Energy efficiency is important when choosing the best heating system for your home. More efficient furnace systems result in lower annual energy costs. Two key components must be considered when calculating the efficiency of home furnaces: the type of fuel they use and the amount of electricity required to operate the system’s controls and blower motor.
AFUE, short for Annual Fuel Utilization Efficiency, is a percentage-based measurement that reflects how well a furnace converts fuel into heat energy. High AFUE ratings translate into higher-efficiency furnaces. For example, in the mid-1970s, most gas furnaces had relatively low AFUE ratings of around 65 percent. An AFUE of 65 means that only 65 percent of the fuel input into the furnace is converted into the heat necessary to warm a home. The remaining 35 percent is lost during the process. Today home heating systems are much more efficient than they used to be. Residential gas furnaces sold in Canada must have a minimum AFUE of 90 percent (much higher than the U.S, where the minimum remains 78 percent). High-efficiency condensing furnaces feature AFUE ratings as high as 98 percent, meaning almost all of the fuel is turned into heat for your home.
High-efficiency furnaces have higher initial costs than lower-efficiency units. Of course, while you can expect to pay more upfront for high efficiency, these units will recoup this investment over their operating lifetime in the form of reduced annual energy bills. How quickly this happens depends on your home’s unique insulation, local climate variances, and the average local cost of gas and electricity. In our cold-winter climate, the higher the efficiency the better.
For those also concerned about the environment, higher-efficiency furnaces generate fewer harmful emissions.