This non-pressurized vacuum tube solar water heater has a assistant tank in the top of main water tank. The assistant tank can automatically supply cold water. It 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 is 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. Water proof grade: IP *4
5. Hot water can be used directly, or can be used as a pre-heat.
6. Electric heater can be used 1500W or 3000W