The biggest pitfalls when replacing lighting in hot installations are underestimating the actual ambient temperature, ignoring infrared radiation as an additional heat source, and choosing fixtures based on catalog specifications that do not correspond to practice. Standard LED fixtures are simply not designed for environments where heat, radiation, and operational continuity combine. This article addresses the most frequently asked questions about LED lighting in high-temperature environments, from technical limits to installation pitfalls.
What temperature limits apply for standard LED fixtures?
Standard LED fixtures are generally designed for a maximum ambient temperature of 25°C to 40°C. Above this limit, the lifespan of the LED driver and light source rapidly decreases. In industrial environments where temperatures are structurally higher, standard fixtures are therefore unsuitable for reliable, long-term use.
The reason for this lies in the thermal properties of the components. Although LEDs are more efficient than traditional light sources, they still produce heat that must be dissipated through a cooling unit. When the ambient temperature is already high, this cooling mechanism works less effectively. The result: the junction temperature of the LED rises, leading to accelerated degradation of the light output and ultimately premature failure.
For environments with structurally elevated temperatures, such as foundries, steel mills or drying ovens, high temperature armature These are specially designed for this type of condition. Think of fixtures that function reliably at ambient temperatures up to +120°C.
Why does ordinary lighting fail in environments with infrared radiation?
Infrared radiation adds a thermal load that is invisible but has a measurable effect on luminaires. Ordinary lighting does not take this external radiation heat into account when designing. The result is that the thermal load on the luminaire is much higher than the ambient temperature alone would suggest, leading to rapid failure of drivers and optical components.
This is particularly common in steel mills, foundries and other environments where glowing materials, furnaces or melting processes are present. The infrared radiation emanating from these sources is absorbed by the luminaire housing and converted into additional heat. A luminaire that appears suitable on paper for an ambient temperature of 60°C may fail in practice because the radiant heat drives the total thermal load to 90°C or higher.
Fluorescent lamps specially developed for this type of application, such as the Orca HT and Barracuda HT floodlights from JEL Products, are designed with materials and cooling concepts that take into account both ambient temperature and external radiant heat. This makes the difference between a lamp that lasts for years and one that breaks down after a few months.
What are the risks of choosing the wrong lighting fixture in hot zones?
Choosing the wrong lighting fixture in high-temperature zones leads to a series of concrete problems: premature failure, increased maintenance workload, unexpected downtime, and in the worst case, safety risks. In environments where continuity is critical, such as 24/7 production facilities, these are not theoretical risks but daily operational challenges.
The most common consequences of a wrong choice are:
- Early failure of the LED driver due to overheating
- Rapid light degradation, causing the lighting intensity to fall below the required level
- Fracture or deformation of housings due to thermal expansion
- Increased risk of fire or short-circuiting when using non-certified fixtures in high-risk areas
- High replacement frequency and associated costs for labor and materials
- Unsafe working conditions due to poor or inconsistent lighting
Especially in the steel manufacturing context, this is a real problem. Fixtures that are not designed for the combination of heat and radiation can already be completely out of order after a few months. The cost of unplanned replacement in hard-to-reach positions, such as above ovens or on cranes, is significantly higher than the initial investment in the correct fixture.
How do you choose the right fixture for a high-temperature environment?
You choose the correct luminaire for a high-temperature environment based on the actual thermal load at the installation location, not just the nominal ambient temperature. To do this, you must take into account direct heat sources, radiant heat, air circulation, and the position of the luminaire relative to heat-producing installations.
A structured approach looks like this:
- Map out the actual thermal environment. It measures not only the air temperature, but also the radiation temperature of nearby installations and surfaces.
- Determine the maximum Ta of the luminaire. Look in the specifications for the maximum allowable ambient temperature (Ta) and compare this with your measured values, including a safety margin.
- Rate the IP and IK rating. In hot zones, there is often also dust, moisture or mechanical stress present. The IP and IK rating The quality of a fixture determines how well it resists these additional environmental factors.
- Check the driver's certification. The driver is often the weakest part at high temperatures. Choose fixtures whose driver is certified for the intended temperature range.
