Once the weather begins to cool off, you might be thinking about how you’ll make the most of your heating and cooling. After all, HVAC costs routinely contribute a significant piece of your monthly electric bill. To learn new ways to reduce costs, some owners look closely at their thermostat. Could there be a setting they should use to improve efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what does the fan setting provide for your HVAC system? This guide should help. We’ll walk through precisely what the fan setting is and whether you can use it to save money over the summer or winter.

What Is the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting indicates that the HVAC blower fan stays on. Certain furnaces can generate heat at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan over a heating or cooling cycle and switch it off when the cycle is finished.

There are pros and cons to trying the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort requirements.

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more uniform by enabling the fan to keep generating airflow.
  • Indoor air quality should improve as constant airflow will keep passing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the system’s fan helps expand its life span. Because the air handler is usually a component of the furnace, this means you could avoid needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A continuous fan will likely add to your energy bills slightly.
  • Nonstop airflow can clog your air filter soon, 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

Through the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system may pull this warm air into the rest of your home, forcing the HVAC system to work harder to keep up with the preferred temperature. In severe heat, this may result in needing AC repair more often as wear and tear gets worse.

The reverse can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Leaving the fan running could draw more cold air upward, increasing the amount of heating you need to stay warm.

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

Someone in your household suffers from allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on should help to increase indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. All kinds 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 should help minimize these changes by consistently refreshing each room’s supply of air.