Once the weather begins to cool off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses frequently contribute a big portion of your monthly electric bill. To learn new ways to save, some homeowners look closely at their thermostat. Is there a setting they can use to increase efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what can the fan setting provide for an HVAC system? This guide can help. We’ll share just what the fan setting is and whether you can use it to cut costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the HVAC blower fan keeps running. A few furnaces will operate at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and switch it off once the cycle is finished.

There are pros and cons to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your personal comfort requirements.

Advantages to switching to 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 should improve since constant airflow will keep moving airborne contaminants into the air filter.
  • A smaller number of start-stop cycles for the system's fan helps extend 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 could raise your energy bills by a small margin.
  • Constant airflow can 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 Summer/Winter

In the summer, warm air can stick around in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might pull this warm air into the rest of your home, compelling the HVAC system to run longer to keep up with the set temperature. In severe 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 like a basement will hold onto cooler air, which may 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 switch to the fan/on setting, remember 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 stressful on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds of homes deal with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help lessen these changes by steadily refreshing each room’s airflow.