Once the weather starts to cool off, you might be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely contribute a big chunk of your monthly electric bill. To try and find ways to reduce costs, some homeowners look closely at their thermostat. Is there a setting they could use to increase efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what does the fan setting provide for your HVAC system? This guide will help. We’ll share precisely what the fan setting is and how you can use it to cut costs over the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the system’s blower fan remains on. Some furnaces may continue to operate at a low level with this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and switch it off after the cycle is finished.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature in each room more consistent by permitting the fan to keep running.
  • Indoor air quality will be highest because continuous airflow will keep forcing airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is often a component of the furnace, this means you can avoid needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A constant fan could raise your energy expenses slightly.
  • Nonstop 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

Through the summer, warm air can persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system might gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the preferred temperature. In severe heat, this could lead to needing AC repair more often as wear and tear grows.

The reverse can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running may draw 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, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be tough 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 persistent hot and cold spots that quickly return 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.