As the weather is cooling off, you may be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses can contribute a big portion 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 improve efficiency?

The bulk of thermostats have 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 can 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 signifies that the HVAC blower fan stays on. Some furnaces can run at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will start the fan through a heating or cooling cycle and switch it off after the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by allowing the fan to keep running.
  • Indoor air quality will be highest as continuous airflow will keep forcing airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. Since the air handler is usually a component of the furnace, this means you can avoid needing furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan will likely raise your energy bills by a small margin.
  • Constant airflow can clog your air filter up more quickly, increasing the frequency you should 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 can linger in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to work harder to maintain the set temperature. In severe heat, this could result in needing AC repair more quickly as wear and tear grows.

The reverse can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on may pump 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 switch to the fan/on setting, don’t forget 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 other 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 deal with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by constantly refreshing each room’s airflow.