When the weather is cooling off, you might be concerned about how you’ll prepare your heating and cooling. After all, HVAC bills frequently contribute a significant piece of your monthly electric bill. To figure out new ways to save, some homeowners look closely at their thermostat. Could there be a setting they can use to improve efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what can the fan setting provide for the HVAC system? This guide should help. We’ll walk through just what the fan setting is and how you can use it to cut costs in the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the bulk of thermostats, the fan setting means that the HVAC blower fan remains on. Some furnaces can generate heat at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan through a heating or cooling cycle and switch it off once the cycle is complete.

There are advantages and disadvantages to trying the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort requirements.

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more balanced by enabling the fan to keep running.
  • Indoor air quality should improve because continuous airflow will keep moving airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps expand its life span. As the air handler is often connected to the furnace, this means you can avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A constant fan could increase your energy costs somewhat.
  • Constant airflow may clog your air filter up more quickly, increasing the frequency you’ll need to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

During the summer, warm air may persist in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might draw this warm air into the rest of your home, pushing the HVAC system to run longer to keep up with the preferred temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear increases.

The opposite can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan setting on will sometimes pump more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide if you should switch to the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes deal with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help lessen these changes by steadily refreshing each room’s supply of air.