Condensing Gas Furnaces: The Boiled-Down Basics

Condensing Gas Furnaces: The Boiled-Down BasicsCondensing gas furnaces are the embodiment of heating efficiency. In addition to providing up to 98-percent fuel efficiency, condensing furnaces are engineered to resist corrosion, deliver safer operation for occupant health, and maximize home comfort with self-adjusting components. From safe fuel combustion to sealed exhaust, learn the basic features and components that set condensing furnaces apart.

  • When a call for heat is received from the thermostat, the modulating gas valve sends gas to the sealed combustion chamber.
  • The furnace ignites using electronic ignition (no more standing pilot light).
  • The air used for fuel combustion is direct-vented from outside the home, which protects furnace components from corrosive airborne contaminants and doesn’t use up already-heated air in your house.
  • The modulating gas valve quickly heats the furnace, and then scales back to a reduced, more efficient fuel flow, by increments as precise as 1 percent.
  • Heat flows into the primary heat exchanger where sensible heat is utilized to heat the home.
  • Once sensible heat is exhausted, the remaining hot gases flow into the secondary heat exchanger. The hot gases are condensed, and latent heat which would otherwise float up the chimney is utilized for your home.
  • A variable-speed blower forces the heated air through the ductwork to your living spaces. In conjunction with the modulating gas valve, variable-speed blowers precisely deliver only the amount of actual heat needed.
  • Cooled exhaust gases safely exit the secondary heat exchanger through a sealed plastic pipe that typically extends through a wall (sidewall venting), parallel to the direct-vent air intake pipe. An acidic liquid, also a by-product from the condensing process, flows to a floor drain.
  • In addition to direct-vent intake and sealed fuel combustion, sealed sidewall venting prevents furnace-induced back-drafting.
  • Continuous on-board diagnostics control furnace function and reliability, also providing direct readouts for easier troubleshooting.

When upgrading your furnace, remember it all boils down to comfort and safety, along with good energy-saving sense. Contact Geisel Heating, Air Conditioning & Plumbing for more information about condensing gas furnaces. We’ve provided reliable service and installation for homeowners in the Greater Cleveland area, including Lorain, Cuyahoga and Medina counties, for more than 78 years.

Our goal is to help educate our customers in Western Cleveland, Ohio about energy and home comfort issues (specific to HVAC systems).  For more information about condensing gas furnaces and other HVAC topics, download our free Home Comfort Resource guide.

For those Do it Yourselfers who would rather take control of your own indoor comfort, you can shop our online store for replacement parts, products and accessories!   

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