cape breton university mechanic street company house ... · cbcl limited consulting engineers...

112447.00 ● Report. ● Mar 2012

Cape Breton University

Mechanic Street Company House

Applied Research Project

Prepared by: Prepared for:

Cape Breton

University

CBCL Limited Contents i

Contents

CHAPTER 1 Introduction .............................................................................................................. 1

1.1 Purpose ............................................................................................................................... 1

1.2 Site Description ................................................................................................................... 2

CHAPTER 2 Building Structural ..................................................................................................... 8

2.1 Proposed Actions From Contractor .................................................................................... 8

2.2 Structural Engineer Site Review and Recommendations ................................................. 10

CHAPTER 3 Solar-Power / Photovoltaic Component .................................................................... 23

3.1 Solar-Powered / Photovoltaic Systems ............................................................................ 23

3.2 Alternate Photovoltaic Component .................................................................................. 28

CHAPTER 4 Potential Energy Saving Items .................................................................................. 34

4.1 Heat Pump Systems .......................................................................................................... 34

4.2 Water Conservation .......................................................................................................... 35

4.3 Miscellaneous ................................................................................................................... 35

CBCL Limited Consulting Engineers Introduction 1

CHAPTER 1 INTRODUCTION

1.1 Purpose

CBCL Limited was tasked to assess the following:

1. Assess contractors’ proposals for the foundation work.

2. Propose low-cost (under $15,000) but effective means to ensure that the work is durable and

that there will be minimal disruption to the neighbouring half of the duplex. Present the analysis

in illustrated, easy-to-understand terms so that the material can be a resource to the local

renovation industry and to students participating in a charrette workshop and design

competition.

3. Assess the potential for “clean slag” (by-product from the steel plant) to be used in the

foundation work.

4. If a dugout/sonatube foundation is installed (without lifting the house), propose what should be

done to properly insulate the floor and prevent frozen pipes.

5. Assess whether simply pouring a concrete slab under a company house is a viable option.

6. Advise in writing on what steps should be taken to make the foundation work “user friendly” –

that is, to allow inexpensive but effective maintenance over time.

7. Advise on any traditional renovation methods or materials that could be incorporated into the

foundation or energy-efficiency work.

8. Propose, in writing, a low-cost but effective way to incorporate a solar-power/photovoltaic

component. Calculate the potential savings over time.


This report describes the findings and provides the key recommendations.

1.2 Site Description

The subject building at 50 Mechanic St., Glace Bay features the typical design and the typical renovation

issues of a Cape Breton company house. It was purchased (1/2 of complete building) at tax sale by a

CBU faculty member with the purpose of donating it (gratis) for this demonstration/applied-research

project. It is a two story company house with crawl space dating back to the early 1900’s. The total floor

area is approximately 93 m2 (1,000 ft2). The initial construction utilized balloon style timber framing.

The building had been derelict for nearly two years before purchased through the above mentioned tax

sale.


Figure 1 Aerial View of Building Location at 50 Mechanic Street


Figure 2 Typical Company House First Floor Plan


Figure 3 Typical Company House Second Floor Plan


Figure 4 Typical Company House Front Elevation


Figure 5 Typical Company House Side Elevation

CBCL Limited Solar-Power/Photovoltaic Component 8

CHAPTER 2 BUILDING STRUCTURAL

2.1 Proposed Actions

From Contractor Item 1 Foundation and

Floor Repair.

The contractor would

expect to remove all

floorboards, the rotted

floor joists, all flooring

such as carpet or vinyl

floor, load it on a truck or

in the bin for disposal.

Item 2 Concrete Sonotubes

The excavation/digging would all have to be done between the joists, by hand, this would be

slow work and labour intensive. Cement would have to be hauled in by hand and poured in

the sonotubes between the floor joists. All around the perimeter of the home a new pony wall

would have to be constructed. This wall would have to be below ground level and

constructed of pressure-treated lumber.


Item 3 New Joists

The contractor was unable to tell how many joists and main beams have damage, and could

only guess. Proposes repair, replace and level the complete floor system.

Item 4 Install Foam Floor Insulation

The contractor recommends bringing a specialist in, who has the equipment to spray the

foam. This would have to be done after the floor system has been installed and all the

electrical and plumbing run under the floor.

Item 5 Cover Floor

The contractor proposes covering floor with three-quarter inch plywood.

Item 6 Back Extension

The contractor proposes removing the existing back extension, and prepare the wall for a

new door system.

