As the weather starts to cool off, you are probably wondering about how you’ll prepare your heating and cooling. After all, HVAC bills frequently add up to a big piece of your monthly electric bill. To learn new ways to reduce costs, some people look closer at their thermostat. Is there a setting they can use to increase efficiency?
Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what can the fan setting offer for an HVAC system? This guide can help. We’ll share what exactly the fan setting is and when you can use it to cut costs in the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting indicates that the system's blower fan keeps running. Some furnaces may continue to operate at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan over a heating or cooling cycle and shut it off once the cycle is over.
There are benefits and drawbacks to switching on the fan setting on your thermostat, and whether you do or don’t can depend on your unique comfort preferences.
Advantages to trying 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 constant airflow will keep moving airborne pollutants into the air filter.
- A smaller amount of start-stop cycles for the blower fan helps expand its life span. As the air handler is typically part of the furnace, this means you could prevent the need for furnace repair.
Disadvantages to switching to the Fan/On setting:
- A nonstop fan will likely raise your energy expenses somewhat.
- 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
Through the summer, warm air may persist in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to keep up with the preferred temperature. In severe heat, this can result in needing AC repair more quickly as wear and tear increases.
The reverse can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Keeping the fan on may draw more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to figure out if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may be best for you if:
Someone in your household deals with 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 deal with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by constantly refreshing each room’s supply of air.