The OSMOTEC-LAS-F is the all-rounder among our chimneys and therefore perfect for all fireplaces that require a soot fire and moisture-resistant flue system.


With this air/flue gas chimney you will profit from a high energy efficiency and be fully prepared for all future developments:

  • The chimney can be used with all fuel types within the low and high standard temperature range.
  • The type of heat source, the fuel, and the operating mode (positive/negative pressure) can be changed at any time.
  • The air supply can be dependent on ambient air or independent of it.

Product details


The air/flue gas chimney OSMOTEC LAS-F

  • soot fire resistant
  • moisture-resistant
  • W3G certificate
  • independent of ambient air
  • concentric air supply
  • multi-purpose use possible (permitted for up to three fireplaces)
  • all materials used are UV light resistant and non-inflammable

The OSMOTEC LAS-F meets all modern building requirements stipulated by the EnEV (Energie-Einsparverordnung) and BImSchV (Bundes-Immissionsschutzverordnung).

air/flue gas system

air/flue gas systemair/flue gas system

OSMOTEC LAS-F is a three-layer air/flue gas system which not only transports the emissions outside but also supplies your fireplace with the necessary combustion air. Consequently, with the OSMOTEC LAS-F, all fireplaces can be used independent of ambient air.

In contrast to other ways of supplying a fireplace with combustion air, air/flue gas chimneys such as the OSMOTEC LAS-F are the only systems whose suitability for an ambient air-independent use has been empirically proven (by the Fraunhofer Institute and the TÜV-Süd).


W3G-classified quality



OSMOTEC LAS-F is a W3G-classified chimney system. The name “W3G” refers to the fact that the flue system has been tested and that it guarantees a sealed pipe column even in the case of a soot fire or condensate accumulation.

Especially condensing solid biomass fuels such as pellets, wood chips, or grains require chimney systems with a W3G certificate. Thanks to the isostatically pressed fireclay pipes, our OSMOTEC chimney systems are moisture-resistant (even after a soot fire) as well as resistant to temperature fluctuations and corrosion. They are therefore suitable for all fuel types.


Fireclay pipes

Isostatically pressed fireclay pipes

fireclay pipeThe highly-specialised fireclay pipe production process used for the OSMOTEC range chimneys is markedly different from traditional production methods.

Isostatic pressing allows the production of extremely thin-walled ceramic pipes which are completely sealed and resistant to acids and condensates created during the combustion process.

A wall thickness of only 8 mm and a length of 66 cm make our fireclay pipes lighter, longer, and safer than traditional ceramic pipes. The 3 cm sleeve forms a perfect connection between the pipes and, together with our acid-resistant mastic, guarantees a homogenous and sealed pipe column.

Multifunctional duct

An additional duct for cables and connections

OSMOTEC LAS-F mit MultifunktionsschachtModern heating technology such as solar systems and photovoltaic systems is becoming more and more important. The OSMOTEC LAS-F can be optionally equipped with an additional multi-purpose duct allowing the easy fitting of solar system connections. If you want to retrofit any of these systems, the duct will allow you to do so without unnecessary expenses.

Other connections like data, power, or aerial cables and disposal connections (e.g., sewer pipes) can be installed inside the duct anywhere in the house.


Twin-duct chimney

OSMOTEC LAS-F as a twin-duct chimney

The OSMOTEC LAS-F is also available in various combinations as a twin-duct chimney:


zweizügiger Schornstein OSMOTEC LAS-F

Image 1: OSMOTEC LAS-F, twin-duct, with and without multi-purpose duct


doppelzügiger Schornstein OSMOTEC LAS-F

Image 2: OSMOTEC LAS-F and OSMOTEC HS, twin-duct, with and without multi-purpose duct


zweizügiger Schornstein OSMOTEC LAS-F

Image 3: OSMOTEC LAS-F and OSMOTEC AGL-LAS, twin-duct, with and without multi-purpose duct


PDF downloads

Download here our OSMOTEC LAS-F product information brochures and our latest chimney system price list as a pdf file: