<str<strong>on</strong>g>licht</str<strong>on</strong>g>.<str<strong>on</strong>g>wissen</str<strong>on</strong>g> <str<strong>on</strong>g>19</str<strong>on</strong>g> <str<strong>on</strong>g>Impact</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>Light</str<strong>on</strong>g> <strong>on</strong> <strong>Human</strong> Beings 46 34
Office lighting Illuminance, light colour and performance at work are more closely c<strong>on</strong>nected than they appear at first glance. The right lighting not <strong>on</strong>ly makes <str<strong>on</strong>g>of</str<strong>on</strong>g>fice workers more alert; it also motivates and boosts efficiency. 47 Design recommendati<strong>on</strong> Office activities present a wide range <str<strong>on</strong>g>of</str<strong>on</strong>g> requirements. Biologically effective lighting can sustainably strengthen our sense <str<strong>on</strong>g>of</str<strong>on</strong>g> wellbeing, especially in <str<strong>on</strong>g>of</str<strong>on</strong>g>fices and c<strong>on</strong> - ference rooms in which people spend l<strong>on</strong>g periods at work as well as in the winter m<strong>on</strong>ths, when our internal clock is poorly synchr<strong>on</strong>ised with daylight. Illuminance levels and changing colour temperatures should be dynamically tuned to the time <str<strong>on</strong>g>of</str<strong>on</strong>g> day and regulated to take account <str<strong>on</strong>g>of</str<strong>on</strong>g> incident daylight. DIN SPEC 67600 points out that an activating effect, for example, is achieved between 8 and 10 a.m. by 250 lux vertical illuminance at eye level and a colour temperature <str<strong>on</strong>g>of</str<strong>on</strong>g> 8,000 kelvin. The same combinati<strong>on</strong> can also provide a stimulating boost between 1 and 2 p.m. In the evening between 6 and 8 p.m. lighting should help us unwind with around 200 lux vertical illuminance at eye level and a colour temperature <str<strong>on</strong>g>of</str<strong>on</strong>g> no more than 3,000 kelvin. At other times during the working day, the lighting level should be designed to meet the requirements <str<strong>on</strong>g>of</str<strong>on</strong>g> the relevant visual tasks. Designers in Germany thus need to take account <str<strong>on</strong>g>of</str<strong>on</strong>g> not <strong>on</strong>ly DIN EN 12464-1 and DIN 5035-7 but also workplace regulati<strong>on</strong> ASR3.4. Digitisati<strong>on</strong> and globalisati<strong>on</strong> are transforming the <str<strong>on</strong>g>of</str<strong>on</strong>g>fice workplace. Employees are becoming more mobile, new types <str<strong>on</strong>g>of</str<strong>on</strong>g> organisati<strong>on</strong> are emerging and work-time is increasingly project-oriented. Modern lighting c<strong>on</strong>cepts go bey<strong>on</strong>d erg<strong>on</strong>omic and emoti<strong>on</strong>al aspects <str<strong>on</strong>g>of</str<strong>on</strong>g> lighting quality: they bring the dynamism <str<strong>on</strong>g>of</str<strong>on</strong>g> natural daylight indoors and support human biological rhythms. Especially during the darker m<strong>on</strong>ths <str<strong>on</strong>g>of</str<strong>on</strong>g> the year, many people’s internal clock fails to synchr<strong>on</strong>ise with daylight. Biologically effective lighting can have a positive influence <strong>on</strong> mood and wellbeing and thus also boosts the motivati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> employees. <str<strong>on</strong>g>Light</str<strong>on</strong>g>ing soluti<strong>on</strong>s with n<strong>on</strong>-visual effects are particularly recommended for rooms where people spend a good deal <str<strong>on</strong>g>of</str<strong>on</strong>g> time, e.g. <str<strong>on</strong>g>of</str<strong>on</strong>g>fices, c<strong>on</strong>ference and meeting rooms or canteens. Rooms that are not well served by daylight, such as open plan <str<strong>on</strong>g>of</str<strong>on</strong>g>fices or corridors, are also suitable candidates for dynamic lighting. The right light – it’s all in the mix Aided by lighting c<strong>on</strong>trol and sensor technology, biologically effective lighting changes the brightness and colour <str<strong>on</strong>g>of</str<strong>on</strong>g> light dynamically over the course <str<strong>on</strong>g>of</str<strong>on</strong>g> the day. Large-format luminaires and illuminated ceilings simulate the sky during the day, delivering energising planar light with a high blue c<strong>on</strong>tent and more than 500 lux illuminance. In the evening, lighting should not have an activating effect; the body needs a chance to produce sleep horm<strong>on</strong>e, melat<strong>on</strong>in. That is facilitated by lower illuminance and directi<strong>on</strong>al warm white light from direct luminaires. Electr<strong>on</strong>ic c<strong>on</strong>trol Many applicati<strong>on</strong>s and studies show the positive effects <str<strong>on</strong>g>of</str<strong>on</strong>g> circadian-effective lighting: Employees feel more alert. They are measurably more motivated. Small pools <str<strong>on</strong>g>of</str<strong>on</strong>g> higher illuminance and dynamically changing light colours have a positive impact <strong>on</strong> c<strong>on</strong>centrati<strong>on</strong>. Some <str<strong>on</strong>g>of</str<strong>on</strong>g>fice buildings are now completely fitted out with dynamic lighting. At <strong>on</strong>e Hamburg company, lighting is electr<strong>on</strong>ically c<strong>on</strong>trolled throughout the day to create programmed lighting atmospheres that support circadian rhythms. Large-area luminaires fitted with daylight white and warm white fluorescent lamps steplessly produce light <str<strong>on</strong>g>of</str<strong>on</strong>g> any colour temperature between 3,000 and 5,500 kelvin at different illuminance levels. The lighting at workplaces can also be tailored to individual requirements. The energy requirement <str<strong>on</strong>g>of</str<strong>on</strong>g> a complete soluti<strong>on</strong> like this is around 30 percent greater than that <str<strong>on</strong>g>of</str<strong>on</strong>g> a n<strong>on</strong>-regulated, fixed-colour lighting installati<strong>on</strong> with LEDs (as <str<strong>on</strong>g>of</str<strong>on</strong>g> 2014). At the same time, however, employees are more focused and motivated. [46] Dynamic <str<strong>on</strong>g>of</str<strong>on</strong>g>fice lighting makes for a greater sense <str<strong>on</strong>g>of</str<strong>on</strong>g> wellbeing, especially in parts <str<strong>on</strong>g>of</str<strong>on</strong>g> the premises that are less well served by daylight. Following nature’s example, light colour, illuminance and directi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> light change over the course <str<strong>on</strong>g>of</str<strong>on</strong>g> the day. Cool light colours with a high blue c<strong>on</strong>tent activate, warm light colours relax. 35