This is kind of a crazy idea. Probably alot of work, but I think it could work. Running cold water through corrugated plastic panels, that you would have to encase your box in. If you took some kind of soft tubing & cut a slit right down the middle of it, and could fit it to the top & bottom of the panels & hopefully through either hard work or ingenuity get a perfect seal, you could run chilled water through the panels. It would be one helluva job, but I think I could make it work if I had to. I don't know how it would work for the top, but the 4 sides for sure. I dunno, just an idea.
Yeah, that's what I was gonna do, with the walls themselves since they are double walled construction- until I realized in the sun with the slightly dark plastic, it would be a losing battle, or at least cost a ton of electricity. I thought about sheeting the inside with foam sheets, but don't want to give up chamber volume and air space. Thought about putting the sheets on the outside, but it would be ugly and really stand out with those white walls that would eventually desintegrate in the sun anyway. I even considered "misting" inside the walls from the top and recollecting it in the bottom. No worries anymore. I took the plunge and started filling 'er up with great stuff. Actually, I think this is gonna work perfectly. I really worried about overexpansion, so I played around with it a little outside the box first. I figured about how much I needed by timing the sprays (cause I couldn't see in the chamber where I was spraying it). I also read that the stuff doesn't work so well in enclosed spaces, because it took moisture from the air to cure, so after drilling holes, I used a spray bottle and pumped in some mist right before spraying- hope it works. This stuff is generally sticky and messy as hell, but the can reads "adheres to almost anything except for a few type of plastic". Well I guess I got lucky, cause anywhere it poured out, I just easily pulled off with my fingers after a few minutes of drying. It feels like the walls are firming up, so I believe it is curing. I am doing it in a couple layers so it has the best chance to cure. So far I've done the bottom half of the walls, and all is well. No distortions, and I believe it has fully filled any gaps and crevices. I know this stuff has a tendency to continue expanding for hours, so I hope I haven't spoke too soon. I googled for hours on what was better, the original formula, or the "big gap filler", I also tried to find which had a better insulating r-value, but none came up. Since the big gap filler claims to be for filling in spaces larger than 1/2", and the regular says up to 1/2"- I decided to go with the big gap filler which claims to expand 3x more than the regular formulation. I was a bit leery about overexpansion, but I do believe I made the best choice. Since it expands more, theroetically it should be less dense and more insulating, but it's only a guess. This stuff is so insulating, I can't imagine that even a single inch of it wouldn't do a pretty decent job, but we'll see. It's really good for this application too, because it is closed cell foam, which makes it completely waterproof. Fiberglass is only insulating when it's dry, so it would have been a bad choice near all the mist. In the end, it looks like it will take about 9 cans to fully fill the walls of the chamber, which is a bit more than I originally guessed, but total cost should be around $60 and not very much work at all. Best thing is how it magically peels away from the plastics in the chamber, that was a real pleasant surpise. Can you imagine how much money I'll save now, only having to chill my nutes, rather than trying to fight all the sunlight hitting the outer surface of the chamber? I figure I'll run a bunch of coils of JG line through an ice chest filled with water from my chiller. I already ran a clear hose side by side of my JG line that runs around the chamber to the solenoids that I can recirculate from with the chilled water from the cooler. I wrapped the lines together with the JG lines and slid over tubes of that foam pipe insulation stuff from the hardware store and, this way I don't have to worry about the cooled solution warming back up before it get's sprayed. I'll play around with it, but if I chill the nutes to around 50 degrees or so, the insulation should keep the cold inside the chamber like how tree farmer does.
I'm really happy guys, this has been a huge road block for me. Wish me luck that my pod temp will be cooler when I finish spraying tomorrow
