Lumen is the unit of measurement for the total amount of light emitted by a fixture. In industrial LED lighting, the lumen count indicates the light output a lamp or fixture provides, regardless of the direction in which that light falls. The higher the lumen count, the more light is available. However, lumens alone do not tell the full story of how well a space or area is illuminated.

For technical decision-makers in the industry, understanding lumens and related concepts is essential for making the right lighting choices. In this article, we answer the most frequently asked questions about lumens in industrial LED lighting—from basic concepts to practical comparisons.

How many lumens do you need for industrial lighting?

This depends heavily on the application, mounting height, and required illuminance at working level. For heavy industry, Ports and terminals luminaires typically range from 10,000 to over 100,000 lumens per luminaire. Standard office lighting starts at just a few hundred lumens, which clearly illustrates the enormous differences in scale.

Concrete guidelines per application:

• Production hall or workshop minimum 300 to 500 lux on the work surface, which quickly requires thousands of lumens per fixture depending on the mounting height
• Outdoor area or port terminal 50 to 200 lux depending on the activity, with floodlights of 20,000 lumens or more
• Taps and high-mounted installations: high lumen values needed due to the large distance to the work surface
• Climate chambers or cold rooms lower light levels are sometimes sufficient, but the fixture must function reliably in extreme cold

Besides the raw lumen value, mounting height, beam angle, and surface reflection play a significant role. A professional lighting advice A photometric calculation always provides a more reliable picture than the lumen value alone.

Lumen is a measure of the total amount of visible light emitted by a source, while lux is a measure of how much light falls on a surface.

Lumen measures the total light output of a fixture. Lux measures the illuminance on a specific surface, expressed as the number of lumens per square meter. The difference is crucial: a fixture with 50,000 lumens mounted at a high elevation may only deliver 50 lux on the floor, while the same fixture mounted closer will achieve a multiple of that.

The relationship can be easily summarized: lux = lumen divided by area (in m²). But in practice, it's more complex because light is not evenly distributed. The optics of a fixture, the beam angle, and any obstacles all contribute to how light lands on the work surface.

For industrial applications, lux is the most relevant measure when assessing whether a lighting installation meets standards such as NEN-EN 12464 for workplace lighting. Lumens are the starting value you need to calculate those lux values.

Why doesn't lumen say everything about lighting quality?

A high lumen count sounds impressive, but it says nothing about the quality of the light itself. Factors such as color rendering, light color, glare, and the distribution of light over a surface are at least as crucial for how well people can work in a space and how safe the working environment is.

Other important quality parameters besides lumens are:

1. Color Rendering Index how accurately colors are rendered. In industry, a CRI of at least 80 is recommended, and for precise inspection work, even 90 or higher.
2. Color temperature (Kelvin): determines whether light looks warm or cool and affects alertness and visibility. More on this topic is explained on the page about light color and Kelvin.
3. UGR (Unified Glare Rating): a measure of glare. In environments with machines, screens, or precision work, a low UGR is essential for safety.
4. Light distribution A narrow beam luminaire provides a lot of lux on a small area, but leaves the rest in the dark. Wide, uniform distribution is often better for industrial work floors.
5. Flicker Invisible flickering of LED lighting can cause fatigue and safety risks in moving machine parts.

A high lumen count with poor color rendering or strong glare results in a worse workspace in practice than a fixture with fewer lumens but better optical properties.

How do extreme conditions affect the lumen output of LEDs?

Extreme temperatures, vibrations, dust, and moisture can significantly reduce the lumen output of LED fixtures. LED chips perform best at moderate temperatures. As the ambient temperature rises, light output decreases and the degradation of the light source accelerates—a phenomenon known as thermal derating.

In environments such as steel mills, foundries, or areas with infrared radiation, the operating temperature of a luminaire can exceed 60°C. Standard LED luminaires are not designed for this and quickly lose a substantial portion of their light output, or fail completely. Specialized luminaires for High-temperature lighting are equipped with active cooling, heat-resistant materials, and custom electronics that maintain lumen output even in extreme heat.

