Once the weather starts to cool off, you may be thinking about how you’ll prepare your heating and cooling. After all, HVAC costs can contribute a big piece of your monthly electric bill. To figure out new ways to lower their HVAC bill, some people take a closer look at their thermostat. Maybe there’s a setting they could use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what does the fan setting provide for your HVAC system? This guide can help. We’ll share just what the fan setting is and whether you can use it to reduce costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the HVAC blower fan remains on. Certain furnaces will run at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will start the fan over a heating or cooling cycle and turn it off once the cycle is finished.

There are benefits and drawbacks to trying the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your personal comfort requirements.

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more balanced by allowing the fan to keep running.
  • Indoor air quality should improve because constant airflow will keep forcing airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps extend its life span. Since the air handler is usually a component of the furnace, this means you could prevent the need for furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan will likely increase your energy bills somewhat.
  • Nonstop airflow may clog your air filter up more quickly, 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 Each Season

Through the summer, warm air will sometimes persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system may draw this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the preferred temperature. In serious heat, this can lead to needing AC repair more often as wear and tear gets worse.

The opposite can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on may pump more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may 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 enhance indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Lots of homes deal with difficult 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 constantly refreshing each room’s ventilation.