Portable Air Conditioner (No Vent Required)

I often get asked about the ventless portable air conditioner, no vent required units that are found on sale online and in stores. Is it real? Does it even exist? The answer is yes, there really is cooling device that needs no exhaust hose because it makes no hot air and you can buy and run it cheaper than an AC.

I'll let you into a little secret...

The device works amazingly well, but it's not actually a true AC. A true portable or free standing AC needs an exhaust hose for venting the hot, moist air it produces out of the room through a window or dedicated port in the wall, or it would not cool the room or work properly!

There is some confusion as to what kind of cooling device can operate in a closed space and not need venting to the outside. A true air conditioning unit that's not fixed or part of a central heating and cooling system must have a way to expel the hot exhaust air it produces. What could it be, then?

Portable Evaporative Coolers (Don't Need Exhaust Hoses)

portable air conditioner no vent hoseThe alternative to portable AC is the low-cost, low-running-cost swamp cooler, or to give it its correct name, the evaporative cooler. This is a cooling device that works in a different way to AC and does not produce any hot air, only a chilled breeze that is really pleasant to experience on a really hot day.

You can buy swamp coolers in different sizes and output ratings. They range in size from tiny hand-held or desk mounted devices to the larger, free standing units that look very much like their AC counterparts (see image) and even huge wall-size monsters that are used to cool industrial workshops and large factory spaces.

So when you buy an evaporative cooler, you can be quite sure it's not a toy or some kind of elaborate fan. At least not when you see big business using a larger, industrial version to keep their workshops cool and save a lot of money on energy costs.

Economical Cooling

I already mentioned that this type of cooling device is cheaper to run than AC, but I didn't say by how much. Well, a typical evaporative cooling unit will use from 1/4 to 1/20th the amount of electricity that a comparable size AC uses to produce a similar level of cooling.

That's a hefty saving in dollar terms when you calculate your utility bill!

You can buy a range of evaporative coolers online from stores like Amazon. The best brands are generally US-made devices like Portacool that cost a little more but are far more reliable, robust and long-lasting.

There are cheaper import brands that are very popular, such as Honeywell, Luma, NewAir, SPT etc. But I sometimes see people have returned cheaper units because of defects, leakages or poor workmanship which you'd except from a cheap model.

The old saying, "cheap is false economy," is often correct considering purchase price. But remember, evap coolers are a lot cheaper than AC to run and that's good economy!

However, I can already hear the question forming in your mind as you read this:

"If these device are so cheap to run, how come everyone still uses expensive AC to keep cool?"

That's a stinging question, for sure. There is a good reason why most people and businesses still use AC and not evaporative cooling. Humidity.

One reason people return these units is they believe they don't work. That usually happens when people buy a swamp cooler and think it's an AC (it most certainly is NOT).

They try to run it in a humid atmosphere where it will not produce much chilled air (I explain that in more detail below). Please read my explanation of humidity further along in this article, because it's very important.

Before I get to that important detail, I can recommend one the best quality units below:

Portacool PACCYC06 Cyclone 1000 Portable Evaporative Cooler with 300 Square Foot Cooling Capacity

This is a good quality unit that many people pass over because it costs a little more than some cheaper imports. But they're missing out on a powerful, US-built cooler that works indoors or out to provide much needed cold air on a hot day.


The Portacool is well-built, solid and will last a long time. That makes it better value for money than cheaper brands. There are some common questions that I can field here so you know before you decide to buy.

Amazon Disclaimer: The author of this website is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com

Humidity is the Sworn Enemy of Swamp Coolers

The big drawback of low-cost swamp coolers is they simply will not work in areas that have high levels of humidity. Unfortunately, a large area of the United States has high humidity in summer (and some have it all year). Here's why.

humidity hampers swamp coolersThese devices produce cold air through a process of evaporation. The process is much like the way you feel cool when you perspire and a breeze blow across your exposed skin. The perspiration is evaporated by the breeze and that lowers the temperature of the air close to you.

A swamp cooler emulates this process by soaking a large porous membrane with water and forcing a strong "breeze" through it with a powerful fan. The water evaporates and the chilled air is blown out the unit to cool the air in the room.

The problem with humidity comes into play when you try to evaporate moisture into air that is already saturated. As the water vapor level in the air rises, the amount of cooling gets less until you reach saturation point (100% humidity) and no more cooling is possible.

This is what some people experience in really hot, humid places like the Deep South. That's where even though you're perspiring profusely; your body cannot cool itself because the air is already saturated with moisture.

Same thing happens with a swamp cooler.

So remember: High humidity = swamp cooler will not work!

How to Make a Swamp Cooler Work in a Humid Room

Fortunately, some situations where there is high humidity indoors can be remedied by a simple trick. It works as long as the outside air is relatively dry (less than around 50% moisture vapor).

It helps enormously if you crack open a window or two to create a cross-draft of drier, outside air to circulate inside with the swamp cooler running. Doing that allows the moist air put out by the unit to be naturally cycled out of the room so more chilled air can be evaporated into the space.

Incidentally this is a recommendation for running an evaporative cooling device indoors in any case.

The reason for this is because of the way the unit works to produce chilled air. As it evaporates moisture, the moist air is blown into the room's atmosphere, artificially raising the humidity to a point where it will actually choke off its own cooling capability.

For the unit to keep producing a cold breeze, the air must not be allowed to get saturated with moisture. So by creating a natural air cycle with the drier, outside air, you keep the moisture level in the room low enough for the unit to keep working the way it is supposed to.

All this information is important, so please read it and understand it if you are going to buy a swamp cooler. Don't be one of those customers that didn't know how it works and returns it because, hey, "it doesn't work." ...It really does!

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