For new installations a system-based approach is used that based on the installed power density. There are two different criteria:
1. If an entire building would be equipped with a new lighting system, the criterion for the installed light output (including lamps, ballasts and control units) divided by the total floor area in W/m2 must be applied.
In our case: 72W / 19,44m² = 3,70W / m².
2. When in a specific area of a building a new lighting system would be installed, so the criterion for the normalized power density in W/m2/100 lux must be applied. This means the total consumed energy of the lighting (including lamps, ballasts and control units) must be divided by the total floor area, and by a hundredth of the illuminance of the specific area.
In our case: 3,70W/m² / (34,6lx/100) = 10,7 W/m²/lx
