effect on Performance and the Basis of this

The benefits of the displacement ventilation are described above. The energy consequences and control strategy are described in the table below. The underground duct has been sized to preheat (or pre-cool) the incoming outside air. We have assumed a constant ground temperature of 10º C, with the ducts buried approximately 1.5 metres underground. The additional duct length to achieve good heat transfer increases supply fan

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energy use above typical. In fact in CO2 emission terms, the increased fan energy outweighs the heating energy gains compared to conventional system – but the measure has other merits. A thermal wheel is used between the extract air and the supply airstream for heat recovery when required. A final heater coil is provided to temper the air supply to the desired set-point. The proposed system creates a net balance in energy relating to the ventilation system, however this is required since the building is being sealed to reduce the heating energy. The system will be designed to ensure that adequate outdoor air is supplied to all spaces in all areas regardless of external conditions and wind speed/direction as is the present case.

Table indicating electrical and heating energy for ventilation system

Electrical Energy

Heating Energy

Outside air temp oC

Supply air temp oC

Number of hours1

Supply & extract fan energy (kWh) 2

Total heating required (kWh)

Heating energy saving: ground duct (kWh)

Heating energy saving: Thermal wheel (kwh)

Total heating energy (kwh)

-5 to 4 20 360 360 4192 -1258 -1676 1258

5 to 18 19 1,100 1,100 10551 -2113 -4220 4218

19 to 26 18 0 0 0 N/a N/a N/a 26 + 18 150 150 0 N/a N/a N/a TOTAL

1,610

1,610

14,743

-3,371

-5,896

5,476

1 Based on the Test Reference Year for London 2 Based on a specific fan power of 1.0 kW/m3/s

4.2.4 Total Effect on Cost and the Basis for this The total cost of this installation is described below: Cost of Item Cost (£) 1.Cost supply fan, filter, heating coil, thermal wheel, extract fan 12,000 2.Dig trench, lay ducts, fill 3,000 3.Indoor ductwork installation 9,000 4.Testing and commissioning 1,500 Total 25,000 Notes: 1. The cost of this is based on a supply unit of 16 litres/per second per person based on a fully

occupied building of 35 people. i.e. approximately 500 l/s supply and 500 l/s extract. 2. This cost allows for the trench to be dug at approximately 1.5metre underground, which ought

to provide a constant ground temperature of approximately 10deg C. Care will need to be taken to ensuring that ground water cannot penetrate and that damp cannot ingress and

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contaminate the ductwork system. An access panel within the ductwork within Delta House and the Conference centre, which will provide the necessary access.

3. This includes the cost for the complete ductwork installation, volume control dampers components and displacement ventilation terminals.

4. This includes for the cost of balancing the system and setting the control strategy appropriately.

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Typical Floor ventilation duct arrangement

Displacement Ventilation Terminals Ductwork Ductwork Riser

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4.3 CHANGES TO HEATING SYSTEMS 4.3.1 Description of Action/Measure

