On the headline cradle-to-gate number a cement-bonded wood-wool acoustic panel looks lower-carbon than a recycled-PET felt panel: −2.89 kg CO₂e/m² against +2.50, both from third-party-verified EPDs. On the number that actually compares manufacturing emissions, GWP-fossil, the order reverses: the wood-wool panel emits 3.95 kg CO₂e/m² and the PET felt 2.52. The gap is the wood-wool panel’s stored biogenic carbon, which is booked as −6.85 kg CO₂e/m² at the factory and comes back as +6.34 when the panel is incinerated at end of life.
That is the whole comparison in three sentences. The rest of this article shows the two EPDs’ figures module by module, explains why the panels are not quite like-for-like, and says which column to use at concept stage.
The short version
- Wood-wool (Troldtekt, natural grey on FUTURECEM cement, 25 mm unpainted, 11.0 kg/m², EPD-IES-0028640, third-party verified): A1–A3 GWP-total −2.89, GWP-fossil +3.95, GWP-biogenic −6.85 kg CO₂e/m².
- PET felt (Texfel Echo LD 9, 9 mm, 1,000 g/m², 60 % post-consumer recycled PET, EPD-IES-0026653, third-party verified): A1–A3 GWP-total +2.50, GWP-fossil +2.52, GWP-biogenic −0.02 kg CO₂e/m².
- Over A–C with the EPDs’ default end-of-life scenarios the wood-wool panel lands around +4.8 kg CO₂e/m² and the PET felt around +2.9, because the wood-wool’s stored carbon is released in C3.
- They are not like-for-like: 25 mm vs 9 mm, 11 kg/m² vs 1 kg/m², and different absorption depending on the build-up. Compare per m² at the acoustic performance you need.
- Compare on GWP-fossil; report stored biogenic carbon separately as a pathway-dependent quantity.
- All figures here are indicative, for early comparison, not for certification or compliance.
What do the two EPDs declare?
Both EPDs are calculated to EN 15804+A2, published on the International EPD System (Environdec), and independently verified, which is the minimum for putting them in one table.
Wood-wool. Troldtekt A/S, Troldtekt acoustic panels, natural grey based on FUTURECEM cement, EPD-IES-0028640, valid to 22 August 2030, third-party verifier Mirko Miseljic. The main declared variant is 1 m² of 25 mm unpainted panel at 11.0 kg/m²; 15 and 35 mm are declared by linear scaling, and paint is an add-on of +0.433 kg CO₂e/m² in A1–A3 (Troldtekt EPD, Environdec).
PET felt. Fieltros y Tejidos Industriales S.L., Texfel Echo LD 9, EPD-IES-0026653, version 5 November 2025, valid to 5 November 2030, third-party verifier Elisabet Amat (GREENIZE). Declared unit 1 m² of installed panel, 9 mm, 1,000 g/m², density 111 kg/m³, minimum 60 % post-consumer recycled PET, reference service life 50 years, declared absorption class A to EN ISO 11654 (Texfel EPD, Environdec).
Per m², kg CO₂e, rounded from the EPDs’ scientific notation:
| Module | Wood-wool 25 mm: total | fossil | biogenic | PET felt 9 mm: total | fossil | biogenic |
|---|---|---|---|---|---|---|
| A1–A3 production | −2.89 | +3.95 | −6.85 | +2.50 | +2.52 | −0.02 |
| A4 transport | +0.24 | +0.24 | 0.00 | +0.11 | +0.11 | 0.00 |
| A5 installation | +0.97 | +0.45 | +0.51 | +0.19 | +0.14 | +0.05 |
| B1 use | −0.99 (carbonation) | −0.99 | 0.00 | 0.00 | 0.00 | 0.00 |
| C1–C2 | +0.05 | +0.05 | 0.00 | +0.02 | +0.02 | 0.00 |
| C3 waste processing (scenario i, incineration) | +7.47 | +1.13 | +6.34 | ≈ 0.00 | ≈ 0.00 | ≈ 0.00 |
| C4 disposal | — (in scenario i) | — | — | +0.006 | +0.006 | 0.00 |
| D beyond system (scenario i) | −0.79 | −2.55 | +1.77 | +0.02 | ≈ 0.00 | +0.02 |
The Troldtekt EPD declares three end-of-life scenarios; the table shows scenario (i). Scenario (iii), landfill, puts +6.41 kg CO₂e/m² in C4 instead. The Texfel EPD’s C stage is almost empty because its scenario assumes the panel itself is fully recovered and only the fixing screws are partly landfilled or incinerated.
Citation capsule: Troldtekt’s third-party-verified EPD (EPD-IES-0028640) declares a 25 mm unpainted FUTURECEM wood-wool panel at GWP-total −2.89, GWP-fossil +3.95 and GWP-biogenic −6.85 kg CO₂e/m² for A1–A3, with +6.34 kg CO₂e/m² biogenic released in C3 under incineration. Texfel’s third-party-verified EPD (EPD-IES-0026653) declares a 9 mm, 1 kg/m², 60 % recycled PET felt panel at GWP-total +2.50 and GWP-fossil +2.52 kg CO₂e/m² for A1–A3.
Which panel is lower carbon?
Depends which column you read, so read the right one.
Cradle-to-gate total (A1–A3 GWP-total): wood-wool −2.89, PET felt +2.50. Wood-wool “wins” by 5.4 kg CO₂e/m², entirely because of the −6.85 biogenic uptake booked in A1. This is the number most product pages quote, and it is the least useful of the three for a comparison, for the reasons set out in biogenic carbon in EPDs.
