As the weather is cooling off, you may be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC costs frequently add up to a large chunk of your monthly electric bill. To try and find ways to save, some people look closer at their thermostat. Could there be a setting they should use to boost efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what does the fan setting offer for your HVAC system? This guide can help. We’ll walk through just what the fan setting is and how you can use it to save money during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting signifies that the HVAC blower fan remains on. Some furnaces can run at a low level with this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and switch it off once the cycle is over.

There are pros and cons to switching on the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort preferences.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more consistent by permitting the fan to keep running.
  • Indoor air quality can increase since constant airflow will keep forcing airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps expand its life span. Since the air handler is typically part of the furnace, this means you might minimize the risk of needing furnace repair.

Disadvantages to using the Fan/On setting:

  • A constant fan can add to your energy bills slightly.
  • Continuous airflow may clog your air filter soon, increasing the frequency you should replace it.

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

In the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system may pull this warm air into the rest of your home, forcing the HVAC system to work more to maintain the desired temperature. In serious heat, this can lead to needing AC repair more often as wear and tear gets worse.

The reverse can happen in the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Leaving the fan setting on may pump 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, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could work for you if:

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

Your home deals with hot and cold spots. Lots of homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help lessen these changes by consistently refreshing each room’s ventilation.