When the weather starts to cool off, you might be wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely add up to a big piece of your monthly electric bill. To figure out new ways to save, some homeowners look closer at their thermostat. Maybe there’s a setting they should use to boost efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting provide for the HVAC system? This guide should help. We’ll walk through precisely what the fan setting is and when you can use it to save money during the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting means that the system's blower fan stays on. Some furnaces may continue to operate at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will start the fan through a heating or cooling cycle and switch it off after the cycle is finished.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by enabling the fan to keep circulating air.
  • Indoor air quality should improve as steady airflow will keep forcing airborne particles into the air filter.
  • Fewer start-stop cycles for the HVAC fan helps extend its life span. Since the air handler is often connected to the furnace, this means you can avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A constant fan will likely raise your energy bills by a small margin.
  • Constant airflow may clog your air filter in a shorter amount of time, 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

Through the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move this warm air into the rest of your home, compelling the HVAC system to work more to preserve the set temperature. In extreme heat, this could lead to needing AC repair more regularly as wear and tear grows.

The opposite can occur in the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan setting on may draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to figure out if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are different. 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 tough on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds of homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by steadily refreshing each room’s supply of air.