Two weeks ago, we wrote a blog about how to tell that your old furnace should retire. One of those signs is a furnace that costs too much to run. It’s obvious that an aging machine simply won’t be as energy efficient as a newer one. However, there’s more to the improvement in energy efficiency with a new furnace. The technology of furnaces has increased significantly, allowing them to convert their energy source to heating fuel with much less waste than ever before. For example, the average AFUE rating of gas furnaces was once around 60%, which means that only 60% of the energy the furnaces consumed was converted to thermal energy, and 40% went to waste. Today furnaces can score AFUE ratings of 80% up to 97%. How is this possible?
Electronic ignition replacing standing pilot lights
One major change in gas furnace operation is the removal of the old standing pilot light that burns through the entire heating season, using up natural gas even when the furnace isn’t running. An electronic igniter only comes on when it’s necessary to ignite the burners, which results in the furnace using much less energy.
A second heat exchanger
Furnaces known as condensing furnaces have two heat exchangers instead of one. The first heat exchanger collects hot combustion gas, which turns into a vapor as it cools down. Rather than venting this vapor to the outside and wasting it, it sends it to a second exchanger, where through the process of condensation, it releases even more heat. This allows the furnace to get the most heat possible from its combustion gases.
Variable-speed blowers and multi-stage burners
Furnaces no longer need to run at a single power when they come on, either with the burners or the blower fan. High-efficiency models can lower the blower capacity and the burners so they still operate but use less power. The furnace automatically adjusts its power level to match the heating needs of the home, and about 75% of the time will run on lower energy use.
Southeast Air & Heat offers gas furnace replacement and other services in Conway, FL. Don’t delay, call us today!
