As the weather begins to cool off, you are probably wondering about how you’ll prepare your heating and cooling. After all, HVAC costs routinely make up a big piece of your monthly electric bill. To learn new ways to reduce costs, some owners look closer at their thermostat. Maybe there’s a setting they could use to improve efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what does the fan setting provide for the HVAC system? This guide will help. We’ll share what exactly the fan setting is and whether you can use it to save money in the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting signifies that the system's blower fan keeps running. Some furnaces can run at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will run the fan during a heating or cooling cycle and shut it off once the cycle is over.

There are pros and cons to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort needs.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more consistent by allowing the fan to keep generating airflow.
  • Indoor air quality will be highest as constant airflow will keep moving airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps extend its life span. Since the air handler is typically a component of the furnace, this means you can minimize the risk of needing furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan will likely raise your energy costs by a small margin.
  • Nonstop airflow could clog your air filter soon, 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 Summer/Winter

In the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system might draw this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the desired temperature. In extreme heat, this could result in needing AC repair more regularly as wear and tear gets worse.

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

If you’re still trying to decide if you should use 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 work for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be stressful 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. All kinds of homes deal with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help limit these changes by steadily refreshing each room’s supply of air.