Heat exchangersare devices designed to transfer heat between two or more fluids—i.e., liquids, vapors, or gases—of different temperatures. Depending on the type of heat exchanger employed, the heat transferring process can begas-to-gas,liquid-to-gas, orliquid-to-liquid 

Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar collectors to potable (drinkable) water.Heat exchangers can be made of steel, copper, bronze, stainless steel, aluminum, or cast iron. Solar heating systems usually use copper, because it is a good thermal con