Increasing the level of insulation on the entire building envelope (as fully described within section 4.1) results in a dramatic reduction in the amount of energy ‘lost’ through the fabric and hence a reduction in the necessary heating capacity of the plant. We therefore propose to replace the three existing Hamworthy boilers with two smaller units. One gas fired and one which uses wood pellets as its fuel source. An alternative to this is to keep one of the existing boilers to run as the gas boiler thereby alleviating the need and cost for a new smaller gas fired boiler. It is proposed to undertake remedial works to the controls addressing the issues raised in the Action Energy Report. In addition it is proposed to modify the conference centre heating as follows. As the conference centre is only being used 2-3 times a week and even less in the summer period, (it has estimated that it is only used for 20% of the occupied office period), we feel it is unnecessary to heat it continuously to a 20°C set point. Therefore we propose to change the set point to 15°C when the building is unoccupied. Existing System Three existing boilers currently serve the heating requirements of the CIBSE Headquarters. These are 20 years old and as such are nearing the end of their life. These could therefore need replacement in the near future. The Action Energy report highlights that there is currently no outside temperature compensation on the variable temperature circuit serving Delta House and that some radiators are fitted with faulty thermostatic control valves while some have no such valves at all. Based on our thermal analysis and the fuel bills for the buildings it is estimated that the seasonal heating efficiency is currently only in the region of 50%. Proposals We propose to replace the three existing boilers with two new smaller boilers (or keep one of the existing boilers to save cost). The calculations carried out for enhancing the building fabric, indicate that the heating load necessary to maintain comfortable conditions within the buildings reduces to around 25kW. Our proposal would see the installation of a 25kW wood pellet boiler to supply the required heating load to the building for the majority of the year and a 25kW gas boiler, or retain one existing boiler, which would only be used as a ‘boost’ boiler either to heat the building quickly or to maintain internal conditions during times of extreme external conditions. The gas boiler has been selected as the second boiler, instead of a second wood pellet boiler, for two primary reasons. Firstly, as a standby in the event that the wood pellet boiler breaks down, And secondly to provide a separate fuelling system should there be a short fall in the supply of the wood pellets (currently imported from abroad). The wood pellet boiler was selected due to the very low carbon intensity of the wood pellets (virtually zero) and the need to store less (by volume) of the fuel than if wood chips were used, due to their higher calorific value. The current proposal is to leave the existing radiators and pipework in place throughout the buildings. This means that the radiators will be oversized. Where thermostatic control valves are not in place on radiators these will need to be added and set correctly. The wood pellets are currently more expensive per kWh than gas, however there is an emergence of new suppliers in the south and south west of the country and as such it is likely that the cost of pellets will fall by about 25% in the next 12 months.

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A picture of the proposed wood pellet boiler is shown below.

4.3.2 Implications for CIBSE The implications of the proposed changes to the heating system are as follows: 1. CIBSE would have a new heating system to replace their nearly ‘life expired’ existing

system. 2. CIBSE would be eligible for a clear skies grant towards the capital cost of the renewable

energy boiler.

3. It will be necessary to find space for some pellet and ash storage although the reduction in the boiler plant capability will free-up some existing space. It is proposed to hold enough wood pellets to supply the boiler with fuel for one month (based on worst case), this equates to a storage vessel approximately 2.5m3.

4.3.3 Total Effect on Performance and the Basis of this The effect of reducing the heating capacity on the amount of energy consumed has been accounted for in the insulation calculations. By making the modifications in respect to the thermostatic control valves and weather compensation recommended in the Action Energy report, a more ‘efficient’ system is in use with less wasting of energy. It is estimated that by replacing the boiler plant and improving the system control that the overall heating system efficiency will improve to 75%. This equates to a 33% reduction in energy input. Further reductions to carbon emissions are possible due to the zero carbon intensity of the wood pellets (no allowance has been made for the carbon used in delivering the wood pellets to site) The overall effect of these changes is expected to be a reduction of 10.3% in carbon emissions.

Combustion chamber door

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CARBON 60 CHALLENGE




The cost of the boiler itself is in the region of £5,500. This does not include for installation as an exact installation cost depends on many site-specific points and requires a full site survey by the installer to gauge an accurate estimate. The fuel costs for the pellet boiler are currently £120/tonne pellets. Assuming the heating period is 1500 hours the energy required is 1500 x 25 = 37,500 kWh. The energy input to the boiler (assuming 90% efficiency) is therefore 41,667kWh. Wood pellets typically have a value of around 4.7kWh/kg at 8% moisture content and typically have a density of 650kg/m3 pellets. So based on the above the annual wood consumption would be in the region of 8,865kg or 13.6m3 pellets (this equates to approximately 2.5m³ for a worst case month). Assume 9 tonnes of pellets at £120 per tonne = £1,080 per annum. However inside 12 months with the emergence of new supplies the cost per tonne should be £90. This would mean a running annual cost of only £810. The amount of gas used by the small 25kW gas boiler would be around 1500/4 x 25 which equates to 9375kWh of gas. At 1.91p per unit would equate to £179 per annum, assuming the gas boiler is running only ¼ of the overall heating season. So the total running cost for the heating system is reduced to around £1,250 or £1,000 within 12 months. The maintenance cost for a wood pellet boiler however is typically higher than for a standard gas boiler. The maintenance cost is calculated by the number of hours a year for a service engineer to attend site and service the installation. For a wood pellet boiler this would typically be two to three times more than for a gas boiler and as such the maintenance cost would rise by the same amount. However, the boilers would be smaller than the existing installation and so the overall costs would not increase dramatically.

