GUIDANCE | WORKPLACE LIGHTING We need to emphasise what electricity is consumed, rather than the installed load, for this to become accepted though. Glare Toranomon Hills Business Tower, Tokyo, Japan, by Sirius Lighting Office, winner of the Radiance Award at the 2021 International Association of Lighting Designers Awards: the volume of the space continues to take on more importance, with an emphasis on lighting vertical surfaces and objects Glare is the unpleasant sensation caused by bright surfaces in the visual field such as illuminated surfaces, parts of light sources, windows and skylights and can be psychological or physiological. To select a luminaire suitable for the lighting installation in a particular room, the rating of the psychological glare emanating directly from the fitting must be calculated according to the CIE unified glare rating (UGR) table method. In addition, a new informative annex to the standard describes the recommended procedure for the application of UGR in unusual situations. There are further details on the procedure for example, for unusual luminaire sizes, irregular surface shapes and arrangements of fittings as well as deviating degrees of room reflection. Flicker and stroboscopic effects (also referred to as temporal lighting artefacts, or TLA) can lead not only to reduced visual comfort and work performance, but also to physiological effects, such as fatigue and headaches. So, lighting systems should be designed to avoid the negative effects of flicker and stroboscopic effects throughout the dimming range. Flicker is described by using the IEC short-time flicker indicator (PstLM). Flicker can be perceived by the eye at a frequency below 80Hz. Stroboscopic effects can be objectively quantified with the stroboscopic visibility measure (SVM) method. A PstLM of 1 and an SVM of 0.9 should not be exceeded. From 2023, the SVM limit will be cut to 0.4. BS EN 12464-1:2021 refers to the European Ecodesign Directive, in which the limit values for lamps operated directly on mains voltage are specified. This currently affects retrofit lamps in particular details can be found in the directive but beware: in the next stage, these Task area Immediate surrounding area Border area KEY CHANGES Differentiated illuminance Visual and non-visual effects of light Walls, ceilings and cylindrical illuminances Design considerations Task, surround and background area Glare requirements Flicker and stroboscopic effects Example requirements of different applications Requirements for railway installations specifications could also apply to LED luminaires. Discussions on this are under way. Other practical approaches and methods are presented in the appendices, which describe the room brightness and detection of objects and people. In Appendix B, there is additional information on visual and nonvisual effects of light. It notes that light is not only essential for vision, but also produces biological, non-visual and emotional effects that are important for human performance, wellbeing and health. However, current lighting practices, and the demand for energy conservation, tend to reduce illuminance. This can create conditions that are not conducive to human wellbeing and visual performance. The importance of darkness and daylight rhythms especially before, after and during bedtime are also described, and it is noted that changes in the distribution of the light spectrum at different times of the day can be helpful to stabilise circadian rhythms. The non-visual effects depend on the amount and time of exposure, spectral power distribution, exposure duration and personal parameters, such as circadian rhythms. These goals can be achieved with daylight and electric lighting. The appendices give examples of lighting designs for an open-plan office, an industrial workshop, and a manufacturing area. Starting from the basic requirements of the tables, the individual requirements are analysed step by step, which can lead to modified maintenance values of the different areas. This is a brief overview of the main revisions to what may be the most important standard for lighting designers. There are some welcome changes, which start to make an adjustment away from lighting engineering to lighting design in its fullest sense. CJ HELEN LOOMES FSLL, of the Trilux Akademie, is vice-president of the Society for Light and Lighting. BS EN12464-1 Light and lighting lighting of workplaces, published in August 2021, is available at shop.bsigroup.com Background area Defined areas for task, immediate surrounding and background one change is that the visual task or activity can be horizontal, vertical or inclined Material source: Trilux Akademie. For more on the standard, visit www.trilux.com/e-learning/ register and enter the code Academy to get to registration page. 28 January 2022 www.cibsejournal.com CIBSE Jan 22 pp26-28 Workplace lighting.indd 28 23/12/2021 15:40