Solar water heater vacuum tube aborbs solar energy converting it into heat for use in water heating. each evacuated tube consists of two glass tube made from extremely strong borsilicate glass. the outer tube is transparent allowing light rays to pass through with minimal reflection. the inner tube is coated with a special selective coating(AL-N-AL) which features excellent solar radiation absorption and minimal reflection properties. the top of the two tubes are fused together and the air contained in the space between the two layers of glass is pumped out while exposing the tube to the high temperatures.this "evacuation" of a glass forms vacuum, which is an important factor in the performance of the evacuated tubes. the vacuum in the evacuated glass tube is less than 5x10-3 pa. this can only be reached and maintianed over a long period of time through a specialized evacuation process in production resulting in an almost total elimination of convection and conduction loses from the tube.