If we were to talk about glare, I bet a large number of lighting people would mention UGR, and in particular a UGR 19 fitting, writes Iain Macrae.
Fundamentally, there is not much wrong with that … except for misunderstanding glare. It is not about UGR and it certainly cannot be claimed that you have a UGR 19 compliant luminaire, well legally anyway. So back to the start. Remember the old days of fluorescent luminaires, T8 or even T12 lamps? Three or four lamps per fitting with an opalised drop dish diffuser or flat panel below? If you do, you will remember the glare they caused. Large lamps, bright diffusers, ceilings full of them to get enough light onto typewriters and drawing boards. Glare was a real issue, leading to strained eyes and headaches.
Move on a decade and we develop the louvre, using state-of-the-art, 99.9% pure aluminium and stick one over on glare by hiding the direct view of the lamp and directing light where it needed to go. At the same time, we saw increases in efficacy and fewer fittings in the ceiling. Glare understandably dropped.
Add now the modern (for the 1990s) cathode ray tube PC screen and we find reflected glare in these screens becomes the issue. Lighting manufacturers jumped at the challenge and dark light Category 1,2 and 3 louvres were born.
View/download a pdf of the full article at Glare Iain Macrae