On the other end of the spectrum, low temperatures in climate chambers or cold storage facilities present other challenges: condensation, material shrinkage, and the effect on the LED driver. Fixtures that must reliably function from -45°C to +120°C require a completely different design than standard industrial lighting.

Vibrations and shocks, such as those encountered with mobile machinery and cranes, can also indirectly affect lumen output by causing mechanical wear on connections and optical components. A robust construction and the correct IK rating are therefore just as important as the initial lumen value.

What is lumen maintenance and why is it important?

Lumen maintenance is the ratio of a luminaire’s light output after a certain number of operating hours to its original light output at the start of operation. It is expressed as an L-value: L80 means that after a certain number of hours, the luminaire still delivers 80% of its original lumen output.

In the industrial sector, this is a critical parameter, because lighting systems often last for years or even decades without the fixtures being replaced. A luminaire that, after 50,000 operating hours, delivers only 60% of its original light output may no longer meet the minimum lux standards for safe working conditions.

High-quality LED fixtures for industrial use are typically rated at L80B10 or L70B50 for 50,000 or 100,000 operating hours. This indicates that 80% or 70% of the light output, respectively, is maintained, and that no more than 10% or 50% of the fixtures in an installation will fall below that threshold. When comparing luminaires, it is essential to consider not only the initial lumen output but also lumen maintenance over the expected service life.

Examples from practice: DFDS Terminal Lighting

A striking example of how lumen values work out in practice is the project for DFDS — a major terminal operator that needed its entire outdoor lighting for a terminal in Vlaardingen to be redesigned. The technical challenges were significant: the fixtures had to withstand salty sea air, high wind loads, and continuous operational pressure, while the illuminance at ground level had to meet strict safety standards.

During the design phase, fixtures with a wide beam pattern and high lumen output per fixture were deliberately chosen to limit the number of poles without compromising the required lux levels. The mounting height and beam angle were calculated photometrically to ensure uniform light distribution across the entire terminal — precisely where the lumen count alone is insufficient and a full photometric analysis makes the difference.

An important lesson from this project: the initial lumen count is just the starting point. The actual performance is determined by the combination of optics, mounting position, and lumen maintenance over the lifespan of the installation. Fixtures with a high initial lumen count but poor L-values can drop below the required lux standards after only a few years. More details about this project and similar approaches can be found on the DFDS Seaways Terminal Lighting Project Page.

How do you compare lumen values between different LED fixtures?

When comparing luminaires, it's crucial to note whether you're looking at the lumen output of the light source (lamp lumens) or the actual light output of the complete luminaire (luminaire lumens or luminous flux efficiency). The difference can be as much as 20 to 30 percent due to losses in optics, housing, and thermal management.

A fair comparison takes into account the following points:

• Luminaire Lumens vs. Lamp Lumens Always ask for the certified lumen value of the luminaire, not the theoretical value of the light source
• Lumens per watt (efficiency): A higher lm/W value means more light per unit of energy, which directly impacts operating costs.
• Test Conditions: Lumen values are measured at a specific ambient temperature. Check if the test conditions match the actual installation environment.
• Certification: Reliable manufacturers provide luminaires with LM-79 or LM-80 test reports that independently confirm lumen values.

For an accurate comparison in a specific project, a photometric simulation is the most reliable. It combines the actual lumen values, optics, and installation position into a realistic forecast of the lux levels in the workplace.

How JEL Products Helps You Choose the Right Light Output

JEL Products helps organizations in heavy industry translate lumen requirements into a comprehensive, reliable lighting solution. This process begins with understanding the environment and specific requirements, and ends with an installation that delivers long-term performance.

What JEL Products specifically offers:

• Custom photometric calculations, tailored to the actual installation position and environmental conditions
• Fixtures with certified lumen values and documented lumen maintenance for the longest lifespan
• Specialized solutions for extreme conditions, from climate chambers to steel mills and corrosive environments
• A complete process from engineering and lighting design to installation and commissioning
• ISO9001 and VCA** certified, with proven experience in high-profile industrial projects

Do you want to know which lumen values and fixtures are best suited for your specific situation? Get in touch with the specialists at JEL Products for a no-obligation consultation.

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