I don't have a digital camera right now, but i can make a sketch and describe all the fittings. Pretty soon i will post pictures of all my renewable energy inventions. I've gotten a patent before. Investors, contracts, lawyers, etc. I spent a fortune and never made a dime. So anything i invent now will be shared freely with the public domain from the very start. I would make them and sell them, but i would have to charge a premium for the labor.
Here's a quick run down. I removed my 30gal electric water heater and drained the water out. I installed two new steel nipples (a short pipe with threads on both ends) into the hot and cold inlets. I used one of those as a handle and dragged the empty tank up on to my roof. I built a doghouse platform out of OSB and treated 2x4 lumber, such that i would have a level place to set the tank, and also to distribute the weight across 3 rafters. I removed the cover plates over the upper and lower heating elements, and removed elements and thermostat. I used a steel reducer bushing to screw into the holes left by the upper and lower heating elements. I used both teflon tape and pipe dope (rectorseal high temp) on the threads. I then used 1/2 in. cpvc male adapters to screw into the reducer bushings. I coated them with all-purpose cement (pvc glue) to prevent leaks, then quickly screwed them in by hand. I used cpvc female adapters on the hot and cold inlet nipples, again coated in glue and hand tightened.
For the collector i used a piece of economy tin roofing from Home Depot. I used tin snips to cut the 10 ft sheet into 2- 2 1/2 x 5 pieces. I used a tubing cutter to cut some type m hard copper pipe into lengths about an inch longer than the tin, one piece for every valley or "wave" in the tin. I cut small pieces of pipe to make the loops, and used copper 90's to attach them on alternating sides, so the water must zig-zag up the copper collector. Once the pieces where fitted, i glued the pipe sections to the tin with black silicon adhesive. Silicon is very heat resistant. I then put masking tape on the ends of the pipes and spray painted the collector with flat black BBQ paint. then i put flux on all connections and soldered them up with silver solder using a torch with mapp gas. The inlet and outlet ended up on the same side of the collector, not that it matters.
The collector was then put into a box made from OSB (oriented strand board) which is used for roofing and is very weather resistant. The inside of the box was lined with styrofoam board insulation attached with silicone adhesive, foil side up. I placed the box on the roof of my power shed which is tilted toward the sun, and lower than the roof where i put the tank. The collector must be lower than the tank for this to work. Two holes were drilled in the side of the box for the inlet and outlet pipes which i soldered on first, then put the collector in the box. Then i took an old window with an aluminum frame and glued it on top of the box with silicon adhesive. On the inlet side, i soldered on a tee. To the downhill side of the tee i soldered on a sill cock for use as a low point drain for both the collector and the tank. on the other side of the tee, i soldered a check valve (one way gate valve) and then a copper female adapter. On the outlet side i soldered on another tee. On the downhill side i soldered on a copper female adapter. Using tape and dope, i screwed into the adapter, a temperature and pressure relief valve. on the up-hill side i soldered on a copper female adapter. Using CPVC male adapters coated with glue, i hand tightened them in place. The tank and collector where ready for connection by CPVC pipes.
I made two "telephone poles" by using my skill saw to rip a 16ft. treated 2x4 down the middle. I then used a post hole digger to set them at 10ft apart or so. This is because my sun is so far from the house which is fully shaded. The tank and collector do not need to be far apart. I then attached the house cold water supply to the tanks cold inlet. I then attached the tanks hot outlet to the the hot water line of the house (all in CPVC). I ran CPVC pipe from the lower connction at the tank to the collector inlet, and pipe from the collector outlet back to the tanks upper connection. I then filled the tank by: slightly opening the low point drain valve at the collector, and holding open the T&P relief valve on top of the tank (between the hot and cold inlets on most tanks.) as soon as water came out the low valve i turned it off. When waters came out of the T&P valve on top of the tank, it was full. There were no leaks at the tank or collector, but a hairline fracture in the CPVC pipe started spewing water everywhere! I cussed several times, shut off the water, and drained the tank with the low point valve at the collector. Once i had cut out the bad section of pipe and glued in a coupling, i refilled the tank and collector. No leaks! By that point, the sun had gone down. No hot water, but whats one more day after two months of cold showers.
How it works: Because cold water is more dense than hot, it is also heavier. The cold water sinks to the bottom of the tank where it flows out the outlet and downhill to the collector. As soon as it enters the collector, it gets heated by the sun and starts to rise up the zig-zag of black, copper pipes. by the time it exits the collector it can be as hot as 130F or more. It continues back uphill, to the upper connector at the tank, where it mixes with the cold water as sinks back to the bottom. This is the process of convection, and the thermosiphon effect will continue until all of the water in the tank is the same temperature as the water at the collector, or until the sun is not shining on the collector anymore. The check valve prevents reverse thermal circulation at night. After just a couple of hours of sun, almost the entire tank is full of really hot water. No gas. No electricity being used. Completely renewable hot water for washing, taking showers, doing the dishes. I think the thermosiphon hot water heater is one of the most elegant systems in the world. Too bad i didn't invent it!
