If the greenhouse were bigger (which in time- I plan on... maybe 10 years LOL) it would work really well. It really is still a lot for this size place. I picked it up from homedepot... I think they run like 600-800 for the pump alone, then you gotta get the line, nozzels, fittings blah blah.. was a really expensive piece of the g/h
the thing right next to it is my swamp cooler-- I don't have a wet wall like you describe (where a wall is wet and fans on the other side pull air through the pads) so mine tends to create cool areas where the air blows directly and warmer areas where the air is more stale... but it works out well so I can put plants in the different climates. So same concept but it still only makes my place about 35% humidity alone. (since it pushes out the air it humidifies as it goes) so a high pressure fogger like this seems to be the only thing that can keep up with the air transfer I have.
Before I got this fogger I had a aquafog 400 (as seen in the fogger video above my head...) here is their site with information and video of it in operation
http://www.jaybird-mfg.com/Video_700.htm it worked okay-- but the particles were too big.. even bigger than my fogger put out with the .15 orfices in. so the ground down the middle was always drenched, it ran a LOT to keep the humidity up, and it has a pump in it... which, for some reason... would stop working so I'd walk in and the fan would be running but no water- when I shut it off and back on, it would be fine. The manufacture and I never did find out the problem though. So I call that item a "no go" for this use... (but looking at their site, they now have a aquafog700 in place of the 400.. and it no longer has a sump so they've removed the pump I always had a problem with.. hmmm.. interesting
) Supposedly the turbo xe is better at making smaller particles, but it also says it's too big for something my size, so I don't trust it.
Back when I had my littler g/h thing set up, I was looking at these other fogger pumps... I just pulled it up and they have one that is 1/4 gpm, I don't know what the pressure though, or how fine a fog it puts out.. You really need to be careful, when I was looking into it, a lot of them wanted to say they had "foggers" but really there were misters. So, be careful you don't get wrapped up in the name, look at the particle size and determine if it is a fogger yourself....
http://www.cloudburst.com/catalog/coldblast-14-gpm-p-208.html I think they're only like 160 psi though from memory.. So I wouldn't expect much of a fog, more of a mist, out of it.
andrew
edit: guess my pump was more than I thought LOL here it is:
http://aeromist.com/store/viewItem.asp?idProduct=26
and to edit mistakes.. where I said I now run .08 orfices.. it's actually .008 and where I said .15 it is .14
Also, they have a slower rate one now.. which may actually work for you.. if you want a big dawg like this LOL
http://aeromist.com/store/viewItem.asp?idProduct=24