Once the weather is cooling off, you may be thinking about how you’ll prepare your heating and cooling. After all, HVAC expenses frequently add up to a large piece of your monthly electric bill. To try and find ways to reduce costs, some homeowners look closer at their thermostat. Maybe there’s a setting they can use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what does the fan setting provide for an HVAC system? This guide should help. We’ll review just what the fan setting is and whether you can use it to cut costs over the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the bulk of thermostats, the fan setting indicates that the air handler’s blower fan stays on. A few furnaces will generate heat at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will start the fan through a heating or cooling cycle and switch it off once the cycle is finished.

There are benefits and drawbacks to using the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your unique comfort requirements.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by enabling the fan to keep running.
  • Indoor air quality should improve as constant airflow will keep passing airborne contaminants into the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps expand its life span. As the air handler is typically connected to the furnace, this means you might avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A constant fan will likely raise your energy costs slightly.
  • Constant 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 Summer/Winter

In 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 work more to keep up with the preferred temperature. In extreme heat, this could result in needing AC repair more regularly as wear and tear gets worse.

The reverse can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which may 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 stay warm.

If you’re still trying to figure out if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be best for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.

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