Once the weather begins to cool off, you may be wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely add up to a large piece of your monthly electric bill. To try and find ways to reduce costs, some people take a closer look at their thermostat. Is there a setting they should use to improve efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what will the fan setting provide for the HVAC system? This guide will help. We’ll share just 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 indicates that the air handler’s blower fan stays on. Certain furnaces will operate at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and turn it off once the cycle is finished.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more balanced by enabling the fan to keep running.
  • Indoor air quality will be highest as constant airflow will keep passing airborne particles into the air filter.
  • Fewer start-stop cycles for the system's fan helps lengthen its life span. Because the air handler is often a component of the furnace, this means you can avoid needing furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan will likely increase your energy expenses somewhat.
  • Nonstop airflow could clog your air filter up more quickly, increasing the frequency you’ll need to replace it.

Should My Thermostat Be on Fan or Auto in Summer/Winter

In the summer, warm air may stick around in unfinished spaces like 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 run longer to keep up with the preferred temperature. In serious heat, this may result in needing AC repair more regularly as wear and tear gets worse.

The opposite can take place over the winter. Cooler spaces such as a basement will hold onto cooler air, which may 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 stay warm.

If you’re still trying to decide if you should try the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be best for you if:

Someone in your household has allergies. Allergies and other 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. All kinds of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help lessen these changes by steadily refreshing each room’s airflow.