No water enters the heat-transfer tube and thus blocking of water passage and turn impair of the output power resulted from scale in the vacuum tube are basically eliminated.

The used special freezing-protection technology prevents the heat-tube from being frozen even under-50 air temperature. The heat-tube type collector tube is low in heat capacity and fast in start, and under sunshine it can start to out put energy in 2minutes.

The superior selective absorption coating and the vacuum thermal-insulating technology ensure a daily mean thermal efficiency above 48% even at cloudy climate or winter.

It has excellent wind-resistance and hail-resistance and withstands the impact by typhoon and hail of a diameter up to 35mm.

Because of its high bearing capacity, when connected into a large-surface heat-collection system, it has unique advantages in the press-urized hot water system varying with the pressure of circulation pump and is highly resistant to both the cold and the heat impact. Thereby, the trouble that the entire system is impossible to run because of damage of a single collector bube is eliminated. Is is easy and simple in installation, maintenance and fixation, safe and reliable in running, low in wind resistance, and highly resistant to typhoon.