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When you think of humidity, you probably also think of heat; after all, they tend to go hand in hand. That said, most people who live in those high-humidity areas depend on their air conditioners.

It’s been said that air conditioners dehumidify the air as they run—but is it true?

This post will look at the dehumidifying ability of air conditioners, the distinctions between them and dehumidifiers, and the pros and cons of each.

So, let’s get started!

But first, a down and dirty to the question of the hour.

Table of Contents

Do Air Conditioners Also Dehumidify?

Air conditioners do dehumidify as they cool the air, but not to the same extent as a dehumidifier. Because air conditioners and dehumidifiers both work through the refrigerative cycle, the moisture naturally collects on the cooling coils as the air passes through.

Dehumidifiers and air conditioners are built and operate fairly similarly, but they aren’t meant to provide the same function. So let’s explore their similarities and differences a bit more in-depth.

Why Air Conditioners Dehumidify

The short answer is an AC dehumidifies because, similar to a dehumidifier, it cools the air significantly before releasing it back into the room. In order to cool it, the machine must cycle the air over copper coils coated in the refrigerant.

When the air passes over these coils, it becomes so cold that a lot of the moisture is automatically released onto them.

If you’re unfamiliar with the refrigerant cycle, this might sound confusing. But don’t worry—we’ll be diving into that in just a moment.

Dehumidifiers and air conditioners both contain those copper coils coated with refrigerant. In this aspect, because they are both working to remove some of the moisture from the air, they are pretty similar. However, outside of this, the two also have many differences.

What Is the Refrigeration Cycle, and How Does It Work?

The refrigeration cycle is the process of circulating warm air through coils (that have been cooled down significantly) and then releasing that cooled air back into the atmosphere.

There are four components to the refrigeration cycle:

The compressor
The condenser
The expansion device
The evaporator

These four components actively work together to cycle and cool the air. How does this work?

The compressor controls the flow of the refrigerant. It does this by functioning as a motor and pump. The compressor takes the refrigerant and compresses it, as its name suggests.

Illustrated diagram of the Refrigeration Cycle — Courtesy of InterN ACHI

The condenser works to condense the refrigerant after it has already cycled through the compressor. When the refrigerant is released from the compressor, it’s become sweltering and fully pressurized. The condenser cools the refrigerant into a liquid state.

The expansion valve releases some of the pressure of the refrigerant and cools it even more.

Finally, the evaporator turns the refrigerant back into a gas and releases it onto the coils that collect the moisture as the air passes through.

How Dehumidifiers and Air Conditioners Work

Both dehumidifiers and AC systems run on the refrigeration cycle. Actually, any appliance that works to cool something down does, for example, your refrigerator.

While both machines work with the refrigeration cycle, the process is quite different. The way the air is brought in and circulated throughout the device is an entirely different process with dehumidifiers versus air conditioners.

Let’s look at how exactly each machine works so that we can better understand what this looks like.

How Air Conditioning Works

Air conditioners run on a split system, which just means that there’s an inner part and an outer part to the machine. They work by bringing in hot air, cooling it down, and releasing it into the room as cold air.

We’ll try to explain this as simply as possible. The compressor compresses the refrigerant into a gaseous form at the beginning. From there, it begins moving toward the condenser. When the refrigerant is sent through the compressor, it gets hot! The condenser combats this characteristic.

Central air conditioner units on the exterior of a home.

The condenser’s job is to start removing some of the heat in the refrigerant. The process of heating and cooling the refrigerant causes it to shift from gas to liquid. However, the liquid is still very hot.

At this point, the refrigerant passes through the metering device, where it changes back into gas. The gas is then sprayed on the cooling coils where the cool air comes out. From there, the refrigerant continues back up the suction line, and the process repeats.

If this was a little confusing, check out this article for more information.

How A Dehumidifier Works

Dehumidifiers work by repeating the same process again and again. They pull in the moist air and run it over a cold coil that the refrigerative process has cooled. This coil is known as the evaporator. Because the evaporator is frigid, the moisture easily falls out of the air and into the water tank.

A homeowner opens the water collection chamber of a dehumidifier to empty it

One of the main differences between dehumidifiers and AC is that dehumidifiers take the air and heat it back up before releasing it into the room.

This process continues until most of the humidity has been released from the room.

How Much Does an Air Conditioner Dehumidify?

Air conditioners do help lower humidity levels in your home thanks to the cooling process of the air. However, the primary purpose of AC isn’t to dehumidify—it’s to cool the room. So the question then becomes, how much precisely does an air conditioner help dehumidify?

It turns out not that much. If you live in a more tropical environment, your humidity levels will be through the roof.

