How to Choose Acoustic Panels: NRC, Density & Fire Rating

author: ValuedHouse

2026-09-09

How to Choose Acoustic Panels: NRC, Density and Fire Rating Explained

Every acoustic panel on the market claims to absorb sound, but the claims are not created equal. Choosing acoustic panels for an office, school or studio project means reading specifications instead of marketing: the NRC value, the density and thickness, the fire rating and the test reports behind each number. This guide explains how to choose acoustic panels with confidence and how to spot supplier claims that do not survive inspection.

Start with NRC: The Number That Matters

NRC (Noise Reduction Coefficient) is a single number between 0 and 1 describing how much sound a panel absorbs across the speech frequency range. An NRC of 0.85 means the panel absorbs 85% of the sound energy that hits it. For offices, classrooms and meeting rooms, look for acoustic panels with NRC 0.85 or higher. Two rules apply: always ask for the NRC test report for the exact model you are buying - a report for a different thickness or construction proves nothing - and remember that NRC describes absorption in a lab, so real rooms still need enough panel area to hear a difference.

Density and Thickness: What They Change

Thicker and denser acoustic panels absorb more low-frequency sound, while thin panels handle mainly mid and high frequencies. In the PET felt category, 9 mm high-density felt is the practical baseline for speech-focused spaces; 12 mm or thicker boards extend absorption lower and suit music rooms and larger volumes. When comparing suppliers, ask for the density specification, not just the thickness - a thick but low-density board can perform worse than a thinner high-density one. Panels should also be consistent in density across the board; inconsistent pressing shows up as soft spots that absorb unevenly.

Fire Rating: Non-Negotiable for Commercial Projects

For public and commercial buildings, acoustic panels must meet the fire classification of the destination market - in Europe this is typically tested to the relevant EN standard with classes such as B-s1,d0 for quality PET felt products, and similar classes apply in other regions. Never accept a verbal assurance: request the fire test certificate showing the exact model and finish. A supplier who cannot produce certificates for its acoustic panels cannot supply commercial projects.

Material Comparison in One Minute

PET felt panels are the balanced choice for most commercial acoustic work: good absorption across the speech range, moisture tolerance, easy cutting, many colours and shapes, and fire-rated options. Wood slat acoustic panels add a premium architectural surface with a felt backing doing the absorbing. Foam is cheap but absorbs a narrower range, ages quickly and has weaker fire performance. Fiberglass absorbs well but needs wrapping and careful handling. For most projects, PET felt acoustic panels offer the best combination of performance, safety and design range.

Check the Construction Details

Look behind the marketing image. Is the felt pressed to a consistent density or does it feel soft in places? Is the colour dyed through or only on the surface? Are edges cleanly cut for tiling patterns? Do hexagonal and square panels share the same thickness so they can be mixed on one wall? Small construction details decide how professional the finished installation looks and how consistently the panel performs.

How Many Panels and Where

Cover roughly 20-30% of the reflective wall area in speech-heavy rooms for a clearly audible improvement. Prioritise the wall behind speakers or the noisiest surface, first reflection points in listening rooms, and ceilings in large open areas. For open-plan offices, ceiling-mounted acoustic baffles often outperform wall panels because they catch sound before it travels across the room.

Sourcing Checklist for Importers

Before ordering acoustic panels from a manufacturer, collect these five documents and numbers: the NRC report for the exact model, the fire test certificate for the destination market, density and thickness specifications, panel dimensions and weight per square metre for freight planning, and the MOQ for mixing designs and colours. A factory that supplies samples and certificates quickly is a factory that controls its production. ValuedHouse manufactures PET felt acoustic panels, hexagonal panels, 3D felt boards, wood slat acoustic panels and baffles in one facility, and provides NRC documentation and fire certifications for export orders. Contact us for samples, test reports and project quotations.

Frequently Asked Questions

Q1: What is a good NRC for office acoustic panels?

NRC 0.85 or higher is the practical target for speech-focused spaces such as offices and classrooms.

Q2: Is thicker always better?

Thicker panels absorb lower frequencies, but density matters as much as thickness. Compare the density specification, not just the depth.

Q3: Do I need fire-rated acoustic panels?

For commercial and public buildings, yes - the panels must meet the fire class of the destination market. Request the certificate for the exact model.