As the weather starts to cool off, you may be concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely make up a large portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some homeowners look closer at their thermostat. Is there a setting they could use to boost efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what can the fan setting offer for the HVAC system? This guide should help. We’ll walk through what exactly the fan setting is and how you can use it to save money during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting indicates that the HVAC blower fan remains on. A few furnaces can generate heat at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan over a heating or cooling cycle and shut it off when the cycle is finished.

There are pros and cons to switching on the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your personal comfort needs.

Advantages to trying 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 continuous airflow will keep passing airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. Because the air handler is often connected to the furnace, this means you might prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan will likely raise your energy expenses somewhat.
  • Constant airflow may clog your air filter in a shorter amount of time, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

During the summer, warm air may linger in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system might pull this warm air into the rest of your home, forcing the HVAC system to run longer to keep up with the preferred temperature. In extreme heat, this may lead to needing AC repair more often as wear and tear increases.

The reverse can happen in the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan setting on may 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, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be best for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by steadily refreshing each room’s supply of air.