Non-pressurized vacuum tube solar water heater works with pressure up to 0.2 Mpa and can normally work in all climate. The absorptive coating is ALN/ALN-SS/CU. This coating has high absorbing ratio(0.94) and low emission ratio(0.6). The heat efficiency is 0.64. The life span of the vacuum tube is 15 years. The vacuum tube ia made of borosilicate 3.3.

Characteristics:
1. It is not easy to be frozen and cracked down even in hash weather.
2. The shortcoming of bursting of tube or water leakage due to aged rubber ring is eradicated;
3. The water tank is welded scientifically under the high frequency weld and argon-arc weld. The non-pressurized vacuum tube can be directly connected with tap water system to operate automatically with pressure-bearing.
4. The inner tank is made of SUS304-2B stainless steel (thickness: 0.4mm). There is copper coil(optional) in the tank, and the heat water just come from the copper not from the tank;
5. The outer tank is made of SUS304-BA stainless steel(thickness: 0.4mm). The material of heat insulation layer is imported PU(thickness: 55-60mm).
6. The frame is made of stainless steel(thickness: 1.2mm)
7. Volume of water tank: 80L 90L 100L 135L 155L 165 L 185L
200L 220L 250L 300L 400L 500L