The combination of annual heating load, energy source and equipment efficiency determines the annual cost of heating.
If you are presently heating with oil and are thinking of converting to a more efficient oil heating system, you may be interested in determining the savings you could expect. Table 1 (page 39) and the following formula can provide
you with reasonably accurate figures. You need to know your annual fuel cost and the type of heating technology you are using.
Example: How much would you save by changing from an old oil furnace to a new oil furnace with a high-static burner at 85% efficiency, if your present annual fuel cost is $1, 205?
The seasonal efficiency of the new furnace with a high-static burner is taken to be 85%, and the present oil furnace efficiency is 60%. Hence, A = 85%, B = 60%, (these numbers represent an average of the efficiency ranges given in Table 1) and C = $1, 205.
Thus, you would save $354 per year with this new oil furnace.
|Energy Source||Technology||Seasonal Efficiency (AFUE) %||Energy Savings % of Base*|
|Oil||Cast-iron head burner (old furnace)||60||Base|
|Flame-retention head replacement burner||70–78||14–23|
|High-static replacement burner||74–82||19–27|
|New standard model||78–86||23–30|
|Integrated space/tap water (mid-efficiency)||83–89||28–33 space|
|Vent damper with non-continuous pilot light||62–67||3–10|
|High-efficiency condensing furnace||89–97||33–38|
|Integrated space/tap water (condensing)||89–96||33–38 space|
|Electric furnace or boiler||100|
|Air-source heat pump||1.7 COP**|
(ground-source heat pump)
|Vent damper with non-continuous pilot light||64–69||3–10|
|Conventional stove (properly located)||55–70|
|“High-tech ”stove*** (properly located)||70–80|
|Advanced combustion fireplace||50–70|
* "Base" represents the energy consumed by a standard furnace.
** COP =Coefficient of performance, a measure of the heat delivered by a heat pump over the heating season per unit of electricity consumed.
*** CSA B415 or EPA Phase II tested.
You may be interested in calculating the cost of heating with oil and even comparing this amount to the costs of heating with other energy sources such as electricity, natural gas, propane or wood. If this is the case, you can use the
following procedure. You need to find out the cost of the energy sources you wish to compare and the types of heating technologies that you might wish to use.
Call your local oil, gas and electricity suppliers to find out the cost of energy sources in your area. This should be the total cost delivered to your home, and it should include any basic cost that some suppliers might charge, along with
necessary rentals, such as a propane tank. Be sure to get the prices for the energy sources in the same units as shown in Table 2. Write the costs in the spaces provided. If your local natural gas price is given in gigajoules (GJ) , you can convert it to cubic metres (m3) by multiplying the price per GJ by 0. 0375. For example, $5. 17/GJ x 0. 0375 = $0. 19/m3.
|Energy Source||Energy Content||Local Price|
|Oil||38.2 MJ/L||140 000 Btu/gal. (U. S.)||$0. ______/L|
|Electricity||3.6 MJ/kWh||3413 Btu/kWh||$0. _____/kWh|
|Natural Gas||37.5 MJ/m3||1007 Btu/cu. ft.||$0. ______/m3|
|Propane||25.3 MJ/L||92 700 Btu/gal. (U. S. )||$0. ______/L|
|Hardwood*||30 600 MJ/Cord||28 000 000 Btu/cord||$______/cord|
|Softwood*||18 700 MJ/Cord||17 000 000 Btu/cord||$______/cord|
|Wood Pellets||19 800 MJ/Tonne||20 000 000 Btu/ton||$______/tonne|
Conversion 1000 MJ = 1 GJ
* The figures provided for wood are for a “full ”cord, measuring
1.2 m x 1.2 m x 2.4 m (4 ft. x 4 ft. x 8 ft. ).
Choose the type of equipment you want to compare from the list of appliance types in Table 1 on page 39. Note the efficiency figures in the column titled “Seasonal Efficiency. ”By using these figures, you can calculate the savings you can achieve by upgrading an older system to a newer, more energy-efficient one or by choosing higher efficiency appliances with alternative energy sources.
If you know your heating bill and the unit cost of your energy source, you can determine your Annual Heating Load in gigajoules from the following equation.
For example, you have an oil bill of $1, 220, an oil cost of $0. 329/litre and an old conventional oil furnace and burner (seasonal efficiency of 60% from Table 1).
If your bill also includes tap water heating from the same energy source, you can still calculate your annual heating load, but it will require a little more care and calculation to separate out only your heating portion.
If you can ’t get your heating bill, you can estimate your annual heating load in GJ from Table 3 (page 43) by selecting the house type and location that is closest to your own.
The annual heating cost is calculated as follows:
The result should give you an approximate heating cost for your house. If you know your actual annual heating costs, as well as the type of heating system you have, you can modify the heating load originally taken from Table 3 to suit your specific house.
Sample calculation: You have a new semi-detached home in Fort McMurray and you would like to find out what the annual heating cost would be with a mid-efficiency oil furnace at 83% efficiency. To use the above formula, we can define the cost of oil as $0. 30/L, the house heating load as 80 (Table 3) and the energy content as 38. 2 (Table 2).
Annual cost of oil heating:
If you would like to compare this heating cost with those of other types of heating systems or energy sources, replace the numbers in the formula with the appropriate ones or your comparison using Tables 1 and 2 (pages 39 and 40).
|City||Old Detached||New Detached||New Semi-
Note: “New ”means houses built in 1990 or later, and “old ”means houses built before 1990. Due to construction practices, “weatherizing ” and re-insulating (which can be different from house to house) , these figures are meant to be used only as general guidelines; they should not substitute for an accurate heating requirement determination, as discussed in Chapter 5.
Old detached – approximately 186 m2 (2000 sq. ft.)
New detached – approximately 186 m2 (2000 sq. ft.)
New semi-detached – approximately 139 m2 (1500 sq. ft.)
Townhouse – inside unit, approximately 93 m2 (1000 sq. ft.)
Source: Natural Resources Canada (NRCan) - Office of Energy Efficiency