When the weather is cooling off, you are probably wondering about how you’ll make the most of your heating and cooling. After all, HVAC costs frequently contribute a large piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners look closely at their thermostat. Is there a setting they can use to increase efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what can the fan setting offer for an HVAC system? This guide will help. We’ll share what exactly the fan setting is and how you can use it to save money in the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the system's blower fan stays on. Certain furnaces may continue to run at a low level with this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will turn on the fan through a heating or cooling cycle and switch it off once the cycle is finished.

There are benefits and drawbacks to trying the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort preferences.

Advantages to utilizing 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 since steady airflow will keep moving airborne pollutants into the air filter.
  • Fewer start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is typically connected to the furnace, this means you could prevent the need for furnace repair.

Downsides to utilizing the Fan/On setting:

  • A continuous fan can add to your energy costs somewhat.
  • Continuous airflow can 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

Through the summer, warm air can stick around in unfinished spaces such as 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 more to preserve the preferred temperature. In extreme heat, this may result in needing AC repair more quickly as wear and tear increases.

The opposite can happen during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running may draw more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be best for you if:

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

Your home has hot and cold spots. All kinds of homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by consistently refreshing each room’s ventilation.