When the weather starts to cool off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills frequently make up a big chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some people look closer at their thermostat. Could there be a setting they can use to boost efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what does the fan setting provide for an HVAC system? This guide can help. We’ll walk through what exactly the fan setting is and how you can use it to cut costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the air handler’s blower fan stays on. Some furnaces can generate heat at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and switch it off when the cycle is over.

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 in each room more consistent by enabling the fan to keep running.
  • Indoor air quality can increase because steady airflow will keep moving airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps extend its life span. As the air handler is often connected to the furnace, this means you can minimize the risk of needing furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A constant fan could increase your energy costs slightly.
  • Continuous airflow could clog your air filter soon, increasing the frequency you will want to replace it.

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

In the summer, warm air can stick around in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to work harder to maintain the preferred temperature. In serious heat, this may result in needing AC repair more often as wear and tear increases.

The opposite can take place over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Keeping the fan on may draw 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 use the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household deals with allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Lots of homes deal with difficult 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 constantly refreshing each room’s airflow.