As the weather is cooling off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC expenses routinely make up a large portion of your monthly electric bill. To figure out new ways to save, some owners take a closer look at their thermostat. Could there be a setting they can use to boost efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what does the fan setting offer for your HVAC system? This guide can help. We’ll walk through precisely what the fan setting is and whether you can use it to cut costs over the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting signifies that the air handler’s blower fan keeps running. Certain furnaces will run at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and turn it off when the cycle is complete.

There are pros and cons to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your distinct 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 generating airflow.
  • Indoor air quality should improve as constant airflow will keep moving airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps lengthen its life span. Since the air handler is typically connected to the furnace, this means you could minimize the risk of needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A nonstop fan can increase your energy costs slightly.
  • Continuous airflow may clog your air filter soon, increasing the frequency you should replace it.

Which Setting for My Thermostat? Fan or Auto in Each Season

In the summer, warm air may stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might pull this warm air into the rest of your home, compelling the HVAC system to work more to preserve the preferred temperature. In extreme heat, this can lead to needing AC repair more quickly as wear and tear gets worse.

The reverse can occur over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Keeping the fan on will sometimes pump more cold air upward, increasing the amount of heating you need to stay 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 not the same. Leaving the HVAC system’s fan on might be ideal for you if:

Someone in your household suffers from 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 has hot and cold spots. Many homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help lessen these changes by steadily refreshing each room’s supply of air.