When the weather is cooling off, you may be concerned about how you’ll prepare your heating and cooling. After all, HVAC bills routinely contribute a significant piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some homeowners look closely at their thermostat. Could there be a setting they should use to boost efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what will the fan setting offer for the HVAC system? This guide will help. We’ll review what exactly the fan setting is and when you can use it to cut costs during the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting means that the air handler’s blower fan keeps running. A few furnaces may continue to operate at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will run the fan during a heating or cooling cycle and turn it off once the cycle is over.

There are advantages and disadvantages to trying the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort preferences.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more uniform by enabling the fan to keep running.
  • Indoor air quality can increase because constant airflow will keep moving airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps expand its life span. As the air handler is often connected to the furnace, this means you could minimize the risk of needing furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A continuous fan will likely increase your energy costs by a small margin.
  • Nonstop airflow can clog your air filter up more quickly, increasing the frequency you will want to 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 persist in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system may gradually move this warm air into the rest of your home, pushing the HVAC system to run longer to keep up with the preferred temperature. In severe heat, this can lead to needing AC repair more often as wear and tear increases.

The opposite can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on could pump more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be ideal for you if:

Someone in your household has allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Many homes deal with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help limit these changes by constantly refreshing each room’s supply of air.