Modifications recommended in Action Energy Report

£500.00

New 25kW pellet boiler £5,500.00 £2,500.00 with

clear skies grant

New pellet storing device £2,000.00

Installation/commission new heating system

£15,000.00

TOTAL (Assuming clear skies grant is applied for)

£23,000.00 £20,000.00 (if old

boiler retained)

It appears that as a non profit making organisation CIBSE will qualify for a clear skies grant to the value of 50% of the capital cost of new plant or £100,000.00 whichever is the smaller. So in this case the new cost of the pellet boiler will be reduced to £2,250.00. There are conditions that have to be fulfilled to qualify for the grant, however, these will not require major changes in the way the building is currently operated.

CARBON 60 CHALLENGE



4.4 CHANGES TO LIGHTING SYSTEMS 4.4.1 Description of Action/Measure

We propose to reduce the energy (and carbon emissions) associated with lighting by replacing the existing luminaires with higher efficacy luminaires and to incorporate lighting control devices which would improve the lighting management.

Existing System

The Action Energy report states that the general offices of both the Delta and Conference Houses have luminaires that use T8 lamps. However, areas such as the Delta House central corridors, kitchens and toilets use prismatic and wide-tube T12 lamps which are not efficient when compared to modern T5 lamps. The report also states that no lighting control system is in existence within the buildings. All luminaires are operated using switches. The assumptions made on the current lighting design are as follows: Current Lighting Load – 13W/m2

No lighting control system Diversity – 1 Hours of operation – 10 hours a day, 5 days a week and 50 weeks a year Ceiling – White Floor to ceiling height – 2.7m General Office Areas

Following the daylight factor calculations (as shown below) for the general offices, it was established that the typical daylight into the rooms is generally more than 2%. Hence, we propose installing new light fittings with T5 lamps which have integral daylight sensors and presence detectors. An integral daylight sensor and presence detector within the luminaire would eliminate the extra cost of a specific lighting control system and its wiring within the office areas. In addition, a 3-hour self-contained remote emergency pack will be installed to the luminaires which would be use as emergency lighting in all areas of the building. The daylight sensor within the luminaire would dim/switch off the luminaire when the room receive a lighting level greater than the amount of lighting level programmed in the sensor whilst the presence detector would switch off the luminaire after a certain period when presence is not acknowledged in the room. This process would reduce the energy absorbed by the luminaires by approximately 15% annually. Furthermore, we recommend using the positions of the existing luminaires to eliminate the use of additional wiring for the light fittings. This would also reduce the installation costs. The proposed luminaire for the office areas is shown below.

CARBON 60 CHALLENGE



2 x 35W T5 Suspended Bi-directional Luminaire with integral daylight and presence detector Daylight factor calculations for the general offices Area Average Daylight Factor (%) Delta House – Secretary to CEO 1 Delta House – Deputy CEO 3 Delta House – CEO 3 Delta House – Membership 2 Delta House – Head Professional Development 2 Delta House – Professional Development 2 Delta House – Professional Development 2 2 Delta House – Head of Accounts 4 Delta House – Accounts 2 Delta House – Public and Events 1 Delta House – Publications 4

Delta House Central Corridors We recommend replacing the prismatic T12 lamps and their respective light fittings with luminaires which use high frequency ballast and compact fluorescent lamps. The proposed luminaire for the central corridor is shown below. In this area, the existing wiring would be re-configured to suit the new lighting layout to ensure lighting levels are met. However, the existing light switches would be re-used to operate the luminaires, reducing installation cost.

1 x 32W Recessed Downlighter

CARBON 60 CHALLENGE



Kitchen, Stores, Plant rooms and Toilets

We recommend replacing the existing luminaires with high efficiency surface batten light fittings and lighting control presence detectors. The proposed luminaire for these areas is shown below. The presence detector would switch off the lights when the rooms are not occupied. Due to occasional use of these rooms, it is estimated that the lighting energy consumption could be reduced by 50% annually.

