A simple evaluation method of external Venetian blind shading performance for nearly zero energy buildings

In recent years, nearly zero energy buildings have developed rapidly in China, and they will scale construction and expansion in the future. The application of external Venetian blind shading can further improve the comprehensive energy efficiency and indoor comfort level of nearly zero energy buildings. However, existing studies lack a convenient method to evaluate the shading performance of external Venetian blind shading for nearly zero energy buildings in different climate zones. Therefore, based on the theoretical analysis of external Venetian blind shading, a simple evaluation model of the shading performance of external Venetian blind shading suitable for nearly zero energy buildings is established. This method innovatively divides shading devices' energy-saving performance into two parts: heat insulation and radiation shielding. Furthermore, the recommended values of each parameter in the model are identified by EnergyPlus numerical simulation. The actual solar direct transmittance of the glass in different cities and orientations has little difference, the solar direct transmittance of shading device is positively linearly correlated with the slat angle, the proportion of solar radiation energy-saving of the EVBS of south shading is the largest, and this percent is in the range of 30%∼50% for other orientations. These results quantify the shielding and heat insulation effects of glass and shading systems in different climate zones.