When the weather begins to cool off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses can contribute a large portion of your monthly electric bill. To try and find ways to reduce costs, some people look closer at their thermostat. Could there be a setting they can use to boost efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what can the fan setting offer for your HVAC system? This guide will help. We’ll share just what the fan setting is and how you can use it to cut costs in the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the air handler’s blower fan keeps running. Certain furnaces can generate heat 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 shut it off when the cycle is finished.

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 using the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by allowing the fan to keep circulating air.
  • Indoor air quality will be highest since constant airflow will keep moving airborne particles into the air filter.
  • Fewer start-stop cycles for the system's fan helps extend its life span. As the air handler is typically part of the furnace, this means you might prevent the need for furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A nonstop fan can add to your energy costs slightly.
  • Constant airflow could clog your air filter in a shorter amount of time, 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 Each Season

In the summer, warm air may stick around in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to work harder to keep up with the set temperature. In serious heat, this can result in needing AC repair more often as wear and tear increases.

The reverse can take place during 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. Keeping the fan on will sometimes pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide if you should switch to the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might be ideal 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 improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help minimize these changes by consistently refreshing each room’s ventilation.