Furnace fans use electricity to circulate air heated by the furnace through a home’s duct system into the living space. For homes with central air conditioning, the furnace fan also serves to circulate cooled air during the cooling season.
In 2014, DOE established the first national efficiency standards for furnace fans. The new standards, which took effect in 2019, specify a maximum fan energy rating (FER) that varies based on the airflow provided by the furnace fan. FER is expressed in terms of power consumption (W) per delivered airflow (1000 cfm) and incorporates energy consumption in three different modes: heating, cooling, and constant circulation. The standards will reduce the electricity consumption of furnace fans by about 50%.
Furnace fans are among the largest users of electricity in a typical household. Typical inefficient furnace fans used in homes today consume about 1,000 kWh of electricity per year on average, or nearly 10% of an average household’s electricity use. The efficiency of furnace fans can be significantly improved by using brushless permanent magnet motors, which are much more efficient than typical permanent split capacitor (PSC) motors.