EN12464-1:2011

The fundamental philosophy behind the new norm requirements is a wish for better ergonomics on peoples’ work places through increased illuminance on wall and ceiling and through improved conditions for visual communication.

More light on walls and ceilings will increase well-being and improve navigation in a work environment. Also, newer studies have shown that increased light levels in the room can improve concentration and recognition.

Visual communication is interaction between people based on mimicry and body language. This assumes more vertical light, i.e. light on a vertical surface. One measure for vertical light is called cylindrical illuminance.

The cylindrical illuminance Ez is the average of all vertical light on an imaginary cylinder. The modelling effect is the ratio between cylindrical and horizontal illuminance (Eh).

 

As the figure shows, this is the average of all light that hits vertical surfaces on your head. But a lot of light in your face is not enough. To read facial expression requires that the light does not wash out all details, but that it creates shadows and contrasts. This can be measured with what we call the modelling effect, which is the ratio between light from all sides (cylindrical illuminance) and light that hits the top of your head (horizontal illuminance). To have an optimal modelling effect, this ratio should be between 0,3 and 0,6 in the new norm. The recommended values for cylindrical illuminance and modelling effect only applies in so called activity planes that are positioned in the room based on where the user is or where the visual communication is intended to take place. The figure shows the layout of activity planes in an office landscape.

Activity planes in an office landscape; One at 1,2 metres where people sit and one at 1,6 metres where they stand and walk.

The complexity in the new lighting scheme increases somewhat because the norm separates between recommendations and requirements. The required values are lower than the recommended. In environments with increased need for visual communication, like e.g. offices, hospitals and classrooms, the recommended values should be followed. What the industry practice will be on this matter remains to be seen because the norm is still new. Glamox Luxo always recommends the best ergonomic solution because this will increase the workers’ well-being and productivity.

To comply with the new norm will in most cases lead to a significant improvement of the work environment but it may also lead to increased lamp wattage, more luminaires and a different luminaire lay-out. Hence it is important that the luminaire manufacturer, end user, electro consultant and builder enter a dialogue to understand the consequences of the new requirements. Glamox Luxo has already evaluated how the new norm affects our concepts for school, office and health care. In many cases, the lamp wattage must be increased or more luminaires are needed. Energy savings should not be prioritised at the expense of light quality, we think.  Rather, focus should be on turning the light off when nobody is present. Glamox Luxo recommends lighting solutions that are individual, energy saving and flexible for all users and customers.