How Do Portable Air Conditioners WorkPortable air conditioners are a practical way to cool down a room.

They’re also great devices for assisting a central air system that cannot keep up with the demands of the household.

In this post, we’ll address the most common topics and provide answers related to the question “How do portable air conditioners work?”

By the end of this guide, you’ll have a clear understanding of how does a portable air conditioner work to cool down your home.

To find out what your options are, take a look at our guide on the best portable AC units.

We also have a guide on the best cheap portable AC units too.

How Does a Portable Air Conditioner Work (Explained)

The main purpose of a portable air conditioner is to extract the heat out of a room and transfer that heat outside.

In order for this process to work, a portable conditioner must have three key components:

  1. Refrigerant (to cool the air)
  2. Compressor (to compress the refrigerant)
  3. Fan (to move the air)

How does a portable air conditioner work refrigeration cycle

With those three components combined, here is how a portable air conditioner works:

  1. The fan spins around and draws the hot and humid air from an indoor room inside the portable air conditioner.
  2. Inside the unit, the hot air is cooled down by the condenser coils. This process also extracts the moisture from the humid air by condensing the water vapor onto the coils.
  3. As the hot air is transferred to the refrigerant in the coils, the energy applied to the refrigerant causes it to heat up and turn into a high-pressure gas that moves through the AC system.
  4. The collected moisture from the air is removed in either two ways: through a self-evaporative system that vents the water vapor to the outside or collected into an internal buck that must be emptied.
  5. During this entire process, the refrigerant must be compressed by the compressor for everything to work. And the heat that is generated with these components must be vented to the outside. That is why portable air conditioners use an exhaust hose.

One thing to note is that when the condenser coils get dirty, the refrigerant cannot absorb as much heat from the indoor environment.

Dirty coils can cause the compressor to work harder to do its job, and this can eventually cause the compressor to overheat and stop working.

Single Hose Versus Dual Hose Portable Air Conditioners

You just learned how do portable air conditioners work to cool down a room. And one of the steps in the process is to vent hot air from the components to the outdoors.

Portable air conditioning units will either have one exhaust hose or two, also known as a “dual hose portable air conditioner”.

If your unit has one hose, it takes air from the room that it is placed to cool down the system. However, because it is being removed from the room, it can cause some negative pressure.

If your portable AC unit has two hoses, then one hose will be used to bring air in from the outside to cool down the unit, while the other will exhaust it to the outdoors.

Because of their design, dual hose portable air conditioners do not create negative pressure like single hose units.

Can You Extend the Exhaust Hose on a Portable Air Conditioner?

It is not ideal to lengthen the hose on your portable air conditioner.

The hose is designed at a specific length for the machine to operate most efficiently.

Extending the hose could also cause your unit to overheat and will void the manufacturer’s warranty.

Venting the Exhaust Hose

The most common way to vent a portable air conditioner exhaust hose is out a window.

Therefore, most portable AC units come with a window kit that fits traditional size windows.

It is much harder and more complicated to use a sliding glass door to vent the exhaust hose.

The standard window kits usually are not long enough to extend to fit the entire height of a sliding glass door.

If you want to install your portable air conditioner to a sliding glass door then you have two options:

  • Purchase an extension kit, if one is available.
  • Fill the empty void with styrofoam or plywood to cover up the open area.

No matter which installation route you plan on using, it is important to check the owner’s manual to make sure all guidelines are followed.

Do You Have to Drain Water from a Portable Air Conditioner?

On some models of portable air conditioners, you do have to drain the water. But there are various methods for how to do this.

As you learned, one of the main jobs of a portable air conditioner is to take moisture out of the air so that it is less humid.

Portable air conditioners have several different ways of dealing with condensation and moisture.

Fully Self-Evaporative Model

These types of portable air conditioners are the most convenient to own.

Self-evaporative portable air conditioners work to evaporate the moisture automatically out of the exhaust hose at the same time as the hot air.

With this model, you will rarely have to empty any collected water from an internal bucket (or tank).

This model of portable AC is one of the most popular because of the little maintenance involved.

Some of the top brands that have a fully self-evaporative system are Avallon, DeLonghi, and Whynter.

Gravity Drain With or Without a Condensate Pump

This style of portable air conditioner gets rid of water through a drain hose that can be attached to the unit.

These drain hoses usually come with the portable air conditioner when purchased.

As the name suggests, gravity pulls the water down and out of the portable AC unit and lets it drip outside of the unit.

To get this method to work, all you need to do is hook up the hose to the unit, then route the other side of the hose to a nearby drain on the floor.

If you don’t have a floor drain or want to move the collected moisture to another location, then you can attach a condensate pump to the drain hose.

A condensate pump will draw the water into the device and pump it upwards so that you can dispense the collected moisture into a sink or out a window.

Collection Bucket (or Tank)

A third option for draining water from a portable air conditioner is to use the internal collection bucket.

Over time, the moisture removed from the air will be collected in this tank and you will have to empty it.

To perform this step, all you need to do is turn the portable air conditioner off, then remove the collection bucket and empty out the water.

Finally, replace the bucket back on the unit for it to start working again.

Portable Air Conditioner Requirements

Different models of portable air conditioners will require different things, but most of them are easily set up.

The whole point of a portable AC unit is to remove hot and moisture from a room while also cooling it down.

For this to work, the following requirements are necessary:

  • A window or other opening to the outside for the exhaust hose to connect to.
  • Free space next to the window or opening for the unit to be positioned.
  • A 115/120 volt power outlet. The exception here are portable AC units that use 14,000 BTUs or more. These air conditioners may require to be on their own circuit with a differently sized outlet.

