Bill Weber’s DIY Solar Water Heater.

Bill Weber knew that he wasn’t going to go for that $2000 commercial solar water heating units, so he decided to build his own:

First, build a glass-covered wood "hot box" to catch the sun’s heat.

Second, install a manifold of copper water pipes—inside this collector box—so the gathered warmth will heat water.

Third, hook the outlets from the manifold to a storage tank (this container should be set above the heat collector) so the thermosiphon principle will move water from the collector to the tank.

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