BS 5925:1991

Committees responsible
Foreword
Section 1. General
1 Scope
2 Definitions
3 Symbols
Section 2. General principles of ventilation
4 Basic data
5 Application
6 Provision for ventilation
7 Choice between natural and mechanical ventilation
Section 3. Natural ventilation
8 General
9 Flow characteristics of openings
10 Generation of pressure differences
11 Meteorological variables
12 Determination of natural ventilation rates
13 Other mechanisms of natural ventilation
14 Fire ventilation
15 Air infiltration
16 Normal building practice for natural ventilation in
    dwellings
Appendix A - Bibliography
Appendix B - Calculation of contaminant concentration
Appendix C - Calculation of ventilation rates to reduce
            the risk of surface condensation under steady
            state conditions
Appendix D - Determination of ventilation requirements
Appendix E - Calculation of reference wind speed ur
Appendix F - Calculation of natural ventilation rates for a
             simple building
Index
Publication(s) referred to

Recommendations for designing for the natural ventilation of buildings for human occupation. Reasons for the provision of ventilation and, where possible, recommends quantitative air flow rates. The basis for the choice between natural and mechanical ventilation and guidance on the design of natural ventilation systems.

This British Standard gives recommendations on the principles which should be observed when designing for the natural ventilation of buildings for human occupation. The standard is in three sections, as follows: Section1. General Section2 outlines the main reasons for the provision of ventilation and, where possible, recommends quantitative air flow rates. It is shown that these form the basis for air supply recommendations for different types of buildings and rooms characterized by usage. The basis for the choice between natural and mechanical ventilation is given. The design of mechanical ventilation systems is dealt with in BS5720. Section3 gives recommendations on the design of natural ventilation systems and on the estimation of air infiltration rates in housing. AppendixA is a bibliography and reference to publications listed in it are shown as: (see AppendixA [15]). AppendixB gives recommendations on evaluating contamination risks. AppendixC gives recommendations on calculating ventilation rates to reduce the risk of surface condensation under steady state conditions. AppendixD gives recommendations on determining ventilation requirements. AppendixE gives recommendations on calculating reference wind speed. AppendixF gives recommendations on calculating natural ventilation rates for a simple building. This standard does not attempt to address thermal comfort aspects of ventilation such as indoor air movement, temperature stratification, exact position of ventilation openings etc. NOTE The titles of the publications referred to in this standard are listed on the inside back cover.