kratos015
Well-Known Member
Hey guys,
Wanted to share something I just finished building, it's a cheaper (and in my case ghetto/Mickey Mouse'd) version of an Evaporative Cooling Wall that normally costs thousands of dollars. I built this for less than $125, not including the cost of fans. The fans I chose cost ~$115 a piece, so the total cost of this project for me was ~$360. Not bad considering you'll be spending at least 3-4 grand on one of these from a greenhouse store.
Just a disclaimer, this will only work if you live in an environment with less than 20-25% humidity outdoors. This is for those of us that live in desert like climates where the humidity is an average of 5-10%, sorry to those of you on the east coast/midwest! For certain parts of California, all of Arizona, New Mexico, parts of Texas and Colorado, and pretty much anywhere with under 10% humidity this is something worth looking into.
Evaporative Coolers (also known as Swamp Coolers) work by saturating pads with water. You then use a fan to draw airflow through the saturated pads. The hot air will evaporate the water in the pads and will proceed to cool the entire room as a result. The hotter and drier your environment gets, the more efficient this works. For people like me that have summers with 120-130 degree weather, this is a god send.
My current environment is ~80 degrees with ~20% humidity and this still cools my greenhouse by 10-15 degrees. When it's 120+ outside, this will keep my greenhouse at ~80 degrees easily.
So how did I do it?
The entire greenhouse is covered in visqueen/plastic sheeting instead of shade cloth for two reasons. The main reason is because the visqueen creates a near perfect seal, forcing the air to go through the pads and no where else. If all of the airflow you're drawing in is not going through those pads this will not work. The other reason is the visqueen gives me more useable sunlight than shade cloth, which blocks out between 40-90% of the sunlight.
That wash bucket is my reservoir. I have a basic submersible pump that is attached to 3/4" PVC pipe, the pipe goes to the tops of the pads and drips the water onto the pads. You can't quite see it, but at the bottom of the pads I have visqueen directing the flow of the water into a basic raingutter that directs the flow of water back into the reservoir.
The reservoir is filled with a basic garden hose that is attached to a float valve. As the water empties, the float valve releases water until the water rises enough to settle the float. The pump is attached to a digital timer, the timer turns the pump on for exactly 1 minute every 5 minutes to ensure that the pads are constantly saturated in water.
The air is drawn in through the pads via 2 18in fans with enclosed waterproof motors, each fan blowing ~6300CFMs.
That's pretty much the gist of it. Seeing as outdoor season is upon us, I thought this might be useful for some of you. Until I discovered this I was unable to even think about having a greenhouse since shadecloth is not going to protect my plants from 120-130 degree weather. July is murder out here, it never gets below 90 degrees all month even at night and the afternoon temps are always 115 at a bare minimum.
Hope someone else finds this useful. As you can see, even my shoddy work makes this useful. Someone with a bigger budget and more experience with tools can obviously do much better than me.
Wanted to share something I just finished building, it's a cheaper (and in my case ghetto/Mickey Mouse'd) version of an Evaporative Cooling Wall that normally costs thousands of dollars. I built this for less than $125, not including the cost of fans. The fans I chose cost ~$115 a piece, so the total cost of this project for me was ~$360. Not bad considering you'll be spending at least 3-4 grand on one of these from a greenhouse store.
Just a disclaimer, this will only work if you live in an environment with less than 20-25% humidity outdoors. This is for those of us that live in desert like climates where the humidity is an average of 5-10%, sorry to those of you on the east coast/midwest! For certain parts of California, all of Arizona, New Mexico, parts of Texas and Colorado, and pretty much anywhere with under 10% humidity this is something worth looking into.
Evaporative Coolers (also known as Swamp Coolers) work by saturating pads with water. You then use a fan to draw airflow through the saturated pads. The hot air will evaporate the water in the pads and will proceed to cool the entire room as a result. The hotter and drier your environment gets, the more efficient this works. For people like me that have summers with 120-130 degree weather, this is a god send.
My current environment is ~80 degrees with ~20% humidity and this still cools my greenhouse by 10-15 degrees. When it's 120+ outside, this will keep my greenhouse at ~80 degrees easily.
So how did I do it?
The entire greenhouse is covered in visqueen/plastic sheeting instead of shade cloth for two reasons. The main reason is because the visqueen creates a near perfect seal, forcing the air to go through the pads and no where else. If all of the airflow you're drawing in is not going through those pads this will not work. The other reason is the visqueen gives me more useable sunlight than shade cloth, which blocks out between 40-90% of the sunlight.
That wash bucket is my reservoir. I have a basic submersible pump that is attached to 3/4" PVC pipe, the pipe goes to the tops of the pads and drips the water onto the pads. You can't quite see it, but at the bottom of the pads I have visqueen directing the flow of the water into a basic raingutter that directs the flow of water back into the reservoir.
The reservoir is filled with a basic garden hose that is attached to a float valve. As the water empties, the float valve releases water until the water rises enough to settle the float. The pump is attached to a digital timer, the timer turns the pump on for exactly 1 minute every 5 minutes to ensure that the pads are constantly saturated in water.
The air is drawn in through the pads via 2 18in fans with enclosed waterproof motors, each fan blowing ~6300CFMs.
That's pretty much the gist of it. Seeing as outdoor season is upon us, I thought this might be useful for some of you. Until I discovered this I was unable to even think about having a greenhouse since shadecloth is not going to protect my plants from 120-130 degree weather. July is murder out here, it never gets below 90 degrees all month even at night and the afternoon temps are always 115 at a bare minimum.
Hope someone else finds this useful. As you can see, even my shoddy work makes this useful. Someone with a bigger budget and more experience with tools can obviously do much better than me.
