When the weather starts to cool off, you may be thinking about how you’ll prepare your heating and cooling. After all, HVAC bills can add up to a big portion of your monthly electric bill. To learn new ways to reduce costs, some people look closely at their thermostat. Maybe there’s a setting they could use to improve efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what can the fan setting provide for the HVAC system? This guide can help. We’ll share precisely what the fan setting is and how you can use it to reduce costs over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the HVAC blower fan stays on. Certain furnaces will operate at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and turn it off after 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 requirements.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more consistent by allowing the fan to keep running.
  • Indoor air quality should improve since constant airflow will keep moving airborne pollutants 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 often connected to the furnace, this means you might avoid needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A constant fan will likely add to your energy bills slightly.
  • Continuous airflow may clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

Through the summer, warm air will sometimes linger 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, pushing the HVAC system to work harder to preserve the desired temperature. In severe heat, this can result in needing AC repair more often as wear and tear grows.

The reverse can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually flow into the rest of your home. Keeping the fan on could draw more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to figure out if you should try the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be ideal for you if:

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

Your home has hot and cold spots. Many homes wrestle with difficult 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 steadily refreshing each room’s supply of air.