Answered: Should My Thermostat Be on Auto or Fan?

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

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what does the fan setting provide for your HVAC system? This guide should help. We’ll share just what the fan setting is and how you can use it to reduce costs over the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the majority of thermostats, the fan setting means that the air handler’s blower fan stays on. Certain furnaces may continue to generate heat at a low level in this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will run the fan over a heating or cooling cycle and shut 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 preferences.

Advantages to trying 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 can increase because steady airflow will keep moving airborne particles through the air filter.
• A smaller amount of start-stop cycles for the system’s fan helps extend its life span. As the air handler is usually part of the furnace, this means you could prevent the need for furnace repair.

Disadvantages to utilizing the Fan/On setting:

• A continuous fan will likely raise your energy bills slightly.
• Nonstop airflow could clog your air filter in a shorter amount of time, increasing the frequency you should replace it.

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

Through the summer, warm air can stick around 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, pushing the HVAC system to work harder to keep up with the preferred temperature. In extreme heat, this may result in needing AC repair more quickly as wear and tear increases.

The opposite can happen in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually drift into the rest of your home. Keeping the fan on could pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to figure out 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 might be ideal for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds of homes wrestle with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help limit these changes by consistently refreshing each room’s ventilation.