Aerodynamics in lighting
Hainan 20th July 2010
Continuing on my typhoon story yesterday, I forgot to mention that I saw several street lighting poles “up rooted” as well. I must say one of the poles was heavily loaded with banners, which probably explains why it succumbed to the typhoon winds. You seldom see the actual light fitting blown away, unless they are not properly fixed. The weak link seems to be the structure they are mounted on as good quality outdoor fittings are generally sturdy and resistant. Glass used is impact resistant and the fitting sealed off to its proper IP rating.
Except for some street lights, specifically those with indirect reflectors and solar panels on the top, which have big surfaces and as a result quite a number did not look so “healthy” anymore after the storm. I saw several blown off and deformed reflectors. This raises the question if exterior light fittings that will be exposed to the weather elements are actually designed aerodynamically. I know light fittings are tested for ingress of dust and water, electrical safety, etc, but are they ever tested in a wind tunnel for aerodynamics? To be honest I don’t really know, maybe someone can enlighten me on this? I do know that reputable manufacturers of floodlights provide wind load data, but I believe that is more an engineered calculation based on size etc.
Lights mounted on moving objects such as planes, trains and automobiles surely are part of the aerodynamics test of the vehicle itself, but by then the lights have been recessed in such a way that they are located behind a smooth and flush mounted outer cover glass of some sorts. The actual light fitting itself from my observation is far from being aerodynamic. So are there applications or situations that call for aerodynamically designed light fittings.
I think outdoor street lights and floodlights that are used in typhoon/ tornado/ heavy wind storm prone areas certainly merit the consideration.