Theoretical And Experimental Investigation On The Optical Properties Of DSF With Blinds

Double skin fa?ade with blinds is widely used in hot-summer and cold-winter zone,but energy performance of DSF with blinds isn't not good without considering its acclimation. The radiant energy absorbed by layers of DSF with blinds will strongly influence its thermal performance, then the entire building energy consumption and optimization, so it's necessary to research on the optical model of DSF with blinds. Besides,experiment investigation on the optical properties of DSF with blinds is not so much that verifying methods to calculate the optical properties of DSF with blinds is not easy. This article focused on theoretical and experimental investigation on the optical properties of DSF with blinds, aiming to provide reference for research fellows engaged in related work.First, the optical model of blinds was established based on a radiosity method and principle of reflection with the hypothesis that blinds aren't perfect diffuser. And the experimental verification was carried out. Besides the effect of different design parameters(such as the sun profile angle?the slat angle?the shining factor and the blind geometry) on effective optical properties of blinds was also investigated.Second, two main methods to calculate the optical properties of the glazing system—surface radiation balance and ray-tracing are presented. The experimental verification and comparison of two methods to calculate the optical properties of the glazing system without shading devices was conducted.Then, two optical models of DSF with blinds through which its reflectivity?transmittivity and absorptivity can be obtained were established based on blind's optical model and two methods to calculate the optical properties of the glazing system.Finally, the experiment platform construction built in Changsha,a typical hot-summer and cold-winter area, and experiment scheme on the optical properties of DSF with blinds is introduced. Experimental research on the optical properties of DSF with blinds was conducted with pyranometers. And The experimental verification and comparison of two methods to calculate the optical properties of DSF with blinds was conducted. The reason of the discrepancy was also discussed.The research showed that there was a moderate discrepancy between the optical properties calculated by surface energy balance and experimental results. So was between the optical properties calculated by surface energy balance and experimental results. But the optical properties of DSF with blinds calculated by ray tracing was closer to experimental results.More consideration is supposed to be took when the two methods or some softwares based on it are used to calculating the optical properties of DSF with blinds.