Once the weather starts to cool off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses can add up to a large chunk of your monthly electric bill. To learn new ways to save, some homeowners look closer at their thermostat. Could there be a setting they can use to increase efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting offer for an HVAC system? This guide can help. We’ll review what exactly the fan setting is and when 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 signifies that the air handler’s blower fan remains on. A few furnaces can run at a low level with this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will run the fan over a heating or cooling cycle and switch it off once 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 distinct comfort requirements.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more uniform by permitting the fan to keep generating airflow.
  • Indoor air quality can increase since continuous airflow will keep passing airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps expand its life span. Because the air handler is usually connected to the furnace, this means you can avoid needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A continuous fan will likely raise your energy bills slightly.
  • Continuous airflow can clog your air filter soon, increasing the frequency you will want to replace it.

Should My Thermostat Be on Fan or Auto in Summer/Winter

Through the summer, warm air will sometimes linger in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system might gradually move this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the preferred temperature. In severe heat, this may lead to needing AC repair more quickly as wear and tear gets worse.

The reverse can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Leaving the fan setting on may draw more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to figure out if you should use the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could be best for you if:

Someone in your household suffers from allergies. Allergies and similar respiratory conditions can be tough 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. All kinds of homes wrestle with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help lessen these changes by consistently refreshing each room’s ventilation.