When the weather is cooling off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC costs frequently make up a large portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners take a closer look at their thermostat. Is there a setting they should use to increase efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what can the fan setting provide for an HVAC system? This guide will help. We’ll walk through precisely what the fan setting is and whether you can use it to reduce costs in the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the air handler’s blower fan remains on. Some furnaces will generate heat at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan over a heating or cooling cycle and shut it off after the cycle is finished.

There are advantages and disadvantages to switching on the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your personal comfort needs.

Advantages to trying the Fan/On setting:

  • You can keep the temperature in each room more balanced by allowing the fan to keep generating airflow.
  • Indoor air quality should improve because constant airflow will keep moving airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps extend its life span. Since 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 continuous fan can raise your energy bills by a small margin.
  • Continuous airflow may clog your air filter in a shorter amount of time, 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

During the summer, warm air will sometimes persist in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system may gradually move this warm air into the rest of your home, pushing the HVAC system to run longer to maintain the set temperature. In extreme heat, this can result in needing AC repair more quickly as wear and tear grows.

The reverse can take place in the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Keeping the fan on could 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, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might be ideal for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on is more likely 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 return to a temperature different from the rest of the house. The fan setting should help lessen these changes by steadily refreshing each room’s airflow.