The maintenance factor is multiplier, which refers to the decrease in light output caused by aging or contamination of the lamp. The maintenance factor refers to the light losses that occur over time and is also known as the loss factor.
The maintenance factor is multiplier, which refers to the decrease in light output caused by aging or contamination of the lamp. The maintenance factor refers to the light losses that occur over time and is also known as the loss factor.
In light sources, a decrease in light output, i.e. lumen value, can be seen during the use. In addition, contamination of light sources cause some decrease in light output. This decrease due to aging and contamination should also be taken into account when calculating light levels.
In all indoor and outdoor lighting applications, light levels cannot be remain constant throughout the operating time. Due to the lumen degradation and contamination of the light source, decreases can be seen over time. If this is an indoor lighting, the reflection in the ceiling and wall of the room will decrease over time, resulting in a decrease in light levels.
Maintenance factor is calculated according to lamp type, ballast type, fixture type, maintenance intervals, operating time, room reflection rates and environmental effects. There are special softwares developed for this calculation.
Maintenance factor (MF) can also be calculated by multiplying the lamp lumen maintenance factor (LLMF), lamp survival factor (LSF), luminaire maintenance factor (LMF) and room surfaces maintenance factor (RMF or RSMF) by the following formula.
MF = LLMF x LSF x LMF x RMF
LLMF refers to the time-dependent decrease in the light flux of the lamp. This value is usually specified by the light source manufacturer.
LSF refers to the fault state of the light source. If the lamp change is made immediately in case of failure, this value can be taken 1 and its effect can be ignored.
LMF specifies the resulting light losses caused by contamination of the fixture by environmental impacts. Values in the range 0.93-0.98 can be taken for clean environments in indoor implementations.
RMF or RSMF, shows the time-dependent decrease in the reflection values of room surfaces. In a clean environment, this value can be taken in the range 0.95-0.97.
Maintained luminous flux can be calculated by multplying maitenance factor and initial luminous flux.
When lighting applications are made, the maintenance factor should be taken into consideration and values above the minimum light levels specified in the relevant standard should be noted at the beginning. Loss of light over time should not cause lighting conditions to fall below the specified criteria.
