Once the weather begins to cool off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC bills routinely contribute a big portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners take a closer look at their thermostat. Could there be a setting they can use to increase efficiency?

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

How Do I Access the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting signifies that the system's blower fan remains on. Some furnaces will generate heat at a low level with this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will run the fan through a heating or cooling cycle and shut it off after the cycle is finished.

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 needs.

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest since continuous airflow will keep forcing airborne contaminants into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. Since the air handler is often a component of the furnace, this means you could prevent the need for furnace repair.

Downsides to utilizing the Fan/On setting:

  • A nonstop fan will likely increase your energy costs by a small margin.
  • Nonstop airflow may 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 stick around in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system might gradually move this warm air into the rest of your home, compelling the HVAC system to work harder to keep up with the desired temperature. In extreme heat, this may result in needing AC repair more often as wear and tear increases.

The reverse can occur in the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow 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 determine if you should use the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may work for you if:

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

Your home experiences hot and cold spots. All kinds of homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help limit these changes by constantly refreshing each room’s airflow.