BS EN 13141-5:2004 – Ventilation for buildings — Performance testing of components/products for residential ventilation — Part 5: Cowls and roof outlet terminal devices
1 Scope
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.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1 506:1 997, Ventilation for buildings – Sheet metal air ducts and fittings with circular cross-section – Dimensions.
EN 1 2792:2003, Ventilation for buildings – Symbols, terminology and graphical symbols.
EN 1 31 41 -4:2004, Ventilation for buildings – Performance testing of components/products for residential ventilation – Part 4: Fans used in residential ventilation systems.
ISO 5801 , Industrial Fans – Performance testing using standardized airways.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1 2792:2003 and the following apply.
3.1
cowl
air terminal device with or without moving component, intended to be fitted on top of an exhaust duct, with aim, by creating negative pressure depending of the wind speed, to avoid reverse flow and to increase the extracted flow rate in presence of wind
3.2
assisted cowl
cowl fitted with an auxiliary device using other energy source than wind to compensate for lack of suction effect
3.3
fan assisted cowl
assisted cowl where the auxiliary device is a fan
3.4
roof outlet
air terminal device used for mechanical ventilation systems
3.5
pressure factor
measure of the suction effect due to the wind. Ratio of the measured pressure difference to the dynamic pressure of the wind at a given vertical wind approach angle
3.6
test-voltage
voltage to be used for supplying the motorised cowl during the testing
BS EN 13141-5:2004 – Ventilation for buildings — Performance testing of components/products for residential ventilation — Part 5: Cowls and roof outlet terminal devices