LIGHT LOSS FACTORS (LLF)

Factors that allow for a lighting system's operation at less than initial conditions. These factors are used to calculate maintained light levels after a given period of time and under specified conditions. It takes into account the dirt accumulation on luminaires and room surfaces, lamp depreciation, maintenance procedures and atmosphere conditions. LLFs are divided into two categories, recoverable and non-recoverable. Examples are lamp lumen depreciation and luminaire surface depreciation.