Once the weather starts to cool off, you might be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC costs can contribute a significant piece of your monthly electric bill. To learn new ways to reduce costs, some people take a closer look at their thermostat. Could there be a setting they should use to increase efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting offer for an HVAC system? This guide will help. We’ll review just what the fan setting is and how you can use it to save money over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting indicates that the system’s blower fan stays on. Some furnaces will operate at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will start the fan through a heating or cooling cycle and switch it off when the cycle is complete.

There are advantages and disadvantages to switching on the fan setting on your thermostat, and what’s ideal {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 allowing the fan to keep generating airflow.
  • Indoor air quality will be highest since constant airflow will keep passing airborne particles into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is often a component of the furnace, this means you could avoid needing furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan could raise your energy costs slightly.
  • Constant airflow can 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

Through the summer, warm air can persist in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might gradually move this warm air into the rest of your home, pushing the HVAC system to run longer to keep up with the set temperature. In serious heat, this can result in needing AC repair more often as wear and tear increases.

The reverse can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running may pull more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to figure out if you should use 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 could be ideal for you if:

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

Your home deals with hot and cold spots. Many homes wrestle with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help limit these changes by constantly refreshing each room’s airflow.