When the weather begins to cool off, you may be concerned about how you’ll make the most of your heating and cooling. After all, HVAC expenses frequently add up to a big piece of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners take a closer look at their thermostat. Could there be a setting they should use to boost efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting offer for an HVAC system? This guide will help. We’ll walk through just what the fan setting is and whether you can use it to save money over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the HVAC blower fan keeps running. Certain furnaces will operate at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan through a heating or cooling cycle and shut it off once the cycle is complete.

There are advantages and disadvantages to trying the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your personal comfort requirements.

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more uniform by permitting the fan to keep running.
  • Indoor air quality will be highest because steady airflow will keep passing airborne contaminants into the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps lengthen its life span. Because the air handler is often part of the furnace, this means you could prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A continuous fan can add to your energy expenses somewhat.
  • Nonstop 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 Each Season

During the summer, warm air will sometimes persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system may draw this warm air into the rest of your home, forcing the HVAC system to run longer to maintain the desired temperature. In serious heat, this may result in needing AC repair more quickly as wear and tear gets worse.

The opposite can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually drift 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 keep warm.

If you’re still trying to determine if you should switch to the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could work for you if:

Someone in your household suffers from allergies. Allergies and other 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 has hot and cold spots. Many homes wrestle with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help lessen these changes by consistently refreshing each room’s airflow.