Optimisation example 1 Lighting control
Measures are to be undertaken in an office building to reduce the energy consumption.
In the first step, the lighting system is modernised. The conventional ballasts of the fluorescent lamps are replaced by electronic ballasts. Accordingly, the electrical power consumption of the fluorescent lamps is reduced by about 30 %.
In order to further optimise the energy consumption, an additional constant lighting control is introduced. The intention is to provide a constant lighting intensity of 500 Lux on the working surfaces. The brightness sensor measures the current lighting intensity for this purpose. Using the current value and the difference to the required lighting intensity, the light controller calculates a brightness setting for the dimming actuators. Between 28 % and 66 % of electrical energy used for the lighting can be saved with this control method – depending on the season, the weather and the location of the building (see ABB field study on pages 10 and 11).
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Finally, it is possible to detect the occupancy of the room using a presence detector and to implement an occupancy dependent lighting control system. If the room is not occupied, the lighting can be switched off automatically if someone has neglected to switch it off manually. The automatic presence-dependent control can yield a further 13 % of savings.