Vacuum tube solar collectors have several advantages compared with flat panel solar collector, let's see the details as following:
1. Due to the cylindrical shape and the location of the vacuum tubes, vacuum tube solar collectors can collect the sun's rays optimally throughout the day, while the flat collectors operate at maximum efficiency only during the midday, when the sun rays are perpendicular to the absorbent layer.
2. By extracting the air from the tubes, the vacuum is created in them. The vacuum has very good insulating properties, so the heat losses through conduction and convection are significantly reduced. The phenomenon is similar to the principle on which a thermos is built, thus the wind and cold air will influence the efficiency of vacuum tube solar collectors too little. Because in the case of the flat panel solar collector an insulating layer cannot be inserted between the absorbent layer and the solar rays, during the cold periods the heat losses will increase.
3. In case of damage, vacuum tube solar collectors can be remedied by the quick and easy replacement of the damaged tube, without the need to drain the entire system. However, in case of damage to the glass of the flat collector, it must be replaced completely and the heating system must be emptied, then brought under pressure again.