When the weather starts to cool off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC expenses can contribute a large portion of your monthly electric bill. To figure out new ways to save, some people look closer at their thermostat. Is there a setting they should 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 does the fan setting provide for an HVAC system? This guide can help. We’ll review 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 HVAC blower fan remains 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 start the fan over a heating or cooling cycle and switch it off once the cycle is finished.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more uniform by enabling the fan to keep running.
  • Indoor air quality should improve since constant airflow will keep moving airborne particles into the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps lengthen its life span. Because the air handler is typically part of the furnace, this means you can prevent the need for furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A continuous fan can increase your energy expenses somewhat.
  • Constant airflow can clog your air filter up more quickly, increasing the frequency you will want to replace it.

Should My Thermostat Be on Fan or Auto in Summer/Winter

In the summer, warm air will sometimes persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to work harder to maintain the preferred temperature. In severe heat, this can lead to needing AC repair more regularly as wear and tear increases.

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

If you’re still trying to figure out if you should use the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might be ideal for you if:

Someone in your household suffers from allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.

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