How does a Passive Solar Water Heater work?
These systems use the basic principles of the greenhouse effect to produce heat. The hole idea is to trap some fluid (air, water, etc) in a place, and leave sunlight through the “walls” in order to heat the inside. This technology might seem too simple, but it is productive enough. In fact, some systems provide efficiency up to 70%. That means that they harvest the 70% of the solar energy radiated at an area and transform it to hot water. The 5 basic types of passive solar water heater systems available in the global market: • Glazed Flat plate collectorsThese consist of an insulated metal box with a glass or plastic cover and a black absorber plate. The box is filled with air or water. When sun hits the absorber plate, heat is transfered to the fluid in the box. Tubes filled with circulating water pass through the liquid and absorb the heat. Temperatures reach up to 30-70C (86-158F). Thus, flat-plate collectors are ideal for water heating for homes and solar space heating. • Unglazed
