BS 476-24  Fire test on building materials and structures Part 24. Method for determination of the fire resistance of ventilation duct

0. Introduction

This International standard has been prepared because a fire resistance test for ventilation ducts has become necessary in order to permit evaluation of ducts designed to prevent fire spread across fire barriers in the absence of fire dampers. It should be read in read in conjunction with ISO 834.

The annex provides explanatory notes which give important background information,but it does not constitute a mandatory part of this International Standard.

1. Scope

• This International Standard specifies a method test and criteria for the determination of the fire resistance of vertical and horizontal ventilation ducts under standardized fire conditions.

• The general purpose of this test is to measure the ability of a representative duct of duct assembly to resist the spread of fire from one fire compartment to another without the aid of fire dampers.

• It is applicable to vertical and horizontal ducts,with or without branches,taking into account joints,air supply and exhaust openings,as well as suspension devices,etc.

 2 .  Reference

 ISO 834 Fire-resistance tests — Elements of building construction