When the weather starts to cool off, you might be concerned about how you’ll prepare your heating and cooling. After all, HVAC costs frequently add up to a significant chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some people look closer at their thermostat. Could there be a setting they can use to increase efficiency?

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

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting signifies that the air handler’s blower fan remains on. Certain furnaces may continue to run at a low level in this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and shut it off after the cycle is complete.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more consistent by allowing the fan to keep generating airflow.
  • Indoor air quality will be highest because steady airflow will keep moving airborne contaminants into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps extend its life span. Since the air handler is typically part of the furnace, this means you could avoid needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A continuous fan could raise your energy costs by a small margin.
  • 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 can linger in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system can draw this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the preferred temperature. In serious heat, this could lead to needing AC repair more quickly 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 can eventually drift 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 decide if you should try the fan/on setting, remember that every home and family’s comfort needs are not the same. 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 can help to improve indoor air quality, helping your family breathe easier.

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