1 x 28W T5 Surface mounted Batten

4.4.2 Implications for CIBSE The recommended office luminaires are bi-directional (with uplighting and downlighting components). Hence, the light distribution across the room will be a combination of indirect and direct light. This would improve the uniformity of light in the space and will help to reduce glare (this conforms to LG3 requirements). Hence, creating a good visual impression for occupants. The revised lighting layout would produce an average lighting level of 300-400 lux in the office spaces as shown in the table below. Area Average luminance (lux) Delta House – Secretary to CEO 400 Delta House – Deputy CEO 390 Delta House – CEO 360 Delta House – Membership 350 Delta House – Head Professional Development 410 Delta House – Professional Development 340 Delta House – Professional Development 2 400 Delta House – Head of Accounts 300 Delta House – Accounts 440 Delta House – Public and Events 470 Delta House – Publications 430 All the new proposed luminaires are high efficacy luminaires which means that they use less energy to generate a higher light output. This would in turn reduce the amount of energy used as well as electricity cost and carbon emissions. A good lighting visual impression would create a pleasant environment for occupants that will help promote motivation. In addition, the heat gains from the luminaires will be reduced and this will provide lower peak summertime temperatures which will improve occupants comfort and reduce the need for local electric fans (and their associated energy). Following our review of the building, we feel that the ceilings and walls in all areas of the Delta House are to be painted white. This would increase the wall and ceiling reflectances and

CARBON 60 CHALLENGE



contribute to creating a pleasant environment for occupants as well as increasing the light level on the working planes. In addition we propose that the space plan layout of the offices are to be re-considered to aid the distribution of light into the working planes to enhance the visual impression of lighting.

4.4.3 Total Effect on Performance and the Basis of this Our new proposed lighting layout estimates that lighting energy used within the building will be reduced from 34,725kWh/annum to 19,769kWh/annum, a reduction of 43 per cent. This would respectively reduce the carbon emission from 4.072kgC to 2,443kgC, a saving of 40 per cent or 7.5% of the total.


We estimated that replacing the luminaires, adding of the lighting control system, revision and re-using of the wiring system and labour charges would approximately cost £25,000 using SPON’s 2004 as our cost estimation guide. Furthermore, based on our recent review of the building, we also propose to re-use some of the existing containments. In addition the changes would result in an annual energy cost saving of £1,047 per year. This equates to a payback of 24 years. We have taken a realistic view on the cost of our light fittings and lighting control system. However, cheaper light fittings can be procured which will reduce the installation works and commercial payback years.

CARBON 60 CHALLENGE



4.5 CHANGES TO SMALL POWER USE 4.5.1 Description of Action/Measure

We propose to reduce small power energy demand (and carbon emission) by replacing the CRT monitors and using auto power down facility within PC’s and reducing the use of local electric fans currently used within the building. The Action Energy report states the amount of PC’s and CRT monitors currently used within the building, and their power requirements. In addition we understood, whilst reviewing the plan layout, the other types of the equipment used within the building that require small power. We estimated the average load assessment for small power using the information we derived from the Action Energy report and plan layout to be 8.75 W/m2. A substantial reduction of small power energy could be achieved by replacing the CRT monitors with flat screens. Currently, the power requirement for each CRT monitor is 150W whilst a 17” flat screen will absorb a maximum power of 50W. Therefore, by replacing all the CRT monitors (a total of 35), the energy consumption would be reduced by 5,000kWh. It is also proposed to reduce PC energy further by implementing an automatic system to power down PC’s and screens during periods of inactivity. In addition it will be encouraged to shut down PC’s and screens when they are not being used (particularly at night). It has been estimated that this would save a further 3,246kWh per year. In previous sections, we have recommended a better technique of insulating the cladding of the building and ventilation. Due to the changes of the building fabric and ventilation, and the reduced heat gains from PC’s and CRT monitors, it is expected that the use of the local electric fans currently used within the building (a total of seven) can be eliminated. This would produce an extra energy saving of 42kWh. In addition to replacing the CRT monitors, we propose replacing some of the computers to laptops. This would further reduce the small power energy by 50% as the energy consumption of laptops is minimal when compared to desktop computers and would also aid mobility.

