Difference Between Air Conditioner and Dehumidifier

What is the difference between a air conditioner and a dehumidifier?

The difference between an air conditioner and a dehumidifier is where the warm air and condensation that the unit is generating are dispelled.

Air conditioners dispel the heat and moisture outside of the house and a dehumidifier dispels the heat and moisture inside of the house. (Though most modern dehumidifiers have a port to drain the water with a garden hose to a sink or outside)

Mechanically they are very much the same. Both have a hot side and a cold side.

The difference is how they are used.

And the air conditioner is primarily used to cool down a room. So the hot side of the air conditioner is outside.

A dehumidifier is used to reduce the moisture in the air. Instead of dispersing the hot air outside of the room, it releases it back into the room.

Releasing the hot air back into the room helps the dehumidifier continue to draw out more humidity from the air.

Do dehumidifiers cool a room?

A dehumidifier is not made to cool a room. Though indirectly it will help the room feel more comfortable because of the reduction of humidity.

But remember the heat generated from the dehumidifier is being released back into the room as it is dehumidifying.

And though the heat may not be significant because of the lack of moisture in the air now that the dehumidifier is running, there is still going to be an increase in the temperature.

Do dehumidifiers help with heat?

Dehumidifiers do help with heat in directly because they reduce the moisture in the air that is perceived as heat.

But you should know that the room that the dehumidifier is being used in is not going to be cooler.

How much heat does a dehumidifier create?

Think about it this way. If you were to take a window air conditioner and sit in the middle of the room, one side of the air conditioner would be cool and the other side would be hot.

With a dehumidifier, you’re only getting the hot.

Dehumidifiers are meant to reduce the humidity in the home more as a way to reduce the effect of moisture on the structure of the house and as a preventative for mold growth then they are as a way manage the climate in the house.
The fact that a dehumidifier can make the room feel more comfortable is more like a happy side-effect.

Air conditioner as a dehumidifierAir conditioner as a dehumidifier

Does AC dehumidify?

An air conditioner also dehumidifies the air as it is operating. Part of the way it is able to cool the air is it is pulling moisture out of the air and draining it outside.

Air conditioning is infinitely better as a dehumidifier because it not only cools the house as it is dehumidifying, it disperses the hot air outside and drains the condensation in the outside as well.

Many central air conditioners come with a dry mode setting to be able to dehumidify a room without cooling it when the outdoor temperature is more muggy than hot.

Is dry mode more economical?

Dry mode consumes much less energy than cool mode on the AC because it runs the compressor at about half-speed.

Does a dehumidifier use a lot of electricity?

Dehumidifiers are known energy hogs.

If you look at it a breakdown aware most of your energy cost are going,
It is to the main appliances like the refrigerator and the HVAC that use compressors.
99% of dehumidifiers on the shelf run off of a compressor. So you can expect your electric bill to show a small increase when you run the dehumidifier.

is it cheaper to run an AC or dehumidifier?

A dehumidifier uses only about a tenth of the electricity that an air conditioner uses. An standard AC runs full on and then off as the temperature is reached.
And then restarts when the temperature rises above the temperature designated on the thermostat. This repeated cycle results in an enormous amount of energy consumed and a very high energy bill. See Inverter AC

A dehumidifier doesn’t cycle off and on like a AC which keeps the cost much lower than an AC.

But though the air conditioner is a dehumidifier, its primary use is to cool down the air so it doesn’t reduce the humidity in the air as much as a dedicated dehumidifier.

Also air conditioning is typically not ran to the basement or crawl spaces.

And those are two of the main spots you need a dehumidifier to reduce moisture.

Portable air conditioner as a dehumidifier?

If an air conditioner and a dehumidifier are mechanically the same, does that mean I can use a portable air conditioner as a dehumidifier?

It does sound great in theory, but a portable air conditioner does not drain condensation like a dehumidifier.

The condensation of a portable AC  basically spits out through the rear show the unit and drips of a drainage hole.

Collecting the water so that it is not become part of the humidity problem that you’re trying to resolve is not easily solved.

Unfortunately when it comes to portable air conditioners and portable dehumidifiers, they are not interchangeable.

Though in many cases they are combined into one unit.


Dehumidifiers and air conditioners are very closely related and mechanically run nearly the same.

The main difference is or how they expel the heat and condensation that they generate.

The AC dispels the heat and condensation outside and a dehumidifier dispels the heat and condensation inside.

But how they are used and what they are used for is the real difference.

Air conditioning is used to cool off a room. De-humidification just happens to be part of that process.

Dehumidifiers are not made to cool off a room but to reduce moisture.

Though running an AC can help reduce the humidity in a room, a portable dehumidifier will do much more to reduce moisture and can go
into areas where there is no air conditioning like the moldy basement and crawl space.

Dehumidifiers also do not cool of a room directly and in fact will make a room temperature rise.

Published by

Dennis Reed

Dennis Reed Owner and Author @ BreatheBetterAir.org