As the weather begins to cool off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills can contribute a large portion of your monthly electric bill. To learn new ways to save, some people look closely at their thermostat. Maybe there’s a setting they could use to boost efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what can the fan setting provide for an HVAC system? This guide will help. We’ll walk through precisely what the fan setting is and how you can use it to reduce costs over the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the system’s blower fan remains on. Some furnaces may continue to run at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will start the fan over a heating or cooling cycle and turn it off when the cycle is finished.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more balanced by permitting the fan to keep running.
  • Indoor air quality will be highest since continuous airflow will keep forcing airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps extend its life span. Because the air handler is typically a component of the furnace, this means you can prevent the need for furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A constant fan could raise your energy costs by a small margin.
  • Continuous airflow can 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 Summer/Winter

In the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system may draw this warm air into the rest of your home, compelling the HVAC system to work harder to maintain the set temperature. In serious heat, this could result in needing AC repair more regularly as wear and tear increases.

The reverse can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Leaving the fan running may draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be best for you if:

Someone in your household deals with allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on is more likely to increase indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. All kinds 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 can help limit these changes by constantly refreshing each room’s ventilation.