"K Barrett" wrote in message
news
I used a lot of the advice from Charley's greenhouse when I built my GH.
I've provided a link to their tips page. I used their formulas to calculate
how large a swamp cooler (evaporative cooler) I'd need as well as how large
a heater. My GH was 8x16 and I put Charley's swamp cooler in it which was
over kill, but when I expanded the GH to 8 x 30 I didn't have to get a
larger cooler. It still works fine.

http://www.charleysgreenhouse.com/index.cfm?page=_tips

OK. I checked them out. The air here is not dry but quite humid from spring
to fall. It's only dry in the winter but the plants still thrived even with
the 20 to 30% humidity. Wetting the gravel in winter with the hose would
bring it up to maybe 40 or 45% for a few hours - when the hose wasn't
frozen. Then I'd use a 1g spray bottle. These swamp coolers wouldn't help
much as they only drop the temps down 5 to 10F for the affordable one.
That's not much when you're dealing with 120/130+ all summer long. Also, I
don't know how many sq. feet the Rion is because of the roof shape. The
larger SC is $590 and needs a constant water supply. Blasting the
limestone to run a line is cost prohibitive as is this cooler. We've
already spent a lot more than we figured on on the Rion GH, what with all
the gravel, cement, rebar, bubblewrap, shade-cloth, fans, heaters, extra
weather stripping etc. etc... etc... ad infinitum................