1)The medium and the direct flow pipe exchanges the energy directly, so the heat collecting effectiveness is very high, and without the problem of performance recession.

2)Because of the forced circulation of medium, you can disposal the collector tube conveniently. You can get more energy just by rotating the vacuum and make it face to the sun directly.

3)Compare to the heat-pipe collector, you can get a high collecting effectiveness no matter you install it horizontally or vertically. So it is very suit for the veranda-installed solar water heater, and can solve the installation problem for the high-stairs effectively.

4)Able to endure the high pressure, able to be deployed neatly-realize once heat exchange and twice heat exchange in enveloped state.