As the weather is cooling off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC bills frequently contribute a large piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some homeowners look closer at their thermostat. Could there be a setting they could use to boost efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what can the fan setting provide for the HVAC system? This guide will help. We’ll walk through precisely what the fan setting is and when you can use it to cut costs over the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting means that the HVAC blower fan stays on. Certain furnaces may continue to generate heat at a low level in this setting, but in general heating or cooling isn’t being produced. 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 advantages and disadvantages to using the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your personal comfort requirements.

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 should improve because constant airflow will keep forcing airborne particles through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is often part of the furnace, this means you could minimize the risk of needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A continuous fan will likely raise your energy expenses slightly.
  • Constant airflow may clog your air filter up more quickly, 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

During 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 might gradually move this warm air into the rest of your home, forcing the HVAC system to work more to keep up with the preferred temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear increases.

The reverse can occur in the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan running may pull more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine 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 could be ideal 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 experiences hot and cold spots. Lots of homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help minimize these changes by consistently refreshing each room’s ventilation.