When the weather is cooling off, you are probably wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely contribute a big portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some people take a closer look at their thermostat. Maybe there’s a setting they could use to boost efficiency?

The bulk 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 your HVAC system? This guide can help. We’ll walk through what exactly the fan setting is and when you can use it to cut costs during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the system's blower fan stays on. A few furnaces can run at a low level with this setting, but in most cases 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 finished.

There are pros and cons to trying the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your distinct comfort preferences.

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality can increase since steady airflow will keep moving airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the system's fan helps lengthen its life span. As the air handler is often part of the furnace, this means you can minimize the risk of needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan could raise your energy bills somewhat.
  • Continuous 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 persist in unfinished spaces like 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 work more to keep up with the preferred temperature. In serious heat, this may result in needing AC repair more quickly as wear and tear grows.

The opposite can take place 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 will sometimes pull 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, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could work 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 is more likely to enhance indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. All kinds of homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help minimize these changes by consistently refreshing each room’s airflow.