The Economics of Heating
Here are some things to consider when buying a Heating System:
Since January 1, 1992 the minimum Annual Fuel Utilization Efficiency (AFUE) rating for forced air gas furnaces in Ontario has been 78% making all furnaces installed after that date mid or high-efficiency.
Annual Fuel Utilization Efficiency (AFUE) - percentage efficiency ratings are as follows:
Forced Air (gas/oil)
Conventional - 55 - 60 %
Mid - 80 - 84 %
High - 85 - 90 %
Boiler (gas/oil)
Conventional - 55 - 60 %
Mid - 85 %
High - 90 %
Electric - are 100% efficient (although creation of electricity through fossil fuels is about 40% efficient making electricity the most expensive "fuel").
Comparing Fuels and Efficiencies - each fuel used costs a different amount and yields a different amount of heat (Btu). In order to properly compare therefore, you must do a calculation of the cost per Btu. That calculation is:
Cost per Btu = (100 X P) divided by (F X AFUE)
where
F = Btu content of a unit of fuel
P = Price per unit of fuel (dollars)
AFUE = Annual fuel utilization efficiency (percent)
Mid-Efficiency versus High-Efficiency? - check twice before you buy. A general rule of thumb is that you need about a 2,000 square foot home to get your pay back from a high-efficiency unit.
Increasing the efficiency of your furnace doesn’t always equate to instant savings. For example, if you increase the efficiency of a your furnace from a mid-efficiency at 84% AFUE to a high efficiency at 92% AFUE your percentage savings on fuel is 8.6% (12% (92-84) divided by 92%) a year. While a nice savings, this must be compared with the increased purchase price and maintenance costs if any of a high-efficiency unit. If you spent $600 in fuel with the a mid-efficiency unit then you’ll save $52 (8.6% X $600) a year in fuel switching to high-efficiency. If the unit costs $500 more it would take about 10 years ($500 divided by $52) to re-coup your costs or before you’d start to save.
A high-efficiency unit is not unlike a finely tuned racing car. For best performance, regular maintenance (tune-ups) are required which can be more costly than non-high performance units. This, coupled with higher costing parts and labour to repair same, may defer or increase the pay-back period as well.
Back |
