Self Evaporating Portable Air Conditioner: It Does What?

When you're tired of draining an aging free standing AC, maybe it's time to buy a fully self evaporating portable air conditioner that doesn't need to be drained.

That might sound like a great idea, but before you rush out to the store you should probably make sure that you know what this type of cooling appliance is and how it works. That's where this site comes in!

How Does an Air Conditioner Work?

To understand what a fully self-evaporating portable AC is, it helps to know how a conventional air conditioner works.

self evaporating portable air conditionerKnowing that will help to illustrate what a portable unit does to keep on creating the puddle of water in its tray that you're forever needing to empty if you want your cooler to keep cooling.

Making Chilled Air

Air conditioners create their chilled air by making use of a refrigeration process much like your domestic fridge that's working away in your kitchen to keep your food cold. It basically transfers heat from one set of coils to another, so that one set cools down while the other heats up.

The air is passed through the chilled coils, which cools it down and that cold air is blasted out into the room to cool that down. The heated coils produce hot air and also a lot of moisture, which is taken from the chilled air, so what's left is a lot of hot, moist air that needs to go somewhere other than the space that's being cooled.

Hot Air Exhaust

That hot, moist air is exhausted through ducts or pipes to the outside, but not all of the moisture is expelled that way. Some moisture condenses on the cold coils just like steamy air in the shower condenses on the cold glass surface of the shower enclosure.

In an air conditioner, the condensed moisture forms large drops that drip down into a catchment area or tray located near the bottom of the unit. As it fills up, it needs to be drained periodically.

Failure to empty a full tray may cause a sensor in the unit to cause it to shut itself off until it is emptied and the automatic is shut-off reset.

What is a Self Evaporating Portable Air Conditioner?

It was discovered that the conventional air conditioning process could be enhanced somewhat by making use of that excess condensation in the cooling process. By re-evaporating the condensate, the moisture is recirculated through the cooling coils to increase their efficiency in cooling the air.

That evaporated water vapor absorbs more heat from the cooling coils and is then circulated through the exhaust ducts to the outside, instead of being allowed to condense again and drain into a tray. This is what the newer breed of self evaporating air conditioners do.

All the excess moisture is evaporated and expelled to the outside negating the need to empty a tray at least in most climate situations aside from extremely high humidity.

The Advantages

The main advantage of owning one of these devices is the elimination of the need to drain or empty a water tray. Maybe you have experienced this messy chore yourself.

This can be a frustrating and even messy operation. It can often happen that some portable units need to be raised onto a box or a table to allow the water to drain down into a bucket, since gravity is the only way to get the water from the tray to the bucket!

What's also frustrating is when the water tank is full, most AC units will trigger the auto-shut-off mechanism and you're left with no cooling. This invariably will happen when the weather is at its hottest and most uncomfortable!

But not with self-evaporating AC units!

Another less realized advantage is that evaporating air conditioners run more efficiently than conventional ones. That means they tend to use less energy to produce the same level of cooling.

This can result in reduced household energy consumption and a visible saving in dollars when the electricity bill arrives!

The Disadvantages

What could possibly be viewed as a disadvantage to these much improved mechanisms on a tried and trusted air cooling formula already?

Well, the additional cost of purchasing one of these units could be seen as a downside. However, the small extra cost is soon offset by the reduced running costs thanks to the increased efficiency and economy thanks to making good use of the re-evaporated moisture to aid in the cooling process.

Excessive Humidity

Another downside could present itself if the unit is used in a room with very high humidity in the air. In this case, the unit's self-evaporating ability may become overwhelmed by so much excess moisture condensing inside the unit that it can't realistically recycle it all.

In rare cases such as this, there is a backup solution in a water tray that can retain the excess condensate. The downside is this will need to be emptied whenever it gets full, just like any ordinary portable air conditioner.

To avoid this occurring, it would be a good idea to take steps to reduce the humidity in the room. Options include not using it in am unvented bathroom or kitchen where a lot of steam gets into the air either from very hot baths or showers in the bathroom, or boiling a lot of water on the stove in the kitchen.

Fitting ventillation fans in humid rooms such as these will help reduce that humidity by expelling the moist air out through the vent before the air conditioner has to deal with so much moisture.


If you use a portable air conditioning unit to keep you cool when perhaps it is not possible to have a window or mini-split unit or central AC as a cooling solution, it can be advantageous to choose a fully self evaporating portable air conditioner, preferably one with a dual hose design for the best efficiency and economy.

The simple sounding yet often problematic process of draining or emptying a conventional portable unit is eliminated. That's one less unwanted chore to have to undertake any more!

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There are more pages of information on the topic of keeping cool using a variety of AC equipment that you may find interesting. Please click any of the links to each page that are listed below:

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