As the weather starts to cool off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC costs can make up a significant chunk of your monthly electric bill. To learn new ways to reduce costs, some owners take a closer look at their thermostat. Maybe there’s a setting they should use to boost efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what will the fan setting offer for your HVAC system? This guide should help. We’ll walk through precisely what 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 the bulk of thermostats, the fan setting means that the HVAC blower fan remains on. Some furnaces will run at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will run the fan during a heating or cooling cycle and switch it off once the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest because steady airflow will keep moving airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is typically a component of the furnace, this means you might 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 up more quickly, 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

Through the summer, warm air will sometimes persist in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system can pull this warm air into the rest of your home, pushing the HVAC system to work harder to keep up with the set temperature. In extreme heat, this may lead to needing AC repair more regularly as wear and tear grows.

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

If you’re still trying to determine 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 might work for you if:

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

Your home has hot and cold spots. All kinds of homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help lessen these changes by steadily refreshing each room’s airflow.