Once the weather starts to cool off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses routinely make up a large portion of your monthly electric bill. To try and find ways to reduce costs, some owners look closely at their thermostat. Is there a setting they can use to improve efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what can the fan setting provide for an HVAC system? This guide can help. We’ll review precisely what the fan setting is and how you can use it to save money during the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For most thermostats, the fan setting indicates that the system’s blower fan keeps running. Certain furnaces can operate at a low level with this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan through a heating or cooling cycle and turn it off when the cycle is over.

There are advantages and disadvantages to trying the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your distinct comfort requirements.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more uniform by enabling the fan to keep circulating air.
  • Indoor air quality will be highest since constant airflow will keep passing airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps extend its life span. Because the air handler is usually a component of the furnace, this means you might minimize the risk of needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A nonstop fan can increase your energy expenses somewhat.
  • Constant airflow could clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.

Should My Thermostat Be on? Fan or Auto in Summer/Winter

During the summer, warm air may stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might pull this warm air into the rest of your home, forcing the HVAC system to work more to preserve the desired temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear increases.

The opposite can occur during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running will sometimes pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine if you should try the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on should help to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes wrestle 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 constantly refreshing each room’s airflow.