3. Provisions for mechanical smoke extraction

3.1 Operating principle

Mechanical smoke extraction is ensured by mechanical smoke extraction and natural or mechanical air supply arranged to sweep the volume concerned. This sweeping can be supplemented by relative overpressurization of the spaces to be protected from smoke.

If a room is permanently ventilated (air renewal, heating or air-conditioning), its ventilation system can be used for smoke extraction, provided it complies with the provisions of this chapter and does not interfere with the natural movement of smoke. Filters or sound traps may be installed on the supply air network under the conditions defined in articles CH 32 and CH 38 (§ 7.2.3 and 7.2.9 of