As the weather begins to cool off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently add up to a large piece of your monthly electric bill. To try and find ways to save, some homeowners take a closer look at their thermostat. Maybe there’s a setting they should use to boost efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting offer for the HVAC system? This guide should help. We’ll review just what the fan setting is and whether you can use it to cut costs during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the system’s blower fan remains on. Some furnaces may continue to generate heat at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and switch it off once the cycle is finished.

There are advantages and disadvantages to switching on the fan setting on your thermostat, and whether you do or don’t {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 uniform by enabling the fan to keep generating airflow.
  • Indoor air quality will be highest as constant airflow will keep passing airborne contaminants through 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 part of the furnace, this means you can avoid needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan could increase your energy costs by a small margin.
  • Nonstop airflow can clog your air filter in a shorter amount of time, 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 may stick around in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system may draw this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the set temperature. In extreme heat, this may result in needing AC repair more often as wear and tear gets worse.

The opposite can occur over the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually flow into the rest of your home. Leaving the fan setting on could 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, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could 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 should help to enhance indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes wrestle with stubborn hot and cold spots that quickly shift 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.