Compare Annual Heating Costs of Heating Systems and Energy Savings

The annual heating cost is determined by the combination of annual heating load, energy source and equipment efficiency. To determine the savings you could expect if you upgrade your current system, you can use the formulas for each energy source or use our heating calculator.

Upgrading an oil system

If you are thinking of converting your oil furnace to a more efficient oil heating system, you may be interested in determining the savings you could expect. Table 1 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.

Annual $ Savings = A – B

———— X C

A = Seasonal efficiency of proposed system
B = Seasonal efficiency of existing system
C = Present annual fuel cost

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 percent 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 percent, and the present oil furnace efficiency is 60 percent. Hence, A = 85%, B = 60%, C = $1, 205.

Annual $ savings = 85 – 60

————— X 1205 = $354

In this example you would save $354 per year with this new oil furnace.

Table 1 – Typical Heating System Efficiencies and Energy Savings
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
	Mid-efficiency furnace	83–89	28–33
	Integrated space/tap water (mid-efficiency)	83–89	28–33 space 40–44 water
Natural Gas	Conventional	60	Base
	Vent damper with non-continuous pilot light	62–67	3–10
	Mid-efficiency	78–84	23–28
	High-efficiency condensing furnace	89–97	33–38
	Integrated space/tap water (condensing)	89–96	33–38 space 44–48 water
Electricity	Electric baseboards	100
	Electric furnace or boiler	100
	Air-source heat pump	1.7 COP**
	Earth-energy system (ground-source heat pump)	2.6 COP**
Propane	Conventional	62	Base
	Vent damper with non-continuous pilot light	64–69	3–10
	Mid-efficiency	79–85	21–27
	Condensing	87–94	29–34
Wood	Central furnace	45–55
	Conventional stove (properly located)	55–70
	“High-tech ”stove*** (properly located)	70–80
	Advanced combustion fireplace	50–70
	Pellet stove	55–80
* “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.

Upgrading a Gas System

If you are thinking of converting your gas furnace to a more efficient gas heating system, you may be interested in determining the savings you could expect. Table 2 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.

Annual $ Savings = A – B

———— X C

A = Seasonal efficiency of proposed system
B = Seasonal efficiency of existing system
C = Present annual fuel cost

Example: How much would you save by changing from a conventional gas furnace to a high-efficiency gas furnace at 96 percent efficiency if your present annual gas cost for space heating is $800?

The seasonal efficiency of the new condensing furnace is 96 percent, and the efficiency of your present gas furnace is 60 percent. Hence, A =96 percent, B =60 percent C =$800.

Annual $ Savings = 96 – 60

————— X 800 = $300

In this example, you would save $300 a year in energy costs and you would eliminate the need for a chimney.

Table2. Gas Heating Appliances – Features and Efficiency Ranges
Type	Features	Seasonal Efficiency (AFUE) (%)
Conventional furnace¹	chimney draft hood with continuously lit pilot light with electronic ignition and vent damper	60 62–67
Conventional boiler¹	chimney draft hood with continuously lit pilot light with electronic ignition and vent damper	55–65 60–70
Standard-efficiency furnace¹	chimney or side wall vent draft hood electric ignition powered exhaust	78–84
Standard-efficiency boiler¹	similar to mid-efficiency furnace	80–88
Condensing furnace²	no chimney no draft hood electric ignition multi-stage heat exchanger condenses water vapour from flue gases PVC or ABS flue pipe to side wall	90–97
Condensing boiler ²	similar to condensing furnace	89–99
Conversion burners for oil equipment¹	chimney pilot light or electric ignition special barometric damper or draft hood	63–68
Direct-vent wall furnace¹	vent sealed combustion pilot light or electric ignition	70–82
Room heaters¹	vent pilot light or electric ignition draft hood or sealed combustion	60–82
¹If this appliance is fired with propane rather than natural gas, add 2 percent to the efficiency. ² If a condensing appliance is fired with propane rather than natural gas, subtract 2 percent from the efficiency.

Changing Your Energy Source

You can use the following procedure to compare the cost of heating with various energy sources, such as oil, electricity, natural gas, propane or wood. First, find out the cost of the energy sources you wish to compare and decide what types of heating technologies you might wish to use.

Determine the Price of Energy Sources in Your Area

Call your local fuel 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 3. 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.

Table 3. Energy Content and Local Price of Various Energy Sources
Energy Soure	Energy Content		Local Unit Price
	Metric	Imperial
Electricity	3.6 MJ/kWh	3 413 Btu/kWh	$0._____ /kWh
Oil	38.2 MJ/litre	140 000 Btu/gal (US)	$0._____ /litre
Natural Gas	37.5 MJ/m³	1 007 Btu/ft³	$0._____m³
Propane	25.3 MJ/litre	92 700 Btu/gal (US)	$0._____litre
Hardwood*	30 600 MJ/cord	28 000 000 Btu/cord	_____$/cord
Softwood*	18 700 MJ/cord	17 000 000 Btu/cord	_____$/cord
Wood Pellets	19 800 MJ/cord	20 000 000 Btu/cord	_____$/cord
Conversion: 1000 MJ= 1 gigajoule (GJ) * The figure provided for wood are for a “full” cord, measuring 1.2m x 1.2m x 2.4m (4 ft. x 4 ft. x 8ft.)

