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

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what can the fan setting offer for your HVAC system? This guide should help. We’ll review just what the fan setting is and how 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 remains on. Certain furnaces will run at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and shut it off when the cycle is complete.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more uniform by allowing the fan to keep running.
  • Indoor air quality should improve because steady airflow will keep passing airborne particles into the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps expand its life span. As the air handler is typically a component of the furnace, this means you can prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan could raise your energy expenses by a small margin.
  • Constant airflow can clog your air filter soon, increasing the frequency you’ll need to replace it.

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

During the summer, warm air may persist in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system might draw this warm air into the rest of your home, forcing the HVAC system to run longer to keep up with the preferred temperature. In severe heat, this may lead to needing AC repair more quickly 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 flow 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 keep warm.

If you’re still trying to figure out 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 might be ideal for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots of homes wrestle with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help minimize these changes by constantly refreshing each room’s airflow.