Did you know that “Furnace fans consume about 1,000 kilowatt-hours per year, or almost 10% of the total electricity use of an average U.S. home.”? As a comparison, typically a room air conditioner consumes 600kWh per year, a refrigerator is 450kWh per year and a dishwasher is 300kWh per year. Most residential owners of furnace fans are not aware of this because the fan is a component of a larger system and the associated energy consumption with operating the fan is not monitored.
According to ACEEE, there is a new standard that will take effect in 2019 to address the performance and efficiency of furnace fans. “On a national level, DOE estimates that the new standards will reduce electricity consumption by about 500 billion kilowatt-hours over thirty years of sales, an amount equal to the annual electricity use of about 47 million U.S. households, and will save consumers $29 billion. ” Joanna Mauer, Technical Advocacy Manager
What can be done to meet this new standard? Well if your existing fan motor is permanent split capacitor type it may be replaced with a brushless permanent magnet (BPM) motors (depending on age, condition, existing wiring). In addition to improving motors, the standard also includes guidelines on furnace controls: multi-stage or modulating furnaces. Furnaces are commonly setup for on/off operation which is not optimal for matching the furnace output with the actual demand for heat. A more efficient method of operation are multi-stage furnaces that generally operate continuously and improve comfort by reducing temperature swings.