solar heating

Specification of all-glass Evacuated Solar Collector Tubes
1). Structure: all glass tube 
2). Glass material: high borosilicate glass 3.3
3). Absorptance: >0.92
4). Emittance: <0.08 (80)
5). vacuum:   <5*10-3 Pa
6). Stagnation>230./KW
7) average heat loss:    <0.8w/ .
8). Lifetime>15years
9). Spec:

solar heating
All glass vacuum tube solar collector, have high performance of absorptance and low reflection ratio.