When the weather starts to cool off, you might be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses can make up a significant piece of your monthly electric bill. To try and find ways to reduce costs, some homeowners look closer at their thermostat. Could there be a setting they should use to increase efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what can the fan setting offer for an HVAC system? This guide should help. We’ll share precisely what the fan setting is and when you can use it to reduce 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 stays on. A few furnaces can run at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will run the fan over a heating or cooling cycle and shut it off after the cycle is over.

There are advantages and disadvantages to using the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your unique comfort requirements.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more consistent by enabling the fan to keep running.
  • Indoor air quality will be highest because steady airflow will keep forcing airborne particles into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is usually part of the furnace, this means you might minimize the risk of needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A nonstop fan will likely raise your energy expenses somewhat.
  • Constant airflow could clog your air filter up more quickly, increasing the frequency you should replace it.

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

In the summer, warm air will sometimes linger 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 run longer to maintain the preferred temperature. In severe heat, this can result in needing AC repair more quickly as wear and tear grows.

The opposite can happen during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan running 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 switch to the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may be best 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 can help to improve indoor air quality, helping your family breathe easier.

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