Frequently asked questions
Which luminaire do I need for my cleanroom class?
Match the luminaire to the room's ISO 14644-1 class or EU GMP grade. Our panels are offered in versions the manufacturer states for ISO 3–4, ISO 5–6 and ISO 7–9. For a GMP room, use the grade's ISO equivalent: grade B is about ISO 5 at rest and ISO 7 in operation, grades C and D about ISO 7 and ISO 8. If a room sits between two ranges, choose the cleaner version.
Is a luminaire certified to an ISO class?
No. Cleanroom classes apply to rooms, which are classified by measuring their air. A class stated for a luminaire is the manufacturer's statement about its design, sometimes backed by tests such as particle emission or leakage. We quote what the manufacturer states and where it comes from, and send any supporting documents we have. Your validation team decides whether it suits the room.
How do EU GMP grades relate to ISO classes?
On particles of 0.5 µm and larger, grade A is equivalent to ISO 5 at rest and in operation. Grade B is ISO 5 at rest and ISO 7 in operation. Grade C is ISO 7 at rest and ISO 8 in operation. Grade D is ISO 8 at rest, with in-operation limits set by the manufacturer from a risk assessment. Annex 1 also sets microbial limits that ISO 14644-1 doesn't cover.
What does IP65 room side mean?
It means the face of the luminaire that you see from the room is dust-tight and protected against water jets, under IEC 60529. The ceiling side, in the void above, is often rated lower, such as IP20, because it doesn't face cleaning. If a datasheet gives a single IP figure, ask which side it applies to. For wet-cleaned and washdown areas, IP65 or IP66 on the room side is a sensible minimum.
How does the luminaire seal to the ceiling?
Usually with a continuous gasket around the frame, compressed against the ceiling as the luminaire is fixed. The ceiling opening must be cut accurately, fixings tightened evenly, and cable entries sealed. Some cleanroom ceiling systems also call for a sealant bead. A good seal matters because cleanrooms run at a pressure difference, so any gap leaks air all the time.
Frameless or framed: which should I choose?
Frameless (flush) luminaires have no visible frame or fixings between diffuser and body, so the face is close to one smooth surface and quicker to clean. They're often preferred for ISO 5 and cleaner rooms and where cleaning is frequent. Framed panels hold the diffuser in an aluminium frame and are widely used in ISO 7 to 9 and general hygienic areas. Both can be well sealed.
Glass or PMMA diffuser?
Glass is hard, scratch-resistant and tolerates most cleaning agents. Laminated glass stays in place if it breaks, which matters over open product. Micro-prismatic PMMA controls glare better, but it is softer and some alcohols and solvents can craze it, so it is often supplied behind a glass cover. Choose by the cleaning regime, the glare limit and whether there is exposed product below.
Will the luminaire withstand our disinfectants?
It depends on the agent, its strength, contact time and how often it's used. Alcohols, hydrogen peroxide, peracetic acid and chlorine-based agents affect metals, coatings, plastics and gaskets differently. Send us your cleaning schedule and we'll ask the manufacturer to confirm resistance for each part. Where a datasheet doesn't state resistance to an agent, we'll tell you rather than assume.
Can glass diffusers be used in food production?
Yes, if the risk is controlled. Food safety schemes such as BRCGS expect glass and brittle materials to be controlled, and lighting over exposed product to be protected against breakage. Laminated glass holds together if it breaks, so it is a common choice. Record each luminaire in the site's glass register, and check the approach with your auditor. We don't certify luminaires against food safety schemes.
When do I need CRI 95?
Where people judge colour closely: operating theatres, treatment rooms, colour inspection and visual checks of product, tablets or vials. EN 12464-1 asks for Ra 90 in operating theatres and for colour inspection. CRI 95 versions give more margin, and high R9 (saturated red) matters for blood and tissue. For general production, CRI above 80 meets the standard and is a little more efficient.
