BS EN 16475-4:2020

What is BS EN 16475-4 about?  

BS EN 16475 discusses various chimney accessories like chimney silencers, chimney fans, flue dampers, rain caps, etc. 

BS EN 16475-4 is the fourth part of the series that specifies the characteristics and test methods for flue dampers that are used as components carrying flue gas in order to limit the flow in a chimney or to prevent back flow of soot during cleaning of the chimney. 

BS EN 16475-4 specifies the requirements for marking, manufacturers’ instruction, product information and information on the AVCP (Assessment and Verification of Constancy of Performance). 

Compliance with BS EN 16475-4 helps ensure the efficient regulation of airflow, thus preventing excessive smoke and heat while the fireplace is in use.  

BS EN 16475-4 only covers: 

• Flue dampers that are incorporated in housing and installed inside a building. 
• Flue dampers with sealing made of elastomeric materials for temperature classes up to T 200 and corrosion class 1 or 2 or sealing materials for dry applications with a fire reaction class A1. 
• Flue dampers with motor drive, casing and flue damper plate which are interlocked in such a way that they can only be separated by using tools. 
• Flue dampers for biomass boilers ≥ 1 000 kW and industrial applications with limit switches. 
• Mechanical flue dampers where any motor is in accordance with EN 60730-2-14 and the cover for electrical components of the flue damper fulfils minimum protection class IP40 according to EN 60529. 
• Flue dampers where it is possible to identify the position of the flue damper flap totally closed, manually driven flue dampers (type 1) which have a facility to adjust the position of the flue damper flap. 
• Totally closed, manually driven flue dampers (type 1 and totally closed, mechanically driven flue dampers (type 2). 

Note 1: Under BS EN 16475-4 flue dampers which are integral parts of system chimney products or other chimney components like flue liners, connecting flue pipes are not covered. 

Note 2: BS EN 16475-4 does not specify issues for electrical parts. 

Who is BS EN 16475-4 for? 

BS EN 16475-4 on requirements and test methods for flue dampers is useful for:  

• Chimney accessories manufacturers and suppliers 
• Flue dampers manufacturers and suppliers 
• Contractors 
• Architects 
• Installers 

Why should you use BS EN 16475-4?  

A flue damper is a metal plate on a spindle fitted inside a flue system whose purpose is to close or partially close a flue. Flue dampers can be manually adjusted sited in connecting flue pipes or chimneys in order to reduce the burning rate or to work as a shut-off slide preventing back flow of soot during cleaning of the chimney or mechanically driven for reducing the flue in order to reduce the stand-by losses or to prevent the backflow of the flue gas. 

A proper functioning flue damper is essential to prevent dangers of smoke inhalation and carbon monoxide exposure.  For this purpose, compliance with BS EN 16475-4 can help prevent such outcomes due to product failures.  

BS EN 16475-4 helps you in testing and evaluating flue damper thus, ensuring optimal performance of the overall chimney system. You will also be able to avoid the escape of conditioned air from the flue when a fireplace is not in use.