For Rockwool Adriatic in Zajci, Croatia, JEL supplied more than 50 Barracuda HT, more than 20 Snapper HT and more than 30 Linear HT luminaires in 2024, for a factory where the ambient temperature exceeds 110 °C and the melting furnace emits infrared radiation. The drivers are cooled outside the hot zone, and since April 2024 the installation has delivered more than 100 lux on the shop floor, non-stop.
Client
100+
luminaires
>100 lux on
the workplace
Rabbits,
Croatia
230 °F
Ambient temperature
5-year warranty
in this environment
At the Rockwool factory in Croatia, the client was looking for lighting that could withstand the extremely hot ambient temperature and the infrared radiation released during the production process.
A second problem came on top of that: the whole factory is warm, and in summer the outside temperature rises to 40 °C, which caused LED drivers to fail. There was no cool zone to place the drivers in. That is why the drivers now sit in air-cooled control cabinets in the process room.
The biggest challenge was keeping the lighting cool despite an ambient temperature above 110 °C and the additional heat load from infrared radiation. Standard LED lighting fails quickly under those conditions.
At the same time, the LED drivers were not allowed to exceed 50 °C, in a country where outdoor temperatures in the summer can reach 40 °C. The thermal design of both the luminaires and the driver placement was therefore crucial to the project’s success.
The heat and radiation mainly come from the melting furnace. There, and in the surrounding halls, the luminaires are mounted on the ceiling at a height of about 15 metres to light the process from above.
How we approach lighting around ovens and other hot process areas is described on the page lighting for ovens, foundries and dryers.
The requirement was clear: lighting that could withstand extreme heat and infrared radiation in the Rockwool factory. But standard LED lighting,and even many heat-resistant models,fails under these conditions.
JEL therefore approached it as a custom solution: high-temperature luminaires, a separately designed driver solution, and a lighting design engineered outside existing standards.
Project card
Project Type
Industrial production environment, high-temperature LED lighting (customizable)
Location
Rabbits, Croatia
Client
Rockwool Adriatic (stone wool producer)
In operation since
April 2024
Environment
Production environment >110 °C, infrared radiation, outdoor summer temperatures up to ~40 °C
Current situation
Standard and even many heat-resistant LED lights failed under these conditions
Scope
Lighting design and engineering, installation design, supply of the luminaires
Result
>100 lux in the workplace; continues to function at >110 °C and infrared radiation
Standards
EN 12464-1; many aspects custom engineered outside existing standards
Written by Lucas de Graaf, Technical Director, JEL Products. Last updated on 27 October 2026.
Prefer direct contact? +31 33 785 9809
JEL designed the system based on the actual factory conditions: ambient temperatures above 110 °C, infrared radiation from the production process, and summer temperatures that can reach 40 °C outdoors.
By first determining those conditions and the thermal design, and only then selecting the luminaires and drivers, an installation was created that achieves over 100 lux on the work floor and continues to perform under extreme thermal load.
The drivers sit in air-cooled control cabinets, with cables of up to 50 metres to the luminaires. The solution was tested in the middle of summer, when it is 40 °C outside and even warmer inside. The luminaires kept working under those conditions too.
How we design and test custom solutions is explained under engineering and custom solutions.
Step 1
The environment
What is happening at the location determines the design: height, operating hours, environment, standards.
Step 2
The system
Light distribution, uniformity and glare are calculated before a luminaire is chosen.
Step 3
The product
Only after that follows the choice of luminaire, optics, and mounting that matches that calculation.
JEL provided the complete custom solution for the Rockwool factory: from thermal lighting design and engineering to the delivery of the high-temperature luminaires.
Two things are not covered by any standard: how to keep luminaires cool in a hall with hardly any airflow, and how to make them temperature-resistant yet smartly controllable when it is hot everywhere. We worked that out as specialists, together with the local electrical contractor Elektra.
JEL designed the system as a custom solution, tailored to the required illuminance on the work floor and the extreme thermal conditions in the factory.
The selected HT luminaires (Barracuda HT, Snapper HT, and Linear HT) are engineered with materials that allow them to remain cool and operate reliably at ambient temperatures above 110 °C.
The LED drivers must not exceed 50 °C. The driver placement and cooling system have therefore been designed and tested in practice separately from the hot production zones.
The luminaires are resistant to the infrared radiation emitted during the manufacturing process, ensuring that their service life and light output are maintained.
By combining three product types, each zone could be illuminated appropriately: from general work area lighting (Linear HT) to directional spotlights (Barracuda HT and Snapper HT).
Many aspects of this project fell outside existing standards and were entirely custom-engineered; the lighting design was tested against EN 12464-1.
The installation delivers more than 100 lux on the work floor, in accordance with EN 12464-1, with luminaires that maintain this performance under extreme thermal load.
The result is durable LED lighting that continues to operate at ambient temperatures above 110 °C and when exposed to infrared radiation, with a 5-year warranty, even in this demanding environment.
The lighting has been on non-stop since commissioning in April 2024, in a factory that runs day and night.
“At Rockwool there was no cool place for the drivers: the whole factory is warm, and in summer it is already 40 °C outside. Then you have to build the cooling into the design yourself. That is why the drivers sit in air-cooled cabinets, and why we tested the solution in the middle of summer.”
Lucas de Graaf, Technical Director, JEL Products
>100 lux in the workplace
Continues to function at >110 °C and infrared radiation
Used product
For this project, over one hundred luminaires have been supplied: more than 50 Barracuda HT, over 20 Snapper HT and over 30 Linear HT. The HT versions (high temperature) are specifically developed for environments where regular and even most resistant lighting fails.
The combination of three product types made it possible to provide appropriate lighting for every area of the factory, from general shop floor lighting (Linear HT) to directional spotlights (Barracuda HT and Snapper HT).
Standard LED lighting fails quickly under such conditions. For Rockwool, we supplied Barracuda HT, Snapper HT, and Linear HT: luminaires specifically designed to stay cool and operate reliably at ambient temperatures above 110 °C and when exposed to infrared radiation.
The drivers must not exceed 50 °C, while outside in Croatia in the summer it's already nearing 40 °C. We have designed and tested the driver positioning and cooling separately, away from the hot production zones, so that the electronics remain within safe temperatures.
Specifically: the drivers sit in air-cooled control cabinets in the process room, with cables of up to 50 metres to the luminaires.
During the production process, heat radiation (infrared) is released, which heats the luminaires additionally, on top of the high ambient temperature. Our HT luminaires are designed to withstand this from a material technology perspective, thereby preserving their lifespan and light output.
More than 100 lux on the work floor, in accordance with EN 12464-1, with luminaires that maintain this performance under extreme thermal load.
Yes, this installation comes with a 5-year warranty, even in this high-temperature environment.
The Barracuda HT is mainly installed close to the process and as hall lighting on the ceiling, at a height of about 15 metres. The Snapper HT is also used close to the process and near the melting zone. The Linear HT mainly lights the walkways, process rooms and technical rooms. In total there are more than 50 Barracuda HT, more than 20 Snapper HT and more than 30 Linear HT.
Are you working on a lighting project in a factory, foundry, or other environment with extreme heat? JEL designs and supplies custom heat-resistant LED lighting, tested and proven for the most extreme thermal conditions.
| Response | within 1 working day, by an engineer |
| Lighting calculation | free of charge, per zone |
| Trial luminaire | at your own site, on request |
| Warranty | 5 years full, 10 years on the housing with a maintenance contract |
Rather call directly: 033 785 9809
