Flat plate solar water heater advantages: First, it is particularly suitable for building integration requirements. Flat plate solar water heater due to its planar structure characteristics, solar building integrated applications, the morphology flexible casual design from the constraints of shape or size, easy to implement a combination of building components. Coupled with its collector plate made of metal, can be easily adopted silk knot, welding and other connection, installation, maintenance and use convenient. The second is to have a higher thermal efficiency. Vacuum tube solar collector is composed of a number of vacuum tubes, there is a gap between the pipes is sunlight, part of the solar collector is not acceptable. Flat plate solar collectors is a continuous plane, the entire surface of the collector can receive sunlight. So, under the same lighting area and intensity of sunlight, the daily average efficiency of flat plate solar water heater is generally higher than the daily average efficiency of vacuum tube solar water heater is more than 6%. Third, with the good performance of the pressure. Flat plate solar collector absorber plate is made of metal material, the collector and the storage tank connected to metal parts, therefore, can withstand the pressure from the tap water and circulation pump. , City water is generally centralized water supply system, the water pressure is high, which requires the hot water out from the solar water heaters have a certain pressure, and thus, reduce the pressure difference between the water heater outlet and the tap water outlet, for user convenience and comfort. 4 is composed of a large system stable performance. For large spaces, such as hotels, swimming pool, factories, and other places, the use of solar water heaters, often require a lot of solar collector composed of a large-scale water supply systems. If the flat plate solar collectors metal connection between the collector and the system, rather than as connected with rubber parts and vacuum tube solar water heater, you can guarantee the stability of the entire system. Therefore, when the establishment of large-scale solar water heating systems, often using flat plate solar collectors. In addition, due to the structure of flat plate solar water heater is simple, convenient and easy-to-scale production and processing, so that it has a low manufacturing cost, installation cost provincial and long service life characteristics. Of course, the problem of the presence of high heat loss and antifreeze flat plate solar collectors, through scientific and technological innovation to further solved.