Vacuum tube: 3.3high borosilicate glass

Vacuum tube:

3.3high borosilicate glass

The vacuum tube of our solar water heater has the high absorption rate and low emission rate,

the absorption rate is 0.90-0.93 (AM1.5)

the emission rate is 0.05-0.075 (80±5)

vacuum tightness is P≤5.0*0.0001Pa

idle sunning property parameters is Y=220-260./KW

the average heat loss coefficient is Ult=0.6-0.7W(.)

It means the temperature in the water tank is range from  50 to 95.