When the weather starts to cool off, you may be wondering about how you’ll make the most of your heating and cooling. After all, HVAC costs can make up a large portion of your monthly electric bill. To learn new ways to reduce costs, some owners look closer at their thermostat. Could there be a setting they can use to improve efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what can the fan setting provide for an HVAC system? This guide should help. We’ll review just what the fan setting is and how you can use it to reduce costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting indicates that the system’s blower fan remains on. Certain furnaces will operate at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan over a heating or cooling cycle and shut it off after the cycle is over.

There are benefits and drawbacks to trying the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort preferences.

Advantages to switching to the Fan/On setting:

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

Disadvantages to using the Fan/On setting:

  • A nonstop fan will likely increase your energy costs by a small margin.
  • Constant airflow could clog your air filter in a shorter amount of time, increasing the frequency you will want to 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 including the attic or an attached garage. If you use the fan setting, your HVAC system might draw this warm air into the rest of your home, pushing the HVAC system to run longer to maintain the desired temperature. In extreme heat, this may result in needing AC repair more often as wear and tear grows.

The opposite can happen during the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Keeping the fan on may pull more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to figure out if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be stressful 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. Many homes wrestle with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help lessen these changes by constantly refreshing each room’s ventilation.