MORE WAYS TO RECYCLE OLD REFRIGERATORS INTO LOW COST SOLAR WATER HEATERS

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The resulting empty case was then turned on its side and a salvaged, stripped-down, 40-gallon, electric water heater tank was mounted inside the box on wooden supports. (In addition to being stripped, the tank was further modified by the addition of a fitting welded into its original base and the plugging of an "extra" opening on its other end.)

Next an "absorber plate"—much like the scavenged heat exchanger panels used in the refrigerator door flat-plate collectors already described in this article ... except with parallel runs of 1/2-inch copper tubing instead of a serpentine run of 1/4-inch tubing for the circulating fluid to flow through—was put together.

The absorber consists of six parallel lengths of 1/2-inch hard copper pipe spaced 3-3/4" apart and connected across their ends with standard plumbing T's and elbows (see illustration). This manifold was then soldered onto the flattened and trimmed (so it would just fit inside the refrigerator door in place of the removed lining) sheet of steel that had once been wrapped around the insulation on the salvaged water heater tank. Note, 'too, that the manifold was mounted on the sheet of metal with one end slightly higher than the other. This was done on purpose so that any bubbles which might ever form in the tubes willinstead of forming an "air lock"—automatically rise up and flow out of the manifold into the water storage tank above.

The absorber plate—manifold and all—was then painted flat black and mounted inside the insulated refrigerator door. The manifold was connected to the storage tank with two flexible hoses and a double strip of Masonite was added to the door to [1] hold the hoses in place and [2] form one edge of the mounting for the glazing that was installed next. Just as in the refrigerator door flat-plates already described, this glazing consisted of two pieces of glass cut to fit, mounted under the door's rubber gasket on three sides (and on the double strip of Masonite on the other) and scaled in place with silicone caulking.

The whole unit was next mounted on the sunny south wall of MOTHER's research shop and its storage tank was plumbed up with two connections: a cold "in" line from the city water main and a hot "out" line running into the workshop. After all the connections were checked for leaks, mucho insulation (both the fiberglass batting that had originally been removed from the case and as much "extra" homemade cellulose as could be packed in) was stuffed around the storage tank, and the refrigerator case was closed off with a panel of waterproof Masonite.

You'll notice that this sheet of Masonite has aluminum foil glued to its front (to reflect a little more solar fall down onto the collector panel). If you look closely at the opened solar water heating system, you'll also see that the two hoses running from the collector panel to the insulated storage tank pass through elongated slots in the sheet of Masonite fastened over that tank. These slots allow the hoses to " fold up" inside the insulated cavity, thereby making it possible for the flat-plate collector door to be swung up and closed at night and on overcast days. This [1] protects the unit from freezing up during subzero weather, [2] protects the critical parts of the system from vandals at night, and [3] makes it possible to heat a tank of water with solar radiation on a bright, sunny day ... and then save and use that hot water as desired throughout as much as a following week of overcast, cold weather.

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