As the weather is cooling off, you may be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills can contribute a big portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners look closer at their thermostat. Could there be a setting they should use to improve efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what can the fan setting provide for an HVAC system? This guide should help. We’ll review precisely what the fan setting is and how you can use it to save money during the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting indicates that the air handler’s blower fan remains on. Some furnaces will run at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and shut it off once the cycle is complete.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by permitting the fan to keep running.
  • Indoor air quality can increase as continuous airflow will keep forcing airborne contaminants through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is usually a component of the furnace, this means you might minimize the risk of needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A constant fan could increase your energy costs somewhat.
  • Continuous airflow can 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 Summer/Winter

Through the summer, warm air will sometimes stick around in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system can pull this warm air into the rest of your home, compelling the HVAC system to work more to maintain the set temperature. In extreme heat, this may result in needing AC repair more regularly as wear and tear grows.

The reverse can occur during 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 pull more cold air upward, increasing the amount of heating you need to stay 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 may be best for you if:

Someone in your household deals with allergies. Allergies and similar 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 deals with hot and cold spots. Lots of homes wrestle with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help minimize these changes by steadily refreshing each room’s ventilation.