Natural light, which is variable, constitutes an important factor for well-being. Consequently, it should be managed properly in order to avoid glare, which is an intense source of eye fatigue, particularly on computer screens.
As is the case with heat, visual comfort guarantees the efficiency of employees while they work and forms the subject of regulations* setting their work conditions.
* Europe: Article 16, paragraph 1 of Directive 89/1/391/EEC.
France: Labour Code Articles R232-7-5
Germany: EEC treaty, paragraph 118a, "Bildschirmrichtlinie" Directive (89/391/EWG) of 28 May 1990 and its update 90/270/EWG.
An overview of glass buildings
Glass, which is a material symbolic of high-performance modern architecture, is now given priority by building designers in order to facilitate the entry of natural light, outward visibility, panoramic views, and the well-being of employees. Benefiting from suitable solar protection enables optimal control of the contribution made by natural light.
Factors enabling glare control to be measured are the optical factores Tv or TL (Visual transmission) and OF (Openness factor).
All fabric weaves are effective for controlling glare. They must be chosen based on the global geographic location and the layout of the buildings.
Solar protection fabric enables the window's level of luminance to be controlled (natural light diffused in the room) and a reduction in disturbing light & dark contrasts within the field of vision. Depending on its colour, a solar protection fabric can become a light source if sunlight strikes it directly.
An example of the level of luminance of surfaces according to standard NF X 35-103 :
• Acceptable within a field of vision = 16 to 150 Cd/m².
• On the edge of the field of vision = 5 to 500 Cd/m².
For your information, a sheet of paper = 100 Cd/m², a computer screen = 50 Cd/m².
Dark fabric provides better control of glare because it diffuses less light.
The Sunscreen® fabrics in the Mermet® collection have excellent glare control properties due to their various openness factors (Co, OF) and weaves. They can filter up to 97 % of light rays.
Mermet® fabrics for external or internal blinds combine with glass and double-skin façades because they protect against both heat and glare. Their coated fibreglass yarns base composition provides them with exceptional transparency and a range of technical qualities such as excellent mechanical resistance and perfect dimensional stability, including in relation to temperature variations.
Protect yourself against UV rays
With values from 280 to 380 nm within the overall solar spectrum, UV rays are responsible for natural ageing and consequently you should protect yourself against them properly.
The fabrics in the Mermet® collection protect interiors from the discolouring effect of UV rays. Depending on the type of fabric, they block 90 to 100 % of them.
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