Although there are many different types of thermostats available today, they all have one basic control in common that’s a frequent source of confusion — the fan setting button that offers a choice of “on” or “auto.” If you’re unsure about the best thermostat setting to use, here’s a helpful primer on the two settings and advice on which one you should use with your home’s cooling system.
How Do the “On” and “Auto” Settings Differ?
Your thermostat’s “on” and “auto” settings control when the blower fan operates. When the button is set to “on,” the fan runs continuously, even when the cooling equipment cycles off. When it’s in the “auto” position, the fan cycles on and off in tandem with the cooling coil.
The “Auto” Setting
Setting the fan control to auto is the best choice when you’re running a cooling system with a single-speed fan motor. On this setting, the fan operates at optimal energy efficiency and since air circulates through the HVAC filter fewer times a day, you won’t have to replace it as often. On the downside, you may notice that the house starts to feel stuffy due to lack of air movement whenever the A/C cycles off.
The “On” Setting
Using the “on” setting isn’t recommended when you have the cooling system running, because a continuously-operating fan sends warm, humid air from the ductwork out into your home whenever the cooling coil is off. This erodes your comfort, adds to the equipment’s workload and increases your energy bills. Then, there’s the added cost of electricity used by the fan itself, which is comparable to a running refrigerator.
The only real advantages of using the “on” setting are increased air movement and better filtration, but upgrading to a system with a variable-speed blower is a more energy-efficient option. This type of blower fan runs almost continuously on low, but it intuitively modulates its speed to match the system’s airflow needs.
For expert answers to questions you may have about choosing the right thermostat setting, contact the Lorain home comfort pros at Energy 1 Heating & Air Conditioning today.
Our goal is to help educate our customers in Lorain, Ohio about energy and home comfort issues (specific to HVAC systems). For more information about thermostat settings and other HVAC topics, download our free Home Comfort Guide or call us at 440-201-2959.
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