Luminaire Maintenance Factor

Generally, luminaire manufacturers have sufficient experience with the operating behaviour of their own products, especially since they are developed with the aims of a long service life and low maintenance effort. On the basis of the luminaire maintenance factors according to CIE publication 97.2 and in consideration of real measurements on luminaires taken from installations as well as based on experience, the luminaire maintenance factors in  table 1.25 to table 1.28 for generic luminaire designs (luminaire groups 1 through 4) were determined for operating durations between one and six years in very clean, clean, normal and dirty rooms.

Since the end of 2005, the updated CIE publication 97.2:2005 "Guide on the maintenance of indoor electric lighting systems" has been available. The luminaire maintenance factors contained therein confirm the values of the luminaire maintenance factors for the luminaire groups 1, 2, 3 and 4 according to table 1.25 to table 1.25. They correspond to the luminaire types A, B, D and F defined in CIE publication 97.2. Furthermore, there is explicit reference to the luminaire maintenance factors according to the data of the respective luminaire manufacturer.

Luminaire group 1

Table 1.25: Open-distribution luminaires. Also, direct or direct-indirect-distribution specular louvre luminaires without top cover, with compacted louvre or reflector surfaces particularly resistant to soiling.

Luminaire group 2

Table 1.26: Direct-indirect-distribution specular louvre luminaires without top cover. Also closed luminaires with additional specular reflectors on the inside.

Luminaire group 3

Table 1.27: Closed luminaires, e.g. diffuser luminaires. Also luminaires with optical systems open on the bottom and closed on top, e.g. direct or mostly direct-distribution specular louvre luminaires.

Luminaire group 4

Table 1.28: Luminaires with indirect portions over 80% and optical systems mostly closed on the bottom. Also exclusively indirect-distribution luminaires.