Once the weather starts to cool off, you are probably wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC costs frequently contribute a significant chunk of your monthly electric bill. To figure out new ways to reduce costs, some homeowners take a closer look at their thermostat. Could there be a setting they should use to improve 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 offer for an HVAC system? This guide can help. We’ll walk through what exactly the fan setting is and when you can use it to reduce costs over the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting means that the air handler’s blower fan keeps running. Some furnaces can run at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will run the fan during a heating or cooling cycle and shut it off when the cycle is complete.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by permitting the fan to keep circulating air.
  • Indoor air quality should improve because constant airflow will keep forcing airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is usually connected to the furnace, this means you can minimize the risk of needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A nonstop fan can raise your energy expenses somewhat.
  • Nonstop airflow may 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 will sometimes linger in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to run longer to keep up with the preferred temperature. In extreme heat, this could lead to needing AC repair more often as wear and tear increases.

The opposite can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on will sometimes draw more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to determine 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 could be best for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help limit these changes by consistently refreshing each room’s airflow.