Revision of dataType OpticalProperties
The dataType OpticalProperties enables to specify reflectance, transmittance and emissivity of a construction, but not the absorptance. Especially for opaque materials, simulation systems like EnergyPlus support the specification of this parameter. That due to physical laws the absorptance can principally be calculated on base of reflectance, transmittance and emissivity is totally irrelevant in this context: It is much better to directly specify the needed parameter instaed of three non-needed parameters.
In addition to reflectance, transmittance and emissivity, the dataType OpticalProperties has a parameter glazingRatio, specifying the glazing ratio of a ThermalOpening referencing the Construction. Conceptionally, glazing ration is not an optical property, but a structural parameter of either a Construction or a ThermalOpening.
It is therefore proposed
- to introduce a new dataType Absorptance,
- to extend OpticalProperties with a new attribute absorptance: Absorptance [0..*],
- to eliminate the attribute glazingRatio.
In which class (Construction or ThermalOpening) the glazingRation shall be specified is open for discussion.
