All gas furnaces use a heat exchanger to transfer the heat the gas creates. Normally, heat exchangers sit next to the furnace burners and heat up just like a pan on the stove. These parts, made from metal, absorb heat and the air that the blower sends over it warms. It enters the ductwork and heats your home.
Some combustion furnaces use two heat exchangers to increase efficiency. As gas burns, it creates water vapor that holds a good deal of heat. Instead of going up the chimney, these gases pass over the second exchanger that extracts nearly all the remaining heat. These condensing furnaces have the highest efficiency rating of all combustion furnaces, and some can extract nearly 99% of all heat that the gas creates.
Important Considerations
In all furnaces, it’s important to keep the heat exchangers clean. Dust covering the heat exchanger insulates it and it will take the furnace longer to heat your home, raising energy bills and reducing comfort. Changing the air filter routinely keeps much of the dust off this part. During the annual maintenance check, an HVAC technician will thoroughly clean it so it operates efficiently.
Since they’re made from metal, heat exchangers expand as they heat up and contract when they cool down. This constant expansion and contraction eventually stresses the metal. When cracks form, the exchanger can release carbon monoxide (CO) into your home’s air.
Cracks in heat exchangers almost always prompt an expensive furnace repair or a complete replacement, since CO is a lethal gas. If an HVAC contractor finds cracks in the exchanger, he has to disable the furnace by law. Having a working CO detector that shows the CO level intermittently is essential if you’re using an aging furnace, or one that hasn’t been routinely maintained.
The heat exchanger is an essential part of the furnace and performs most efficiently and lasts longer when it’s clean. To learn more or schedule furnace maintenance, contact Hartman Brothers Heating & Air Conditioning, providing trusted HVAC services for Fort Wayne homeowners.
Our goal is to help educate our customers in New Haven, Indiana and surrounding Fort Wayne area about energy and home comfort issues (specific to HVAC systems). For more information about heat exchangers and other HVAC topics, download our free Home Comfort Guide or call us at 260-376-2961.
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