Once the weather begins to cool off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC costs frequently make up a large chunk of your monthly electric bill. To try and find ways to reduce costs, some people look closer at their thermostat. Maybe there’s a setting they should use to boost efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting offer 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 in the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting indicates that the system's blower fan remains on. A few furnaces will generate heat at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and turn it off when the cycle is finished.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more balanced by permitting the fan to keep running.
  • Indoor air quality should improve as steady airflow will keep forcing airborne particles into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. Because the air handler is typically connected to the furnace, this means you can minimize the risk of needing furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A constant fan could increase your energy bills somewhat.
  • Constant airflow could clog your air filter soon, 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

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

The reverse can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow into the rest of your home. Leaving the fan running could pump more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to figure out if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may work for you if:

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

Your home deals with hot and cold spots. Many homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help minimize these changes by constantly refreshing each room’s supply of air.