EN 13141-5:2004

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Performance testing of aerodynamic characteristics
  4.1 Pressure drop
      4.1.1 Test installation
      4.1.2 Test procedure
      4.1.3 Analysis of results
  4.2 Suction effect of a cowl
      4.2.1 Test installation and conditions
      4.2.2 Measurement conditions and uncertainties
      4.2.3 Preliminary test
      4.2.4 Wind effect and flow rate tests
      4.2.5 Test procedure
      4.2.6 Analysis of results
  4.3 Presentation of results
5 Additional testing for fan assisted cowls
  5.1 General
  5.2 Aerodynamic testing
  5.3 Acoustic testing
  5.4 Effective power input
      5.4.1 Test Method
      5.4.2 Analysis of results
      5.4.3 Presentation of results
Annex A (normative) Derivation of values through the
        similitude law
Bibliography

This document specifies methods for measuring the aerodynamic and acoustic characteristics of cowls and roof outlets used in both natural and mechanical ventilation. Only those cowls and roof outlets fitted onto ducts which project above the roof surface are covered by the present standard.Regarding the assisted cowls, only the fan assisted cowls are covered by the present standard, other types (such as injection assisted cowls) being too recent to be adequately considered for the time being.The performance testing of the "assistance" provided by the auxiliary fan of an assisted cowl is excluded for the scope of this standard.