Select the Type of Heating Equipment

Choose the type of equipment you want to compare from the list of equipment types inTable 2. Note the efficiency figures in the column titled Seasonal Efficiency. 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 equipment with alternative energy sources.

Determine Your Home’s Annual Heating Load

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. Or you may wish to use our Heating cost calculator.

Annual Heating Load = Heating Bill Seasonal Efficiency

—————— x —————————— x Energy Content

100 000 Energy Cost/Unit

If you don’t have a heating bill, you can estimate your annual heating load in GJ fromTable 4by selecting the house type and location that is closest to your own.

If your bill also includes tap water heating from the same energy source, and even equipment rentals, 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.

Example – Oil : You have an oil bill of $1,220, an oil cost of $0.329/litre and an old conventional oil furnace and burner with a seasonal efficiency of 60 percent.

Annual Heating Load = 1220 60

———— x —————————— x 38.2 = 85 GJ

100 000 Energy Cost/Unit

Example – Natural Gas: Your annual bill for space heating with natural gas is $687, gas costs $0.22/m3, and you have an old conventional gas furnace with a seasonal efficiency of 60 percent. The energy content of natural gas is 37.5 MJ/m3.

Annual Heating Load = 687 60

———— x —————————— x 37.5 = 70 GJ

100 000 Energy Cost/Unit

The annual heating cost is calculated as follows:

Energy Cost/Unit Annual Heating Load

Heating Cost = —————————– x ——————————— x 100,000 = $

Energy Content Seasonal Efficiency

Enter the cost per unit of energy and divide it by the energy content of the energy source; both numbers come from Table 3.

Select the annual heating load for your type of housing and location from Table 4; divide it by the seasonal efficiency of the proposed heating system from Table 1 or 2.

Multiply the results of these two calculations, then multiply that result by 100 000. 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 4 to suit your specific house.

Sample Calculation – Oil : 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 standard-efficiency oil furnace at 83 percent efficiency. To use the above formula, we can define the cost of oil as $0.30/L, the house heating load as 80 and the energy content as 38.2.

$0.30 80

Annual cost of oil heating = ————— x ——— x 100,000 = $757

38.2 83

Sample Calculation – Gas : You have an old detached home in Edmundston, and you would like to find out what the annual heating cost would be with a high-efficiency condensing natural gas furnace at 96 percent efficiency with gas costing $0.18/m3. The house heating load is 120 GJ, and the energy content is 37.5 MJ/m3.

$0.18 120

Annual cost of gas heating = ————— x ——— x 100,000 = $600

37.5 83

Sample Calculation – Electricity : You have an new detached home in Toronto and you would like to know what it would cost you annually to heat your dwelling with an electric force-air system with a seasonal efficiency of 100 per cent. Using the above equation, use an electricity cost of $0.0826/kWh, a heating load of 80 and an energy content of 3.6.

$0.0826 80

Annual cost of heating with electricity = ————— x ——— x 100,000 = $1835.55

3.6 100

To compare your heating cost to those of other types of heating systems or energy sources, replace the numbers in the formula with the appropriate ones for your comparison using Table 1 or 2. and Table 3. Or you may wish to use our Heating Cost Calculator.

Table 4. Typical Annual Heating Loads in Gigajoules (GJ) for Various Housing Types in Canadian Cities
City	Old Detached	New Detached	New Semi-Detached	Town-house
Victoria	85	60	45	30
Prince George	150	110	80	60
Calgary	120	90	65	50
Edmonton	130	95	70	55
Fort McMurray/ Prince Albert	140	105	80	60
Regina/Saskatoon/ Winnipeg	130	90	70	50
Whitehorse	155	115	85	60
Yellowknife	195	145	110	80
Thunder Bay	130	95	70	55
Sudbury	120	90	65	50
Ottawa	110	75	55	40
Toronto	95	65	45	35
Windsor	80	55	40	30
Montréal	110	80	60	45
Québec	115	85	65	50
Chicoutimi	125	90	70	55
Saint John	105	75	60	45
Edmundston	120	90	65	50
Charlottetown	110	80	60	45
Halifax	100	75	55	40
St. John’s	120	85	60	45

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.

Assumptions:
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.)

Use our Heating Cost Calculator

This entry was posted on Tuesday, August 17th, 2010 at 6:50 am and is filed under Heating and Cooling, News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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