Once the weather begins to cool off, you are probably thinking about how you’ll prepare your heating and cooling. After all, HVAC costs routinely add up to a big portion of your monthly electric bill. To try and find ways to reduce costs, some owners look closer at their thermostat. Maybe there’s a setting they can use to improve efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what can the fan setting provide for your HVAC system? This guide should help. We’ll share just what the fan setting is and when you can use it to reduce costs over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the air handler’s blower fan stays on. Certain furnaces will run at a low level with this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will start the fan over a heating or cooling cycle and shut it off after the cycle is over.

There are pros and cons to using 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 enabling the fan to keep running.
  • Indoor air quality will be highest 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. Since the air handler is usually a component of the furnace, this means you might prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan can add to your energy bills slightly.
  • Constant airflow could clog your air filter up more quickly, 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 Each Season

Through the summer, warm air may stick around in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system can draw this warm air into the rest of your home, forcing the HVAC system to run longer to keep up with the desired temperature. In severe heat, this could lead to needing AC repair more regularly as wear and tear gets worse.

The reverse can happen in the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually drift 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 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 might work for you if:

Someone in your household suffers from allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on is more likely to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Many homes deal with stubborn 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 steadily refreshing each room’s supply of air.