When the weather starts to cool off, you may be concerned about how you’ll make the most of your heating and cooling. After all, HVAC expenses routinely make up a significant chunk of your monthly electric bill. To learn new ways to reduce costs, some homeowners look closer at their thermostat. Could there be a setting they can use to boost efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what will the fan setting offer for your HVAC system? This guide will help. We’ll share just what the fan setting is and when you can use it to reduce costs over the summer or winter.

Should I Use My Thermostat's Fan Setting?

For most thermostats, the fan setting means that the air handler’s blower fan stays on. Certain furnaces can run at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and turn it off after the cycle is finished.

There are advantages and disadvantages to trying the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your unique comfort preferences.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest because steady airflow will keep passing airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. Since the air handler is typically connected to the furnace, this means you could minimize the risk of needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A nonstop fan could increase your energy expenses by a small margin.
  • Continuous 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 Summer/Winter

In the summer, warm air can persist in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to work harder to keep up with the desired temperature. In severe heat, this can lead to needing AC repair more often as wear and tear increases.

The reverse can occur over the winter. Cooler spaces like 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 determine 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 could work 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 should help to enhance indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Many homes deal with stubborn 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 consistently refreshing each room’s ventilation.