Item 7 New Door

The wall where the new door system will be installed would have been clean of all the old

gyprock and debris when they were removing the little extension. This wall would now have

to be covered with house wrap, the door system framed, the wall shingled and the door

system installed. Also at this time the contractor would

run the wiring for your exterior light and maybe a

ground fault plug on the exterior of the home.

Item 8 New Roof

The contractor proposes a new roof.

Item 9 Interior

The contractor proposes gutting interior of home.


2.2 Structural Engineer Site Review and Recommendations

The building is in generally rough condition. After several

inspections, and review of the contractor’s notes, the

following structural sketches and notes were submitted and

recommended.

Figure 6 Structural Sketch 1


Figure 15 Structural Sketch General Notes


During construction, temporary support for the rear wall and roof was required. The following

structural sketch was issued:

Figure 16 Structural Sketch for Temporary Support of Rear Wall and Roof


For over a century the Sydney Steel Corporation operated a large steel making plant in Sydney.

“Clean slag” (by-product from the steel plant) is an abundant recycled resource for construction in

the local area. Slag could be utilized for driveways, etc… as long as it meets the spec degradation for

the particular gravel specified, and is approved by a geotechnical engineer for specific usage. There

are several types of slag available; type 1, pit run, type 2, and crushed run.

Although pouring a concrete slab under this company house was not a viable option in our particular

case, it should not be ruled out as a possible option for other company house renovations.

Although there is definitely value in the historic sense to use traditional materials, (such as vintage

windows ) energy efficiency should always be a priority. If vintage windows were utilized, the owner

should be aware of the energy implications involved (take a hit on energy efficiency). Storm

windows could be installed to minimize reduced efficiency.

It should be noted that each renovation should be treated as a separate entity unto itself. The

aforementioned structural recommendations, can be utilized as a reference for possible future

alternate company home renovations, and that during construction, an associated and dedicated

structural review will have to be undertaken.


CHAPTER 3 SOLAR-POWER / PHOTOVOLTAIC

COMPONENT

3.1 Solar-Powered / Photovoltaic Systems

The system components include:

1. Photovoltaic cells connected together into modules.

2. Photovoltaic modules clustered together to make up a panel.

3. Photovoltaic panels clustered together to make up an array.

4. Electrical sub-panel.

5. Electrical transfer switch.

6. DC / AC Inverter

7. Batteries (6 volt)

8. Battery charger controller

9. Wiring / battery cables

10. DC Breaker Panels w/ electrical breakers


The roof area dictated that a maximum photovoltaic array of seven panels was reasonable.

Figure 17 Front Elevation with Photovoltaic Panel Array


Figure 18 Side Elevation with Photovoltaic Panel Array

This is what is regarded as a fixed structure (i.e. the panels are fixed to the roof). There are more

complicated tracking systems available, which enable the panels to rotate and track with the moving

sun.

The selected photovoltaic panels are approximately 230 watts each.


Utilizing RETScreen Energy Modelling software (Natural resources Canada), the projected payback

period for this system was much too large (in excess of 1000 years) to be recommended.

Pure photovoltaic systems should always be investigated for “Off the Grid” scenarios and if Feed In

Tariffs are implemented in Nova Scotia. A Feed-in Tariff is where the local utility would pay a

premium rate for the electricity you are producing with your photovoltaic panels. This would make

paybacks more favorable.


RETSreen energy model for seven panel photovoltaic array system


3.2 Alternate Photovoltaic Component

Due to cost and paybacks of the pure solar-powered / photovoltaic system, we reviewed using solar

for a possible seasonal building heating application or a domestic hot water heating application. The

solar domestic hot water system was pursued due to the fact it allows the owner to benefit from the

possibility of sunlight exposure all 365 days a year whereas if we used it for building heating, the

only benefit is during heating season. A typical household will always require domestic hot water.

The company who manufactures the equipment is Thermo-Dynamics and is located in Dartmouth,

Nova Scotia. This system would also utilize a small photovoltaic panel to power its associated closed

loop circulator pump. This domestic hot water solar heating system consists of several key

components:

1. Model S32A-P (4ftx8 ft) solar collector panel.

2. Model S32B-P (4ftx8 ft) solar collector panel.

3. SBM-13DC solar boiler module:

-Solar pump (pump/motor/linear current booster/controller)

-Heat exchanger

-Expansion tank

-Glycol reservoir (complete with 4 litres of heat transfer fluid)

-Water and glycol ports

-Pressure relief valve

4. PV20 – 20 watt photovoltaic module

5. K1060 – Photovoltaic mounting kit

6. K1055 – serpentine collector mounting kit (mounts flush to roof)

7. K2030-50 Copper tube kit (connects collector to solar boiler module, 50 ft distance between):

-50 ft supply copper tube (3/8” diameter)

-50 ft return copper tube (3/8” diameter)

-60ft 18/4 LVT wire

-100ft pipe insulation

8. GLYUSM -4 litres of heat transfer fluid for topping up the system.

9. SAS-10 – 10K Thermistor temperature sensors

10. Brass kit (TPRV, sedimentation faucet, ball valve, air vent, fittings.


How the system works:

the procedure began with sizing the panel array system. There are six (6) building additions and all


- The solar collector panels absorb sunlight and convert it to heat.

