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.
CBCL Limited Consulting Engineers Introduction 2
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.
CBCL Limited Consulting Engineers Introduction 3
Figure 1 Aerial View of Building Location at 50 Mechanic Street
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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.
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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.
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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
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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
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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.
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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
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The roof area dictated that a maximum photovoltaic array of seven panels was reasonable.
Figure 17 Front Elevation with Photovoltaic Panel Array
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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.
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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.
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RETSreen energy model for seven panel photovoltaic array system
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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.
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How the system works:
the procedure began with sizing the panel array system. There are six (6) building additions and all
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- 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.
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RETSreen energy model for domestic solar hot water system with PV panel
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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.