4.5.2 Implications for CIBSE Replacing the CRT monitors to flat screens would reduce the heat gains currently produced by the monitors into the environment. Hence, providing a better comfort for occupants. In addition, flat screens according to LG3 would facilitate the higher amount of lighting level which was proposed in section 4.4 because flat screens do not reflect lights which can cause occupant glare. Hence, a greater amount of light can be produced into the environment.

4.5.3 Total Effect on Performance and the Basis of this Implementing the measures described above will reduce the small power energy consumption by approximately 25% this equates to 8,287kWh per year saving £580 and a reduction of 970kgC carbon emission per year (4.4% of total).

4.5.4 Total Effect on Cost and the Basis for this We have assumed that there is no cost of replacing all the CRT monitors with flat screens as the cost would be part of the budget for IT upgrades over the next 3 – 5 years. The cost for implementing the automatic shut down system is also considered to be negligible as the facility already exists on most PC’s.

CARBON 60 CHALLENGE



4.6 CHANGES TO HOT & COLD WATER SYSTEMS 4.6.1 Description of Action/Measure

The Action Energy report identifies that the hot water is by direct electric storage. We estimate that the energy associated with heating hot water equates 7,980 kWh (4.3% of the total carbon emissions). Methods of reducing carbon emissions were considered including; the use of gas fired hot water systems, solar heating and reducing hot water use. Due to the low overall energy demand it was found that solar water heating and gas water heating both would have excessive payback periods. However, the optimum method of reducing energy use was found to be by means of reducing water use. Reductions in water use could be achieved by changing to ‘low-flow’ taps or alternatively by the use of flow restrictors and/or percussion taps. It has been assumed that regular taps are presently in use. As identified in the Action Energy report it is also recommended to install automatic urinal controls to save water

4.6.2 Implications for CIBSE There are no significant reductions in performance to the users since hot (and cold) water use is normally in excess to that required. In addition to reductions in heating energy use this would also reduce water (hot & cold) use which would result in additional cost savings although no direct reductions in carbon emissions (there would be an indirect reduction of energy use at the pumping station and filtration plant).

4.6.3 Total Effect on Performance and the Basis of this It has been estimated, based on a number of assumptions, that hot water use could be reduced by 20% by the use of flow restrictors. This equates to a reduction of 1,956kWh or 0.9% of the total carbon emissions. This would save £137 per year.


The cost for carrying out this work has been estimated to be £800 that would be simply paid back within 6 years.

CARBON 60 CHALLENGE



4.7 CHANGES TO ENERGY MANAGEMENT 4.7.1 Description of Action/Measure

It is normally possible to reduce energy use (and therefore carbon emissions) by improvements to Energy management. This includes more staff (and management) involvement and ownership of the requirement to reduce consumption. Proposals for improving the energy management at the CIBSE headquarters includes:

• Nominating a ‘Carbon Champion’ within the management structure with clear responsibilities for carbon emissions (developing monitoring staff awareness).

• Developing a carbon policy and action plan with the full commitment of top management. • Motivating staff at all levels to reduce emissions. This includes simple things like

switching off lights as well as changing the organisational culture and encouraging employees to take ownership in the overall process.

• Improved energy monitoring and targeting and provision of regular reports to all staff on progress.

• Developing awareness of carbon use/reductions both external to the organisation and internally.

• Developing an investment strategy for reducing energy consumption and costs. • Checking energy bills and negotiating tariffs to ensure best value.

Obtaining staff involvement will be crucial to the success of this strategy and in order to assist we propose that a ‘Carbon Monitor’ is clearly displayed within the building’s reception. This will advise staff and visitors on the actual carbon use profile against predicted targets. An example of the Carbon Monitor can be seen below. Its purpose is to continuously keep staff aware of Carbon emissions to ensure that they do not lose focus from meeting targets. The targets can be estimated in advance using predictions and/or previous usage and degree-days. The information could be collated manually using utility bills or ultimately automatically using an automatic meter reading and simple software. The Monitor will also provide a public face to the achievements of CIBSE in reducing its carbon emissions. A version could be published regularly in the Journal or CIBSE website providing good publicity. EXAMPLE CARBON MONITOR

CARBON 60 CHALLENGE



In addition it is recommended that the headquarters building displays externally a voluntary energy label as a means of making a public commitment of its intentions.

