Learning How a Condensing Furnace Works
Furnace efficiency is a significant concern for many homeowners who want to get the best performance out of their heating systems. Those who want the highest-efficiency furnace available can purchase and install a condensing furnace. The following should help you understand how condensing furnaces work.
The function of a condensing furnace is similar to a regular fuel-based forced-air furnace. The heating cycle begins with the thermostat, which detects when temperatures drop inside your home. The thermostat activates the furnace. Burners inside the furnace ignite, creating heat that’s captured by the heat exchanger. A powerful fan blows air across the heat exchanger. The air absorbs heat and is directed into the ductwork and distributed throughout your home, while exhaust gases are vented outdoors. Expended air is pulled back into the furnace through the return ducts and is filtered and heated again as needed.
A condensing furnace adds an additional component to the heating cycle in the form of a second heat exchanger. This additional heat exchanger is used to extract heat from the exhaust gases before they’re vented away, reclaiming heat that would otherwise be wasted through ventilation. Condensing furnaces are so efficient at this process and remove so much heat from the exhaust, that the gases often cool off and condense into water and carbon dioxide. This process creates carbonic acid, which is drained away through a PVC pipe and into a drain in the floor. Any remaining exhaust gases are vented away as usual.
Condensing furnaces carry extremely high-efficiency ratings. Their annual fuel utilization efficiency, or AFUE rating, can be as high as 98 percent. This means that 98 percent of the energy in fuel burned by the furnace is turned into heat to warm your home.
Contact us today for more information on condensing furnaces and whether a condensing furnace is right for your home.
Our goal is to help educate our customers in Delaware, Pennsylvania, Maryland and New Jersey about energy and home comfort issues (specific to HVAC & plumbing systems).
Image Credit: Mark Brannan