When adjusting your home’s thermostat, you may notice that it has two different fan settings. There’s an “on” setting and an “auto” setting. Most thermostats have these two fan settings. Regardless of which one you use, it shouldn’t affect the temperature inside of your home. So, what’s the difference between the “on” and “auto” settings?
What is the On Setting?
The “on” setting means the fan will constantly run. Your heating, ventilation and cooling (HVAC) system has a fan that’s designed to blow conditioned air through the ductwork and into your home. It’s usually found in the attic or crawl space near the evaporator coil. When activated, the fan’s blades will spin while subsequently blowing air into your home.
If you use the “on” setting on the thermostat, the fan will run indefinitely. To turn it off, you’ll have to switch the thermostat to the “auto” setting. The “on” setting simply tells the fan to run all the time.
What is the Auto Setting?
The “auto” setting, on the other hand, means the fan will only run when the air conditioner or furnace is running. With the “auto” setting, the fan will be synchronized to the air conditioner and furnace. Whether you’re trying to cool or warm your home, the fan will run until the temperature set on your thermostat has been reached. The fan will automatically shut off upon reaching this temperature.
The “on” and “auto” settings are both used to control the fan. The “on” setting is designed to constantly run the fan, whereas the “auto” setting is designed to only run the fan when the air conditioner or furnace is running.
Choosing the Right Fan Setting
Most HVAC experts will agree that the “auto” setting is the better choice. Your HVAC system will consume less energy, for instance, if you use this setting. The fan requires electricity to spin and blow air. If you use the “on” setting, it will constantly run, meaning it will constantly consume energy.
Because it consumes more energy, using the “on” setting can lead to higher utility bills. You’ll have to pay more for electricity if you use this setting. To save money, many homeowners opt for the “auto” setting.
Using the “auto” setting can also protect your HVAC system from wear and tear. Fans contain many different moving parts. The longer the fan runs, the greater its risk of failure. You can make your fan last longer by using the “auto” setting.