- Consider the mounting angle and heat dissipation. A fixture mounted horizontally dissipates heat differently than a fixture in a sloping or vertical position. This has an impact on the lifespan.
- Request a customized lighting calculation. In extreme environments, a standard level of light is often not sufficient. Create a calculation that takes into account reflections, dust, and the specific tasks that are being performed.
When is an ATEX certification mandatory when replacing equipment?
ATEX certification is mandatory when the installation takes place in an area where an explosive atmosphere may be present. This applies to environments with flammable gases, vapors, mist, or dust. In heavy industry, these situations occur in refineries, chemical plants, storage tanks, and certain processing processes.
When replacing lighting in hot installations, this issue is particularly relevant, as heat and the risk of explosion often go hand in hand. A luminaire that does not have the correct ATEX classification may not be legally placed in a zoned area. This also applies when replacing an existing luminaire with a new model: the new luminaire must comply with the zone classification determined for that location.
In case of doubt, always have an authorized party assess the zone classification before proceeding with replacement. The combination of extreme temperatures and ATEX requirements makes this a specialized process where errors have immediate safety consequences. More information about the options available lighting in heavy industry provides insight into what is technically possible within these constraints.
What is often overlooked during the installation itself?
The installation itself is a phase where a lot can go wrong, even if the correct fixture is chosen. The most common mistake is ignoring the thermal environment during installation: a fixture that is placed too close to a heat source, or where heat dissipation is hindered by the construction, performs worse than the specifications promise.
Other installation pitfalls that are regularly underestimated:
- Use of standard cabling that is not resistant to the local ambient temperature
- Insufficient consideration is given to thermal expansion of structural components, resulting in fasteners loosening
- The failure to ground electrical equipment in environments with inductive or electromagnetic influences
- Incorrect cable input causing heat to be conducted through the cable to the driver
- Not taking maintenance accessibility into account after installation, which makes later replacement unnecessary expensive
In addition, commissioning is often overlooked as a formal step. In extreme environments, it is advisable to perform a thermal measurement after installation to verify that the fixture operates within the designed parameters. This prevents surprises in the long term.
Practical example: Rockwool Croatia
For the Rockwool factory in Zajci, Croatia, lighting was needed that could withstand ambient temperatures above 110 °C and the infrared radiation from the production process. Standard LED lighting, and even many heat-resistant versions, fail under those conditions. A second problem lay outside the process: in the summer, temperatures outside reach 40 °C, which led to the failure of LED drivers. Because the drivers cannot be heated above 50 °C and cannot be placed in the production areas, driver positioning and cooling are designed and tested separately. The JEL delivered light output was more than 50 Barracuda HT, more than 20 Snapper HT and more than 30 Linear HT, providing more than 100 lux on the work floor.
When replacing a light fixture, the focus is usually on the fixture itself, while the installation around it is at least as crucial. Where the driver is placed and what the temperature there is in the summer determines the lifespan of the entire system. A heat-resistant fixture with a driver in the wrong place will still fail, and the cause of the failure is not the product itself but the installation.
Read more about the Rockwool Croatia project
How to JEL Products help with the replacement of lighting in hot installations
JEL Products It supports organizations throughout the entire process of replacing lighting in hot installations, from the initial technical analysis to commissioning and maintenance. The focus is on customization: not a standard solution that fails in practice, but an approach that aligns with the specific environment and operational requirements.
Specifically, JEL Products offers:
- Technical advice based on the actual thermal environment, including assessment of radiant heat and air circulation
- Customized lighting design tailored to the client's tasks, safety requirements, and continuity needs
- High-temperature armature from the HT-line of DCbright, JEL exclusively distributed by , designed for environments up to +120°C
- Lighting for the parts of the space that are not zoned, with a referral to a certified Ex manufacturer for the ATEX zones themselves
- Complete hassle-free service: from engineering and delivery to installation, commissioning and maintenance planning
- ISO9001 and VCA** certified process for quality assurance in every phase
Would you like to know which approach is best suited to your installation? Then contact us via the JEL Products Contact Page for a no-obligation consultation with a specialist.