There was a thread here asking about manufacturers of swamp cools for which I wrote a long and learned discussion , but it vanished into cyber space when I uploaded my answer. So I will try again with a shorter version.
Lenomex is the most common brand in my area. There are also a number of locally made units. They come a variety of sizes for in-wall mounting and for roof-top/whole house applications.
It has been my personal experience that portable (roll around) units are worthless.
(This post was edited by Rolly on May 20, 2007, 5:21 PM)