As the weather is cooling off, you are probably concerned about how you’ll make the most of your heating and cooling. After all, HVAC expenses can add up to a significant portion of your monthly electric bill. To figure out new ways to reduce costs, some owners take a closer look at their thermostat. Could there be a setting they could use to boost efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what does the fan setting provide for your HVAC system? This guide will help. We’ll review 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 indicates that the air handler’s blower fan keeps running. Some furnaces will operate at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will run the fan over a heating or cooling cycle and switch it off when the cycle is finished.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more consistent by enabling the fan to keep circulating air.
  • Indoor air quality should improve as continuous airflow will keep passing airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is often a component of the furnace, this means you can avoid needing furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A continuous fan can increase your energy costs by a small margin.
  • Constant airflow could clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

Through the summer, warm air will sometimes linger in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system may draw this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the preferred temperature. In severe heat, this may result in needing AC repair more quickly as wear and tear increases.

The opposite can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Leaving the fan setting on will sometimes draw 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 use the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be ideal 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 should help to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots 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 might help lessen these changes by constantly refreshing each room’s supply of air.