As the weather begins to cool off, you might be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses routinely make up a big piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some people look closer at their thermostat. Maybe there’s a setting they can use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what can the fan setting provide for your HVAC system? This guide will help. We’ll share what exactly the fan setting is and when you can use it to reduce costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting indicates that the air handler’s blower fan keeps running. Some furnaces may continue to run at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan over a heating or cooling cycle and shut it off after the cycle is complete.

There are benefits and drawbacks to switching on the fan setting on your thermostat, and the ideal option {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 balanced by allowing the fan to keep generating airflow.
  • Indoor air quality can increase because constant airflow will keep passing airborne contaminants through the air filter.
  • Fewer start-stop cycles for the blower fan helps lengthen its life span. As the air handler is usually a component of the furnace, this means you might avoid needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A nonstop fan can raise your energy expenses by a small margin.
  • Constant airflow can clog your air filter soon, increasing the frequency you will want to replace it.

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

Through the summer, warm air may stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system can draw this warm air into the rest of your home, pushing the HVAC system to work harder to maintain the preferred temperature. In extreme heat, this could lead to needing AC repair more quickly as wear and tear gets worse.

The opposite can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Keeping the fan 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, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots of homes wrestle with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help minimize these changes by consistently refreshing each room’s airflow.