4.7.2 Implications for CIBSE Improvements in energy/carbon management would have no negative implications to CIBSE, however, positive implications would arise from the external awareness of CIBSE and its ability to reduce carbon emissions significantly before regulatory requirements. As well as reducing energy and carbon emissions it will be possible to reduce revenue costs associated with ‘better purchasing’. This would involve savings achieved from the following:

• Checking energy bills (approximately 3% of energy bills are thought to be overestimated) • Selecting best tariffs • Selecting best suppliers • Paying reduced VAT by using (partial) charitable status • Reduced water and sewage costs

4.7.3 Total Effect on Performance and the Basis of this It is usually considered that a reduction of at least 10% of energy use can be achieved by simply focussing attention to energy management. In this case we have assumed that around 60% reduction on carbon emissions will be achieved using the other methods identified in this report. We have therefore estimated that a reduction of only 4% (i.e. 10% of 40%) can be achieved. This is still a significant reduction and it should be considered an important part of the overall aim to monitor and reduce carbon emissions.

4.7.4 Total Effect on Cost and the Basis for this The additional work associated with this proposal should not be under estimated although clearly it would be unreasonable to employ an energy/carbon manager for an organisation with annual fuel bills of around £5,000 (after reductions). It has been assumed that the roles outlined above could be incorporated into job profiles of the existing employees at minimal cost, (particularly if CIBSE expect the recognition and rewards associated with reducing carbon emissions). Some cost should be allocated for energy metering equipment and information systems to facilitate the energy/carbon monitoring suggested above.

CARBON 60 CHALLENGE



5.0 PROPOSALS FOR FUNDING AND MANAGEMENT

It is recommended that the reduction be delivered in a programme that minimises financial risk to CIBSE. Note that budgeting for the delivery of this programme is difficult without information on CIBSE’s finances. It is also worth noting that all measures contained within this report are investments in CIBSE headquarters. As investments these proposals should compete with other business opportunities. Appreciation must be given to the inter-relations between the various proposals and the implications this has on the implementation of a carbon reduction project. The two most cost intensive measures are conceptually interlinked, which does have an implication on financial outlay. Building fabric improvement and building ventilation have to be introduced at the same time or building performance will be compromised. Boiler Installation/Re-sizing is also a part of this scheme though the existing system would be able to cope at partial load. It is recommended that careful budgeting and project management is required to ensure delivery of the two proposals in tandem. Further details of the project management of the scheme can be found in the implementation plan. It should be highlighted that the identification of a ‘Carbon Champion’ with an active role in CIBSE’s headquarters is essential in the management of the scheme. There is a possibility that as a showcase building the Carbon Manager would be able to enter discussions to reduce equipment costs. The first Carbon 60 development in the UK, and as the headquarters of a historic institution, the project may create publicity to which many manufacturers would like their equipment to be associated. There is difficulty in obtaining external funding for the project. One the organisation could apply for would be the Clear Skies renewable energy grant. This grant would enable the organisation to receive up to £100,000 in grants for the wood fired boiler and up to £10,000 towards a feasibility study. The proviso to this grant being issued is that the body in question is a community organisation. It may be open to debate whether CIBSE falls into this category. The effective implementation of the proposals contained within this report relies on a clear and effective energy management structure at the heart of CIBSE. The appointment of a Carbon Manager as a champion of environmental issues is crucial in this goal. The job of the Carbon Manager is to identify opportunities, appraise possible projects, to collect data, to provide information and to effectively present projects to the managing board. In turn, the managing board must take a proactive approach, with a long-term view of energy and carbon matters as part of a detailed environmental strategy.

