Once the weather is cooling off, you may be concerned about how you’ll prepare your heating and cooling. After all, HVAC costs frequently contribute a big chunk of your monthly electric bill. To learn new ways to save, some owners look closely at their thermostat. Is there a setting they can use to boost efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what will the fan setting offer for an HVAC system? This guide can help. We’ll review what exactly the fan setting is and when you can use it to reduce costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting signifies that the air handler’s blower fan remains on. Some furnaces will generate heat at a low level in this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will start the fan over a heating or cooling cycle and shut it off after the cycle is finished.

There are advantages and disadvantages to trying the fan setting on your thermostat, and the ideal option {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 permitting the fan to keep circulating air.
  • Indoor air quality will be highest because steady airflow will keep moving airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the system's fan helps extend its life span. Because the air handler is typically connected to the furnace, this means you could prevent the need for furnace repair.

Downsides to utilizing the Fan/On setting:

  • A continuous fan can add to 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

During the summer, warm air can stick around in unfinished spaces including 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, forcing the HVAC system to work more to maintain the set temperature. In extreme heat, this can lead to needing AC repair more often as wear and tear increases.

The opposite can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Leaving the fan setting on may pull more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might work for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Many homes wrestle 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 supply of air.