Which is better a Window AC or a dehumidifier
A window AC and a dehumidifier are equally capable of reducing the humidity in a room. They work in the same way. The only difference is that the window AC will cost more and can also cool your room meaningfully.
A common perception is that a dehumidifier is better at dehumidifying because it is “specialized.” In reality, the internal workings of both a dehumidifier and an air conditioner are almost exactly the same.
A thermoelectric dehumidifier works by maintaining a cold and a hot side. A fan blows air over the cold side and the lower temperature causes water to condensate and fall into a collection tank. The result is drier air.
This process is more or less exactly how an air conditioner works. The difference is that the fan on the “hot side” of a window air conditioner is outside so that the colder air from the cooling element reduces room temperature while the heat escapes into the outdoor air.
When a window AC is not in “dehumidification mode,” its fan will blow faster and its expansion coil will be colder than those components in a standard dehumidifier. This is because a window AC’s primary aim is to make your room colder.
A dehumidifier runs a slower fan so the moisture in the air stays in contact with the cooling element for longer and has more time to condensate. The cooling element doesn’t need to be as cold as an air conditioner, just cold enough to be at the dew point of the moisture in the air.
The dew point is the temperature at which water vapor condenses and it changes depending on the humidity of the air.
But these differences are not an advantage for dehumidifiers. A window AC in dehumidification mode will raise the evaporation coil’s temperature and slow its fan to maximize condensation.
There is another kind of dehumidifier that works differently from a window AC. A desiccant dehumidifier does not use temperature but rather a chemical called “desiccant” to pull moisture out of the air.
As far was whether a dehumidifier is better than a window AC? That depends on whether you also want air conditioning and how much you’re willing to pay for that function. Most people in the US have or want air conditioning, so a window AC makes sense provided that’s the best kind of air conditioner for you.
Just make sure you buy a unit with a “dehumidification” mode.
Mark is a journalist who has written about home products for two years. He holds a masters degree with distinction from the London School of Economics and an undergraduate degree from the University of Edinburgh.