DIY Solar Hot Water Heat Exchanger

[bennelson]

I just built a heat exchanger for my DIY solar hot water system.

I am planning on an INSTRUCTABLES on this, but I thought I would tease you all with some photos for now.

Basicially, it's a tube inside a tube to that anti-freeze that is heated by a solar panel can heat up otherwise cold water that then goes into an insulated storage tank (an old electric water heater) and then into my standard natural gas water heater.

This is sort of a little experiment, and I have never done copper soldering before, so, yes, I already know how sloppy it is!

Hot fluid from solar goes in and out the the skinny inner tube, and water to be warmed in the hot water tank thermo-siphons through the thicker outer tube through the T-connections.

See all photos at:
Solar Heat Exchanger construction - a set on Flickr

[dremd]

nifty; do you have it working yet?
What kind of collectors do you have?

[bennelson]

The collector is a 4'x10' panel which I bought used in good condition.

I showed the heat exchanger to a friend today who has some experience with solar and copper work. He thought the heat exchanger looked pretty good.

Next, I need to figure out how to couple the 1" pipe thread to a 1" machine thread. They are the same size, but pipe thread tapers, and machine thread doesn't.

The heating elements in the side of the electric water heater are the perfect place to connect the heat exchanger, I just need to make some sort of adapter.

I will be showing this project to some of the building group on Sunday and get some advice.

[dremd]

assuming the straight thread is SPT (o-ring)(standard pipe thread) you can get a nice adapter at a "real" plumbing supply.
OR you can also make an adapter out of the CPVC (hot water) adapters at lowes 1 with the rubber gaskets inside (looks kind of like a female garden hose end), a regular threaded NPT adapter, and a short piece of pipe.