As you probably know, any air conditioner is going to use a considerable amount of energy. So it is important to keep other high energy devices on a separate circuit to keep from overloading one circuit.

Additional requirements for your particular brand and model can be found in the portable air conditioner owner’s manual.

Using a Portable AC Unit in More Than One Room

Depending on the size of your particular AC unit, you may be able to cool several rooms.

Just like a regular window air conditioner, these machines can cool an immediate area, but the cold air will not be able to travel down long hallways or doorways not connected to the space.

If you are trying to cool two rooms with large openings between them, then it may work to cool these two areas; however, the cooling may not be even.

How well do portable air conditioners work for this type of setup will depend on the distance between each room and the sizes of them. Just make sure that the two rooms are connected to each other and that any doors are open for the cold air to flow into them.

For small rooms, you won’t need a very large unit. You may even be able to get away with another type of air conditioner altogether.

Take a look at our guide on the best AC for small room to see what options are available.

Are Portable AC Units a Good Choice?

Portable air conditioners are a good option for people who fall into any of these categories:

  • You who want an AC unit that they can be moved around the house from room to room.
  • You want an air conditioner that’s easy to install without any heavy lifting.
  • You want a cooling unit that doesn’t have to be permanently installed inside a window.

If any of those situations apply to you, then you will want to consider a portable air conditioner for your home or apartment.

These AC units are a good choice for people who want a cooling device that gives you more flexibility than a window-mounted air conditioner.

Do Portable Air Conditioners Work Without a Window?

The most common method for installing a portable air conditioner is to vent it out a window. The hot air from the unit must be expelled somewhere.

You can’t run a portable air conditioner without venting the hot air out of the room.

However, a portable AC unit doesn’t necessarily have to be vented out a window.

Instead, you could vent the hose through a drop ceiling, up a chimney, through a hole in the wall that leads to the outside, or connect it to an existing dryer vent that flows to an exterior wall.

A portable air conditioner can work without a window, but you’ll have to do some modifications to make it work efficiently.

Do You Have to Put Water in a Portable Air Conditioner?

No, you do not put water in a standard portable air conditioner that uses an exhaust hose.

These portable air conditioners work by extracting moisture out of the air and expelling it outside through self-evaporation, collecting it in a bucket (also known as a tank), or letting the water flow out through a hose into a drain.

You do not put water inside the tank of these air conditioners.

There is another type of portable AC unit called a “ventless air conditioner” and these units do require you to put water in the device.

Ventless AC units are basically a big fan system that pulls the water up out of the tank and mists it into the air as a way to cool down a room. These air conditioners can work without water, but they won’t cool as efficiently.

Why are Portable Air Conditioners Bad?

Some people consider portable air conditioners to be a bad deal because they are not perfect units. They do have some flaws in the way they work.

The most common reason a portable air conditioner is considered to be bad is that they take up floor space. These units are not installed inside a window, and therefore, they must be positioned right next to the window, and that takes up floor space.

Another reason people don’t prefer portable air conditioners is because they can be noisy. Even when these units are not actively cooling a space, the fan will still continue to run. These units do not turn off and become silent like window air conditioners.

Some people also don’t like the fact that portable air conditioners are only good at cooling down a single room. However, there are no available cooling units that can provide air conditioning to more than one room at a time except for a central air conditioning system.

And finally, some portable air conditioners are less efficient than other types of AC units. That means they can cost more to run each month than other air conditioning options.

Common Portable Air Conditioner Features

Now that you know how does a portable air conditioner work, you may be wondering what type of features these units come equipped with.

The set of features will vary by brand and style but here are the most common options you will find on a new unit:

  • Auto Mode: After you set the temperature, the unit will turn the compressor on an off to maintain the set degree.
  • Dry/Dehumidify Mode: The unit will extract moisture from the air without changing the temperature of the room.
  • Fan Mode: The unit will circulate air through the room without altering the temperature or extracting moisture.
  • Timer: This allows you to set a delayed start or stop for the air conditioner according to the time of day.
  • Remote: This allows you to operate the AC unit from a distance.
  • Oscillation: The air vents on the portable air conditioner will move from side to side to cool the room more evenly.

Portable Air Conditioner Maintenance

If you want to keep your portable air conditioner working well and extend the life of the unit, then you can follow these basic maintenance tips:

  • Clean the air filter every two weeks. Dirt and debris that is collected from the air will clog this filter. To clean it, just wash the filter using a mild dishwashing detergent and warm water. Then, rinse the filter thoroughly and shake out the excess water. Always, let the air filter fully dry before putting it back into the air conditioner.
  • Wipe down the air vent grill regularly to prevent blocked airflow from any trapped hair particles.
  • Clean the exterior of the unit using a damp, lint-free cloth and mild dishwashing soap. Always unplug the portable air conditioner before performing this maintenance step to prevent shock or fire hazards.
  • If your unit does not self-evaporate, then empty the water collection bucket or tray on a weekly basis to prevent mold growth. Also, clean this tray before storing the unit.
  • When storing the AC unit, keep it in a cool, dry area, and cover it with a sheet or put it back in the carton that it came packaged in.

How Do Portable Air Conditioners Work Summary

We hope you enjoyed this guide on how do portable air conditioners work.

Hopefully, the information provided here answered all of your questions about how does a portable air conditioner work to cool down a room.

As you discovered, these units include several internal components to extract hot air out of a room and have a variety of methods for removing collected moisture.

There are many different brands and models of portable air conditioners but they all mostly work in the same way.

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About David Morrison

David is an Air Quality & Comfort Technician. He has expert knowledge on the technology and design of air purification, air conditioning, and heating systems. His main role is to write content that helps people get the most value out of their air purifiers, air conditioners, and heating units. (See Full Bio)