Solved: Should My Thermostat Be on Auto or Fan?

As the weather starts to cool off, you might be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC bills routinely make up a large piece of your monthly electric bill. To try and find ways to reduce costs, some people look closer at their thermostat. Could there be a setting they could use to increase efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what does the fan setting provide for an HVAC system? This guide can help. We’ll review what exactly the fan setting is and when you can use it to cut costs during the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting signifies that the system’s blower fan stays on. A few furnaces may continue to run at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and switch it off after the cycle is over.

There are pros and cons to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort needs.

Advantages to trying the Fan/On setting:

• You can keep the temperature in every room more balanced by allowing the fan to keep running.
• Indoor air quality can increase since steady airflow will keep passing airborne pollutants through the air filter.
• A smaller amount of start-stop cycles for the HVAC fan helps expand its life span. Because the air handler is often part of the furnace, this means you can minimize the risk of needing furnace repair.

Disadvantages to utilizing the Fan/On setting:

• A constant fan will likely add to your energy bills somewhat.
• Constant airflow can clog your air filter soon, increasing the frequency you’ll need to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

Through the summer, warm air will sometimes stick around in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system may draw this warm air into the rest of your home, pushing the HVAC system to work more to preserve the preferred temperature. In serious heat, this can lead to needing AC repair more quickly as wear and tear increases.

The reverse can happen during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually flow into the rest of your home. Leaving the fan running could draw more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide if you should use the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household has allergies. Allergies and similar respiratory conditions can be stressful 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. Lots of homes wrestle with difficult 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 ventilation.