As the weather is cooling off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC bills frequently add up to a large piece of your monthly electric bill. To try and find ways to save, some people look closely at their thermostat. Could there be a setting they can use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what will the fan setting provide for your HVAC system? This guide should help. We’ll walk through what exactly the fan setting is and whether you can use it to cut costs over the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the majority of thermostats, the fan setting means that the system’s blower fan remains on. A few furnaces can operate at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and turn it off when the cycle is complete.

There are benefits and drawbacks to trying the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your personal comfort requirements.

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality will be highest as steady airflow will keep forcing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the blower fan helps expand its life span. Because the air handler is typically connected to the furnace, this means you could avoid needing furnace repair.

Downsides to using the Fan/On setting:

  • A continuous fan can raise your energy expenses by a small margin.
  • Constant airflow could clog your air filter soon, 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 persist in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might pull this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the desired temperature. In severe heat, this could lead to needing AC repair more often as wear and tear grows.

The reverse can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which may 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 decide if you should use the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might work 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 should help to improve indoor air quality, helping your family breathe easier.

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