Violet gold tube is higher than that of ordinary vacuum absorption improvement of 12%, emission ratio decreased by 30% - 40%, super absorbent, and less heat loss, fast temperature rise. Three Zijin pipe, super absorption, high thermal efficiency, fast heating, in the same light according to the premise, than the ordinary pipe to more high temperature hot water; alpine tube, due to copper ion emission Bibi aluminum ion low 0.2, so heat loss rarely, in the alpine environment can still work. - 30 DEG C as usual hot water; high temperature special effect tube, stainless steel ion in the film due to high temperature, anti air drying, coating at 400 DEG C under the premise of not aging, not decay, do not change color. And in the same light according to the premise, ordinary tube heat absorption as well as three Zijin high, even can not meet the requirements bathing; in low temperature, heat loss is greater, heat collecting efficiency decreased, affecting the normal use; especially drying in the air more than 270 DEG C when the film began to aging, loss, absorption rate decreased rapidly, greatly shortened life expectancy. And three purple tube not float to the surface the situation, so at present, three Zijin pipe is the replacement for the ordinary vacuum tube solar, is a market trend!