Once the weather begins to cool off, you are probably concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses frequently contribute a large piece of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners take a closer look at their thermostat. Could there be a setting they could use to improve efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what will the fan setting offer for the HVAC system? This guide can help. We’ll share precisely what the fan setting is and how you can use it to save money over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting signifies that the air handler’s blower fan stays on. A few furnaces may continue to run at a low level in this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan over 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 the ideal option {will|can|should]] depend on your unique comfort requirements.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by allowing the fan to keep circulating air.
  • Indoor air quality will be highest as constant airflow will keep forcing airborne contaminants through the air filter.
  • A smaller amount of start-stop cycles for the system's fan helps extend its life span. Because the air handler is typically part of the furnace, this means you could avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A nonstop fan will likely increase your energy costs by a small margin.
  • Continuous airflow could 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 may stick around in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to work harder to preserve the set temperature. In serious heat, this could lead to needing AC repair more regularly as wear and tear increases.

The reverse can occur during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running could pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to figure out if you should switch to 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 may 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 is more likely to enhance indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. All kinds of homes deal 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.