When the weather begins to cool off, you may be thinking about how you’ll prepare your heating and cooling. After all, HVAC bills can make up a large chunk of your monthly electric bill. To learn new ways to save, some people look closer at their thermostat. Is there a setting they should use to improve efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what can the fan setting provide for the HVAC system? This guide can help. We’ll walk through precisely what the fan setting is and whether you can use it to cut costs over the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting signifies that the air handler’s blower fan stays on. A few furnaces can operate at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will run the fan over a heating or cooling cycle and shut it off after the cycle is over.

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 using the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by permitting the fan to keep circulating air.
  • Indoor air quality will be highest as steady airflow will keep forcing airborne particles into 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 could minimize the risk of needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A nonstop fan can raise your energy costs somewhat.
  • Constant airflow may clog your air filter up more quickly, 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

Through the summer, warm air can stick around in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to work harder to keep up with the set temperature. In serious heat, this could lead to needing AC repair more quickly as wear and tear grows.

The opposite can occur over 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 setting on could pump 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 are different. Leaving the HVAC system’s fan on could be ideal 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 can 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 shift to a temperature different from the rest of the house. The fan setting should help minimize these changes by consistently refreshing each room’s ventilation.