Hi D.W. Kim
Plz refer to the contents below. I once write this summary for my thesis.
For solar distribution, there are five choice inside EnergyPlus, namely ?minimal shadowing?, ?full exterior?, ?full exterior with reflections?, ?full interior and exterior? and ?full interior and exterior with reflection?. In this thesis, ?full interior and exterior? is used.
By using full interior and exterior, all transmitted beam solar is traced its route, to make sure which internal wall it falls on. The effect of exterior shadowing surfaces and window shading devices are taken into account.
When shading effect is tested, the ?full interior and exterior with reflections? is used. In this algorithm, the effect of reflection from outside shading devices to envelope exterior surfaces is considered.
For window transmitted diffuse solar radiation, it is first distributed according to approximate view factors which have been introduced in internal long wave radiation part.
The reflected part of diffuse solar radiation is added
together with the reflected portion of direct solar and lighting diffused heat
gain part. These diffuse radiation part is distributed uniformly to interior
surfaces in proportion to an index which are production of area and
absorptance.
RGDz
Zhang XiangJing
Solar Energy Research Institute of Singapore