As the weather is cooling off, you may be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses can add up to a significant piece of your monthly electric bill. To figure out new ways to reduce costs, some homeowners take a closer look at their thermostat. Could there be a setting they can use to improve efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what does the fan setting provide for the HVAC system? This guide can help. We’ll share just what the fan setting is and whether you can use it to reduce costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting signifies that the HVAC blower fan remains on. A few furnaces will run at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and turn it off after the cycle is complete.

There are benefits and drawbacks to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your personal comfort needs.

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by enabling the fan to keep circulating air.
  • Indoor air quality should improve as continuous airflow will keep passing airborne contaminants into the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps expand its life span. Because the air handler is often a component of the furnace, this means you can prevent the need for furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A constant fan will likely add to your energy expenses slightly.
  • Continuous airflow may clog your air filter in a shorter amount of time, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

Through the summer, warm air can persist in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system can pull this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the set temperature. In serious heat, this can lead to needing AC repair more quickly as wear and tear gets worse.

The opposite can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running will sometimes pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should try the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may work for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on can help to enhance indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots of homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help limit these changes by steadily refreshing each room’s ventilation.