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Does a dehumidifier alone use less energy than an air conditioner?

Bill Yribia | Posted in Energy Efficiency and Durability on

I live in South Florida (very humid) in a small apartment that has an air conditioner with a dehumidifier. The “Mode” control has four positions: fan, cool, energy saver, and dehumidifier. The brand is LG. Will I save any energy by using the dehumidifier mode instead of the air conditioner mode? If so, how much energy, roughly, will I save? Thanks.

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  1. Cramer Silkworth | | #1

    Is it a window unit or a split unit? On window units "dehumidification mode" usually just sets the fan speed to low to give the air more residence time at the coil to pull out more moisture, but energy use doesn't change much - only the difference in fan speed, maybe 25-50W lower than high speed. Get yourself a Kill-A-Watt meter to find out.

    If it's a split system dehum mode may be slightly more intelligent in that it will try to not overcool the space while dehumidifying, but I don't think you'll see much energy savings here either.

    At the end of the day there's always a compressor running. The difference is whether or not AC makes the space too cool while dehumidifying. If it does, a freestanding dehumidifier is probably the better way to go - but energy use will be roughly the same for the same amount of humidity removed.

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