Energy demand, Thermal and Luminous Comfort in Office Buildings: a computer method to evaluate different Solar Control Strategies

Many contemporary office buildings are characterized by large glazed surfaces, often located without any consideration about orientation. Without a suitable solar control strategy, this fact implies several problems related to visual comfort, thermal comfort and energy demand, which is mainly related to HVAC and, to a smaller extent, to artificial lighting. Moreover, if the office room is large, the values of physical parameters influencing comfort are relevantly variable from point to point, mainly as a function of the distance from glazed surfaces. Typically, daylighting requirements of occupants located far from the windows can conflict with the thermal comfort requirements of occupants located next to the windows. In this work a case-study is analysed. It consists in a medium size office room located in a typical office building, in an urban context of the Northern Italy. Different solar control devices and related control logics are compared; their effects on global comfort conditions and energy demand are assessed. The considered devices consist of different kinds of movable external slats, some of which incorporating PV cells. This analysis is performed by means of a specific software: "Ener_Lux", already presented in previous PLEA Congresses. Once defined the kind of devices and the related operating logic, the program simulates the dynamic thermal and luminous behaviour of the physical system, provides various comfort assessment index values and calculates the primary energy demand for HVAC and lighting