Once the weather begins to cool off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC expenses frequently contribute a big portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners take a closer look 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 running during a normal cycle, what does the fan setting provide for the HVAC system? This guide should help. We’ll review precisely what the fan setting is and how you can use it to save money over the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting indicates that the HVAC blower fan keeps running. Some furnaces may continue to run at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will start the fan over a heating or cooling cycle and shut it off once the cycle is finished.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more balanced by allowing the fan to keep circulating air.
  • Indoor air quality can increase since constant airflow will keep forcing airborne particles through the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps lengthen its life span. Since the air handler is typically connected to the furnace, this means you could minimize the risk of needing furnace repair.

Downsides to using the Fan/On setting:

  • A nonstop fan could increase your energy bills by a small margin.
  • Continuous airflow can clog your air filter up more quickly, 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

In the summer, warm air will sometimes linger in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might pull this warm air into the rest of your home, forcing the HVAC system to work more to preserve the preferred temperature. In severe heat, this may lead to needing AC repair more often as wear and tear gets worse.

The opposite can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually drift 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 figure out 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 might work for you if:

Someone in your household has 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 deals with hot and cold spots. All kinds of homes wrestle with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help minimize these changes by constantly refreshing each room’s ventilation.