Acoustic panel specifications look intimidating if you're not a materials engineer. NRC numbers, fire rating codes, VOC limits, density ranges — it's easy to either over-specify (and pay too much) or under-specify (and fail project requirements).
This guide explains what each specification actually controls, which ones matter most for your project type, and how to write specs that Chinese suppliers can realistically meet.
Understanding NRC (Noise Reduction Coefficient)
What it is: NRC is a single number (0.0 to 1.0) that represents how much sound a material absorbs across speech frequencies. An NRC of 0.6 means the material absorbs 60% of sound energy and reflects 40%.
NRC Reality for PET Panels
| Configuration | Typical NRC Range | Best For |
|---|---|---|
| 9mm panel, surface-mounted | 0.30 - 0.45 | Light echo control, decorative acoustic |
| 12mm panel, 25mm air gap | 0.55 - 0.70 | Standard office, meeting room linings |
| 18mm panel, 50mm air gap | 0.70 - 0.85 | Higher performance, critical listening spaces |
| Perforated panel, cavity backing | 0.85 - 0.95 | Auditoriums, broadcast studios, maximum absorption |
Key insight: Installation method affects NRC as much as material thickness. A 12mm panel mounted directly on a wall performs worse than a 9mm panel mounted with an air gap. Always specify mounting method along with material spec.
Common mistake: Tender documents that specify "NRC ≥ 0.90" for all acoustic panels, regardless of mounting. This eliminates cost-effective wall-mounted solutions and forces perforated or backed systems everywhere — even where not needed.
Better spec: "Wall panels: NRC ≥ 0.60 with 25mm air gap. Ceiling systems: NRC ≥ 0.85."
How to Request NRC Data from Suppliers
Ask for "NRC test report per ASTM C423 or ISO 354". Legitimate test labs include:
- China: National Center for Quality Supervision, provincial testing institutes
- Europe: Accredited labs under EN ISO/IEC 17025
- US: Labs certified for ASTM C423 testing
If the supplier sends a generic table of NRC values without a lab report, it's theoretical data (calculated, not tested). For compliance-critical projects, insist on actual test reports.
Fire Rating: Which Standard Applies to You?
Fire ratings are regional — there is no single global standard. Most confusion happens when buyers request "fire-rated panels" without specifying which standard they need.
Major Fire Rating Systems
| Region | Standard | Common PET Ratings |
|---|---|---|
| China | GB 8624-2012 | B1 (flame retardant) |
| Europe | EN 13501-1 | B-s1,d0 or C-s2,d0 |
| United States | ASTM E84 | Class A or Class B |
| UK (post-Grenfell) | BS 476 / BS EN 13501 | Class 0 or B-s1,d0 |
| Australia | AS/NZS 3837 (ISO 9705) | Group 1 or 2 |
Critical point: A panel certified as GB 8624 B1 (China) is NOT automatically compliant with EN 13501-1 B-s1,d0 (Europe). The tests measure different properties. If your project requires European compliance, you must request EN certification specifically.
Fire Treatment Reality
Fire retardant treatment adds cost (typically 20-40% premium) and slightly changes material properties:
- Surface-treated: Cheaper, but fire performance degrades over time or if cut/routed
- Through-treated: More expensive, more durable, fire performance maintained even after CNC cutting
If you're specifying CNC grooved panels or complex shapes, insist on through-treated fire retardant, not surface-only.
Pro tip for tender writers: Instead of just listing "fire rating required," specify: "Fire rating [Standard] [Class]. Provide certified test report from accredited lab dated within 24 months."
This prevents suppliers from submitting old certificates or certificates from unrelated products.
VOC Emissions: Indoor Air Quality Requirements
What it is: VOC (Volatile Organic Compounds) limits control how much chemical off-gassing is allowed from interior materials. Relevant for schools, healthcare, LEED projects, and any space with stringent indoor air quality requirements.
Common VOC Standards
- China GB 18580-2017: E1 grade (≤ 0.124 mg/m³) or E0 (≤ 0.050 mg/m³)
- US EPA / CARB: California Air Resources Board Phase 2 limits
- EU EN 16516: Indoor emission testing for construction products
- GREENGUARD: Third-party certification for low-emitting products
PET panels typically perform well on VOC because the base material (polyester fiber) is inert. Problems arise from adhesives, fire retardant chemicals, or dyes. When specifying low-VOC panels, clarify:
- Which VOC standard (country/region)
- Whether fire treatment is required (affects VOC profile)
- Whether test report is needed for tender submission
LEED and Green Building Considerations
For LEED-certified projects in the US, you'll likely need:
- Recycled content documentation: Proof of post-consumer recycled PET percentage
- VOC emissions data: CDPH Standard Method v1.2 or GREENGUARD Gold
- HPD (Health Product Declaration): For Materials and Resources credits
Not all Chinese PET suppliers have these documents ready. If LEED compliance is critical, ask during initial inquiry and verify documentation before committing to a supplier.
How to Write Specs Suppliers Can Meet
From a supplier's perspective, the easiest specs to quote accurately are:
- Material: "PET polyester acoustic panel, 65%+ recycled content, density 1800-2200 kg/m³"
- Dimensions: "2440×1220mm × 12mm thickness" (or custom, with tolerances)
- Fire rating: "[Specific standard] [Specific class], provide lab test report"
- NRC: "NRC ≥ 0.60 when mounted with 25mm air gap (per ASTM C423)"
- VOC: "[Specific standard] compliant, provide test report"
- Color: RAL code, Pantone reference, or "to be selected from supplier's stock range"
Vague specs like "high quality acoustic panels, eco-friendly, good fire rating" waste everyone's time and generate incomparable quotes.
Final Checklist: Specifications for Your RFQ
- Material type and recycled content percentage
- Dimensions and thickness (with tolerances if critical)
- Fire rating standard and required class
- NRC requirement and installation method
- VOC standard if applicable
- Color specification method (RAL, Pantone, sample matching, or stock selection)
- Quantity and delivery location
- Required certifications and test reports
- Delivery timeline expectations
The more specific you are upfront, the more accurate quotes you'll receive — and the fewer surprises during production.