Once the weather is cooling off, you might be concerned about how you’ll prepare your heating and cooling. After all, HVAC expenses can contribute a significant portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some people take a closer look at their thermostat. Is there a setting they should use to boost efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting provide for an HVAC system? This guide will help. We’ll review what exactly the fan setting is and how you can use it to save money during the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the HVAC blower fan keeps running. Certain furnaces can run at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will start the fan over a heating or cooling cycle and switch it off when the cycle is complete.

There are advantages and disadvantages to using 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 every room more uniform by permitting the fan to keep running.
  • Indoor air quality should improve as constant airflow will keep passing airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. Since the air handler is usually connected to the furnace, this means you can avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A constant fan could add to your energy expenses slightly.
  • Nonstop airflow may clog your air filter soon, increasing the frequency you should replace it.

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

In the summer, warm air may persist in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can pull this warm air into the rest of your home, forcing the HVAC system to run longer to keep up with the set temperature. In serious heat, this could lead to needing AC repair more regularly as wear and tear gets worse.

The opposite can occur in 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 setting on may pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide if you should try the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may work for you if:

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

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