As the weather starts to cool off, you might be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely add up to a large portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some people take a closer look at their thermostat. Could there be a setting they should use to boost efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what can the fan setting offer for an HVAC system? This guide can help. We’ll share precisely what the fan setting is and how you can use it to reduce costs 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 keeps running. Certain furnaces may continue to operate at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and switch it off after the cycle is finished.

There are pros and cons to switching on 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 running.
  • Indoor air quality should improve because steady airflow will keep forcing airborne contaminants through the air filter.
  • Fewer start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is typically part of the furnace, this means you might prevent the need for furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A constant fan can increase your energy expenses by a small margin.
  • Constant airflow can 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

Through the summer, warm air can stick around in unfinished spaces such as 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, pushing the HVAC system to run longer to keep up with the desired temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear increases.

The reverse can take place over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually flow into the rest of your home. Leaving the fan setting on will sometimes pump more cold air upward, increasing the amount of heating you need to remain 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 might be best for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on can 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 should help limit these changes by constantly refreshing each room’s supply of air.