How to Build a Solar Water Heater

With many commercial solar water heaters costing upward of $3,000, building your own can be a great, inexpensive alternative. By doing some smart shopping, you can find all the materials you need for less than a third of the commercial unit cost. Add a little of your own labor, and you're well on your way to the first of many free, Earth-friendly hot showers.

Supplies

In the way of supplies, you'll need lumber, pegboard Masonite, plastic foam insulation and a sampling of copper items. An old water heater will work for your storage tank, and you can resurrect used aluminum storm windows in place of buying expensive glass panels. A relief valve, nails, black plastic pipe, and fittings for connecting the units round out the list of needed materials. (Find a detailed list of components and the appropriate measurements in A Homemade Solar Water Heater by William J. Weber.)

Construction

Once you've collected the parts, the first step is to construct the 'hot box' (a wood box covered with glass, or, in this case, a segment of the storm windows) to catch the heat from the sun. Inside the finished box, use the copper collector sheet and water pipes to build a manifold. This is where the collected solar heat will warm the water.

You can then connect the storage tank (positioned above the collector box) and manifold outlets. This system transfers the warm water up into the storage tank and sends the cooler water down to be warmed in the collector. (This system is not outfitted for use in cold climates. Please see the full A Homemade Solar Water Heater article for cold weather suggestions.) It's a good idea to fill the system and check for leaks before you begin regular use. If you find water escaping from any point, empty the system completely before re-soldering the leaking area.

Final Touches

Finally, apply black paint to the manifold and collector sheet and protect any visible wood with an oil-based coating. Place the water heater at a 45 degree angle and connect the water tank. You're ready to go!

For specific instructions and a detailed list of parts, read A Homemade Solar Water Heater.