In the case of constant pipe diameter, lengthening the length of vacuum tube is an effective way to increase the total heat of solar waterheater!
在管径恒定的情况下，加长真空管的长度是增加太阳能热水器总得热量的有效途径和方向！
2
The construction, performance and the working principle of VH vacuum heating waterheater unit are discussed. The applications of the unit are also introduced.
阐述了VH真空热水机组的工作原理、结构组成和性能特点，介绍了该机组在供热、采暖系统中的应用。
3
Solar waterheater is renewable energy sources product which widely used in China. It can be devided into vacuum tube solar waterheater and flat panel solar water heater.