When 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 expenses routinely add up to a large chunk of your monthly electric bill. To try and find ways to reduce costs, some homeowners look closely at their thermostat. Maybe there’s a setting they could use to boost efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what will the fan setting offer for your HVAC system? This guide will help. We’ll review just what the fan setting is and how you can use it to cut costs during the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting means that the HVAC blower fan remains on. Some furnaces may continue to run at a low level with this setting, but in general 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 finished.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more uniform by allowing the fan to keep circulating air.
  • Indoor air quality can increase because steady airflow will keep forcing airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps expand its life span. Because the air handler is typically connected to the furnace, this means you can prevent the need for furnace repair.

Downsides to switching to the Fan/On setting:

  • A continuous fan will likely increase your energy costs somewhat.
  • Nonstop airflow can clog your air filter up more quickly, increasing the frequency you’ll need to replace it.

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

Through the summer, warm air will sometimes persist in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system can pull this warm air into the rest of your home, compelling the HVAC system to run longer to maintain the set temperature. In serious heat, this can lead to needing AC repair more often as wear and tear gets worse.

The opposite can take place in 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 will sometimes 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 try the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be ideal for you if:

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

Your home experiences hot and cold spots. Lots of homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help limit these changes by consistently refreshing each room’s ventilation.