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A salesman told me that they do not call heater (not water heater that you use in bathroom but it is the one that warm up the air around) a heater. They call it dehumidifier.

Anyone kind enough to tell me whether the word heater can be called dehumidifier?

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All said, it may not be fair to call the salesman a liar, as such. He could have chosen his pitch carefully to mean that his dehum serves you the same purpose as a heater, in which case, he is technically correct. Think air-cooler in reverse. – Kris Nov 29 '11 at 9:57
up vote 8 down vote accepted

No. They do completely different things.

A dehumidifier reduces the moisture in the air.

A heater raises the temperature of the air.

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Marked as answer - very organized & clear cut executive summary. – Larry Morries Nov 29 '11 at 7:52
+1 In the summer, a dehumidifier has the effect of making you feel cooler. In the winter I don't know if it has that effect, but it sure doesn't have the opposite effect. So not only is it not a heater, but it doesn't even help you feel heated. – Monica Cellio Nov 29 '11 at 15:20
In practice a closed loop dehumidifier must also warm the place up, but if it is well designed a small fraction of it's power draw is converted to heat and the rest goes to condensing the water vapor. – dmckee Nov 29 '11 at 17:11
@dmckee: It necessarily converts 100% of its power draw to heat, but hopefully takes out a lot of moisture with that power. – Charles Nov 29 '11 at 22:02
@Charles is correct. All the energy used by an appliance ends up as waste heat. – MετάEd Nov 29 '11 at 22:40

No. The primary job of a dehumidifier is to remove the moisture vapour (humidity) from the air and not to heat the air.

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+1 For explaining and answering No - Now, I know that the Salesman is actually lying. – Larry Morries Nov 29 '11 at 7:51
@Larry Morries Well, you can have a humidifier and a heater in one appliance. Nothing stopping that from happening. – Phoenix Nov 29 '11 at 10:45

The word dehumidifier does not have the same meaning as the word heater.

Now, practically speaking, a typical dehumidifier does not significantly heat the room. It transfers heat from the air into itself, which cools the air and causes condensation. Then it transfers the heat back into the cold air and recirculates it. The net heating is zero – except that any electrical appliance, even a light bulb, creates some waste heat in its operation, and will cause its environment to be slightly warmer.

Suggest this question be moved to DIY which is a better place to get answers to questions about home appliances.

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+1 For the clear explanation to describe that there is differences between the two term. – Larry Morries Nov 29 '11 at 7:50
Actually asking in here cause I am looking for differences & meaning between the two term. – Larry Morries Nov 29 '11 at 7:54
For a dehumidifier, the amount of waste heat could be significant, and warm the area more than slightly. – Nate Eldredge Nov 29 '11 at 13:51
A $178 Frigidaire 30 pint dehumidifier is rated at 390 watts. So the amount of waste heat is equivalent to several bright incandescent lightbulbs. A small Crane flat panel space heater is rated at 1500 watts but costs only $49 and does not need to be emptied periodically. (Prices courtesy of Lowe's.) So the waste heat from a dehumidifier is comparable to the waste heat from the vanity lights in the bathroom, but can't compete with an actual heater. – MετάEd Nov 29 '11 at 19:25
@MetaEd: So that dehumidifier gives off about a quarter of the heating of the space heater, while the vanity lights (if they're like the three in my bathroom) are about 1/40th. – Charles Nov 29 '11 at 22:05

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