The Annual Fuel Utilization Efficiency (AFUE) is a measure of how efficiently your furnace uses its fuel. Since the main function of a furnace is to produce heat for warming the house, AFUE is a measure of how much fuel is used in heating the house. This rating is necessary because a furnace doesn't convert all of the fuel it receives into energy; some wastage is inevitable. For example, some partially burnt fuel is exhausted and vented out of the house.
The AFUE is calculated as a percentage of the fuel that is used in heating the house. For example, if a furnace consumes 10 gallons of fuel and uses 8 of them to heat the house, then the furnace has an AFUE rating of 80%. The higher the AFUE, the more efficient your furnace is since a high AFUE means the furnace converts most of the fuel into heat energy.
Since AFUE is a measure of efficiency, you can use it to determine several issues associated with your heating. Below are some of these critical issues.
The AFUE rating gives you a rough idea of how much fuel you will need to keep your home warm. The lower the AFUE is, the more fuel you will need to keep your home warm since most of the fuel will be wasted. This is important if you have a fuel reserve in your home, such as a propane tank. With a low AFUE, you need to get a big tank if you don't want to order for fuel too frequently.
An AFUE rating also gives you an indication of how much money you will be using to heat your home. For example, for two furnaces with AFUE ratings of 65% and 85%, the second furnace will attract lower heating costs than the first one since the second one doesn't waste a lot of fuel.
Burning fossil fuel affects the environment in two main ways. First, fossil fuel is a limited natural resource that is mined, and many mining methods pollute the environment. Secondly, burning fuel releases some dangerous gases into the atmosphere. The more fuel you waste, the more you hurt the environment. Thus, a furnace with a high AFUE is good for the environment since it doesn't use a lot of fuel.
Although you do need to consider AFUE rating when shopping for a furnace, you should be careful about how you make your comparison. For example, comparing the AFUE of a natural gas furnace and an oil furnace is not a good comparison because these fuels have different costs. In fact, the type of fuel may be a better comparison for furnace running costs than AFUE. However, AFUE gives you a good point for comparison for furnaces that use the same type of fuel.
For more information on residential heating, contact local professionals.