How to Build Your Own Solar Batch Hot Water Heater

Prepare the water heater tank. Remove the pipes and insulation. Wash the interior of the drum with a bleach and water solution to remove mildew. Rinse thoroughly. Paint the exterior with the black paint. Assemble the hoses and fittings onto the tank with one opening at the top and another at the bottom. Seal off any other openings.

Cut the hose lengths. Cut a 3-foot section for the drum interior. Measure and cut a section for the cold-water inlet valve. Measure and cut a section for the hot-water outlet valve. These measurements will depend on the distance from the water heater to the valves.

Locate the site. Site the water heater in an area receiving direct sunlight most of the day. Determine the path of the sun over the location. You want to set up the water heater tank to face the sun. Measure and mark an area 5 feet by 5 feet square.

Dig a 4-inch deep trench within the marked area.

Build the foundation. Lay the foundation blocks in the trench. Set the blocks both lengthwise and crosswise to fit the trench. Pack soil around the foundation. Lay out a second layer of blocks on top of the first layer.

Build the walls. Place a row of blocks along the outer edge of the west, north and east sides. Set the initial block of the next row on the west wall, half a block length from the end of the preceding row. Build the remaining row as you did the previous row, stopping half a block length at the end. Repeat this process until your walls reach seven levels, decreasing half a block length at both ends of the new row.

Leave a space on the sixth row of the north wall for the outlet hose. Add another space on the east side of the same row for the intake hose.

Fill in the ends of the west and east walls. Construct braces to support the cement using the 1 inch by 6 inch by 6 inch boards by placing a board on either side of the blocks. Line up the top edge of the boards with the top edge of the walls. Attach the boards with clamps at each end. Fill the spaces between the braces with cement. Smooth over the surfaces to match the incline of the boards.

Build the support form for the drum. Use the 2 inch by 4 inch lumber for the drum supports. Measure the inside base of the cinder block frame from back to front. Measure this length three times on the 2 inch by 4 inch board. Cut the board at the markings. Set one of the boards against the bottom of the drum so that there is a 1-inch allowance between the side of the board and the side of the drum bottom. Trace the outline of the drum onto the board. Cut the outline. Repeat this process with the other two boards. Attach the boards to the base at equidistant intervals to support the drum.

Insulate the chamber. Measure and cut the insulation for the chamber. Install the insulation against each interior surface so the shiney side faces outward. You will need to cut out sections for the base because of the support boards.

Set up the drum. Position the drum to rest evenly on the support boards. Make sure the holes for the hoses are at the highest point on the drum. Guide the hoses through the respective holes in the walls. Turn on the cold water valve to fill the drum. Allow the drum to fill while checking for leaks.

Attach the cover. Lay a bead of caulking around the top of the walls toward the inner edges. Lay the glass over the caulking. Press down gently to get the glass to adhere to the caulking. Set a board of 2 inch by 4 inch by 4 inch lumber over each side of the glass so that it overlaps the glass and the walls evenly. Drill concrete screws through the wood into the walls to attach the glass to the frame. Do not drill through the glass.