Once the weather is cooling off, you are probably wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC bills routinely contribute a large piece of your monthly electric bill. To figure out new ways to save, some people look closely at their thermostat. Is there a setting they can use to improve efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting offer for the HVAC system? This guide will help. We’ll share just what the fan setting is and when you can use it to save money in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting signifies that the HVAC blower fan keeps running. Certain furnaces can operate at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will turn on the fan through a heating or cooling cycle and shut it off after the cycle is finished.

There are benefits and drawbacks to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort needs.

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more uniform by permitting the fan to keep running.
  • Indoor air quality will be highest since constant airflow will keep moving airborne particles through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps expand its life span. As the air handler is often a component of the furnace, this means you can prevent the need for furnace repair.

Drawbacks to switching to the Fan/On setting:

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

Should My Thermostat Be on Fan or Auto in Summer/Winter

During the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system can draw this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the set temperature. In severe heat, this could result in needing AC repair more regularly as wear and tear gets worse.

The reverse can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually drift into the rest of your home. Leaving the fan setting on could draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should switch to the fan/on setting, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could work for you if:

Someone in your household suffers from 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 deals with hot and cold spots. All kinds of homes wrestle with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help lessen these changes by consistently refreshing each room’s ventilation.