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What is a Ventless Air Conditioner?

If you're wondering just what is meant by ventless with regards air conditioners, this should answer your questions and teach you something about them.

There are several different types of climate controlling devices available to help regulate the temperature inside your home, office, garage or workshop.

Each has its merits and failings. But such a device that does not need to be vented to the outside has some intriguing benefits over other types, as we shall see.

Venting and Why Air Conditioners Have It

portable air conditioner with ventMost true air conditioning units, be they fixed or portable, need to be vented to the outdoors for a very good reason. The process that creates the nice chilling effect that cools our interior spaces when it gets hot outside has a hot secret that many people are not aware of.

In order to generate a cold breeze, the process going on inside an aircon unit, to keep things simple, is known as a "heat exchange" where the room's warm air is chilled using a refrigeration process much like a domestic fridge. The operative word here is "exchange".

In order to produce a cold breeze, an equal and opposite reaction has to happen inside the unit and an equal amount of hot breeze is produced as a by-product. If that heat were allowed to circulate inside the room, it would naturally negate the coldness and the temperature would not be reduced.

In fact, if anything there would be more heat produced than cold and there would actually be a net rise in temperature!

The hot exhaust is therefore vented to the outside of the building, so that only the coldness is circulated around the room. Fixed aircon units have two parts, with the chilled air producing unit inside that is linked via a "vent" through the wall to the exterior unit which expels the heat using powerful fans, similar to a cooker extractor only more powerful.

Portable Units Also Need to be Vented

Portable aircon units also have a flexible exhaust vent that must be connected to the back of the unit with the open end placed out a convenient window or other opening to vent the hot exhaust to the outside. This is a major disadvantage for this type of device as the need to connect to a suitable opening in an exterior wall of the house limits its portability somewhat.

In fact many people that bought portable aircon units found they ended up keeping them in a static position in a room because it was just too much hassle to unhook the exhaust vent from its opening to move it to another room!

How Does a Ventless Air Conditioning Unit Work?

In truth, there is no such thing as truly vent-free airconditioning as the process will always produce an equal amount of heat that has to go somewhere and inside the room being cooled is not that place! However, there is a different kind of climate controlling unit that produces lots of chilled air and can reduce the temperature inside a room by as much as 30 degrees or more.

The device often referred to as a "ventless air conditioner" is actually better known as an "evaporative" or "swamp" cooler and it cools the atmosphere in a different way to the more traditional aircon devices. Instead of passing warm air through a heat exchange process, evaporative coolers pass it through a damp membrane (usually cloth) and cooling is achieved by evaporation of that moisture.

Because there is no heat exchange process, there is no heated air produced and therefore no need to vent anything. This makes this type of cooler totally portable!

It works in a very similar way to how the human body regulates its temperature by sweating. As the sweat evaporates on the skin, its temperature is reduced producing that cool feeling you get, especially when a light breeze blows across your body.

A regular fan produces the same effect when it blows directly on you. In fact a regular fan doesn't cool the room at all, it just cools YOU when you are positioned in the breeze it creates.

If you don't believe me, set a thermometer in a room and turn on a fan and leave it running for a while. Check the temperature after a few minutes and you'll see there is no change!

Swamp Coolers Lower a Room's Temperature

The difference between a regular fan and a swamp cooler is that the latter will reduce the temperature in a room by several degrees which you can test by placing a thermometer in there. The cooler doesn't need to blow wind at the thermometer, just anywhere in the room to produce the result you want. You can see some of the top rated high power evaporative coolers by clicking that link to read my article on this site.

The only downside to the effectiveness of a swamp cooler lies in the humidity present in the atmosphere in the room. If the humidity is low, then the unit will work very well and can rapidly drop the thermometer reading by as much as 30 degrees Fahrenheit to create a very comfortable space.

However, if the humidity is high, the effectiveness of the cooler is greatly reduced. This is because only so much moisture can be present in the room's atmosphere before the device fails to produce a cooling effect any more.

When the humidity rises toward 100% then no cooling is possible with this type of device. If you live or work in an area that has very high humidity, then you're unfortunately stuck with the regular vented solution to keep your space at a comfortable temperature.

However, if you live in an area with less than around 50% humidity, you are in luck. You can use one of these great machines to stay cool at a fraction of the cost of a comparable air conditioning unit. Evaporative coolers can also be great portable outdoor air coolers for your porch, patio or terrace to blast cold air at hot sunbathers or just keep a crowd of friends or family cool outside when the weather is too hot for comfort!

They are so cheap to run, it's no big deal to have one outside because the extra electricity consumption is so low. Now isn't that worth considering?


Posted on Tue, Jan 20 2015 in Air Conditioning | 1 Comment

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1 thought on "What is a Ventless Air Conditioner?"

Santos says:
February 9, 2015

I live in CO where its very dry heat in summer. I bought a big swamp cooler installation for the whole house and it keeps it beautifully cool. Running costs are about a tenth of what my neighbor pay for the big AC system she has in her place, same size as mine. Best investment I ever made! – Santos