Short description
This VDI Expert Recommendation describes a new measurement setup that can be used to measure the angle-dependent radiant transmittance of building enclosures, especially for samples with laterally extended structural elements. Recommendations are given for the application of the measurement setup and the use of the results. The VDI Expert Recommendation is a supplement to DIN EN 14500. It also describes how measured transmittances can be converted into a discretely resolved bidirectional transmittance distribution function (BTDF), supported by a simulation model.