Evaporative Cooling - Beat the Heat.
Evaporative cooling: is an economical way to lower your greenhouse temperature 10 to 25 degrees. This works best in arid climates. But doesn't do much when humidity is close to 100%. The Hydrofogger, misting nozzles http://www.azmist.com , evap. coolers are all good options. I wanted to try pumping cool water from the ground (50 degrees here), run it through nozzles with air and use the water for irrigation. This is called geo-thermal air-conditioning with water mist heat exchanger.
Here's a plan for one out of the Ortho Greenhouses book:
- According to the Ortho book: "Previously, most pads were made of aspen
shavings, excelsior or plastic. Now on the market are cellulose pads impregnated with insoluble antirot salts. Another modern cooling pad system
consists of a bonded plastic fiber pad coated with an absorbent cellular foam. Unaffected by continual exposure to moisture, disinfectants, chlorine or water
acidity, these new pads are so efficient that you do not even see water trickling down the side. All of the new evaporative cooling pads fit existing systems; they are easy to install and clean.
- "The size of the pad is important. It is determined by dividing the required air
flow by 150. Thus an 8- by 12-foot greenhouse needing an air exchange of 2,000 cfm requires about 13 square feet of pad (2,000 /150 = 13.3). The most
effective pad is one that extends across the entire wall."
Here's a link to a supplier or two: