When the weather starts to cool off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses routinely contribute a significant chunk of your monthly electric bill. To learn new ways to save, some homeowners take a closer look at their thermostat. Is there a setting they should use to improve efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what can the fan setting provide for the HVAC system? This guide can help. We’ll review what exactly the fan setting is and when you can use it to reduce costs during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting signifies that the air handler’s blower fan stays on. A few furnaces may continue to generate heat at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan over a heating or cooling cycle and switch it off once the cycle is over.

There are advantages and disadvantages to trying the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your unique comfort requirements.

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by allowing the fan to keep circulating air.
  • Indoor air quality will be highest as steady airflow will keep moving airborne contaminants into the air filter.
  • Fewer start-stop cycles for the blower fan helps expand its life span. Because the air handler is usually a component of the furnace, this means you might minimize the risk of needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A constant fan can raise your energy expenses by a small margin.
  • Constant airflow may clog your air filter up more quickly, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

Through the summer, warm air can persist in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to work harder to preserve the desired temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear grows.

The reverse can happen in 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 may pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine if you should use the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household suffers from allergies. Allergies and similar 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 deals with hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help limit these changes by steadily refreshing each room’s airflow.