[esp-r] absorptivity and absorption of 5 angles???

[Dr.QIU]

Dear all,

In ESP-r's "material database", each type of glass has some properties as follows:

Thick 8mm
Conductivity 1.05 W/m.C
Density 2500 kg/m3
Specific heat 750 kJ/kg.c
Emissivity 0.84
Solar absorptivity 0.27

and at the same time I can define the "optical property" for the above glass(traparent construction) through specifying one certain item from the "optical database". its optical property may be as follows:

ISO 6946 U values (horiz/upward/downward heat flow)=  5.630  6.774  4.595 (partition)  3.737
Direct transmission @ 0, 40, 55, 70, 80 deg
   0.230 0.224 0.212 0.172 0.104
 Layer| absorption @ 0, 40, 55, 70, 80 deg
    1  0.329 0.358 0.381 0.388 0.358

My questons are,
(1)	For Solar Absorptivity(0.27 here) and absorption of 5 angles(0.329,0.358,0.381,0.388,0.358 here), which one is used in the calculation?
(2)What relationship exists between Solar Absorptivity and "absorption of 5 angles"?

I tried again and again, and I find that the simulation result will not change if only either of the above two is changed. The simulation result will change if both of them are changed.

Any answers are welcomed.

Thank you in advance.

Regards,

Qiu