November 5, 2015
Permanent lighting - Part 2
The previous post calculated that if lighting in a building was on 18 hours a day, 6 days a week, for 50 years, the lights would have around 281,000 hours on them. 200,000+ hours to L70 life is a realistic possibility right now. There are a couple of Visa Lighting fixtures that, based on test data, could theoretically hit this mark. That’s 35 years of operation, 18 hours a day, 6 days a week.
But the fixtures won’t last that long, at least not the entire fixtures. In these cases it’s not the LEDs themselves but the power supplies or drivers that will fail first. Drivers have well understood wear-out mechanisms but even the best won’t last 200,000 hours (or at least they won’t be warranted to last that long). This still leaves the lighting as something that has to be worked on at least a couple of times during the life of the building, which means cracking open the fixtures to replace power supplies, probably using a ladder and maybe even needing a scissor lift.
What if the AC-to-DC drivers weren’t in the fixtures? What if they were remote-mounted, in an electrical closet or supply panel? The fixtures wouldn’t need to be touched (except to be cleaned) and if and when a driver fails, it’s a quick ladder-free job to change it out. This isn’t a new concept. Visa Lighting and many other companies have offered systems like this for some time, but most of the time this system is justified on the basis of total installed cost or power conversion efficiency. I haven’t heard the longevity argument
brought up yet.
I think it’s possible in the not-too-distant-future that lighting could come to be looked at as a permanent part of a building, room, or home that only needs to be replaced if it gets damaged, like the building wiring itself. Lighting might be specified with the same mindset as door locks or furniture. Yes, you can buy something cheap that will eventually wear out and need to be replaced, or you could buy something high quality and never need to think about it again.
Whether we’re still in the age where any one person, business, or organization actually plans to occupy a building for 50 years…that’s another question.