Once the weather starts to cool off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC costs can contribute a big chunk of your monthly electric bill. To learn new ways to save, some owners look closely at their thermostat. Could there be a setting they can use to improve 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 offer for an HVAC system? This guide should help. We’ll share what exactly the fan setting is and when you can use it to reduce costs during the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For most thermostats, the fan setting signifies that the system’s blower fan remains on. Certain furnaces can operate at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and switch it off when the cycle is finished.

There are advantages and disadvantages to trying the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your distinct comfort preferences.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep generating airflow.
  • Indoor air quality will be highest because constant airflow will keep moving airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is often connected to the furnace, this means you can prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan will likely increase your energy bills slightly.
  • Constant airflow may clog your air filter in a shorter amount of time, increasing the frequency you should 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 like the attic or an attached garage. If you keep the fan running, your HVAC system may draw this warm air into the rest of your home, compelling the HVAC system to run longer to maintain the set temperature. In serious heat, this can lead to needing AC repair more quickly as wear and tear gets worse.

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

If you’re still trying to decide if you should try the fan/on setting, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could work for you if:

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

Your home experiences 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 might help limit these changes by steadily refreshing each room’s supply of air.