As the weather is cooling off, you are probably wondering about how you’ll make the most of your heating and cooling. After all, HVAC costs can make up a big piece of your monthly electric bill. To figure out new ways to reduce costs, 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 can the fan setting offer for the HVAC system? This guide should help. We’ll walk through precisely what the fan setting is and whether you can use it to cut costs during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the air handler’s blower fan remains on. Some furnaces can operate at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will run the fan over a heating or cooling cycle and switch it off when the cycle is over.

There are advantages and disadvantages 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 switching to the Fan/On setting:

  • You can keep the temperature in each room more balanced by permitting the fan to keep generating airflow.
  • Indoor air quality should improve since steady airflow will keep forcing airborne particles through the air filter.
  • Fewer start-stop cycles for the system's fan helps extend its life span. Because the air handler is usually part of the furnace, this means you can minimize the risk of needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A constant fan could add to your energy expenses somewhat.
  • Constant airflow could clog your air filter up more quickly, increasing the frequency you’ll need to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

In the summer, warm air can persist in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system can pull this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the set temperature. In severe heat, this may lead to needing AC repair more often as wear and tear grows.

The opposite can take place in 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 could pull more cold air upward, increasing the amount of heating you need to stay warm.

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

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

Your home experiences hot and cold spots. Lots of homes wrestle with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help minimize these changes by steadily refreshing each room’s airflow.