Once the weather starts to cool off, you are probably thinking about how you’ll prepare your heating and cooling. After all, HVAC expenses can add up to a big piece of your monthly electric bill. To try and find ways to save, some people look closely at their thermostat. Could there be a setting they could use to increase efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what does the fan setting offer for your HVAC system? This guide can help. We’ll review what exactly the fan setting is and whether you can use it to cut costs during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the air handler’s blower fan stays on. A few 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, in contrast, will run the fan over a heating or cooling cycle and shut it off when 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 unique comfort preferences.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more consistent by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest because continuous airflow will keep moving airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. As the air handler is usually a component of the furnace, this means you might prevent the need for furnace repair.

Downsides to utilizing the Fan/On setting:

  • A nonstop fan can raise your energy bills somewhat.
  • Nonstop airflow may clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

In the summer, warm air will sometimes persist in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the desired temperature. In extreme heat, this can lead to needing AC repair more quickly as wear and tear increases.

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

If you’re still trying to figure out 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 may work for you if:

Someone in your household has allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on is more likely to increase 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 return to a temperature different from the rest of the house. The fan setting can help minimize these changes by consistently refreshing each room’s airflow.