AFUE Ratings and Your Heater: A Guide to Installation and Replacement

Here at Air Mechanical, Inc., we know that installing a new furnace can be a difficult decision with a lot of new terminology to decipher. Choosing a system may mean learning a little bit about heat loads and sizing, but we recommend you let a technician figure out those parts for you. After you get the right size and decide on a brand, you can choose whether or not to have variable speed settings or other optional features. And if you don’t choose a system with a high AFUE (annual fuel utilization efficiency) rating, your monthly bills could suffer.

What Does AFUE Mean?

You may have realized that a higher AFUE (annual fuel utilization efficiency) rating means a more efficient heating system. Most furnaces installed in the U.S. must have a 78 AFUE at minimum, but what does this number represent? 80 is the percentage of energy that your heater actually uses to heat your home. While 80% of the energy or fuel goes directly toward heating your home, 20% doesn’t become heat, but escapes through the flue or in other ways.

Which AFUE Should I Choose?

The AFUE rating you choose for your new heating system will depend on a couple of factors. If you live in a colder climate like ours, it’s very well worth the extra upfront cost to get a system with an AFUE rating above 90, if possible. The monthly savings averages out over the years, and the total savings can actually offset that extra cost faster than you may think. However, if you live in a warmer climate where the heat is used sparingly, a very high AFUE might not be a major improvement over one closer to 80.

Other Considerations for Efficiency

You could choose the highest AFUE rating available, but you still might not save energy if the system is not installed correctly. This means calculating heat load to get the proper size for your needs. A system that is either too small or too large will do a poor job of meeting your needs, and you may end up with high bills and frequent repairs. Contact the friendly folks at Air Mechanical, Inc. for heating installation and replacement in Ham Lake.