- When there is sufficient sunlight, the photovoltaic module produces electricity and powers

the pump.

- The pump circulates the heat transfer fluid (food grade propylene glycol/water mix) through

the solar collectors.

- Heat is transferred to the heat transfer fluid in the solar collector panels.

- The heat transfer fluid is returned to the heat exchanger in the Solar Boiler Module.

- The heat is transferred to the water which circulates naturally to the top of the solar storage

tank.

- Solar heated water is stored in the solar storage tank until water is drawn from the auxiliary

tank.

- As hot water is drawn from the electric auxiliary tank, it is replaced with solar heated water.

- The electric auxiliary tank increases the temperature of the water if required.


RETSreen energy model for domestic solar hot water system with PV panel


This analysis of the Thermo Dynamics solar domestic hot water system concluded that the system’s

estimated probable cost would be approximately $6,629.00. If you include possible energy rebates

($1,250), this is reduced to $5,379.00. Based on this estimated capital cost and assuming a

household of four, the simple payback was approximately 8 years. The cumulative cash flow graph

indicated approximately positive $12,000.00 (estimated owner’s future savings) after 25 years which

is the estimated lifespan of the equipment.

CBCL Limited Potential Energy Saving Items 34

CHAPTER 4 POTENTIAL ENERGY SAVING ITEMS

4.1 Heat Pump Systems

A building heating option to flag would be the air to air heat pump system. Now, although 50

Mechanic Street currently has no mechanical heating infrastructure, typically company houses run

the gamut in this department. A company house could have electric heat, oil fired forced air, oil

fired hot water with baseboard, etc…

An air to air heat pump is not as efficient as a ground source heat pump, but requires less capital

cost to install. This system would include an outdoor condenser unit, an indoor evaporator unit and

associated fans, refrigerant piping, and ductwork.

An analysis of an air to air heat pump system (approximate 10 kw) utilizing an incremental

estimated probable cost of the system of approximately $11,000.00. The air to air heat pump was a

high efficiency variable speed type. This does not take into account any possible rebates and was

compared to straight electric heat. The simple payback was calculated to be approximately 6.5

years. The cumulative cash flow graph indicated approximately positive $32,000.00 (estimated

owner’s future savings) after 25 years which is the estimated lifespan of the equipment.

This is why it is so important to look at each company house site as a site by site basis. If the existing

company house being retrofitted had an existing oil fired furnace with associated infrastructure (i.e.

ductwork, etc.) the economics of converting to the high efficiency air to air heat pump would be

even greater.

Unfortunately due to budget constraints, the client was unable to pursue the air to air heat pump on

this particular project.

CBCL Limited Potential Energy Saving Items 35

4.2 Water Conservation

Recommend low flow fixtures to reduce water consumption in the household. This includes low

flow showerheads, low flow faucets (built in aerator), low flow toilets (1.28 gpf), and energy star

appliances (best in class).

4.3 Miscellaneous

-Recommend minimum R20 insulation for walls and R40 insulation for roof with associated vapour

barriers.

-Recommend heat recovery ventilator to provide building ventilation air required by National

Building Code. This unit recovers heat from exhausted airstream.

-Recommend digital programmable thermostats for heating/cooling terminal units. This enables

nighttime and daytime setbacks tailored to occupant’s schedules.

-Recommend high efficiency windows.

- Recommend insulated doors with associated weatherstripping.

-Recommend taking advantage of passive solar heating opportunities (south facing windows with

thermal mass to absorb and retain heat energy in the home)

It should be noted that the opinion of probable costs (estimated costs) are presented in this report

on the basis of experience, qualifications, and best judgement. It has been prepared in accordance

with acceptable principles and in accordance with acceptable principles and practices. Sudden

market changes, non competitive bidding, and unforeseen labour and material availability are

beyond the control of CBCL Ltd. and as such cannot warrant or guarantee that actual costs will not

vary significantly from the opinion provided.

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