As the weather is cooling off, you might be wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills can add up to a significant piece of your monthly electric bill. To learn new ways to reduce costs, some owners look closer at their thermostat. Could there be a setting they should use to increase efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what does the fan setting offer for an HVAC system? This guide should help. We’ll share what exactly the fan setting is and when you can use it to reduce costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting indicates that the HVAC blower fan keeps running. Certain furnaces can generate heat at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will start the fan through a heating or cooling cycle and turn it off when the cycle is over.

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 preferences.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep circulating air.
  • Indoor air quality will be highest because constant airflow will keep moving airborne pollutants into the air filter.
  • Fewer start-stop cycles for the system’s fan helps extend its life span. Since the air handler is often a component of the furnace, this means you could minimize the risk of needing furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan can add to your energy costs by a small margin.
  • Nonstop airflow can clog your air filter up more quickly, increasing the frequency you will want to replace it.

Which Setting for My Thermostat? Fan or Auto in Summer/Winter

During the summer, warm air will sometimes stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system may gradually move this warm air into the rest of your home, pushing the HVAC system to work harder to maintain the set temperature. In serious heat, this can lead to needing AC repair more often as wear and tear gets worse.

The opposite can happen in the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Keeping the fan on will sometimes draw 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, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could be best for you if:

Someone in your household deals with allergies. Allergies and other respiratory conditions can be tough 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. Lots of homes deal with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help minimize these changes by steadily refreshing each room’s ventilation.