Lighting in the glass industry must withstand extreme heat, intense infrared radiation, and a harsh industrial environment. Fixtures near glass furnaces are exposed to ambient temperatures that can reach above 100°C, which places specific requirements on the thermal resistance, IP class, and construction of the fixture. In this article, we answer the most frequently asked questions about lighting requirements in the glass industry at high temperatures.
What temperatures are found in a glass factory?
In a glass factory, ambient temperatures vary greatly per zone. Near the melting furnaces, ambient temperatures can reach 80°C to 120°C, while the radiant heat from melted glass and oven walls further increases the load on nearby installations. In production areas further from the furnace, temperatures are lower, but even there the thermal load is structurally higher than in a standard industrial environment.
What makes this so challenging is not just the temperature itself, but the combination of factors. Infrared radiation from melted glass mass and oven walls penetrates fixtures and heats internal components such as drivers and LED modules faster than the ambient temperature would suggest. Moreover, glass factories often operate 24/7, meaning fixtures are continuously exposed to heat without the chance to cool down.
This makes the choice for heat-resistant lighting in the glass industry, it is not a luxury, but an operational necessity.
What are the standards and certifications for lighting in high temperatures?
Fixtures that are used in high-temperature zones must be demonstrably suitable for the thermal and mechanical loads in that environment. The most relevant qualifications are the IP class (protection against dust and moisture), the IK class (impact resistance) and the maximum ambient temperature (Ta value) specified for the fixture.
For glass factories, the following points are usually decisive when selecting luminaires:
- IP65 or higher protection against dust particles and water jets, essential in production environments with cooling water, steam or cleaning processes
- High T-value: the maximum ambient temperature at which the luminaire still functions correctly; for zones near ovens, a minimum of 80°C, for direct exposure, 120°C
- Impact-resistant housing (IK08 or higher): protection against mechanical shocks caused by vibrations from machines or moving parts
- Infrared-resistant optics and housing: Standard polycarbonate and plastic components degrade quickly under intense IR radiation
For more information about what IP and IK classes mean in practice, read the page about IP and IK rating.
Why do standard LED fixtures not meet the requirements in the glass industry?
Conventional LED fixtures are designed for ambient temperatures up to 40°C to 50°C. In a glass factory, the thermal conditions exceed that limit structurally, causing standard fixtures to fail prematurely. The LED driver, the weakest thermal component in most fixtures, rapidly loses power and lifespan when exposed to sustained high temperatures.
In addition, infrared radiation plays a role that is completely absent from standard lighting specifications. Melted glass and oven walls emit intense IR energy that heats the housing and internal components of a fixture from the outside. Even if the air temperature at a certain height appears acceptable, the radiation load can push the operating temperature of the fixture above the specifications.
In short: a luminaire that functions perfectly in a logistics hall can break down within a few months in a glass factory due to thermal overload.
What lighting intensity (lux) is required in the work area of a glass factory?
The required lighting intensity in a glass factory depends on the specific task being performed there. As a general starting point, production halls and work areas in the heavy industry require a minimum of 200 to 300 lux for safe and efficient work. For precise visual tasks, such as quality control of glass products, the norm can rise to 500 lux or more on the work surface.
In addition to the absolute luxury value, the following factors also play a role:
- Uniformity A too large difference between light and dark zones increases the risk of errors and accidents. A uniformity ratio (Emin/Average) of at least 0.5 is a common starting point.
- Blinding In environments where heat and concentration already strain the attention of operators, avoiding direct glare is especially important.
- Light color (color temperature): A neutral to cool white light (4000K to 5000K) supports alertness and makes color differences in glass products more visible.
- Reliability in temperature changes: The light output must not decrease significantly as the ambient temperature rises.
How do you choose the right fixture for a high-temperature zone?
The selection of a luminaire for use near glass ovens begins with the thermal specifications. Always check the specified maximum ambient temperature (Ta) and check whether the manufacturer has also taken radiation heat into account. A luminaire with a Ta of 80°C is not automatically suitable if the IR load further increases the operating temperature of internal components.
In addition to thermal resistance, the construction materials are decisive. Aluminum enclosures with integrated heat sinks perform better than plastic variants, because they dissipate heat more effectively. Tempered glass as a cover is resistant to thermal shocks and IR radiation, while polycarbonate quickly yellows and becomes brittle under these conditions.
In practical terms, it also pays to consider the mounting options. In high-temperature zones, fixtures are often difficult to access for maintenance. A fixture with a long lifespan, reliable driver, and as few components susceptible to maintenance as possible pays off in lower maintenance costs and fewer unplanned outages.
What are the maintenance requirements for lighting in a glass factory?
Lighting in a glass factory requires a proactive maintenance strategy. Due to the continuous exposure to heat, dust, and sometimes moisture, fixtures age faster than in less demanding environments. Regular inspection of the housing, seals, and optics is essential to detect early degradation before a fixture fails completely.
In practice, this means that glass factories prefer to use fixtures that are designed for minimal maintenance. This means: a sealed housing that prevents dust accumulation on internal components, a driver with a high MTBF (mean time between failures), and optics that do not tarnish or become contaminated under the influence of heat and fumes.
Because downtime in a glass factory is costly, it is also wise to provide critical zones with an emergency lighting strategy or backup capacity, so that a failure of one light fixture does not immediately lead to an unsafe working situation.
Practical example: Rockwool Croatia
At the Rockwool factory in Croatia, the lighting had to function at ambient temperatures above 110 °C and under the infrared radiation that is released during the production process. Standard LED lighting, and even many heat-resistant versions, failed there. JEL Linear Leveraged a bespoke process from light design and engineering to delivery, with more than 50 HT Barracuda, more than 20 and Snapper HT more than 30 HT. Linear HT provides general workplace lighting, HT and Barracuda Snapper HT directional lighting. The installation achieves more than 100 lux on the work floor; the lighting design was tested to EN 12464-1, while many aspects were custom-engineered outside existing standards.
In a glass factory, the same demand applies per zone: high temperatures and radiant heat near the furnaces, lower loads further away. By using a different product type per zone, the entire hall does not have to be equipped with the heaviest version, and each location receives the light distribution that suits the task.
Standards provide the lower limit for the lighting intensity, but say little about the thermal load. Where conditions fall outside the range of existing standards, the thermal design must be substantiated separately.
Read more about the Rockwool Croatia project
How JEL Products lighting in the glass industry helps with high temperatures
JEL Products Has specific experience with lighting solutions for environments where heat, infrared radiation and 24/7 operations are the norm. The Orca high Barracuda -temperature floodlights have been developed for just such applications, with thermal resistance up to +120°C and a construction that is resistant to the combined load of heat and IR radiation.
Specifically, JEL Products the following support is available for glass factories and similar high-temperature environments:
- Technical advice and a detailed analysis of the thermal conditions per zone in the factory
- Lighting design with lux calculations tailored to the specific work tasks and safety requirements
- Supply of luminaires with the correct IP class, Ta value and construction materials for high-temperature zones
- Guidance from engineering to installation and commissioning
- Support for maintenance and monitoring of the installation during the operational phase
Would you like to know which lighting solution suits your specific situation in the glass industry? Get in touch with the specialists at JEL Products for a no-obligation consultation.