BS EN 14501:2021

What is BS EN 14501 about? 

BS EN 14501 applies to the whole range of shutters, awnings and blinds defined in BS EN 12216, described as solar protection devices in this document. 

It specifies the corresponding properties and classifications: 

• Relating to thermal comfort 
• The solar factor (total solar energy transmittance) 
• The secondary heat transfer factor 
• The direct solar transmittance 
• Relating to visual comfort 
• The darkening performance 
• The night privacy 
• The visual contact with the outside 
• The glare controls 
• The daylight utilization 
• The rendering of colours 

NOTE 1: The characteristics covered by BS EN 14501 are specific requirements that are complementary to the intrinsic requirements that internal blinds, external blinds or shutters shall fulfil in accordance with EN 13120, EN 13561, and EN 13659, respectively 

NOTE 2: Some of the characteristics (e.g., gtot) are not applicable when solar protection devices are not parallel to the glazing (e.g., folding-arm awnings). 

BS EN 14501 is not applicable to solar protection devices using fluorescent materials. 

Who is BS EN 14501 for? 

BS EN 14501 on blinds and shutters is useful for :  

• Construction industry  
• Architects 
• Manufacturer, supplier and installer of shutters 
• Workplaces 
• Civil engineer 
• Contractor of building 
• Researcher or producer of solar devices 
• Operators of solar protection devices 

Why should you use BS EN 14501?  

Thermal comfort is mainly governed by the operative temperature within the room depending on the air temperature, the air velocity and the temperature of the surrounding surfaces.  

Solar protection devices influence thermal comfort in three aspects: 

• The mean operative temperature and/or the cooling loads are influenced by the solar gains which mainly depend on the size of the windows and the total solar energy transmittance gtot. BS EN 14501 guides you in calculating total solar energy transmittance gtot 
• The solar protection device may cause higher local values of θop when irradiated by the sun due to higher temperatures on the inner surface of the glazing or solar protection device. This effect can be quantified with the help of BS EN 14501 
• The solar protection device may prevent persons and surroundings in the room from being irradiated directly. The direct-direct solar transmittance τe, dir-dir specified in BS EN 14501 helps you quantify this effect 

BS EN 14501 helps you to determine solar protection device after being fitted to a window that is directly illuminated by the sun for characterizing the incident radiation which is mainly directional, the transmitted radiation which is partially directional or partially diffuse 

Thermal comfort helps you to protect from direct transmission of heat or solar by controlling solar energy transmission and heat factors of solar transmission. While visual comfort helps you with darkening performance that represents the capacity of an internal blind, external blind or a shutter in the fully extended and closed position to reduce light penetration and visual contact with outside. 

What’s changed since the last update? 

BS EN 14501:2021 supersedes BS EN 14501:2005, which is withdrawn 

The main modifications of this project of revision are relating to: 

• The revision of the performance classification for the darkening performance 
• The revision of the performance classification for glare control. The new classification is based on GDP (daylight glare probability) calculations and considers the cut-off angle of the curtain material 
• The addition of a fifth reference glazing (triple glazing) 
• The addition of an informative annexe giving recommendations on the class for glare control to be used depending on the location and orientation of the building, as well as on the size of the glazed area, the distance from the façade and the light transmittance of the glazing