As the weather begins to cool off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC costs routinely contribute a large portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners look closely at their thermostat. Is there a setting they could use to boost efficiency?

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

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the HVAC blower fan stays on. Some furnaces can operate at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will run the fan during a heating or cooling cycle and switch it off after the cycle is complete.

There are benefits and drawbacks to using the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your personal comfort needs.

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more consistent by allowing the fan to keep generating airflow.
  • Indoor air quality will be highest because constant airflow will keep passing airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps extend its life span. Because the air handler is typically a component of the furnace, this means you could avoid needing furnace repair.

Downsides to using the Fan/On setting:

  • A nonstop fan will likely increase your energy costs 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 Each Season

Through the summer, warm air can persist 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, forcing the HVAC system to work harder to keep up with the desired temperature. In severe heat, this can result in needing AC repair more quickly as wear and tear increases.

The reverse can occur over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Keeping the fan on will sometimes pump 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, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could work 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 should help to improve indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. All kinds of homes deal with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help minimize these changes by consistently refreshing each room’s supply of air.