BS EN 13141-5:2020

What is BS EN 13141‑5 about?  

BS EN 13141 discusses ventilation for buildings. BS EN 13141‑5 is the fifth part of BS EN 13141 multi-series and discusses performance testing of components/products for residential ventilation.  

BS EN 13141‑5 specifies methods for measuring the aerodynamic characteristics of cowls, fan-assisted cowls, and roof outlets, the electrical and acoustic characteristics of fan-assisted cowls. BS EN 13141‑5 is applicable to cowls, assisted cowls, and roof outlets used in natural, hybrid, or mechanical ventilation and that are meant to be fitted onto ducts that project above the roof surface.  

Note: BS EN 13141‑5 does not apply to assisted cowls assisted by a device other than a fan (e.g., injection assisted cowls) and roof exhaust fans 

Who is BS EN 13141‑5 for? 

BS EN 13141‑5 on ventilation for buildings is useful for: 

• Ventilation components/products manufacturers and suppliers  
• Architects 
• Builders 
• Quality control personnel   

Why should you use BS EN 13141‑5?  

The aerodynamic characteristics of the ventilation cowls become a critical issue to estimate the overall performance of the cowl. In use, the cowl performance will combine both the suction effect due to the wind and the pressure drop due to the air flowing through the cowl.  

The tests methods described in BS EN 13141‑5 measure the performance of the cowl when these two effects are combined. The test method described in BS EN 13141‑5 is used to characterize the effect of the fan for fan-assisted cowls in the absence of wind.  

In use, when the auxiliary fan of an assisted cowl is switched on, the assisted cowl performance combines both the suction effect due to the wind and due to the fan. The test described in BS EN 13141‑5 characterizes the performance of the assisted cowl when these two effects are combined. BS EN 13141‑5 helps you in manufacturing cost-effective and high-quality ventilation cowls.  

What’s changed since the last update? 

BS EN 13141‑5:2020 supersedes BS EN 13141‑5:2004, which is withdrawn. BS EN 13141‑5:2020 includes some technical changes with respect to BS EN 13141‑5:2004. These include: 

• Reorganization of the clause concerning the performance testing of aerodynamic characteristics in order to have a more homogeneous organization and modification of all the figures to make them more understandable 
• Modification of the subclause concerning test installation for aerodynamic characteristics, which includes the modification of all test’s installation requirements as well as the distinction between requirements that apply to all the tests and those that apply only to the wind tunnel use 
• Modification of the volume flow rate correction 
• Modification of the formula used to characterize the suction effect of a cowl 
• Replacement of “a wind of sufficient speed to give easily measurable pressure differences” by “a wind of 8 m/s”