Thermostat Fan Settings Explained

On your thermostat’s display, you’ll notice that the fan is set to either “auto” or “on.” What does that mean exactly? The fan refers to your central air system’s blower – the component that helps circulate cool or warm air throughout your home. You can control how and when the fan runs by adjusting your thermostat. Doing so can help improve your comfort and indoor air quality.

Understanding Your Thermostat’s Fan Settings

Setting the fan to auto: The fan kicks on automatically when the AC begins a cooling cycle (or when the furnace begins a heating cycle.) Once the thermostat reaches your setpoint temperature, your central air system powers down and the fan shuts off with it.

Setting the fan to on: The fan will run independently of heating or cooling. In other words, the fan is still operating even if the AC isn’t cooling your home. The fan, however, uses a lot of energy, increasing your electricity bill.

When You Should Set the Fan to Auto

Auto should be your fan’s default setting. It’s the most economical and this setting prevents undue wear and tear because the fan isn’t running nonstop. With few exceptions, you should keep the fan set to auto.

When You Should Set the Fan to On

The “on” setting is useful in certain situations.

When you want to improve your indoor air quality: Operating the fan throughout the day will pull more air through the filter. (Keep in mind, you’ll need to replace your filter more frequently, but allergy sufferers might consider this a small price to pay.)

When you’re painting or remodeling: The fan will help control fumes and dust the project kicks up.

When you want more even temperatures: By constantly circulating air, the fan can help eliminate hot and cold spots.

A Compromise Between Auto and On

Depending on the make and model of your thermostat, there may be a middle ground between auto and on. Some thermostats allowing you to schedule fan runtimes throughout the day, say, 20 minutes each hour between heating or cooling cycles. Honeywell thermostats call this feature “Circ,” short for circulate. Similarly, certain smart thermostats include a setting that keeps the fan on for several minutes after the AC completes a cycle to blow residual cool air into your home. This cuts your cooling costs.

Get More Out of Your Thermostat

The ability to control your HVAC fan is likely your thermostat’s most overlooked feature. If you have a programmable or smart thermostat, there no doubt several other bells and whistles designed to help dial in more comfort and energy savings. For example, placing your HVAC on a schedule around your daily routine can save as much as 10% on your annual heating and cooling costs.

When you’re reading to upgrade from a standard dial to a digital thermostat, turn to the HVAC experts at Premier Indoor Comfort Systems at (770) 749-7667.

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