3000 K or 4000 K?
4000 K (neutral white) is the usual choice in production cleanrooms, laboratories, food processing and operating theatres. 3000 K gives a warmer feel for support rooms or labs where comfort matters more than inspection. Keep one colour temperature across a suite of rooms, so colour judgements stay consistent. Most of our cleanroom panels come in both; some high-CRI versions are 4000 K only.
How much light does a cleanroom need?
It depends on the task. EN 12464-1 sets 500 lx for pharmaceutical production and general laboratory work, 1,000 lx for precision assembly, colour inspection and operating theatres, and 1,500 lx for electronics testing and adjusting. Many clients have their own specifications with higher figures. We calculate each room with real photometric data and a suitable maintenance factor.
How do luminaires fit with filter fan units?
Air handling comes first, so we lay luminaires out on the same grid as the HEPA or ULPA filter units, diffusers and sprinklers. In ISO 7 to 9 rooms there's usually space for recessed panels between filters. In ISO 5 and cleaner rooms with unidirectional flow, filters may cover most of the ceiling, so linear luminaires fitted between filter units are often the answer.
Can luminaires be maintained without opening the room?
Some can. A few luminaires in the range open from the ceiling side, so drivers and LED modules can be changed from a walk-on ceiling or plenum without breaking the room seal. Others are maintained from the room side, usually during a planned shutdown followed by cleaning. Long LED life also reduces how often maintenance is needed. Check each product page for its access route.
What does L90/B10 102,000 h mean?
It describes how the LEDs' light output falls over time. L90 means the LEDs still give at least 90% of their initial flux; B10 means no more than 10% of them fall below that level; 102,000 h is the operating time at which this is stated. It doesn't cover sudden failures or the driver, which has its own lifetime. We use lumen maintenance data to set the maintenance factor in calculations.
Are emergency versions available?
Emergency lighting is required in cleanrooms as in any workplace, and should be as well sealed as the general lighting. Whether a product is available as a self-contained emergency version, or for connection to a central battery system, depends on the product. Ask us for your project and we'll confirm the options and help position luminaires for escape routes and high-risk task areas.
Can the luminaires be dimmed with DALI?
Many of our cleanroom luminaires are available with on/off or DALI drivers, and each product page lists the options. DALI suits rooms with variable use, constant light output and links to a building management system. On/off is common in rooms that run all day. If you use presence detection, make sure lights stay on while someone works still, and that sensors are sealed.
Why do product pages quote LED flux, not luminaire output?
Our product pages quote the LED flux the manufacturer publishes, at 4000 K. That's the light the LEDs produce before it passes through the diffuser. The luminaire's actual output is lower and depends on the diffuser chosen: glass, anti-reflective glass and micro-prismatic options all absorb or redirect some light differently. For design, use the photometric files or ask us, and we'll give luminaire output and calculate with it.
Can I get IES or LDT files?
Yes. Where a file isn't already on the product page, ask us and we'll send IES or LDT (EULUMDAT) files for the versions on your project, for use in DIALux, Relux and other design software. We can also run the calculations for you, using your ceiling and filter layout.
What documents can you provide for validation?
We can send datasheets, photometric files, installation guides and declarations of conformity, along with information on materials, sealing, the stated cleanroom class and cleaning resistance where the manufacturer publishes it. If your validation team needs something we don't have, we'll ask the manufacturer and tell you clearly if it isn't available.
Can I get samples, and what are lead times?
Where possible we can arrange samples so you can check the finish, diffuser and fit in your ceiling. Lead times depend on the product, version and quantity, so we confirm them with each quotation. Tell us your programme early, especially for large orders or special versions, and we'll plan deliveries around it.
What should I send to start a project?
Room data sheets or a room list with the class or grade of each room, the reflected ceiling plan with filter positions, the ceiling system, the cleaning and disinfection regime, and any client lighting specification. If you only have part of this, send what you have and we'll work from there.
Got a clean space to light?
Send us the room layout, the cleanroom class or just a description. A lighting specialist replies within one working day.
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