As the weather begins to cool off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills routinely make up a large piece of your monthly electric bill. To try and find ways to save, some homeowners take a closer look at their thermostat. Maybe there’s a setting they can use to boost efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting offer for the HVAC system? This guide can help. We’ll walk through precisely what the fan setting is and how you can use it to save money in 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 air handler’s blower fan stays on. A few furnaces will operate at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and switch it off once the cycle is finished.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more uniform by enabling the fan to keep circulating air.
  • Indoor air quality can increase because steady airflow will keep forcing airborne contaminants through the air filter.
  • Fewer start-stop cycles for the system’s fan helps expand its life span. As the air handler is typically connected to the furnace, this means you could avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A constant fan could add to your energy costs slightly.
  • Nonstop 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

During the summer, warm air can stick around in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system might draw this warm air into the rest of your home, compelling the HVAC system to work harder to maintain the desired temperature. In extreme heat, this could lead to needing AC repair more regularly as wear and tear increases.

The opposite can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Leaving the fan setting on may pull 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 are different. Leaving the HVAC system’s fan on may work for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help minimize these changes by steadily refreshing each room’s ventilation.