When the weather is cooling off, you are probably thinking about how you’ll make the most of your heating and cooling. After all, HVAC expenses can make up a significant piece of your monthly electric bill. To figure out new ways to save, some owners take a closer look at their thermostat. Is there a setting they should use to increase efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what can the fan setting offer for your HVAC system? This guide should help. We’ll share just what the fan setting is and when you can use it to save money in the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the HVAC blower fan remains on. A few furnaces can generate heat at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan during a heating or cooling cycle and shut it off when the cycle is over.

There are benefits and drawbacks to using the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort requirements.

Advantages to using 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 should improve since constant airflow will keep moving airborne contaminants into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is typically part of the furnace, this means you might avoid needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A continuous fan will likely raise your energy expenses by a small margin.
  • Constant airflow may clog your air filter in a shorter amount of time, 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 may linger in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the preferred temperature. In severe heat, this may result in needing AC repair more often as wear and tear grows.

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

If you’re still trying to decide if you should use 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 other respiratory conditions can be tough on the family. Leaving the fan on is more likely to enhance indoor air quality, helping your family breathe easier.

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