When the weather is cooling off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC costs frequently make up a large portion of your monthly electric bill. To figure out new ways to reduce costs, some owners look closely at their thermostat. Is there a setting they should use to improve efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what does the fan setting offer for your HVAC system? This guide will help. We’ll share just what the fan setting is and whether you can use it to save money during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the system's blower fan stays on. Certain furnaces may continue to generate heat at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will turn on the fan through a heating or cooling cycle and switch it off once the cycle is complete.

There are pros and cons to using the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort preferences.

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more consistent by permitting the fan to keep generating airflow.
  • Indoor air quality can increase because continuous airflow will keep forcing airborne particles through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. As the air handler is often a component of the furnace, this means you could avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A nonstop fan will likely add to your energy costs somewhat.
  • Nonstop airflow may clog your air filter in a shorter amount of time, increasing the frequency you’ll need to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

Through the summer, warm air will sometimes stick around 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 work harder to keep up with the preferred temperature. In extreme heat, this could lead to needing AC repair more quickly as wear and tear grows.

The opposite can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running may pump more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine if you should use the fan/on setting, don’t forget 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 deals with allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Many homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by consistently refreshing each room’s ventilation.