When you’re buying a new furnace, it makes good sense to select one that has the highest efficiency you can afford. You’ll be rewarded with lower heating bills for years to come. Recent technological developments have increased gas heating efficiency to nearly 100 percent. In Western Colorado with our cold winters, this is the smart choice.The efficiency of a furnace is measured in its AFUE (annual fuel utilization efficiency) rating and expressed as a percentage. AFUE ratings closer to 100 percent indicate higher efficiency. The minimum efficiency rating for forced-air gas or oil furnaces currently stands at 78 percent, which means that furnace loses 22 percent of the fuel it uses. High-efficiency furnaces convert 90 percent or more of their fuel into heat.
A number of features contribute to higher efficiency in furnaces, including these characteristics:
- Condensing furnaces. A condensing furnace can have an AFUE as high as 98 percent. These furnaces use two heat exchangers instead of one. The second exchanger removes the heat from the water vapor a gas furnace creates and uses that heat for maximum efficiency. The water drains through a pipe into your home’s plumbing system. These furnaces use horizontal fresh air intake and exhaust vents, which offer advantages over standard rooftop chimney flues.
- Modulating furnaces. These sense the heating load in your home and vary the amount of gas going through the orifice accordingly. They may start the heating cycle using a maximum amount of gas, but once the fan turns on, the modulating furnace will reduce the amount of fuel being delivered to gradually warm the air in your home.
- Variable-speed air handler. Although it doesn’t affect the amount of fuel a new furnace uses, one that has a variable-speed air handler saves energy because the motor uses up to 70 percent less electricity. Run by an electronically commutated motor, these systems run more quietly than single-speed motors and distribute the heated air more thoroughly.
Our goal is to help educate our customers in Aspen, Vail and the surrounding Western slope communities in Colorado about energy and home comfort issues (specific to HVAC systems). For more information about high-efficiency furnaces and other HVAC topics, please visit our website.
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