Downlights with oval distribution are suitable for linear general lighting to illuminate zones and routes. This creates bands of light on the ground which facilitate route guidance and orientation.
With linear arrangements, the luminaire spacing (d) between two downlights may be the height (h) of the luminaire above the working plane as a rough guide for uniform lighting.
Arrangement: d = h
Application area: Circulation routes in high-roofed rooms, e.g. railway stations, stops and underpasses.
In order to illuminate a platform with a width of 2.5m from a height of 5m with 100lx, downlights with oval flood (20° x 60°) distribution and a 24W LED module are required at a distance of 6m.
Wallwashing creates very uniform distribution of light on the surface of a wall. The wall gains a soft character and makes the room appear wide. Lens wallwashers as ground-recessed luminaires are suitable because they can be integrated discreetly into the architecture. Vehicles can drive over them and pedestrians can walk on them.
The wall distance (a) of lens wallwashers should be about one third of the room height (h).
Arrangement: a = 1/3 x h
For good linear uniformity the luminaire distance (d) of lens wallwashers can be up to 1.3 times the distance to the wall (a).
Arrangement: d ≤ 1.3 x a
To uniformly illuminate a 10m-high station concourse with a distance of 3m to the wall and luminaire spacing of 3.5m with 50lx, we recommend wallwashers with 24 watt LED module.
The uniform illumination of ceilings makes rooms look high. Ceiling washlights are available with narrow or wide light distribution. Narrow distribution enables uniform ceiling washlighting in the background, whilst the wide distribution uniformly illuminates ceilings near the walls. The mounting distance (a) from the ceiling determines the luminaire spacing (d) and should be based on design criteria. Distance (a) should be at least 0.8 meters.
Arrangement: a > 0.8m
The luminaire spacing (d) with wide light distribution may be up to 4 times the distance from the ceiling (a).
Arrangement: d = 4 x a
The luminaire spacing (d) with narrow light distribution may be up to 3 times the distance from the ceiling (a).
Arrangement: d = 3 x a
In order to uniformly illuminate the ceiling of a 4m high and 5m wide underpass with 50lx, you require ceiling washlights with wide distribution, a distance from the ceiling of 1.5m, luminaire spacing of 6m and with a 24W LED module. In the case of underpasses with a larger width, a row of ceiling washlights on both wall sides is recommended.