lighting planning

The Swedish Standard SS-EN 12464-1 ‘Light and Lighting – Lighting of workplaces’ specifies the lighting requirements for indoor workplaces in order to meet the need for visual comfort and performance.

First determine the type of activity and the visual information. Find out the physical measurements of the premises and the specific working areas. The working area is the area where the visual task is carried out and normally this is the area with requirements for certain maintained and uniform illuminance.

Surface luminances are important and determined by the reflectance and the illuminance of the surfaces. Proper levels for reflectance factors are:

Ceiling 0.6-0.9
Wall 0.3-0.8
Floor 0.1-0.5
Working area 0.2-0.6

The tables of the norm require maintained illuminance and a maintenance factor must be calculated and determined. The maintenance factor accounts for the characteristics of the light sources, ballasts, surrounding environment, and maintenance schedule etc.

Endeavour to achieve balanced luminance distribution in the field of view and prevent high illuminance variation around the working area. Uniformity means the ratio of the minimum to the average illuminance. A uniformity greater than or equal to 0.7 shall be achieved on the working area and 0.5 in the immediately surrounding area.

Contrast means opposite qualities, but is used for the assessment of the difference in appearance in light and colour of a field of view.

Simply expressed; all we see are contrasts of brightness and colour. Disability glare arises whenever the contrast of any part in the field of view is too high for the eye to adapt to. Reduce the risk of glare by planning correct positioning of the light sources, screen the light sources in the field of view and prevent high luminant reflections.

A luminous intensity diagram in the form of a polar diagram shows the light distribution in different directions. The diagram shows two curves accounting for the working plane along and across the luminaire. The scale shows angles (o) from the luminaire and luminous intensity per 1000 lumen (cd/klm).

Our Customer Support, +46 (0)370-69 07 20, will be glad to assist you with calculations and ideas of solutions.