An empirical validation of modeling solar gain through a glazing unit with external and internal shading screens

Empirical validations are integral components in assessing the overall accuracies of building energy simulation programs. Two test cell experiments were performed at the Swiss Federal Laboratories for Material Testing and Research’s (EMPA) campus in Duebendorf, Switzerland to evaluate the solar gain models with external and internal shading screens in four building energy simulation programs including: (1) EnergyPlus, (2) DOE-2.1E, (3) TRNSYS-TUD, and (4) ESP-r. Detailed information about the shading screen properties, modeling procedures, and thorough statistical and sensitivity analyses of simulation results are provided. For the external shading screen experiment, the mean percentage of the absolute difference between measured and simulated cooling power to maintain a near-constant cell air temperature for EnergyPlus, DOE-2.1E, TRNSYS-TUD and ESP-r were 3.7%, 5.5%, 10.6%, and 7.5%, respectively. EnergyPlus and DOE-2.1E were considered validated within 95% credible limits. For the internal shading screen experiment, the mean percentage of the absolute mean differences for EnergyPlus, DOE-2.1E, TRNSYS-TUD, and ESP-r were 6.7%. 13.8%, 5.7%, and 4.3%, respectively; only ESP-r was considered validated within 95% credible limits.