Light level control for building lighting

摘要

A control system (2) for controlling the interior light level of at least a part of a building (1), the at least part of the building being illuminated by so much natural light through one or more transparent portions (8) as through light generated through one or more electric lights (4); the control system being operatively connected to said at least one interior sensor (3) to detect an interior light level; comprising the control system - at least one electric light controller (4) to control the light level of the one or more electric lights; - at least one window treatment controller (5) to control the level of admitted natural light through the one or more transparent portions; and - a processing unit (7) for handling control setpoints, the control setpoints comprising an indoor light level setpoint, the processing unit being operatively connected to at least one indoor sensor ; in which the processing unit determines a difference between the detected interior light level and the interior light level set point, and in which the light level of the one or more electric lights and the light admission level Naturally admitted through the one or more transparent portions are controlled in parallel by operating the at least one electric light controller and the at least one window treatment controller for, based on the difference between the level of interior light detected and the interior light level setpoint, control the interior light level of at least part of the building, characterized in that the at least one electric light controller and the at least one window treatment controller are operatively connected (28 , 29), so that the at least one electric light controller receives operational information from the at least one window treatment controller, and / or vice versa; and wherein the at least one electric light controller is operated based on the information received from the at least one window treatment controller, and / or the at least one window treatment controller is operated based on the information received from the at least one electric light controller.