When the weather begins to cool off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC costs routinely add up to a large piece of your monthly electric bill. To try and find ways to save, some owners look closer at their thermostat. Maybe there’s a setting they could use to improve efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting offer for the HVAC system? This guide can help. We’ll walk through just what the fan setting is and whether you can use it to save money during the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting means that the air handler’s blower fan keeps running. Certain furnaces will run at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan through a heating or cooling cycle and switch it off once the cycle is complete.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep generating airflow.
  • Indoor air quality should improve because steady airflow will keep moving airborne particles through the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps expand its life span. Since the air handler is typically part of the furnace, this means you could avoid needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A continuous fan could raise your energy bills by a small margin.
  • Constant airflow may clog your air filter soon, 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 Each Season

Through the summer, warm air will sometimes stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system may gradually move this warm air into the rest of your home, pushing the HVAC system to work more to maintain the preferred temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear gets worse.

The opposite can take place over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on could draw more cold air upward, increasing the amount of heating you need to stay warm.

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

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

Your home deals with hot and cold spots. Lots of homes deal with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help limit these changes by consistently refreshing each room’s supply of air.