As the weather is cooling off, you might be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC costs can add up to a big portion of your monthly electric bill. To figure out new ways to lower their HVAC bill, some owners look closer at their thermostat. Is there a setting they should use to boost efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what can the fan setting provide for your HVAC system? This guide can help. We’ll share just what the fan setting is and whether you can use it to reduce costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting indicates that the air handler’s blower fan remains on. Certain furnaces may continue to run at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will run the fan during a heating or cooling cycle and switch it off once the cycle is over.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by enabling the fan to keep generating airflow.
  • Indoor air quality can increase as constant airflow will keep passing airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. Because the air handler is usually part of the furnace, this means you could avoid needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A continuous fan can increase your energy costs by a small margin.
  • Continuous airflow can 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 Each Season

In the summer, warm air may linger in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system might pull this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the desired temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear increases.

The reverse can happen during the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running may 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 different. Leaving the HVAC system’s fan on may 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 can help to increase indoor air quality, helping your family breathe easier.

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