When the weather is cooling off, you are probably thinking about how you’ll prepare your heating and cooling. After all, HVAC expenses routinely make up a significant piece of your monthly electric bill. To try and find ways to reduce costs, some people look closely at their thermostat. Maybe there’s 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 will the fan setting offer for the HVAC system? This guide should help. We’ll walk through precisely what the fan setting is and when you can use it to cut costs in the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the bulk of thermostats, the fan setting indicates that the air handler’s blower fan remains on. Some furnaces can operate at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will run the fan through a heating or cooling cycle and shut it off once the cycle is finished.

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 consistent by permitting the fan to keep circulating air.
  • Indoor air quality can increase since constant airflow will keep forcing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps expand its life span. Since the air handler is often connected to the furnace, this means you could minimize the risk of needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A continuous fan can increase your energy expenses slightly.
  • Constant airflow could clog your air filter in a shorter amount of time, 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 can linger in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system might draw this warm air into the rest of your home, compelling the HVAC system to work harder to maintain the desired temperature. In extreme heat, this can lead to needing AC repair more regularly as wear and tear increases.

The opposite can occur during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way 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 remain 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 will vary. Leaving the HVAC system’s fan on might 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 can help to enhance 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 limit these changes by constantly refreshing each room’s ventilation.