When the weather begins to cool off, you may be thinking about how you’ll prepare your heating and cooling. After all, HVAC expenses frequently add up to a significant portion of your monthly electric bill. To figure out new ways to save, some people look closely at their thermostat. Is there a setting they can use to increase efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what can the fan setting offer for your HVAC system? This guide should help. We’ll review what exactly the fan setting is and how you can use it to save money in the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the system's blower fan keeps running. Some furnaces may continue to run at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan during a heating or cooling cycle and turn it off when the cycle is complete.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more balanced by allowing the fan to keep running.
  • Indoor air quality should improve as steady airflow will keep moving airborne pollutants through the air filter.
  • Fewer start-stop cycles for the system's fan helps expand its life span. Because the air handler is typically a component of the furnace, this means you could prevent the need for furnace repair.

Downsides to using the Fan/On setting:

  • A nonstop fan could add to your energy expenses slightly.
  • Continuous airflow could clog your air filter soon, increasing the frequency you will want to replace it.

Should My Thermostat Be on Fan or Auto in Summer/Winter

In the summer, warm air may stick around in unfinished spaces such as 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, pushing the HVAC system to run longer to maintain the desired temperature. In severe heat, this can result in 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 drift into the rest of your home. Keeping the fan on may draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to decide 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 could be best for you if:

Someone in your household deals with allergies. Allergies and similar 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 deals with hot and cold spots. All kinds of homes wrestle 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 consistently refreshing each room’s airflow.