CARBON 60 CHALLENGE



6.0 SUMMARY OF KEY RESULTS

Proposal

Capital Cost (£k)

Existing Annual Carbon

Emissions (kgC)

Proposed

Annual Carbon

Emissions (kgC)

Reduction

as Proportion

of Total (%)

Enhancing building fabric � External insulation to walls � New windows � Reduced infiltration � Ventilation heating � Changes to Heating System

106.1

11,956

685

51.7

Providing mechanical ventilation

22.5

487

675

-0.9

Reducing hot water use

0.8

934

747

0.9

More efficient lighting system

25.0

4,072

2,443

7.5

Reduced small power requirement

0

3,879

2,909

4.4

Improved Energy Management

0

0

-873

4.0

Other

10

495

495

0

Total

164.4

21,823

7,081

67.6

CARBON 60 CHALLENGE



7.0 INITIAL AND FINAL VALUES AND PERCENTAGE CHANGE FOR:

INITIAL

FINAL

% CHANGE

Gross floor area (m²)

1,073

1,073

0

Treated floor area (m²)

1,010

1,010

0

Net floor area (m²)

880

880

0

Annual carbon emissions (kgC)

21,821

7,080

- 67.6

Annual Electricity Consumption (kWh)

88,726

61,841

- 30.3

Carbon intensity (kgC/kWh)

0.052

0.052

0

Annual gas energy (kWh)

220,000

47,727

- 78.3


0.117

0.117

0

Other Energy Supplies - Biomass (kWh)

0

33,920

+100


0

0

0

CARBON 60 CHALLENGE



8.0 IMPLEMENTAION PLAN Appointment of a Carbon Manager prior to the inception of the project is a prudent course of action as he/she will be instrumental in the planning and the delivery of the carbon reduction scheme. Our proposed plan of implementation is spaced over two and a half years so that the disruption to the building at any one time will be minimal. There is significant scope to reduce the overall project timescale if CIBSE prefer. A project manager should be appointed. He/she could be the Carbon Manager, another member of staff or a specialist from outside the organisation. The project manager would be responsible for appointing a design team, producing a detailed programme and for managing the project. The Gantt chart on the next page illustrates the “Route to Carbon 60” described in our report. A period for design and procurement has been included. This will allow for the design to be properly detailed, and the detail of the costs and project delivery to be agreed. Changes to the building fabric have the highest effect on reducing the carbon emissions and these works will not affect the internal working environment. Hence we propose that this be done initially with replacement of the windows prior to insulation of the building. These works are proposed to commence in summer 2005. Changes to the ventilation strategy requires the most amount of work as constructing the new riser and supply duct network would mean some disruption to the internal working area. However, the ductwork route that we have proposed is mainly in the circulation areas and hence the disruption would be a minimum. Some re-location of the working environment will be required while construction work is being carried out in the localised area. This will minimise the out of hours work and hence the cost. Replacement of the existing boilers and the changes to the heating system would best be carried out in the summer time. This will eliminate the need for any temporary heating within the office at the time of the modifications to the heating system. It is proposed that the changes to the hot and cold water system too are done at the same time. Installation of new light fittings and the replacement of luminaires are proposed to commence once the changes to the heating system and ventilation is complete. This would again minimise any disruptions at one time. Replacement of the CRT monitors and changes to small power is proposed to be undertaken over a two-year period. Energy management would be a continuous process in the “Route to C60” and beyond.

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SALS

Proposal

C

urrent energy source

C

urrent energy use (kW

h)

Proposed

energy use (kW

h)

Saved carbon

(kgC/yr)

Percent

Carbon saving this system

Percent of

overall carbon saved

1 C

hanges to Building Fabric

Gas

209,116

31,367

9,532

95

51.7

2 C

hanges to Means of Ventilation

Gas/electricity

0

1,678

-196

-38

-0.9

3

Changes to H

eating System

s G

as

Included in 1 above

Included in 1

above

Included in 1

above

Included in 1

above

Included in 1

above

4 C

hanges to Hot &

Cold W

ater S

ystems

Electricity

7,980

6,384

187 20

0.9

5 C

hanges to Lighting System

s

Electricity

34,800

20,880

1,629 40

7.5

6 C

hanges to Small Pow

er Use

Electricity

33,150

24,863

970 25

4.4

7 C

hanges to Energy Managem

ent

Electricity 0

0

873 0

4.0

Total

285,046

85,172

12,995 -

67.6

CARBON 60 CHALLENGE



APPENDIX A – HEATING ENERGY CALCULATION

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Existing building heat loss

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cibse - carbon 60 challenge

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