I actually did see the idea of using the heat transfer tank under the crawl space from a tank I saw in Mike Paletta's book on those awesome tanks. This guy had a tank underground where water circulated through. I don't think he had any copper tubing to help, but I'm not sure. I use copper tubing as you describe on a much smaller scale for (get this) a fog-chiller we use at Halloween for our haunted house. The copper coils cool the fog as it blows through just enough to keep the fog on the ground. I thought of doing something similar, but then I just settled for the tank of water under the house. I am hoping that this will "buffer" the water just enough before it goes to the chillers (1 hp) to take a bit of the load off. We'll see.
the "waveloop" is powered by an OceansMotions 4-way. It is what he suggested I use for my particular set-up. Two outlets are plumbed on each far sides of the tank. One high in the rear corner, one low in the front corner. The opposite end is just the opposite. Then the 4-way rotates so that water is "pushed" from one end of the tanks to the other and then back again. Yes the plumbing will be no fun, so WILL, if you can plumb yours first, that would be great! LOL
And I would love to have the help. I am getting the silencers in the overflows now and the drains plumbed to the sumps. This is the part where an abnormal amount of cursing takes place because my "plastic" arm is just a wee bit short. And I wouldn't want any of your tender ears to hear this, so, AFTER THAT I will definitely need some advice and help.
So like I told Tomoko and Ranbo, how's a "bring your extra PVC (and brain) party" sound? I'll provide the beer.