When the weather begins to cool off, you are probably concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC costs routinely add up to a big piece of your monthly electric bill. To figure out new ways to save, some people look closer at their thermostat. Is there a setting they could use to improve efficiency?

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

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the air handler’s blower fan keeps running. Some furnaces will operate at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and shut it off after the cycle is finished.

There are pros and cons to switching on the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your personal comfort preferences.

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more balanced by allowing the fan to keep generating airflow.
  • Indoor air quality can increase as continuous airflow will keep passing airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is usually part of the furnace, this means you could avoid needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A nonstop fan will likely raise your energy expenses slightly.
  • Nonstop 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 may stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move 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 lead to needing AC repair more often as wear and tear increases.

The opposite can occur in the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow into the rest of your home. Leaving the fan running could pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine 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 might work for you if:

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

Your home experiences hot and cold spots. Lots of homes wrestle 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 airflow.