When the weather is cooling off, you might be wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills can make up a significant portion of your monthly electric bill. To learn new ways to save, some homeowners look closely at their thermostat. Could there be a setting they could use to improve efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what does the fan setting offer for an HVAC system? This guide will help. We’ll walk through what exactly the fan setting is and when you can use it to cut costs over the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the bulk of thermostats, the fan setting signifies that the HVAC blower fan stays on. A few furnaces can generate heat 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 during a heating or cooling cycle and switch it off once the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more uniform by permitting the fan to keep circulating air.
  • Indoor air quality should improve since steady airflow will keep moving airborne contaminants through 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 usually part of the furnace, this means you can prevent the need for furnace repair.

Downsides to using the Fan/On setting:

  • A nonstop fan could raise your energy expenses somewhat.
  • Constant airflow may clog your air filter in a shorter amount of time, increasing the frequency you should 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 may linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to run longer to keep up with the set temperature. In extreme heat, this can result in needing AC repair more quickly as wear and tear increases.

The reverse can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually drift into the rest of your home. Leaving the fan setting on will sometimes 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 use the fan/on setting, keep in mind 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 suffers from allergies. Allergies and similar 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. All kinds of 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 lessen these changes by consistently refreshing each room’s airflow.