17 Why does lighting need to be controlled? You want to ensure a certain light level (e.g. 200 lux recommended for dairy cattle barns) inside the building. Yet daylight incidence varies greatly throughout the day. Summer days are also generally light and winter days dark. If the lighting is designed to generate the desired brightness in the building at low daylight levels, then it would be too bright at high daylight levels. This would waste energy. You want to generate a long daylight phase in the barn to increase milk production? You certainly don‘t want to turn on the light very early in the morning and turn it off very late at night every day. Kerbl’s lighting control system has the answer: you can use it to switch the artificial barn lighting on or off with time control and depending on the available daylight, or even achieve a constant lighting level through automatic dimming. Which control methods are possible? Dawn Dusk Lighting constant light level natural daylight Lighting control with an internal sensor The optimum light control set-up can also take account of the influence of the building envelope on the lighting levels inside the building. If, for example, all windows are darkened due to strong sunlight, the lighting inside the building should be switched on regardless. In this case, the light sensor is installed inside the building. The lighting intensity can then be controlled not only by switching the lights on and off, but also by automatic dimming of the lamps. This creates a constant light level in the building between the specified switch-on and switch-off times. Lighting control with an outdoor light sensor LED Lighting Control A light sensor measures the brightness outside. If the light sensor detects that the daylight is sufficient, then the lighting inside the building is switched off. If the available daylight falls below a set threshold, the lighting is switched on. If dimmable lamps are used, you can also specify that the lighting is switched on in a dimmed state. In parallel, you can also pre-set the on and off times in the morning and in the evening using a timer.