As the weather is cooling off, you might be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently contribute a large chunk of your monthly electric bill. To figure out new ways to reduce costs, some homeowners take a closer look 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 your HVAC system? This guide will help. We’ll review precisely what the fan setting is and how you can use it to cut costs during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the system's blower fan stays on. Some furnaces will operate at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will start the fan during a heating or cooling cycle and shut it off when the cycle is complete.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep running.
  • Indoor air quality should improve as steady airflow will keep passing airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the system's fan helps lengthen its life span. Since the air handler is typically part of the furnace, this means you can minimize the risk of needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A continuous fan can raise your energy costs somewhat.
  • Continuous airflow could clog your air filter in a shorter amount of time, 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 can persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to work more to maintain the preferred temperature. In extreme heat, this may lead to needing AC repair more often as wear and tear increases.

The opposite can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually flow into the rest of your home. Keeping the fan on will sometimes pump 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 try the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may work for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes wrestle 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 consistently refreshing each room’s ventilation.