Dehumidifying is a side benefit of running your air conditioner, but it’s like the person at work who only does the job halfway right while the rest of you ensure everything is up to standard. This isn’t bad because it’s not the air conditioner’s job to dehumidify the room.

How much moisture is removed by being run through the air conditioner depends on a few factors.

First, the air conditioner’s size relative to the room you are cooling. Bigger AC units will remove more moisture as they cool the air, but they’re also going to shut off as soon as the temperature gauge has registered that the room is cool enough. Smaller models, on the other hand, aren’t going to shut off but can’t handle the humidity load.

Secondly, how humid is the environment? Because air conditioners aren’t made to dehumidify, they can get overwhelmed with the amount of moisture in the air. Often, this leads to the coils freezing up and other issues.

Finally, dirty air filters prevent the unit from dehumidifying the room well, if at all. When was the last time you thoroughly cleaned your AC unit?

Closeup on a mini-split compressor with a homeowner cleaning it by spraying water into the grille.

When dirt and grime get built up inside the machine, it’s near impossible for the air conditioner to cool the air, much less dehumidify your home.

Air Conditioning vs. Dehumidifying Energy Use

Air conditioning systems use a lot of energy, especially if you live in a sweltering climate. And as we discussed, humidity usually follows heat.

Large AC units consume around 4100 watts every hour, which is a lot! Mid-sized models still use up to 1440 watts per hour. While you can decrease energy usage by using a smaller air conditioner, it won’t do much to cool your home.

Dehumidifiers, on the other hand, use less than 50 watts per hour, which is a vast difference. So even if dehumidifiers cost a little more than air conditioning upfront, the energy usage will be significantly less. The result will be lower costs as time goes on.

AC vs. Dehumidifier: Which Is Better?

When it comes to which of these machines is better for the job, it depends on what the job is.

If you want to cool your home, you should invest in an air conditioner, especially if you live through those southern summers. Dehumidifiers do not release cold air. Instead, they reheat the air after it goes through the cooling process to dehumidify. In essence, the air conditioning skips this step.

If the purpose is to dehumidify, there’s nothing that can take the place of a dehumidifier—removing moisture is why they’re built. These machines cool the evaporator coils to the perfect temperature to make sure as much water vapor condenses as possible before the air is reheated and released.

The evaporator coil of an air conditioner in the grass outside a home — A central air evaporator coil. Courtesy of Rescue Air

One problem with AC systems is that there’s no way to use them as a dehumidifier without also using them to cool the room. In many places, humidity levels stays high even in winter, and who wants to be running their air conditioners all winter?

If you turn the AC on to “fan only” mode, the air isn’t being cooled, which means the cooling coils aren’t working to reduce the humidity level.

The Best Option

If you want the best option available, we recommend having both. In this case, you ensure that the humidity levels are always being controlled, and you’re still making sure to stay cool in the hot weather.

A word of caution, though. Running both of these machines full time can produce air that is way too dry, which creates new problems.

Newer Model Air Conditioners

If you’re insistent on just using air conditioning, we have great news for you. Many newer models of air conditioners are being built to be able to dehumidify without cooling at the same time. Unfortunately, if you have an older air conditioner, this isn’t going to be an option.

However, if you want to upgrade your AC system to a newer model, you can expect almost as much control over humidity levels as you would with a dehumidifier. In addition, these units allow you the power to choose whether or not you would like the machine to cool or dehumidify.

The problem is that, even with newer air conditioners, you can’t expect them to work as well as a dehumidifier. So the energy usage will still be significantly higher if you choose this route.

Of course, this isn’t an option if you have a home with central heating and air. You’ll still have some humidity filtered through as you would with a standard window unit, but it won’t be something you can control, unfortunately.

Our advice is this: If you’re going to get a new AC for dehumidifying, go with a dehumidifier. They’re cheaper, use less energy, and do a much better job dehumidifying the air.

The living room of a Florida home with a dehumidification system on the floor and homeowner sleeping on the couch

Tying It All Together

Living in a high-humidity environment is challenging. It negatively affects your health and the standard of your home, and it’s always best to go ahead and remove most of the moisture if you can.

You can remove the humidity in two ways—either through an air conditioner or a dehumidifier. While they both lessen the humidity to some degree, dehumidifiers do significantly better than central air.

The downside to dehumidifiers is that they don’t have a cooling mechanism, and the air released back into the room is always around the same temperature as the air that went in. The downside to using air conditioners is the high energy usage and the fact that they aren’t built to handle that much moisture.

Conclusion

Both dehumidifiers and air conditioning have their benefits. Air conditioners do dehumidify the air and are a great option in a pinch or if you cannot afford both devices.

However, you must keep the above tips in mind to ensure you make the best decision for yourself and your home.

Does Your Air Conditioner Also Dehumidify? (If So, How?)