Once the weather starts to cool off, you might be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC costs can add up to a significant chunk of your monthly electric bill. To try and find ways to save, some people look closely at their thermostat. Could there be a setting they should use to boost efficiency?

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

Should I Use My Thermostat’s Fan Setting?

For most thermostats, the fan setting signifies that the system’s blower fan remains on. Some furnaces will operate at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will start the fan during a heating or cooling cycle and shut it off when the cycle is over.

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

Advantages to utilizing 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 will be highest because continuous airflow will keep forcing airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps extend its life span. Because the air handler is usually part of the furnace, this means you could minimize the risk of needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A constant fan will likely raise your energy costs slightly.
  • Constant airflow could 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

In the summer, warm air will sometimes stick around in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system might pull this warm air into the rest of your home, pushing the HVAC system to run longer to preserve the desired temperature. In extreme heat, this may result in needing AC repair more often as wear and tear grows.

The opposite can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running may pull 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, don’t forget that every home and family’s comfort needs are different. 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 should help to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help minimize these changes by steadily refreshing each room’s ventilation.