The maintenance factor for lighting is measure of the reduction of output in the luminaire over the lifespan of the installation to ensure that the correct level of light is delivered at the ‘end of life.’
When calculating the Maintenance Factor (MF), the impact of the environment and the depreciation of the lamp are considered. All lighting sources have a maintenance factor, but the methodology for calculating the MF of LED lighting is different to conventional light sources.
Lighting designers use the Maintenance Factor to ensure that the lighting system continues to provide the correct lighting level throughout its lifespan.
The output from LED lamps will decline or depreciate over time. The rate of depreciation depends on three key factors:
A value for the output of the luminaire over time is given for the lamp luminaire (LLMF) that can be used for comparison.
The rate of depreciation of LEDs is measured over a minimum of 6,000 hours. Every 1,000 hours, measurements of the output of the LED are taken, and these are then used to extrapolate an accurate forecast of the lighting performance over a typical lifespan of 50,000 hours.
An L value indicates what percentage of the original light levels will be output after 50,000 hours of use.
A luminaire with a value of L90 will output 90% of its original level after 50,000 hours, and a luminaire with a value of L70 will output 70% of its original performance.
To maintain the correct lighting levels for an environment, lights will need to be replaced as they reach the end of life. This will differ depending on the type of project.
The number of burning hours for lights varies with different types of installation. In a school, the lights may be operating for 1,500 hours each year, while in healthcare environment, the number of hours may be 4,000.
With 1,500 operating hours per year in a school environment, lighting with a 50,000-hour lifespan would need to be replaced after 33 years, whereas in a healthcare environment with 4,000 annual operating hours, the lighting would need to be replaced after 12.5 years.
An annual cleaning regime helps to ensure that lighting levels are maintained over time.
LED luminaires are less prone to losing light due to deposits of dirt and insect matter than luminaires using fluorescent tubes as they have a smaller surface area and do not emit the noise and UV light that attract bugs. However, they should still be cleaned regularly, and dust proof fittings should be installed to minimise dirt.
Speak to a member of our team to learn more about the manufacturing methods for Whitecroft Lighting’s products and how this can lead to lower maintenance and replacement costs over the lifespan of your lighting system.
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