The venetian blind in this study is modeled as an effective layer.
Since the optical properties of the venetian blind are considered nonspecular (diffuse or partly diffuse and partly specular), the mathematical model for an effective layer representing the venetian blind becomes quite complex.
When using the venetain blind installed behind the glass window, the blind can be set in different slat angles under different solar incident directions.
Therefore, the optical properties of the venetian blind are usually dependent mainly on the slat properties, slat angle, nature of interreflection of the radiation between the slat surfaces and solar profile angle.
In this study, the slats are assumed to be perfect diffusers and all of the slats have the same optical properties.