When the weather begins to cool off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC costs frequently contribute a big piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some homeowners take a closer look at their thermostat. Is there a setting they should use to increase efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what does the fan setting offer for an HVAC system? This guide should help. We’ll share just what the fan setting is and whether you can use it to reduce costs in the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting signifies that the air handler’s blower fan remains on. Some furnaces will operate at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan over a heating or cooling cycle and shut it off once the cycle is over.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by allowing the fan to keep circulating air.
  • Indoor air quality can increase as steady airflow will keep moving airborne contaminants into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is usually connected to the furnace, this means you could avoid needing furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan will likely increase your energy costs slightly.
  • Nonstop airflow may clog your air filter in a shorter amount of time, increasing the frequency you should replace it.

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

Through the summer, warm air can persist in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system may draw this warm air into the rest of your home, pushing the HVAC system to run longer to maintain the preferred temperature. In serious heat, this could lead to needing AC repair more often as wear and tear grows.

The reverse can take place over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way 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 keep warm.

If you’re still trying to decide if you should use the fan/on setting, don’t forget that every home and family’s comfort needs will vary. 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 can help to improve indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Lots 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 should help limit these changes by consistently refreshing each room’s supply of air.