This document applies to powered smoke exhaust systems in spaces with a large area and with a ceiling height of minimum 3 m, in which smoke protection is required. It includes tables and calculation methods for the design of clear layers in order to comply, inter alia, with the requirements of various protection objectives.

This document includes information and provisions concerning the requirements for powered smoke exhaust systems, their design and rules for their installation.

NOTE The requirements for testing the ventilators are dealt with in ISO 21927‑3. Other parts of the ISO 21927 series of standards deal with the power supply (ISO 21927‑10), control equipment (ISO 21927‑9) and smoke control ducts and smoke control dampers (ISO 21927‑7 and ISO 21927-8 respectively).

Design, as specified in this document, does not apply to:

— spaces with fixed gas extinguishing systems;

— storage facilities for hazardous materials;

— spaces in which there is a risk of explosions;

— corridors;

— stairwells.