What is maintenance factor in illumination?

The maintenance factor, according to ÖNORM EN 12464-1, indicates how quickly the light intensity in a system decreases. It is relevant to ensure this prescribed value until the end of the system life.

What is the maintenance factor lighting?

A maintenance factor (MF) is applied to a lighting design to take into account a reduction in the output of the luminaires used within any lighting installation and ensure the correct level of light is delivered at the ‘end of life’.

What do you mean by maintenance factor?

The ratio of illumination on a given area after a period of time to the initial illumination on the same area; used in lighting calculations to account for the depreciation of lamps or reflective surfaces (or the like). also see light loss factor.

What is lumen maintenance factor?

The amount of light from the light source at a specific time in the future is referred to as the lamp lumen maintenance factor, or LLMF. The lifetime of a LED module is defined as the time it takes until its light output, or lumen maintenance, reaches 70% of the initial output. This is also called L70.

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What is illumination factor?

It may be defined as “the ratio of number of lumens emitted to the electric power in take of a source” it’s unit is lumen/watt (lm/W) 7) SPACING TO MOUNTING HEIGHT RATIO (SHR) The Spacing to Mounting Height Ratio (SHR) is the spacing between luminaires divided by their height above the horizontal reference plane.

How is illumination calculated?

If you’re trying to figure out LED lighting for your kitchen counter, the illuminated area will be calculated as the length of the counter multiplied by its width. You can use illumination units of lux or foot candles. If you want to recalculate between these units, remember that one foot-candle equals 10.764 lux.

What is depreciation factor illumination?

The reduction of the illumination or luminance occurring in the course of operation is expressed in calculations by the depreciation factor (v). The depreciation factor (v) is the product of the partial depreciation factors (v1, v2 and v3): v = v1 x v2 x v3.

What is a maintenance factor psychology?

maintenance factors. something that predicts the continuation of symptoms over time among those who are symptomatic. protective factors. something that reduces the effects of a risk factor.

What is depreciation factor?

Factors are the percentages that are used to depreciate assets. … In progressive depreciation, the amount of depreciation increases each depreciation period. In digressive depreciation, the amount of depreciation per period decreases over time. In straight line depreciation, the depreciation is the same in each period.

How do you calculate maintenance factor for lightning?


  1. LLMF – lamp lumen maintenance factor.
  2. LSF – lamp survival factor.
  3. LMF – luminaire maintenance factor.
  4. RMF – room maintenance factor.
  5. SMF – surface maintenance factor.
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10 апр. 2019 г.

What is light loss factor?

A Light Loss Factor is a multiplier that is used to predict future performance (maintained illuminance) based on the initial properties of a lighting system. • LLF = 1 – Expected Depreciation. • The Total LLF is determined by multiplying the independent effects of. multiple factors.

What is coefficient of utilization in lighting?

Coefficient of Utilization (CU) is a measure of how much light exiting the fixture will fall on a canopy area of a certain size; CU is an important factor to consider in designing an energy efficient Controlled Environment Agriculture (CEA) facility.

What are the laws of illumination?

The law states that Illuminance at a point on a plane is proportional to the cosine of the angle of light incident (the angle between the direction of the incident light and the normal to the plane). It is the point source Illuminance equation.

How do you calculate Utilisation factor?

It is used to determine the Utilization factor. Hm = Height of luminaire above working plane.


Table 1.7 Typical Reluctance Factors
Color %
Red 20% To 40%

How do you calculate utilization factor?

Utilization Factor = The time that a equipment is in use./ The total time that it could be in use. Example: The motor may only be used for eight hours a day, 50 weeks a year. The hours of operation would then be 2000 hours, and the motor Utilization factor for a base of 8760 hours per year would be 2000/8760 = 22.83%.

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