The standards for the energy efficiency ratings of natural gas furnaces have increased. The U.S. Department of Energy’s ENERGY STAR program now requires that new gas furnaces are manufactured to meet a rating of 90% AFUE or greater in the South and 95% AFUE or greater in the north in order to receive the ENERGY STAR certification. This isn’t a standard that’s difficult to meet for new furnaces. In fact, the reason that the requirements have gone up is because furnaces simply are more efficient now than they’ve ever been.
What accounts for this better energy performance from furnaces? A number of factors:
Furnaces are just better built today, with lighter material and more efficient motors. The heat exchangers can more easily transfer heat from the combustion gases to the air. Manufacturers continue to find better ways to design furnaces so they consume less power.
Condensing furnaces are a type of higher-efficiency furnace that reduces the amount of energy lost through the exhaust of combustion fumes. After the combustion fumes have transferred their heat to the walls of the heat exchanger, the remaining vapor moves to a second chamber, where it is condensed to release even more heat. Condensing furnaces are among the best ways to save energy with a gas furnace.
Instead of needing to run the furnace fan on the same level all the time when the heating system is on, a variable speed fan can drop down to a lower mode whenever necessary. In fact, most of these furnaces will run on the lower, energy-saving speed the majority of the time.
Older furnaces used open combustion chambers to draw in air from the house to use in combusting fuel along the burners. A sealed combustion chamber draws the air from outside the home and seals off the chamber to the inside of the house so there is much less heat loss. (These furnaces also help preventing drying out the air in the house, and they’re safer as well.)
To learn more about our options for a more energy-efficient furnace, call on Raleigh Heating & Air, Inc. We service Wake Forest, NC and the surrounding areas.