Thats a fascinating system you have come up with, but I dont think its going to work like an HPA/AAA setup. You are going to have a system that functions more like an LPA setup than HPA.
You are still thinking in terms of spraying the roots, and thats not what you want to do. The goal is to create an environment of mist at just the correct level.
Many people talk about the (potential) nute/water savings with HPA. You can indeed save a bunch IF the root chamber is sized to match the roots volume AND you create and maintain the correct mist environment - as per Atomizers numbers.
Remember I said in the early part of my grow I throw away 90% plus of the nutes/water? Thats because I am “filling the chamber” with mist, but the roots are not big enough to drink it all during the “hang time” they have to work with. There just isnt enough root mass early on for the chamber size.
Later on, my water use efficiency goes way up once the roots get to filling more of the chamber. Right now Im throwing away maybe 1/4 to 1/3 of the water coming out of the nozzles - but its only that bad because my setup is far from ideal as far as coverage/number of nozzles. I would be doing much better than that in a better designed system.
IF you have good mist quality, AND good hang time, AND the roots come close to filling the chamber, THEN you will have far less water usage than normal. IF all of those are true, you can completely ignore the normal water use your plants would see in regular hydro. They will use less water in HPA then in normal hydro - but only IF…
Im afraid the system you have described will never achieve anything close to that ideal mist environment. Its going to be too leaky and wont hold the mist, so you will have little to no hang time. You dont need to worry about getting more fresh air inside - you’re going to have way too much as it is. They system is going to be too open. Thats going to leave you with just spraying the roots like an LPA setup and letting them dry for a bit then spray again.
Keep in mind that Atomizer uses those same numbers no matter what crop he is growing - tomatoes, lettuce, pot, peas, roses - doesnt matter. They all make use of the exact same mist environment. In other words, he does NOT increase the most density - or flow rates - for different plants that drink more or less than others. How much the plant normally drinks is irrelevant - IF - you have a good mist environment with good hang time. An open system will never have good hang time.
Your setup will create way too much mist where its spraying, but then that mist will be long gone before the nozzles get back to the beginning again. So you will be going from way too wet to way too dry. Your system will function like an EBB/FLOW of LPA setup. Both of those flood the roots, then turn off the water for a while.
That can certainly work, and work well, but you will be missing the main benefit of HPA/AAA that you get from that ideal mist environment that is never too wet and never too dry, but stays just right the entire time.
As far as temp control in the root zone, just spraying mist wont cool things down. You must have some evaporation going on, or there will be no cooling. Inside the chamber, the humidity will be close to 100% (if you have a good mist environment) so very little evaporation. Thats one of the resons I use a fabric chamber. It gets wet with every spray, then the water evaporates carrying the heat to the OUTSIDE of the root chamber as the water evaporates from the fabric. The other reason is so the roots air prune when they grow into the fabric.
That evaporative cooling is so effective that I have to heat the root chamber even in the summer. I have the foam box around the fabric chamber for two reasons. One is light proofing because the fabric is not 100% light proof and roots hate light. No beathable fabric is 100% light proof. The other reason is to make the heater more efficient. I dont want to heat the entire room - just the roots.
I get plenty of fresh air into the chamber. Plus I have to be careful to seal around the net pots. Other folks have mentioned that even the small amount of air that gets in past the net pots/hydroton is enough to air prune the roots and kill them off. Your fresh air needs to be very very gentle and subtle. NO breezes, fans, openings etc. A gente infiltration through some fabric works fine. Any more and its bad news. Those openings for tubes, tracks, etc will be a problem
The other way to cool the root chamber, as you mentioned, is by chilling the source water, but that can be difficult when you have long pipes running around and it is energy intensive. Not something you want when running on solar panels.
I think your tracked nozzles and segmented tubes are really cool and innovative, but I dont see how this will work as an HPA setup. You will get very similar results if you just go with low pressure sprayers and it will save you a ton of money on equipment.
