Workstation design for organizational productivity - National ...

Task Lighting: Task lighting providesboth high illuminance on task surfaces thatrequire it (i.e. paper tasks) and occupantcontrol. Task lighting can also fillshadows caused by shelving units.Under-shelf, partition, and desktoplighting should be considered.Only the task lights are on in this photo,showing how task surfaces can be highlightedwith local, high illuminances. Anunder-shelf luminaire and an adjustabledesktop luminaire have been used.Research:Task/AmbientLightingThe practice of combining lowerambient light levels with targetedtask lighting developed as an energysavingtechnique. Initially, there wasconcern that the resulting non-uniformlight levels across desks would reduceperformance; however, studies have notidentified problems. IRC research foundthat people gave higher ratings oflighting quality and satisfaction to anopen-plan office with task/ambientlighting than to lighting systemsthat did not use tasklighting.L.13Lamps: Fluorescent or Compact Fluorescent Lamps (CFL) are recommendedfor offices by lighting professionals because they are more energy efficientthan incandescent sources. Incandescent lamps(including halogen) are inappropriate forgeneral lighting because their lowefficiency adds unnecessary heat andrequires additional cooling tocompensate. Fluorescent lampscome in a range of colourtemperatures that allow the lightingdesigner to choose lamps that aremost effective for the space,colours, and amount of daylight. Ifcolour discrimination is importantin an occupant task, then thecolour rendering properties of thelamp must be considered. Lampswith a Colour Rendering Index (CRI)of 90 or greater are recommended forcolour identification and matching. A CRIof 70 or 80 is adequate for most office settings.Research:Lamp TypeSome manufacturers of lampsand fluorescent lamp filters claimto have products that mimicdaylight, but no single source canreplace the variability of daylight.Moreover, claims that any particularfluorescent lamp improves health,performance, or comfort do not stand up toscrutiny using reliable scientificmethods. The only exception concernscolour discrimination; if fine distinctionsin colour are necessary fortasks, any lamp with a high colourrendering index (CRI) willimprove task performance.L.1447