Article #138 - Heating and Cooling Equipment Efficiency
High efficiency equipment costs more than standard models but reducing equipment size through energy improvements to the building envelope offsets this extra cost.
AFUE (annual fuel utilization efficiency) - measures the efficiency of furnaces. Units range from a low of 78% to mid-efficiency of 82% to high-efficiency of over 92%. AFUE does not measure the electrical consumption of the furnace blower. An inefficient blower can waste hundreds of dollars over its life. Use the manufacturer's data sheets to compare blower efficiency as well as AFUE.
HSPF (heating season performance factor) - measures the efficiency of an electric heat pump in heating mode. Units range from a low of 6.8 to mid-efficiency of 7.2 to high efficiency of 8.0.
SEER (seasonal energy efficiency ratio) - measures the cooling efficiency of an air conditioner or heat pump. Units range from a low of 10 to mid-efficiency of 12 to high-efficiency of over 13.
Reducing the size of heating and cooling equipment can help pay for energy improvements to the building envelope. Manual J calculation of equipment size is required for correct sizing.
This article is an exerpt from the Energy Checklist: Energy Efficient Construction
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