Once the weather starts to cool off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC expenses routinely contribute a big portion of your monthly electric bill. To figure out new ways to reduce costs, some homeowners take a closer look at their thermostat. Could there be a setting they could use to improve efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what does the fan setting offer for an HVAC system? This guide will help. We’ll walk through what exactly the fan setting is and when you can use it to reduce costs over the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the HVAC blower fan stays 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, conversely, will run the fan over a heating or cooling cycle and turn it off after the cycle is over.

There are benefits and drawbacks to switching on the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your distinct comfort needs.

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more balanced by enabling the fan to keep generating airflow.
  • Indoor air quality can increase because continuous airflow will keep forcing airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps expand its life span. Because the air handler is usually a component of the furnace, this means you could minimize the risk of needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan could add to your energy costs by a small margin.
  • Nonstop airflow can clog your air filter soon, 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 Each Season

Through the summer, warm air will sometimes persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system can gradually move this warm air into the rest of your home, compelling the HVAC system to work more to maintain the desired temperature. In severe heat, this may result in needing AC repair more regularly as wear and tear increases.

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

If you’re still trying to decide if you should use the fan/on setting, remember 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 tough on the family. Leaving the fan on is more likely to enhance indoor air quality, helping your family breathe easier.

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