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What to Know About a Condensing Furnace


A condensing furnace uses technology that makes it the most energy efficient heating system on the market. Instead of releasing the waste gases up the chimney, theyandrsquo;re directed toward a second heat exchanger that extracts nearly all their heat. Most furnaces send 15 to 20 percent of the heat they create up the chimney. Condensing furnaces waste just two to 10 percent of the heat they create.


As gas burns, it creates water vapor that carries a lot of heat. A typical gas furnace has a burner inside it with a heat exchanger that sits next to it. Condensing units have a second heat exchanger that sits nearby. The exhaust that would normally go up the chimney goes past the second heat exchanger.

When this exhaust gas loses its heat, the water condenses, hence the name for these furnaces. The heat from the exhaust goes toward heating your home and the water drains. The remaining gases exit your home through a vent.

Besides such high efficiency, called AFUE (annual fuel utilization efficiency), a condensing furnace improves air quality indoors. The air that goes into the system for the combustion process comes from an outdoor vent that is placed next to the exhaust vent coming from the furnace.


Along with making use of the heat in the exhaust gases, many condensing furnaces have upgrades that increase their energy efficiency and the comfort they offer. Look for a two-stage furnace or one with a variable-speed air handler to save even more energy.

Both of these kinds of condensing furnaces enhance comfort by running at slower speeds for longer periods, which distributes the heat more thoroughly indoors. These systems also run more quietly at lower speeds.

If you want to cut your heating bills and increase your wintertime comfort, consider a condensing furnace. If youandrsquo;d like to learn more, contact Valley Heating, Cooling, Electrical and Solar providing HVAC services for Santa Clara County, Silicon Valley and South Bay Peninsula homeowners. Visit our website or give us at call at (408) 868-5500.

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