As the weather starts to cool off, you are probably thinking about how you’ll make the most of your heating and cooling. After all, HVAC expenses frequently add up to a significant chunk of your monthly electric bill. To figure out new ways to lower their HVAC bill, some homeowners look closer at their thermostat. Could there be a setting they could use to increase efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what will the fan setting offer for an HVAC system? This guide can help. We’ll review precisely what the fan setting is and how you can use it to save money over the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting means that the HVAC blower fan stays on. A few furnaces will operate at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will start the fan through a heating or cooling cycle and turn it off once the cycle is over.

There are pros and cons to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort requirements.

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more uniform by allowing the fan to keep circulating air.
  • Indoor air quality should improve because continuous airflow will keep forcing airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps lengthen its life span. Because the air handler is usually connected to the furnace, this means you could avoid needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A continuous fan could add to your energy expenses by a small margin.
  • Constant airflow may 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

During the summer, warm air may stick around in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system may draw this warm air into the rest of your home, pushing the HVAC system to run longer to preserve the preferred temperature. In extreme heat, this could lead to needing AC repair more quickly as wear and tear gets worse.

The opposite can occur in the winter. Cooler spaces such as 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 figure out if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might 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 enhance indoor air quality, helping your family breathe easier.

Your home experiences 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 should help limit these changes by consistently refreshing each room’s ventilation.