Once the weather starts to cool off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses routinely add up to a significant piece of your monthly electric bill. To learn new ways to save, some homeowners look closely at their thermostat. Could there be a setting they can use to increase efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what will the fan setting offer for the HVAC system? This guide should help. We’ll share precisely what the fan setting is and how you can use it to save money in the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting indicates that the air handler’s blower fan keeps running. Some furnaces will generate heat at a low level in this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will run the fan through a heating or cooling cycle and switch it off when the cycle is finished.

There are benefits and drawbacks to using the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort preferences.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more balanced by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest since constant airflow will keep passing airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the system's fan helps extend its life span. Because the air handler is typically connected to the furnace, this means you can prevent the need for furnace repair.

Downsides to switching to the Fan/On setting:

  • A continuous fan could increase your energy expenses slightly.
  • 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

During the summer, warm air can stick around in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the preferred temperature. In severe heat, this can lead to needing AC repair more quickly as wear and tear gets worse.

The opposite can occur over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift 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 figure out if you should use the fan/on setting, don’t forget 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 deals with allergies. Allergies and other 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 has hot and cold spots. Many homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help lessen these changes by steadily refreshing each room’s ventilation.