When the weather is cooling off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC costs frequently make up a big portion of your monthly electric bill. To try and find ways to reduce costs, some homeowners take a closer look at their thermostat. Is there a setting they could use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what does the fan setting offer for your HVAC system? This guide should help. We’ll walk through what exactly the fan setting is and how you can use it to save money over the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting means that the system's blower fan stays on. Certain furnaces will generate heat at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and turn it off after the cycle is over.

There are benefits and drawbacks to using 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 uniform by permitting the fan to keep running.
  • Indoor air quality can increase because constant airflow will keep forcing airborne particles into the air filter.
  • A smaller number of start-stop cycles for the system's fan helps extend its life span. Because the air handler is often connected to the furnace, this means you can minimize the risk of needing furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan could increase your energy expenses somewhat.
  • Continuous airflow may clog your air filter up more quickly, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

During 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 can gradually move this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the desired temperature. In extreme heat, this could lead to needing AC repair more often as wear and tear grows.

The opposite can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on may pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might be ideal for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help lessen these changes by steadily refreshing each room’s ventilation.