When the weather is cooling off, you are probably concerned about how you’ll make the most of your heating and cooling. After all, HVAC costs frequently contribute a significant chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners look closely at their thermostat. Is there a setting they could use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what can the fan setting provide for an HVAC system? This guide will help. We’ll share just what the fan setting is and whether you can use it to save money during the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting indicates that the system’s blower fan stays on. Some furnaces may continue to generate heat 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 switch it off when the cycle is over.

There are pros and cons to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort preferences.

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality will be highest because constant airflow will keep forcing airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps expand its life span. Because the air handler is often part of the furnace, this means you might prevent the need for furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A continuous fan will likely add to your energy costs slightly.
  • Constant airflow can clog your air filter in a shorter amount of time, 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

During the summer, warm air will sometimes linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system might draw this warm air into the rest of your home, pushing the HVAC system to work harder to keep up with the preferred temperature. In severe heat, this can result in needing AC repair more often as wear and tear grows.

The reverse can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running will sometimes pull more cold air upward, increasing the amount of heating you need to remain 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 different. Leaving the HVAC system’s fan on might be ideal for you if:

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

Your home deals with hot and cold spots. Lots of homes deal with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help limit these changes by consistently refreshing each room’s supply of air.