Once the weather is cooling off, you might be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently add up to a large piece of your monthly electric bill. To figure out new ways to reduce costs, some homeowners look closely at their thermostat. Maybe there’s a setting they can use to increase efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what will the fan setting provide for an HVAC system? This guide can help. We’ll share just what the fan setting is and whether you can use it to reduce costs over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the air handler’s blower fan stays on. A few furnaces may continue to run at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will turn on the fan over a heating or cooling cycle and turn it off after the cycle is over.

There are advantages and disadvantages to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort requirements.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by permitting the fan to keep circulating air.
  • Indoor air quality will be highest since steady airflow will keep passing airborne contaminants into the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps expand its life span. As the air handler is typically part of the furnace, this means you might avoid needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan will likely add to your energy costs by a small margin.
  • Continuous airflow could clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.

Should My Thermostat Be on? Fan or Auto in Each Season

During the summer, warm air will sometimes linger in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to work more to maintain the preferred temperature. In serious heat, this can lead to needing AC repair more regularly as wear and tear increases.

The reverse can take place in 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. Leaving the fan running could draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to decide if you should try the fan/on setting, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be ideal for you if:

Someone in your household deals with 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 has hot and cold spots. Lots of homes wrestle with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help lessen these changes by steadily refreshing each room’s supply of air.