Solar Water Heater

Solar water heating (SWH) or solar hot water (SHW) systems comprise several innovations and many mature renewable energy technologies that have been well established for many years It is very cheap source of energy which will be con-verted into other usable form of energy. Pakistan is the richest country to develop it .SWH has been widely used in Greece, Cyprus, Turkey, Australia, Japan, Australia, China and Pakistan.

In a “close-coupled” SWH system the storage tank is horizontally mounted immediately above the solar collector on the roof. No pumping is required as the hot water naturally rises into the tank through thermosiphen flow. In a “pump-circu-lated” system the storage tank is ground- or floor-mounted and is below the level of the collectors; a circulating pump moves water or heat transfer fluid between the tank and the collectors.

SWH systems are designed to deliver hot water for most of the year. However, in winter there sometimes may not be sufficient solar heat gain to deliver sufficient hot water. In this case a gas or electric booster is normally used to heat the water. Domestic solar thermal systems are commonly used for providing hot water in residential homes. Another promising use for solar thermal systems is for commercial and small industrial applications for: g Hospitals KJ/ Laundries g Schools KJ/ Breweries M Multi-family houses KJ/ Process heat g Solar cooling Solar thermal systems for commercial and industrial applications are more complex than domestic solar hot water systems. These systems require comprehensive design and to be installed for optimal performance.