First I want to say THANK YOU to Other power and all who hang out here! Without this site I most likely would not have done this, keep up the flow of free knowledge. I came here to make a wind gen and found out quickly I live in the wrong place for that, in town surrounded by two story houses would need tower tall enough to take out a couple of cars and maybe a swing set if it ever came down not to mention what would happen if a blade should ever decide to fly off so I went to solar heat and I cant believe the free heat the sun puts out! It should be illegal NOT to use it in new construction!
First I built a collector with 13 1/2" tubes 76" long. 13 because that's all I could fit in.

The collector plate is metal roofing the idea was half of the collector would be looking directly at the morning AND evening sun. The roofing was rolled over a 55 gal. drum to give it an arc then the tubes were screwed to it with 52 1/2" copper pipe straps that dont show after the stove black was applied.
Then I built the box with 1" styrofoam back then a layer of fiberglass to take up the dead air space Not a good solar day but it will go to the roof when summer gets here.

Then came my new girlfriend "TACO" The day after it arrived I called my wife from work and asked her to put a blanket over Taco so she would'nt get cold and when I got home there was a note taped to the box that said Help I'm being held hostage by a derainged woman and I can be set free for some kisses and hugs! Just thought it was cute. Notice the high tech "flow control valve" Don't know if it will be needed after it's on the roof but it's there.

I didn't build this to make DHW it's for heat because that's my biggest bill in the winter so I plumed it to a heater core from a 1989 Chevy Caprice because I had two 5" fans in the basement and it's the rite size for them.

Yesterday it put out 110 degree water for over 6 hours. I can't heat the house it's too big but I can hold the temp! The furnace never ran once the whole day and I never gained OR lost any temp either!
Now on to the next step. After the heat exchanger I want to plumb in the water heater. I have a electric water heater to use as a solar tank I am takeing out the top element to modify for a water port here is my question.
I don't want the second pump so I plan to run 20' of 1/2" inside 19 1/2' of 3/4 soft copper with the usual tee's I see used but then I am going to bend this around a 10" pully to make a spring so to speak, should be 8ish turns streatch it out to reach the drain and intake port of the tank and hope the thermo syphon will work. I know it's pretty horizontal but it WILL be a little up hill. I think it will work? Anyone done this?
And remember this was built to heat the house in winter and the hot tub in summer. The DHW is just a little added bonus.