As the weather is cooling off, you may be concerned about how you’ll prepare your heating and cooling. After all, HVAC costs can add up to a big portion of your monthly electric bill. To learn new ways to reduce costs, some people take a closer look at their thermostat. Maybe there’s a setting they could use to improve efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what does the fan setting provide for your HVAC system? This guide will help. We’ll review precisely what the fan setting is and when you can use it to cut costs over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting indicates that the air handler’s blower fan stays on. A few furnaces may continue to generate heat at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will turn on the fan over a heating or cooling cycle and switch it off when the cycle is complete.

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 preferences.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more balanced by enabling the fan to keep circulating air.
  • Indoor air quality will be highest as constant airflow will keep moving airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. Since the air handler is usually part of the furnace, this means you might prevent the need for furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A constant fan could increase your energy expenses by a small margin.
  • Constant airflow could 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 Summer/Winter

Through the summer, warm air can linger in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system can pull this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the set temperature. In extreme heat, this can result in needing AC repair more often as wear and tear increases.

The reverse can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Leaving the fan running will sometimes pump more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be stressful 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. Many homes deal with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help lessen these changes by consistently refreshing each room’s airflow.