Building a greenhouse?

[Taliesin-DS]

That second design reminds me of shelters made out of snow i saw in some survival show.
In those they dig a pit like that so the coldest air goes down there and the terraces stay warmer.

[GrowinOld]

Monkey,
Here's another pic showing some cooling ventilation & some options for keeping the humidity up & cooling the inside. I showed it with some small solar pumps & fans... (solar panel is shown as a black box on the top of the unit), all you may need & free to operate.


The underground air inlet may be run in a shady area & hence allow cooler air to enter it. What works & what doesn't will have to be experimented to determine. As I don't live in a hot & dry environment, I don't know all the variables you will encounter.

In this set-up, part of the cold-frame will be shaded, however that can help to cool the air some and allow for areas that hold the pumps/fans & water reservoir to be in the shade instead of cooking in the sun. The fans will assist with evaporation which will help cool it a bit. (Indeed this thing will be like a solar oven until you tweak things!)

Reflective paint or material over wood sides & areas will reflect heat & if added to insides will reflect light onto the plants.
There are many other things you can do, but this should get you on your way.

Good luck with it!
Let me know if you ever get it made... love to see pics!

Paul

[kulamauiman]

Could build with a bunch of sliding glass doors. Would need less of them then the one I saw in Northern California that was greenhouse made of all recycled glass sliding doors....

Indeed, people underestimate the potential of cold-frames. They function like a mini-greenhouse that you can't walk into! In fact, some people combine the two forms to make what is referred to as a pit-greenhouse! I created another plan/drawing of one for you. Picture digging out a 2' wide trench down the middle of the cold-frame floor, deep enough to walk thru, and a "door/hatch' at one end instead of along the length. See below and you'll get the idea.



Indeed, the smaller the greenhouse (or cold frame) the more you will need to keep an eye on conditions and keep them from fluctuating too far beyond the needs of the plants. But if you take the time to set it up well, and think things thru with a good amount of common sense, you should be able to create something that will work well for years to come.

I have seen a few Pit Greenhouses, and they are actually very cool! (ie: interesting designs... not necessarily cool temperature-wise!) However, speaking of that, having them underground does indeed help to cool and stabilize the inside environment! (As you thought, yes it does!) It may not do miracles, however it does indeed help to bring you closer to the "zone" you are shooting for.
(Greenhouses simply recreate different zones, depending on how we manipulate their inner environment and workings.... temperature, moisture, humidity, heat, cooling, etc. by how we implement and use things like shading, heater, A/C or swamp cooler, pumps, humidifiers, lights, etc.)

If you don't have much to spend, then patience, work, ingenuity* and effort can get you there. If you don't have those, then indeed lots of money works too!

Well again, good luck.


*Think about it.... even with no electricity, a small solar powered pump and solar powered fan can be used to make a small solar powered "Swamp Cooler'!
(I did one some time back! Small, but it worked!)
Indeed, living in the south with hot temps, modifications to the basic design to keep plants lower, where the cooler air will be, would be possible... but will require stooping down to tend plants. Not a bad thing if it gives you a good place to grow and you don't have bad knees!
Things are only impossible until someone thinks of a way to make them possible! It wasn't that long ago when flying was impossible for man, let alone walking on the moon!!!

[hydro31]

You first form foundation of two 12-foot and 14-foot pine boards. Settle it into place and make sure that it is as flush with the ground as possible all around.Also consider sunlight needs as well.