| System efficacy | At least 120 lm/W; 140–160 lm/W is a strong target for efficient commercial installations. | Higher efficacy can reduce energy consumption while maintaining the required illuminance level. | Check the complete luminaire efficacy in an LM-79-style photometric report, not only the LED-chip efficacy. | Essential | 15% |
| Rated service life | L80 at 50,000 hours or more; preferably with an L70/L80 projection supported by temperature data. | Longer useful life reduces relamping, access equipment, labor, and maintenance disruption. | Review the lumen-maintenance report and the declared case-temperature or ambient-temperature conditions. | Essential | 12% |
| Color rendering | CRI/Ra ≥80 for offices and general areas; CRI/Ra ≥90 for retail, hospitality, healthcare, and design-sensitive spaces. | Accurate color rendering improves visual comfort and helps products, materials, and skin tones appear more natural. | Request the spectral test report and verify R9 performance when saturated red colors are important. | Essential | 8% |
| Color temperature | Fixed options commonly include 3000K, 3500K, 4000K, and 5000K; tunable white is useful for flexible projects. | Different regions and applications prefer different visual atmospheres and workplace lighting practices. | Confirm the actual CCT tolerance, available presets, and whether field adjustment is possible after installation. | High | 6% |
| Color consistency | MacAdam 3-step to 5-step binning, with consistent color between panels in the same installation. | Consistent color prevents visible patchiness across continuous suspended rows or open ceilings. | Check the binning declaration and inspect multiple production samples side by side. | High | 6% |
| Glare control | UGR <19 is a strong target for computer-based offices; use project calculations for the actual room geometry. | Low glare supports visual comfort and reduces reflections on monitors and glossy surfaces. | Request a photometric file such as IES or LDT and calculate UGR for the intended mounting height and spacing. | Essential | 12% |
| Flicker performance | Prefer low-flicker drivers with documented results for PstLM and SVM; avoid visible flicker during dimming and high-speed camera recording. | Flicker can affect comfort, visual tasks, video production, and the perceived quality of the installation. | Review driver test data across the full dimming range rather than checking only the maximum output level. | Essential | 10% |
| Input-voltage compatibility | Choose a region-appropriate input range, such as 100–277 VAC or 220–240 VAC, with 50/60 Hz compatibility. | Correct voltage selection supports reliable operation across different national electrical systems. | Compare the driver label, datasheet, and local electrical requirements before ordering. | Essential | 8% |
| Power quality | Power factor ≥0.90; lower total harmonic distortion is preferable, especially for large projects. | Good power quality helps reduce avoidable electrical losses and potential interaction with sensitive equipment. | Request driver test data at typical, minimum, and maximum rated input conditions. | High | 5% |
| Dimming and controls | At minimum, offer reliable on/off control; preferred options include 0–10 V, DALI-2, or a documented wireless control system. | Control compatibility affects energy savings, scene setting, occupancy response, and future building-management integration. | Test the complete driver-control combination for dimming depth, startup behavior, grouping, and interoperability. | High | 7% |
| Emergency lighting readiness | Offer a compatible emergency module with commonly required autonomy options such as 1–3 hours where local codes require it. | Emergency capability can simplify compliance and avoid replacing the main luminaire in safety-critical areas. | Verify emergency output, battery type, recharge time, test function, and local certification requirements. | High | 5% |
| Thermal design | Use a metal heat-spreading body and maintain stable performance within the declared ambient range, commonly around −20°C to +45°C for indoor products. | Lower operating temperature generally supports better lumen maintenance and driver reliability. | Review thermal test data and confirm the rated ambient temperature for the complete luminaire. | Essential | 6% |
| Ingress protection | IP20 is generally suitable for clean, dry interiors; IP44 or higher may be appropriate for dusty or damp locations when permitted by the design. | The correct protection level helps prevent premature damage from dust, moisture, or cleaning conditions. | Check the enclosure rating and ensure it applies to the fully assembled suspended product, including connectors. | Medium | 3% |
| Suspension system | Adjustable aircraft-cable or rod suspension, secure locking points, and a typical adjustable drop of approximately 0.5–2.0 m. | Flexible suspension simplifies ceiling coordination, improves visual alignment, and supports different ceiling heights. | Check load capacity, adjustment range, anti-drop features, ceiling-fixing options, and installation instructions. | High | 4% |
| Optical diffuser | Uniform opal or micro-prismatic diffuser with no visible LED hotspots at normal viewing angles. | A well-designed diffuser improves appearance and glare control while maintaining useful light output. | Inspect the lit sample from typical observer positions and compare the photometric distribution with the project requirements. | High | 4% |
| Compliance documentation | Provide applicable electrical, photobiological, EMC, RoHS, and energy-performance documentation for the destination market. | Complete documentation reduces customs, approval, installation, and project handover risks. | Match certificates and reports to the exact model, driver, voltage, and configuration being purchased. | Essential | 8% |
| Warranty and spare parts | Prefer a clearly written multi-year warranty, replaceable drivers, and documented availability of critical spare parts. | Serviceability protects the total cost of ownership when a driver or control component eventually requires replacement. | Review warranty exclusions, claim procedure, spare-part lead time, and driver interchangeability. | High | 6% |
| Packaging and logistics | Use impact-resistant packaging, clear carton identification, moisture protection, and modular packing for suspension accessories. | International shipping exposes luminaires to vibration, compression, humidity, and repeated handling. | Check packaging specifications, drop-test evidence where available, carton dimensions, and replacement procedures for transit damage. | Medium | 3% |
