BS 7346-5:2005

This standard BS 7346-5:2005 Components for smoke and heat control systems is classified in these ICS categories:

• 91.140.30 Ventilation and air-conditioning systems
• 13.220.01 Protection against fire in general

This British Standard gives functional recommendations and guidance on the calculation method for smoke and heat exhaust ventilation systems (SHEVS) for time-dependent design fires. A variety of building types is addressed.

For a pre-determined critical time, this British Standard can be used to determine required performance of a SHEVS needed to avoid the onset of a significant danger. Or, for a pre-determined SHEVS, this British Standard can be used to determine the time available between ignition and onset of significant danger.

This British Standard uses accepted and authoritative methods to define some design parameters, e.g. the time needed for safe evacuation or attendance time of the fire-fighting services. This information can be sought from other sources when generating the overall fire-safety concept for a specific building project.

Many of the detailed calculation procedures, and most of the danger criteria defining the boundary between success and failure, are the same for time-dependent design fires as for steady-state design fires, and it is essential that this British Standard be used in conjunction with BS 7346-4.