As the weather is cooling off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses routinely add up to a large chunk of your monthly electric bill. To figure out new ways to lower their HVAC bill, some owners look closely at their thermostat. Could there be a setting they should use to increase efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what does 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.

What Is the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting means that the air handler’s blower fan stays on. Some furnaces can run at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will turn on the fan through a heating or cooling cycle and shut it off when the cycle is over.

There are pros and cons to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort preferences.

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more uniform by allowing the fan to keep running.
  • Indoor air quality will be highest as steady airflow will keep forcing airborne contaminants through the air filter.
  • A smaller amount of 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 avoid needing furnace repair.

Disadvantages to using the Fan/On setting:

  • A continuous fan could add to your energy expenses by a small margin.
  • Continuous airflow can clog your air filter up more quickly, increasing the frequency you will want to replace it.

Should My Thermostat Be on? Fan or Auto in Each Season

In the summer, warm air can linger in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system may pull this warm air into the rest of your home, forcing the HVAC system to work more to keep up with the desired temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear gets worse.

The reverse can take place in the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running will sometimes pump more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine if you should try the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may be best 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 should help to enhance indoor air quality, helping your family breathe easier.

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