cooling greenhouses

[missann]

I have a little greenhouse (6' high, 24" deep, 4' wide) and it got to be 104 in there today (it is in 90%-100% shade for the hottest part of the day) The regular, outside temp. today is 89, and it gets to be 100 later in the summer.

So... to cool my greenhouse down, I opened the plastic cover completely, put it on top of the greenhouse, turned on the fan, and watered down the sheer curtain that I use to cover the front where the opening is. I then covered the greenhouse opening with the wet, sheer curtain so that the almost non-existant breeze would be cooled before getting to my plants. I also cranked up the humidifier and ran the fan so that it blows the cool humid air around. This got the temp down to 79 degrees, but the curtain is already dry and I just soaked it 10 min ago, I am pretty sure that it is going to get hot in there again.

Here are my challenges:
I live in a very very dry climate where it gets to 100 degrees outside,, so even if I do everything I just said above, I am only getting up to 40 percent humidity. I don't think that humidity trays will do any good with all the air circulation going on in the greenhouse with the plastic cover totally open on the front.

If I bring my plants in, I have to put them in a spare bedroom where I never see them, and thus, chronically forget to water them.

I would be willing to buy a swamp cooler if I could find one that is small and lightweight enough for my greenhouse. The smallest one I have found is 25"x16"x12" with a 10 litre water capacity with an additional 4 litre ice tray capacity, which sounds like it will be very heavy and probably won't fit between the shelves in my greenhouse.

Furthermore, if I buy a swamp cooler, I will have effectively spent more money on stuff to grow orchids than I have spent on the plants themselves, and I will have to buy more pretty flowers to justify spending the money. LOL I love woman logic.

I think the biggest problem I have with the notion of a swamp cooler is that it seems so frivolous(sp)?

[jerrymeola]

They make a mister system that attaches to a fan that should work for you for $50-75.

Fan Misting System-International Greenhouse Company Greenhouse Mega Store has everything you need to build, equip, and maintain a commercial, hobby, school or institutional greenhouse.

A garden sprinkler on the roof of the greenhouse can also function as an air conditioner.
You could put it on a timer that would run 5-10 minutes an hour. You will be amazed how much this can lower a temperature.

[Hummer344]

A rose grower I visited put burlap over her greenhouse and ran a drip irrigation system down the middle of the greenhouse on the outside. When the temps got up to hot, she turned on the water and let it drip down the sides of the greenhouse. The overall affect was to shade her cuttings and keep things cool inside. That, combind with an exhaust fan kept the temps in a reasonable range. With a small greenhouse this would be easy to do.