When the weather starts to cool off, you are probably concerned about how you’ll make the most of your heating and cooling. After all, HVAC costs routinely contribute a significant portion of your monthly electric bill. To learn new ways to reduce costs, some people look closer at their thermostat. Is there a setting they should use to increase efficiency?

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

What Is the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting means that the HVAC blower fan keeps running. A few furnaces may continue to operate at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and turn it off after the cycle is complete.

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

Advantages to using the Fan/On setting:

• You can keep the temperature in every room more uniform by allowing the fan to keep running.
• Indoor air quality can increase because continuous airflow will keep passing airborne contaminants into the air filter.
• A smaller number of start-stop cycles for the system's fan helps expand its life span. Because the air handler is typically a component of the furnace, this means you can minimize the risk of needing furnace repair.

Downsides to switching to the Fan/On setting:

• A continuous fan could increase your energy expenses by a small margin.
• Nonstop airflow can clog your air filter soon, increasing the frequency you will want to replace it.

Should My Thermostat Be on Fan or Auto in Summer/Winter

During the summer, warm air will sometimes stick around in unfinished spaces such as 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 harder to maintain the preferred temperature. In severe heat, this can lead to needing AC repair more quickly as wear and tear increases.

The reverse can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on 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 use the fan/on setting, don’t forget 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 has allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on is more likely to enhance 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 should help lessen these changes by consistently refreshing each room’s ventilation.