You want a portable, free standing air conditioner to keep you cool in hot weather but you don't want an ugly vent hose trailing out the window, right?

That would be perfect except for one small detail, as you are about to discover as I look into the concept of ventless air conditioners that are not what they seem.

I remember a few years back when I had no idea about how the new portable AC worked that I'd just bought because I couldn't bear losing any more sleep in my overheated apartment that I wasn't allowed to have a central system installed in. All I knew was the hardware store sold these great looking free standing AC units and they represented a cooler, peaceful night's sleep and I wanted one. Like right now!

The Portable AC Window Kit

When I got the cooler home and unboxed it, I was all ready to plug it in and stand there waiting for all that lovely cold air to run over me like a chilly blanket of goodness.

But out of the same box came this length of corrugated plastic tubing with a fitting of some kind at either end and another smaller box containing something called a window fixing kit.


I did something alien to me back then, which was to read the manual.

Aha moment: The tube fixed to the back of the AC unit and the other end fixed to the window kit which, naturally needed to be fitted to a suitable window.

But why? Why should I need this extra piece of hardware that is, quite frankly, ugly, unsightly and an extra I wasn't expecting!

I'm sure plenty of you reading this are with me so far and remember your own first experience with a portable AC too.

When Portable Does Not Necessarily Mean Portable

So wait. I had to fix this exhaust hose (that's what the manual called it) to a window and tether my moveable, so-called "portable" unit to the same window via this hose or the unit would not cool my room.

In fact, after reading some more, the manual told me that if I did not vent the unit to the outside, it would simply pump hot air out the back along with cold air out the front resulting in a temperature increase in my room!

That meant the unit was not really portable any more, because it had to stay put beneath the window to which it was tethered by aforementioned hose and I could not easily wheel it from room to room. In other words, this was really a "fixed" AC on wheels.

I Do Not Want a Hose on My AC!

You had to experience my situation to know what I felt like. I needed this so bad I just went along with it and plugged the hose into the back of the AC and into the window kit and turned it on.

The cold air that hit me was beautiful. I didn't care. I felt cool in my hot little bedroom for the first time this summer (and the summers before).

After a while, I got to disliking that ugly, cumbersome and totally "In the way" vent hose. As time wore on, I disliked it more and more.

Why didn't the guy in the store just sell me one of those ventless air conditioners so I didn't need the hose or the window or the hassle of not being able to move my unit when I wanted?

I found out later after doing some more research of my own.

Refrigeration Heat Exchange

I found out this one super important fact about all air conditioners. They all produce a lot of heat that must be vented to the outside somehow. That includes portables, window units, mini-split units and whole house central systems. No getting away from it.

All AC uses a refrigeration system just like a domestic fridge to chill the air by compressing Freon gas (or another type of ozone-friendly gas) using a big compressor which, being mechanical, produces a lot of heat in the process. If you ever stood at the back of your fridge and wondered where all that hot air was coming from, now you know!

So why was I hearing so much about a kind of portable air conditioner no vent hose required?

Evaporative Coolers

It seems I wasn't hearing about what I thought I was hearing about. Non-vented air conditioning portables don't exist, but a cooling device that looks remarkably similar but is not a real AC does exist. It's called an evaporative cooler (or swamp cooler).

Swamp coolers don't have compressors or use refrigerant gases to make cold air. They just utilize the process of air chilling by evaporation of ordinary water. Because they don't make any heat at all, they don't need to be vented. What's more, they use a fraction of the electricity used by AC to produce a lot of cold air.

So why doesn't everybody ditch their expensive, energy hog AC and buy up all the swamp coolers in the stores? There is a problem that besets evaporative coolers depending on where they are being used and the climate they're being used in.

You see they don't work in humid conditions, because humid air can't absorb so much of the moist air they produce as does hot, dry air like you get in desert or other inland areas. The higher the humidity, the less effective the cooling ability, as I discovered after reading this useful little blog at:

That means if you happen to live in an area with a relatively dry climate and low humidity, a swamp cooler is the perfect choice to keep cool. But if your live in a humid climate, you're out of luck and will just have to continue using a big ugly old vent hose out the window connected to your portable AC, or if you have deeper pockets, run a central system to keep your home cool.

PS: Which did I end up with? Well, I wasn't so lucky living in south Florida at the time. The air was always really humid and there was no way I could get a swamp cooler to work.

But I didn't stay there. When I moved north and inland some, the drier air meant I could ditch the AC and get an evaporative cooler, which I did. And it works great!