The comparison of an old lighting installation (old installation) of standard class with opal diffuser luminaires and three alternatives for a new lighting installation demonstrates the photometric and energy-related advantages of modern lighting technology (see table as well as figure and figure).
The calculations are based on 1.400 hours of operation per year. This is the period of operation for a school based on the user profile documented in standard DIN V 18599-10 (see chapter “Light and the environment”), where no additional use of rooms for adult education or other purposes is necessary, meaning e.g. for an elementary school. When factoring in the relative absence mentioned in the user profile in addition to that via electronic presence detection, the lighting is turned off over a statistical average of 23,75% of the period of operation (new installation 2). Further savings facilitated by daylight-dependent regulation are also treated like a reduction in operating hours (full load hours) in the standard (new installation 3).