When the weather is cooling off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC bills can make up a big portion of your monthly electric bill. To figure out new ways to reduce costs, some homeowners look closely at their thermostat. Maybe there’s a setting they could use to increase efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting provide for the HVAC system? This guide should help. We’ll share what exactly the fan setting is and how you can use it to reduce costs during the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting signifies that the system’s blower fan remains on. Certain furnaces may continue to operate at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and switch it off when the cycle is finished.

There are pros and cons to using the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort preferences.

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep circulating air.
  • Indoor air quality should improve since continuous airflow will keep moving airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps lengthen its life span. Since the air handler is often a component of the furnace, this means you might prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A continuous fan can add to your energy costs slightly.
  • 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

During the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system may pull this warm air into the rest of your home, forcing the HVAC system to run longer to keep up with the desired temperature. In serious heat, this could lead to needing AC repair more often as wear and tear gets worse.

The reverse can take place in 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 could pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to figure out if you should use the fan/on setting, remember 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 suffers from allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Many homes deal with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help lessen these changes by constantly refreshing each room’s airflow.