Basic Types of Portable Air Conditioners


How do portable air conditioners work?

Portable air conditioners work in the same way as any other air conditioner. They use a refrigerant to to absorb heat and humidity from the air inside a room and then release it outside, making the room cooler and less humid (drier are feels cooler than humid air).

A little more detail about the process:

An evaporator inside the air conditioner contains cold liquid refrigerant. When the warm air from the room blows over the evaporator, the refrigerant absorbs the heat from the air, turning the cold liquid into a low-pressure cold gas. The cold gas cools down the air blowing over the evaporator coil and that cooled air is blown back into the room.

The low-pressure, cold gas is then compressed by the compressor into a high-pressure, hot gas, which releases heat to the outside air as it flows through the condenser coil. The hot gas then turns back into a liquid, and the cycle starts again.

Freon may still be the most commonly known chemical refrigerant, but it’s been replaced with much more environmentally-friendly refrigerants. It is such a memorable name that many consumers still refer to refrigerants in general as “freon” instead of, say, “R-410A”.

Types of portable air conditioners

There are many ways to classify portable air conditioners. We list some of the major classifications below.

Vented versus ventless

Vented (with hoses)

Portable air conditioners that use a refrigerant can reduce temperatures in any kind of environment. The more enclosed the area is – top, bottom and sides – the more effective the cooling can be, using less energy and costing you less.

These air conditioners are vented with hoses that move hot air away from the area being cooled. The hoses on portable air conditioners might look complicated, but don’t be intimidated by the way they look. They are simple to use and make perfect sense once you know the basics of air conditioning.

If the air conditioner is positioned inside the room, the exhaust hose(s) directs the hot air away from the room being cooled. The exhaust hose is directed through a window, an opening between side panels of a tent or booth, or an opening in the wall, ceiling, or floor.

If you don’t like the look of the hoses you can position the portable air conditioner so it blocks the view of the hoses or cover the hoses with something nicer to look at. Don’t block the cold air flow coming out of the unit, though.

Sometimes the portable air conditioner is positioned outside the area to be cooled and cooling nozzles lead into the area, keeping the unit out of site and reducing noise levels.

Ventless / evaporative coolers

Air conditioners that are not vented use water evaporation to cool the more open areas that are usually found in outdoor spaces. Technically, these are not true air conditioners. They are evaporative coolers, commonly called “swamp coolers.” They pump water over pads inside the unit and blow air over the pads. The evaporation of the water cools the air.

Swamp coolers work better in dry climates and conditions than in humid conditions, so if your area is very humid, learn about other cooling solutions like outdoor fans and shade on our in-depth pages, or visit our comparison page for an overview of these methods.

You can learn more about them in our series of articles on swamp coolers.

Air cooled versus water cooled portable air conditioners

Air cooled

Most portable air conditioners use air to cool the condensers (as described above). These are the most common type and are available in the widest range of products and options. They use one or more exhaust hoses to remove the heat from the cooled area and heat that’s generated by the unit, itself. Their set-up is quicker than water-cooled types and they only need electricity to operate. They are larger per the same-sized space than water-cooled models and are not as energy-efficient.

Water cooled

Unlike air cooled units, water cooled air conditioners do not create a lot of heat on their own. They work like true air conditioners but use water instead of refrigerants to remove the heat from a cooled area. They need an ample water supply and a drain rather than a pan, as well as an electrical supply. They are smaller and quieter than air cooled types for the same sized spaces. They are mostly used for medium to large sized spaces because their efficiency increases as they get larger.

Don’t confuse water cooled portable air conditioners with evaporative coolers or “swamp coolers.” Unlike either air cooled or water cooled air conditioners, swamp coolers evaporate water into the area to create a cooling effect. They need fresh air flow into the area being cooled, and add humidity to the air, so they are less effective in humid climates and conditions.

Ventilation: single hose versus double hose portable air conditioners

Single hose

Smaller units use only one vent hose. Warm air from the area to be cooled is drawn directly into the air conditioner where it is cooled and blown out as cold air. Some of that air is used to operate the unit and the rest is sent through the hose away from the area being cooled.

This process creates humidity which is pushed out through the exhaust hose or a drain hose, or collected in a condensate pan.

Double hose (recommended for outdoor cooling)

Double hose units have a separate intake hose that brings in hot air from outside and draws it into the air conditioner where it is cooled and blown into the enclosed area as cold air. A separate exhaust hose directs the hot air and humidity away from the enclosed area.

More powerful units use a double hose system because they handle more air flow than the single hose can.

Double hose portable air conditioners are recommended over single hose units for outdoor cooling. More condensation is removed through the exhaust hose, so there is less to drain or remove manually. Dual hose units are much better at expelling the hot air, making them more efficient. Stellar efficiency is hard to get from a portable air conditioner outdoors, but a dual hose unit can help you achieve it better than a single hose unit.

Other Outdoor Cooling Methods

If you have a more open outdoor area that needs cooling, consider outdoor fans, misting systems, or misting fans which combine misting systems and outdoor fans into a single unit.

Swamp coolers (desert coolers) use a similar technology as misting systems (evaporation cooling), but in a contained unit. They are sometimes called air conditioners, but use a different technology than true air conditioners.

Outdoor shades are a nearly universal solution that combine well with every other cooling option.

Take a look at our comparison page to learn which outdoor cooling solutions may be best for you.