Fossil (A1–A3 GWP-fossil): wood-wool +3.95, PET felt +2.52. PET felt is lower by 1.4 kg CO₂e/m². This is the manufacturing emission that does not cancel out later, and it is the comparable figure. It also makes sense physically: a 1 kg/m² felt of mostly recycled PET has less to make than 11 kg/m² of cement-bonded wood.
Whole life (A–C, default scenarios): wood-wool ≈ +4.8, PET felt ≈ +2.9 kg CO₂e/m². The wood-wool’s stored 6.85 kg comes back in C3 when the panel is incinerated; carbonation of the cement in B1 claws back about 1 kg. The felt’s small C stage reflects an assumed full-recovery scenario for the panel, which is optimistic and should be read as such.
So on the comparable basis the PET felt panel is the lower-fossil product by roughly a third, and the wood-wool panel is the one that stores carbon: about 6.85 kg CO₂ per m² for as long as it stays in a building. Both statements are true. Neither alone is the answer.
Citation capsule: Comparing the two EPDs on GWP-fossil, the PET felt panel (2.52 kg CO₂e/m²) is about a third lower than the wood-wool panel (3.95 kg CO₂e/m²). On A1–A3 GWP-total the wood-wool panel is lower (−2.89 vs +2.50) only because of 6.85 kg CO₂e/m² of stored biogenic carbon that is released in module C3 under the EPD’s incineration scenario.
Why isn’t this quite like-for-like?
Three reasons, all of which matter more than the 1.4 kg difference.
Thickness and mass. 25 mm at 11 kg/m² against 9 mm at 1 kg/m². The felt EPD declares absorption class A for the installed panel; the wood-wool panel’s absorption depends heavily on the build-up behind it (air gap, mineral-wool backing). If your specification needs a class-A ceiling, the wood-wool build-up that achieves it may add a backing layer whose carbon is not in this table. Compare per m² of the assembly that meets the performance, not per m² of panel.
Durability and pathway. The felt declares a 50-year reference service life; Troldtekt’s marketing cites 50–70 years for its panels. Both are long. The bigger pathway question is what happens at refit: a screwed wood-wool panel can be taken down and reused, and so can a felt panel. A glued felt panel cannot. In Elementa’s circularity pathways that is the difference between a reuse factor of 0.15 and a new factor of 1.00 at the next fit-out, which is far larger than the difference between the two products.
Paint and finish. The wood-wool figure is unpainted. Painted adds +0.43 kg CO₂e/m² in A1–A3 on the EPD’s own numbers, which is about 11 % of its fossil footprint.
Citation capsule: The two panels differ in thickness (25 vs 9 mm), mass (11 vs 1 kg/m²), absorption (class A declared for the felt; build-up-dependent for the wood-wool) and finish (unpainted wood-wool; paint adds +0.43 kg CO₂e/m²). A fair comparison is per m² of the installed assembly that delivers the required absorption class, with the end-of-life pathway stated.
Frequently asked questions
What is the embodied carbon of a wood-wool acoustic panel?
For Troldtekt’s 25 mm unpainted panel on FUTURECEM cement (EPD-IES-0028640, third-party verified): GWP-total −2.89 kg CO₂e/m² for A1–A3, made up of +3.95 fossil and −6.85 biogenic. Painted, add +0.43. Grey- and white-cement variants are higher; Troldtekt’s 2022 announcement put FUTURECEM 26 % below its grey-cement panel and 38 % below white.
What is the embodied carbon of a PET felt acoustic panel?
For Texfel Echo LD 9, 9 mm, 1 kg/m², 60 % recycled PET (EPD-IES-0026653, third-party verified): GWP-total +2.50 kg CO₂e/m² for A1–A3, almost all of it fossil (+2.52). Thicker felt panels (12 mm, 24 mm) scale roughly with mass; check the specific EPD.
Is wood-wool carbon-negative?
Cradle-to-gate, the EPD total is negative because of stored biogenic carbon. Over the whole life cycle, with the EPD’s incineration scenario, it is not: the stored carbon is released in C3 and the net is around +4.8 kg CO₂e/m². It is carbon-storing while in use, which is a real but conditional benefit.
Which figure should I put in a pre-assessment?
GWP-fossil for the comparison (3.95 vs 2.52), the stored biogenic carbon as a separate line (6.85 vs ≈ 0), and the fixing method as the pathway signal (screwed = reusable, glued = not). That is how Elementa presents it: the indicative impact class follows the fossil figure, storage is shown alongside, and the pathway is chosen per element.
Can Elementa certify these figures?
No. The figures are the manufacturers’ third-party-verified EPD declarations; Elementa reads them into indicative impact classes for early comparison. Certification and compliance need the EPDs themselves and a qualified assessor.
The takeaway
Two verified EPDs, one honest comparison: the recycled-PET felt panel has the lower manufacturing footprint (2.52 vs 3.95 kg CO₂e/m² fossil), and the wood-wool panel stores about 6.85 kg CO₂ per m² until it is burned. The headline −2.89 is the second fact dressed as the first. Compare on fossil, show the storage, and remember that whether the panel is screwed or glued will matter more at the next refit than either number.
If you want fit-out materials compared on that basis, element by element, with the pathway visible, before formal assessment, start a project.