Once the weather is cooling off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC costs routinely make up a significant portion 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?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what will the fan setting offer for an HVAC system? This guide should help. We’ll walk through precisely what the fan setting is and whether you can use it to save money 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 may continue to operate at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan over a heating or cooling cycle and shut it off after the cycle is complete.

There are pros and cons to trying the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your personal 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 since constant airflow will keep passing airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps extend its life span. Since the air handler is typically part of the furnace, this means you could minimize the risk of needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A nonstop fan will likely raise your energy bills somewhat.
  • Nonstop airflow may 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 Each Season

In the summer, warm air will sometimes stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system may pull this warm air into the rest of your home, pushing the HVAC system to work harder to maintain the desired temperature. In extreme heat, this may lead to needing AC repair more often as wear and tear grows.

The reverse can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually drift into the rest of your home. Keeping the fan on will sometimes pump 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 switch to 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 deals with allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds of homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help lessen these changes by constantly refreshing each room’s airflow.