Once the weather begins to cool off, you might be concerned about how you’ll prepare your heating and cooling. After all, HVAC costs frequently contribute a big piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners look closely at their thermostat. Could there be a setting they can use to boost efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting provide for your HVAC system? This guide can help. We’ll walk through precisely what the fan setting is and how you can use it to cut costs over the summer or winter.

What Is the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting means that the air handler’s blower fan stays on. Some furnaces will generate heat at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will turn on the fan during a heating or cooling cycle and turn it off once the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more uniform by permitting the fan to keep generating airflow.
  • Indoor air quality should improve since constant airflow will keep forcing airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps lengthen its life span. Because the air handler is typically connected to the furnace, this means you can prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A nonstop fan could raise your energy costs by a small margin.
  • Continuous airflow can clog your air filter in a shorter amount of time, 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

Through the summer, warm air will sometimes stick around in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system can pull this warm air into the rest of your home, forcing the HVAC system to work more to maintain the desired temperature. In serious heat, this may lead to needing AC repair more quickly as wear and tear gets worse.

The opposite can take place 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. Keeping the fan on will sometimes draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to decide if you should try the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be ideal for you if:

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

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