Once the weather starts to cool off, you are probably wondering about how you’ll make the most of your heating and cooling. After all, HVAC costs can make up a significant piece of your monthly electric bill. To figure out new ways to reduce costs, some people look closely at their thermostat. Maybe there’s a setting they could use to increase efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what does the fan setting offer for the HVAC system? This guide should help. We’ll walk through just what the fan setting is and how you can use it to save money over 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 stays on. A few furnaces can operate at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will run the fan over a heating or cooling cycle and shut it off once the cycle is complete.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more uniform by permitting the fan to keep circulating air.
  • Indoor air quality can increase because constant airflow will keep forcing airborne pollutants into the air filter.
  • Fewer start-stop cycles for the HVAC fan helps expand its life span. As the air handler is typically part of the furnace, this means you can prevent the need for furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A continuous fan will likely raise your energy bills slightly.
  • Constant airflow may clog your air filter soon, increasing the frequency you’ll need 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 such as the attic or an attached garage. If you keep the fan running, your HVAC system might draw this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the set temperature. In serious heat, this could lead to needing AC repair more quickly as wear and tear grows.

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

If you’re still trying to decide if you should switch to the fan/on setting, don’t forget that every home and family’s comfort needs are different. 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 should help to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds of homes deal with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help limit these changes by constantly refreshing each room’s supply of air.