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Does anyone live in Phoenix (or in Zone 9a/9b) and have a greenhouse FOR COOLING (NOT HEATING) purposes?

Any small succulents I try to grow (like Echeverias) always die in the summer. Not because of too much sun, but because of our high nighttime temperatures. I did some research and learned that unlike most plants, many succulents use CAM photosynthesis, which means they close their stomata all day long and only “breathe” at night when things cool down. For CAM photosynthesis to work, a significant shift in temperature from day to night is required. So when it is still 100 degrees at midnight (for numerous days in a row), they essentially suffocate :(

Obviously this isn't true for ALL succulents, because we have many native species that grow just fine here, but it seems like the species I love are not cut-out for Phoenix weather!!

My husband has agreed to build a 8x12' greenhouse in our backyard with a swap cooler. He says a swap cooler is capable of lowering the temperature by 20-30 degrees. Also, the nice thing about using a swamp cooler instead of a traditional A/C unit is they add humidity to the air, which my Echeverias will like (they don't like our SUPER DRY air). Apparently, the rule of thumb on swamp coolers is to get one that moves enough air to completely refresh the air inside every two minutes. But since that rule of thumb is for an insulated house, not a greenhouse, he wants one that is capable of changing the air out every minute. Has anyone ever used a swamp cooler to cool a greenhouse?

Also, I'm wondering if we should get some kind of glass that doesn't let as much light through? (Since I always have to use some amount of shade cloth). Any advice/tips or previous experience with building a greenhouse in a desert climate would be most welcome!! :)

Not sure how the Echeverias would like it but you could look into wet-walls, they cool down greenhouses a lot, especially at night time. I guess it functions much like a swamp cooler, but cools more. You can also build them pretty cheaply using charcoal materials too, it seems that method is used by farmers in South Africa

I used to live in phoenix a Swamp cooler sounds like a good idea to me. Might not work well in Summer Moonson though.

Monsoon

Sounds like it would work, but glass is rarely used for greenhouses. White poly carbonate is good but you may still have to cover it with shade cloth for mid day sun. Spray misters and a whole house fan might work, too.

Visit some of the commercial cactus nurseries in your area and see how they work.

I am considering something similar. I live in Las Vegas, NV (zone 9a), and I am looking to build a shade house, or some type of protective yet handsome structure for my potted cacti and succulents. It gets cold here in the winter, and we have extreme heat just like Phoenix. I would like to have a place for them will both display them and protect them.

I lived in the low desert for 17 years and some sort of shade was necessary to protect potted plants. I had stuff under trees and in the covered patio which had morning sun filtered through 45% shade cloth. But a shade house that will cover midday and afternoon and keep all your plants and supplies in one place would not be hard to construct and more convenient. The big box hardware stores have everything you need for a shade house.

In Las Vegas you also have frost to contend with, so plan on your species choice. If you make the jump from shade house to greenhouse the costs go way up. Even if you go shade house, it would be nice to have one part with a solid roof for your work area.