When the weather is cooling off, you might be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses routinely contribute a significant piece of your monthly electric bill. To learn new ways to reduce costs, some people look closely at their thermostat. Could there be a setting they should use to improve efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what does the fan setting provide for your HVAC system? This guide should help. We’ll review just what the fan setting is and how you can use it to save money during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the system's blower fan stays on. A few furnaces will run at a low level with this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and turn it off after the cycle is over.

There are benefits and drawbacks to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort preferences.

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by enabling the fan to keep running.
  • 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 HVAC fan helps extend its life span. Since the air handler is usually connected to the furnace, this means you could prevent the need for furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan could add to your energy expenses slightly.
  • Nonstop airflow could clog your air filter in a shorter amount of time, 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 may stick around in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system can pull this warm air into the rest of your home, forcing the HVAC system to work more to keep up with the set temperature. In serious heat, this could result in needing AC repair more regularly as wear and tear increases.

The opposite can happen during the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually flow into the rest of your home. Leaving the fan running could draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should use the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could 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 deals with 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 can help lessen these changes by steadily refreshing each room’s supply of air.