When the weather starts to cool off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses can add up to a big chunk of your monthly electric bill. To figure out new ways to lower their HVAC bill, some people look closely at their thermostat. Could there be a setting they can 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 will the fan setting offer for your HVAC system? This guide should 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 most thermostats, the fan setting indicates that the HVAC blower fan remains on. Certain furnaces may continue to run at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will run the fan over a heating or cooling cycle and turn it off once the cycle is over.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more consistent by allowing the fan to keep circulating air.
  • Indoor air quality will be highest since continuous airflow will keep moving airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps expand its life span. Because the air handler is typically part of the furnace, this means you might minimize the risk of needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A continuous fan could add to your energy expenses slightly.
  • Continuous airflow could clog your air filter in a shorter amount of time, increasing the frequency you will want to 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 may linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system might draw this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the set temperature. In severe heat, this may result in needing AC repair more often as wear and tear gets worse.

The reverse can occur in the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually flow into the rest of your home. Keeping the fan on could 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 use the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household has 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 deals with hot and cold spots. Many homes wrestle with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help lessen these changes by steadily refreshing each room’s supply of air.