It is possible to build a solar hot water heater from salvaged parts. Homeowners can build an effective unit for under $5 if they have access to a local dump and are willing to sift through the refuse for the necessary parts, such as an old refrigerator.
If the homeowner can locate an old, out-of-use refrigerator, he can remove the cooling coil from the back, which can function as the core of a passive, solar hot water heater. Other materials for constructing a frame consist of salvaged wood and glass. Cold water can be siphoned via gravity through the heater to a warm water collection tank or bucket.