Once the weather starts to cool off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC costs routinely add up to a large portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners look closely at their thermostat. Could there be a setting they could use to improve efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting offer for an HVAC system? This guide can help. We’ll walk through just what the fan setting is and whether you can use it to save money during the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the air handler’s blower fan keeps running. A few furnaces can generate heat at a low level with this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will turn on the fan through a heating or cooling cycle and turn it off after the cycle is over.

There are advantages and disadvantages to trying the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort preferences.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more balanced by enabling the fan to keep running.
  • Indoor air quality will be highest because steady airflow will keep moving airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps extend its life span. Since the air handler is often connected to the furnace, this means you can avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A nonstop fan can add to your energy bills somewhat.
  • Nonstop airflow could clog your air filter soon, 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

During the summer, warm air can stick around in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system might pull this warm air into the rest of your home, compelling the HVAC system to work more to maintain the desired temperature. In severe heat, this can result in needing AC repair more often as wear and tear gets worse.

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

If you’re still trying to determine if you should switch to the fan/on setting, remember 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 deals with allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many 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 limit these changes by steadily refreshing each room’s ventilation.