As the weather starts to cool off, you might be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC costs routinely contribute a large portion of your monthly electric bill. To figure out new ways to lower their HVAC bill, some people look closely at their thermostat. Maybe there’s a setting they should use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what can the fan setting offer for the HVAC system? This guide can help. We’ll share what exactly the fan setting is and when you can use it to cut costs during the summer or winter.

Should I Use My Thermostat's Fan Setting?

For most thermostats, the fan setting signifies that the system's blower fan stays on. A few furnaces can generate heat at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and turn it off when the cycle is complete.

There are pros and cons to trying the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more consistent by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest because constant airflow will keep passing airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is usually a component of the furnace, this means you could avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A constant fan will likely raise your energy bills slightly.
  • Continuous 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 including the attic or an attached garage. If you use the fan setting, your HVAC system may pull this warm air into the rest of your home, forcing the HVAC system to work harder to keep up with the preferred temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear gets worse.

The opposite can take place over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Leaving the fan running could pull more cold air upward, increasing the amount of heating you need to stay warm.

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

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

Your home experiences hot and cold spots. Many homes wrestle with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help limit these changes by consistently refreshing each room’s ventilation.