Existing studies on horizontal sunshade systems mainly focus on the influence of the sunshade on the room under or inside the sunshade systems. Meanwhile, the top surface of horizontal sunshade, especially those with mirror surface or made of metal, reflects solar radiation into the indoor and surroundings, resulting in “secondary reflection”. This paper mainly focuses on the influence of secondary reflection on the room above the sunshade, using DesignBuilder software to conduct numerical simulation analysis and building architectural model for field measurement. Results from simulation and field measurement both prove that mirror materials increase secondary reflection reflected into the indoor. Moreover, results from experiments show that retroreflective materials decrease secondary reflection reflected into the indoor. At low latitude, the application of retroreflective materials on the top surface of horizontal sunshade effectively reduces the adverse influence of secondary reflection on the room above the sunshade.

现有水平遮阳系统的研究主要集中在遮阳对遮阳系统下方或内部房间的影响。同时，水平遮阳伞的顶面，尤其是镜面或金属材质的遮阳伞，将太阳辐射反射到室内和周围，造成“二次反射”。本文主要针对二次反射对遮阳上方房间的影响，利用DesignBuilder软件进行数值模拟分析，建立建筑模型进行实测。仿真和实测结果均证明镜面材料增加了反射到室内的二次反射。此外，实验结果表明，逆向反射材料减少了反射到室内的二次反射。在低纬度，