Project Description
Planning the Retrofit
This homeowner approached this retrofit with the aim of reducing energy consumption and saving energy costs, improving the thermal comfort of their home, and reducing their GHG emissions. Following energuide assessment recommendations, they decided to increase the insulation on their exterior walls and then, once the heating load was reduced, electrify their heating equipment.
To maintain the original brick of the home while increasing the insulation R value, holes were drilled into the exterior wythe (vertical sections of masonry that is one unit thick), and cellulose insulation was pumped into the cavity between the two wythes of brick. The home owner found that with this added insulation their furnace oil use dropped by a third compared to what they would typically expect to use.
The homeowner then installed an air source heat pump with a backup electric furnace that would be capable of both heating and cooling the house. Removing the oil furnace improves the overall efficiency of the building, and reduces the carbon footprint, but it also lowers the health risks associated with burning fuel and producing CO2 within the home. These changes alone led to a 61% reduction in the energy consumption in the home.
Before & After
General
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Before |
After |
Building Condition
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Before
Original insulation in main walls with dated heating equipment |
After
Upgraded wall assemblies with a modern air source heat pump heating and cooling system |
Envelope
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Before |
After |
Ceiling/Attic Assembly
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Before
Cathedral ceilings insulated with fiberglass batts *assumed*, Gable attics insulated with blown in insulation |
After
No changes made to attic or ceiling area |
Ceiling/Attic Assembly Effective Thermal Resistance
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Before
R-26.95 |
After
R-26.95 |
Foundation Wall Assembly
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Before
Crawl space walls: fiberglass batts, Interior foundation walls: fiberglass batts, Foundation header: fiberglass batts |
After
No changes made to the foundation walls, crawlspace or headers |
Foundation Wall Assembly Effective Thermal Resistance
|
Before
R-12.59 |
After
R-12.59 |
Wall Assembly
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Before
2×6 wood frame, 16″ centers, uninsulated wall cavity, brick exterior finish |
After
Wall cavities filled with cellulose insulation |
Wall Assembly Effective Thermal Resistance
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Before
R-5.3 |
After
R-20 |
Windows and Doors
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Before
All vinyl, dual pane windows. All but two with Low-E coating. Steel polystyrene core doors |
After
No changes made to windows and doors |
Air Tightness
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Before
10.08 ACH50 |
After
7.16 ACH50 |
Air Sealing
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Before
No proactive air sealing beyond spray foam being added to some window frames |
After
Vapour barrier installed on main floor and second story walls |
Mechanical & Electrical
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Before |
After |
Heating
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Before
Oil furnace 94,000 BTU/h (83% AFUE) |
After
Air source heat pump 85,500 BTU/h (Heating COP 3.07) |
Cooling
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Before
None |
After
Air source heat pump 85,500 BTU/h (Cooling COP 3.11) |
Hot Water
|
Before
Electric storage tank 303L (0.87 EF) |
After
Same as before |
Annual Energy Usage
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|
Before |
After |
Total Annual Consumption
|
Before
390 GJ |
After
84 GJ |
Total Net Consumption
|
Before
390 GJ |
After
84 GJ |
Energy Use Intensity
|
Before
440.38 kWh/m2/a |
After
94.85 kWh/m2/a |
Annual Heating Demand Intensity
|
Before
361.11 kWh/m2/a |
After
39.84 kWh/m2/a |
Annual Cooling Demand Intensity
|
Before
0 kWh/m2/a |
After
7.59 kWh/m2/a |
Annual Electricity Consumption
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Before
12244 kWh |
After
23198 kWh |
Annual Natural Gas Consumption
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Before
173 GJ |
After
0 GJ |
Light and Appliance Energy Consumption
|
Before
19.5 GJ |
After
11.76 GJ |
Other Electrical Consumption
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Before
23.4 GJ |
After
14.28 GJ |
Space Cooling
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Before
0 GJ |
After
6.72 GJ |
Space Heating
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Before
319.8 GJ |
After
35.28 GJ |
Ventilation
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Before
0 GJ |
After
0 GJ |
Water Heating
|
Before
27.3 GJ |
After
15.96 GJ |
Carbon Emissions*
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|
Before |
After |
Annual Operational Carbon Emissions – Electricity
|
Before
464.44 KgCO2e |
After
886.67 KgCO2e |
Annual Operational Carbon Emissions – Oil
|
Before
12352.711 KgCO2e |
After
0 KgCO2e |
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*Based on emissions values from Canada’s Official Greenhouse Gas Inventory 2022 Emissions Values
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