When the weather starts to cool off, you may be concerned about how you’ll prepare your heating and cooling. After all, HVAC costs can add up to a significant chunk of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners take a closer look at their thermostat. Could there be a setting they could use to increase efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what will the fan setting provide for an HVAC system? This guide can help. We’ll review what exactly the fan setting is and whether you can use it to save money over the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting means that the HVAC blower fan stays on. A few furnaces will generate heat at a low level in this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will run the fan over a heating or cooling cycle and switch it off after the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by allowing the fan to keep running.
  • Indoor air quality should improve since continuous airflow will keep forcing airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps expand its life span. Because the air handler is typically part of the furnace, this means you might prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan will likely add to your energy costs by a small margin.
  • Nonstop airflow can clog your air filter up more quickly, increasing the frequency you should 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 can persist in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the desired temperature. In severe heat, this may result in needing AC repair more often as wear and tear grows.

The reverse can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way 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 decide if you should use the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be ideal for you if:

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

Your home has hot and cold spots. Many homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help lessen these changes by steadily refreshing each room’s airflow.