Illuminating a horizontal surface is one of the most common lighting tasks. Most of the lighting tasks governed by work place standards and standards for pedestrian traffic routes come under this category, whether these be the illumination of work surfaces or the actual floor.
Demanding visual tasks not only require general lighting but also additional lighting for the workstation. With task lights the light can be directed to the task in hand. Light structures with fluorescent lamps emit diffuse light. Directional luminaires emit an accentuating light onto the workstation. Indirect light with uplights lends the room general background lighting.
To provide an energy efficient lighting, the general lighting can be lower than the illumination of the working area. Combined lighting with direct and indirect components provides good visual comfort both in the room and on the work surface.
Lighting criteria for task lighting
- illuminance level dependent on activity
- illuminance distribution for avoiding direct-
- and secondary glare
- cut-off angle and position of the luminaire restrict glare and increase visual comfort
- the choice of luminaire determines the light colour and colour rendition
High luminances reflected from surfaces or objects cause secondary glare. The luminaires should not be positioned in the critical areas. Indirect illumination with diffuse light reduces the secondary glare. When aiming the beam of light, care should be taken to avoid shadows on the work surface.
The quantitative lighting criteria are primary considerations for task lighting. Energy can be saved by reducing the general lighting in favour of local task lighting and daylight dependent control.
Preferred luminaire group
- task lights
- light structures
- directional luminaires
Usable areas can be illuminated directly and indirectly: downlights and pendant downlights emit direct illumination into the room. Light structures have a diffuse light distribution. Uplights illuminate the room indirectly with a diffuse, uniform light.
Compared to indirect lighting with diffuse light, the direct aimed light results in better modelling capability. Combined lighting with direct and indirect components ensures good visualcomfort both in the room and on the work surface.
Lighting criteria for usable areas
- illuminance level dependent on activity
- luminance distribution to avoid direct and secondary glare
- cut-off angle and position of the luminaire restrict glare and increase visual comfort
- the choice of luminaire determines the light colour and colour rendition
The quantitative lighting criteria are paramount considerations for lighting usable areas.
Applications
- office workstations
- conference rooms
- workshops and shopfloors
- reception and entrance areas
Preferred luminaire groups
- light structures
- downlights
- uplights
Under consideration of the energy aspects, direct lighting with permanently mounted downlights are the most suitable for large rooms.
Whereas downlights represent fixed-location general lighting, spotlights can be used flexibly in the area of exhibitions and presentations. Due to their narrow-beam light distribution, spotlights have high glare control. Directed light results in good modelling capabilities.
Lighting criteria for usable areas
- illuminance level dependent on activity
- luminance distribution to avoid direct and secondary glare
- cut-off angle and position ofthe luminaire restrict glare and increase visual comfort
- the choice of luminaire determines the light colour and colour rendition
The quantitative lighting criteria are paramount considerations for lighting usable areas. Direct illumination here is considerably more economical than indirect illumination.
General lighting for
- workshops and shopfloors
- museums
- exhibitions
- sales and representational areas
Preferred luminaire groups
- downlights
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