As the weather begins to cool off, you may be thinking about how you’ll prepare 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 people look closely at their thermostat. Is there a setting they can use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what can the fan setting offer for an HVAC system? This guide can help. We’ll walk through precisely what the fan setting is and when you can use it to cut costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting signifies that the system's blower fan stays on. Certain furnaces may continue to run at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and shut it off after the cycle is complete.

There are benefits and drawbacks to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your personal comfort preferences.

Advantages to switching to the Fan/On setting:

• You can keep the temperature throughout your home more uniform by permitting the fan to keep running.
• Indoor air quality can increase since continuous airflow will keep moving airborne particles through the air filter.
• A smaller number of start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is often part of the furnace, this means you could minimize the risk of needing furnace repair.

Downsides to utilizing the Fan/On setting:

• A continuous fan can raise your energy expenses by a small margin.
• Constant airflow can clog your air filter in a shorter amount of time, increasing the frequency you should replace it.

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

Through the summer, warm air will sometimes persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system may gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to maintain the preferred temperature. In serious heat, this can lead to needing AC repair more quickly as wear and tear increases.

The reverse can happen in the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan setting on will sometimes draw 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, remember 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 tough on the family. Leaving the fan on can help to enhance indoor air quality, helping your family breathe easier.

Your home experiences 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 can help lessen these changes by steadily refreshing each room’s airflow.