Controlling venetian blinds based on parametric design; via implementing Grasshopper’s plugins: A case study of an office building in Cairo

Abstract

Venetian blinds are common type of shading devices and are increasingly operated automatically to overcome the limitations of using manual operation. Automated blinds need to be controlled to maximize benefits of daylight on the aspects of redirecting sunlight, occupant comfort and energy consumption. However, the common control methods are focused on minimizing negative impacts of daylight, but they might fail to maximize the positive impacts of daylight. They may often inaccurately predict a blind’s position, resulting in the undesirable blockage of useful daylight needed.This paper puts forward a new control method for automated venetian blinds to optimize the utility of daylight. The proposed control method can not only protect occupants from direct solar glare but also maximize daylight penetration into office rooms based on algorithmic methods. The proposed control method is designed to reflect the incident sunlight into the ceiling, then the reflected light acts as a main source of light for the occupants. The reflecting slats respond to the sun altitudes parametrically, in an individual heliotropic response, which can keep the reflected light relatively steady during daytime. Consequently, this process can exploit the optimal use of natural daylight as a main source of lighting and provide shade simultaneously.