The fireplace lining that defines the flame.
With Thermotte, we present a new generation of combustion chamber linings — engineered for the demands of tomorrow's emission standards, without compromise on the aesthetic language that leading stove manufacturers expect.
THE ESTABLISHED STANDARD
HT15 — Trusted by market leaders
For years, HT15 has been the material of choice for premium stove manufacturers who understand that a combustion chamber is not merely a functional component — it is the visual heart of the appliance. With a customizable surface in light and dark tones, HT15 creates a harmonious, high-end interior. Its tongue-and-groove system ensures precision fit and structural stability from installation onward.
Impressive tensile and compressive strength guarantee robustness under daily use and through the rigors of transport — making HT15 the industry benchmark for durability and design in one.
THE NEXT GENERATION
HT9 — Engineered for the future of clean combustion
The tightening of EU Ecodesign regulations is redefining what a high-performance stove lining must deliver. Thermal insulation — long a secondary consideration — is now a decisive factor, particularly during the critical start-up phase where emissions peak. The current industry benchmark for insulating materials, Vermiculite 900, leaves a clear gap: it insulates adequately, but at the cost of aesthetics and long-term durability.
HT9 closes that gap entirely. Through a targeted further reduction in material density, we have achieved superior thermal insulation performance — surpassing Vermiculite 900 across the full temperature range — while retaining everything that has made our materials the aesthetic standard of the industry.
THERMAL PERFORMANCE — TESTED BY INDEPENDENT CERTIFIED LABORATORIES
Thermal conductivity measurements performed using the hot wire method per EN 993-15:2006 confirm: across the entire measurement range from 20 °C to 600 °C, Vermiculite 900 exhibits 15–20% higher thermal conductivity than HT9 — meaning significantly reduced insulation. HT9 consistently outperforms.
MECHANICAL STRENGTH — WHERE IT MATTERS MOST
PROPERTY | HT9 | VERMICULITE 900 |
|---|---|---|
Compressive strength (low temp.) | >12 MPa | 4 MPa |
Compressive strength (600°C) | >9 MPa | ~5 MPa |
Tensile strength (≤200 °C) | 3.4–3.5 MPa | 1.6–1.8 MPa |
Tensile strength (600 °C) | 2.1 MPa | 1.7 MPa |
Thermal conductivity (20–600 °C) | Lower across full range | 15–20% higher |
The structural superiority of HT9 is particularly relevant in real-world operation: loading the combustion chamber with firewood exerts sudden compressive impact on the lining — a scenario where higher compressive strength directly translates to a longer service life.
THE DECISIVE ADVANTAGE — THE START-UP PHASE
This is where the difference becomes visible in real time. In a direct 1:1 comparison — identical stove, identical fuel charge, identical combustion air settings — the HT9 lining reaches the zone of optimal combustion nearly twice as fast, measured by CO and OGC emissions.
Watch the difference: within just a few minutes, the flame in the HT9 combustion chamber burns bright and clean — a vivid, steady flame, the glass clear, the lining surface free of soot. The Vermiculite ining is still working through the smouldering phase, emissions elevated, the flame thin and restless.
This is not a marginal gain. In the context of the EU Ecodesign tightening, compressing the high-emission start-up phase is one of the most impactful levers available to stove manufacturers — and HT9 delivers exactly that.
SUMMARY OF ADVANTAGES
- Superior thermal insulation. Outperforms Vermiculite 900 — the current industry benchmark for insulating materials — across the full temperature range from 20 °C to 600 °C.
- 2× faster to peak performance. Reaches optimal combustion temperatures in half the time — critical for compliance with tightening Ecodesign emission limits.
- Exceptional compressive strength. Over 3× stronger than Vermiculite 900 at low temperatures — engineered to withstand the impact of firewood loading in daily use.
- Higher tensile strength. Nearly twice the resistance of Vermiculite 900 — significantly reducing cracks and structural wear over the product lifetime.
- Rapid-heat clean look. Fast surface temperature rise minimizes soot buildup — for consistently clear glass and a pristine lining interior.
- Premium finish — no aesthetic compromise. Moves decisively away from the industrial-component look. The combustion chamber becomes a design statement.
Thermotte. Where engineering precision meets the language of fire.
Interested in material samples, technical data sheets, or project-specific consultation?
We look forward to hearing from you.
