This doesn't quite seem to belong in the cool tubes section so....
The solar AC group (one of the Yahoo groups) has one person asking about zeolite cooling methods--how much do you need, for instance.
Sounds like a couple of packs of it, in the description here, of what amounts to a very small refrigerator. Not to mention a parabolic collector, etc.
http://www.eduvinet.de/servitec/cooleep72.htm
Whole link might be pretty useful, but this page starts the zeolite cycle.