A furnace burns fuel — usually natural gas in Colorado, occasionally propane in rural areas — to heat air, then a blower pushes the warm air through your ductwork. Furnaces are rated by AFUE (efficiency) and BTU/hour capacity.
Two main categories
- Standard-efficiency (80% AFUE) — vents through a metal flue. Cheaper to install, less efficient. No rebates.
- Condensing high-efficiency (90-98% AFUE) — a secondary heat exchanger captures heat from the flue gases, condensing the water vapor. Vents through PVC. More efficient, qualifies for rebates.
At Colorado altitude, combustion efficiency drops about 4% per 1,000 feet of elevation — important to factor in when sizing. A 100,000 BTU furnace in Denver delivers ~79,000 BTU; in Evergreen, ~69,000 BTU.
Related: AFUE, Heat Exchanger, Inducer Motor, Flame Sensor. See also: furnace repair, furnace installation.
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Right Way Mechanical is a family-owned HVAC contractor serving Wheat Ridge, Arvada, west Denver, and the Colorado foothills.