LOW-COST PASSIVE SOLAR WATER HEATER.

The development, construction, testing and evaluation of a passive, solar water heater designed to meet the needs of low-income households is described. Criteria to be met included low cost, no auxiliary power or thermosiphon ″head″ requirements, easy retrofit, built-in back-up capabilities, and uncomplicaated construction using standard and recycled materials. The final design uses a recycled water heater as both collector and storage and a manually operated flexible cover as daytime reflector and nighttime insulator. This ″capsule collector″ cam be bio; t om a ,pdest home workshop by a person with limited skills for as little as 30 materials cost. Test data is interpreted to determine collector efficiency, optimal operational times, and heat losses. The degree of success in meeting the design criteria are discussed as well as the future plans for the development of the capsule collector. The collector is evaluated for performance, durability, ease of operation and fabrication, and cost.