Air Transfer Grilles

Firebreather® Air Transfer Grilles for instantly blocking of fire spread between fire cells.

Venting between fire cells can be challenging where condensation and heat occur in rooms where there is a requirement for fire cell limiting construction.

A very good option for venting through fire rated walls is to use completely passive air transfer grilles in walls such as the FB Air Transfer Grille.

This is a simple and inexpensive solution for venting across fire cell separators without compromising on the construction’s fire class.

Click here to see documentation and installation guide.

The FB Air Transfer Grilles satisfies the need for adequate venting through fire rated exterior or interior walls without compromising with the strict requirements of a fire rated construction.

With FB Air Transfer Grilles installed, there will be no flame penetration or no leaking of hot gases to the unexposed side, both instantly and throughout the fire rating period.

FB Air Transfer Grilles have a fully passive vent design, i.e. it contains no moving parts, no detector activating system and no cabling.
The technology allows the air transfer grilles to perform in fires just as you expect from fire rated wall construction: Instant action, integrity (E), insulation (I).
It offers a passive substitute for mechanical fire damper air terminals and in ductwork application.
The solution require no detectors or activation and thus no expensive installation or maintenance costs.

However, visual inspection of the vents should be done to ensure that the perforated steel plates are not clogged by dust, insects or the like which can reduce the airflow. It is recommended to carry out inspection and necessary cleaning at least every five years.

The FB Air Transfer Grilles come in a selection of standard sizes, in addition to customized sizes from 100x100mm up to 600x600mm that can be ordered on request.

All products are supplied in fire class EI30, EI60 and EI90.

Standard sizes:

  • 150x150x40mm
  • 200x200x40mm
  • 500×100x40mm
  • 500x150x40mm
  • 600x600x40mm

Examples of use:

  • Venting through exterior walls.
  • Living rooms
  • Gabel walls
  • Booths
  • Venting of garage facilities
  • Indoor fire separators, between offices, technical rooms, etc.
  • In a fire partition on the ceiling for venting from the gable wall to the gable wall.

Tested and classified according to: NS-EN 1364-5: 2017
Product documentation from RISE Fire Research AS: RISE FR 030-0311

Feel free to contact us if any questions


Environment – Nordic Ecolabelling

FB Air Transfer Grille is listed in the database for building products that can be used in Nordic Swan Ecolabelled buildings.



Standard sizes Louvres - order separately Fire class Article number. Nobbnr.
150x150mm Flexit steel louvres Flexit flap valve TROX OVA louvresTROX RIA coverStretch metal cover EI 30 / EI 60 / EI 90 FBO-150-150-27-60 43756224
200x200mm Flexit steel louvres TROX OVA louvresTROX RIA coverStretch metal cover EI 30 / EI 60 / EI 90 FBO-200-200-27-60 43756353
500x100mm TROX OVA louvres TROX RIA cover Stretch metal cover EI 30 / EI 60 / EI 90 FBO-500-100-27-60 43762301
500x150mm TROX OVA louvres TROX RIA cover Stretch metal cover EI 30 / EI 60 / EI 90 FBO-500-150-27-60 43762316
600x600mm TROX OVA louvres TROX RIA cover Stretch metal cover EI 30 / EI 60 / EI 90 FBO-600-600-27-60 43762653

The concept

Firebreather technology (FB) is a unique concept for the development of passive ventilation grilles which has the exceptional characteristic that they block the spread of flames, heat and embers with immediate effect in the case of fire.


Our products

Cavity barrier

Façade vent

Air Transfer Grilles

Eaves Vent