As the weather is cooling off, you may be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely contribute a big chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners look closely at their thermostat. Is there a setting they could use to improve efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what will the fan setting provide for the HVAC system? This guide can help. We’ll share what exactly the fan setting is and how you can use it to reduce costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the system's blower fan remains on. Certain furnaces will generate heat 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 turn on the fan during a heating or cooling cycle and turn it off once the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more consistent by permitting the fan to keep running.
  • Indoor air quality will be highest as constant airflow will keep moving airborne particles into the air filter.
  • Fewer start-stop cycles for the HVAC fan helps extend its life span. Since the air handler is usually a component of the furnace, this means you can avoid needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan can add to your energy bills somewhat.
  • Constant airflow can clog your air filter up more quickly, 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 Each Season

During the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the desired temperature. In severe heat, this could lead to needing AC repair more often as wear and tear increases.

The reverse can occur during the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually drift into the rest of your home. Leaving the fan running could draw more cold air upward, increasing the amount of heating you need to remain 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 different. Leaving the HVAC system’s fan on could be ideal for you if:

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

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