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pencil.gif (370 bytes) Making a Solar Water Heater Model
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What is a solar water heater?
Solar water heaters usually consist of solar panels mounted on the roof (and called solar collector), water pipes through which water circulates from the collector to the water heater, and a water heater similar to a conventional one. The collector traps
the sun’s heat and this trapped energy heats the water being pumped through the pipes, which pass

through the collector. The heated water returns to the water heater, where it is sometimes heated further. The water is stored here for use. The entire system is well insulated, so as to avoid losing heat.

You will need: A cardboard box, Aluminium foil, Wooden stick, M-seal or putty, Black or silver tape, Plastic wrap, Water can, Black paint, Rubber band, Thermometer, Cellophane tape
Instructions:
1.Cut the box in half along the diagonal as shown, leaving a triangularly shaped top and bottom. Then cut off the top triangle. The leftover piece has two sides that can be cut out to fit flat onto the sides of the remaining box. Then tape them to the sides of the half-box. These side-pieces will add some thickness to the walls and help keep heat inside. Glue aluminum foil to the inside of the box (sides and bottom) with putty or ‘M-Seal’.

2.Tape a small stick of wood across the top corners of the heater box as a brace. Use silver duct tape. Tape clear plastic wrap to the bottom and sides of the box as shown. Make sure it is long enough to have some left over to fold over the top. The fold-over flap can be used as a door to get into the box. You can tape heavy weights to the corners for holding it shut or you can tape the corners down.

3.Use any can that has no leaks. Paint it with flat black paint.

4. Open the top of the heater box. Fill the water can, cover the top of it with clear plastic wrap and put a rubber band around the top of the can to seal it. Place the filled can on the bottom of the heater box and close the top flap. Be sure it is well sealed. Face the front of the box to the south and wait for it to heat up. You can test the temperature of the water by sticking a thermometer into it. You can also experiment with different kinds of cans and jars.