This Target is among these not yet converted to the new high efficiency 2 lamp troffers. I think these fixtures went in around 1983 or so, originally T-12. Currently they have Philips Altos from 2006, 95% still working after over 30,000 hours believe it or not.
@GEsoftwhite100watts actually acrylic diffusers can last almost forever and not yellow at all or very little....my college was built in 1966 and is 46 years old and there are some Silvray-Litecraft Co. wraparounds still in service with original diffusers and still have the T-12 lamps and still in good condition!
Polycarbonate diffusers on the other hand yellows much more easily......1983 is not that old and I see a LOT of 1980s fixtures in great condition in acrylic! I even see acrylic covered fixtures from the 50s still looking GREAT!!!!
@Dave, you know, I have seen retrofits where they put a reflectors in existing fixtures and remove the covers when swapping with T-8s for better lighting...my old former K-mart did that....I think they originally had 4 lamp fixtures but they converted to 2 lamp T-8s on existing lamps but used reflectors that separates the 2 lights (in V or W shaped reflectors) That was when I first observed fixtures with one working light and one light out (which is typical in instant start ballast and lamps...having separate parallel wired lamps instead of series)
Yep but it depends on the ballast some cheap ones might run the lamps in series.
Oh and speaking of diffusers my old high school still had some old troffers from 1968 with clear diffusers. The subway system still has fixtures with white diffusers too and I believe some might be original when the system opened in the mid 50s. Those fixtures look modern but are old enough to have been preheat when installed.
Login
Polycarbonate diffusers on the other hand yellows much more easily......1983 is not that old and I see a LOT of 1980s fixtures in great condition in acrylic! I even see acrylic covered fixtures from the 50s still looking GREAT!!!!
@Dave, you know, I have seen retrofits where they put a reflectors in existing fixtures and remove the covers when swapping with T-8s for better lighting...my old former K-mart did that....I think they originally had 4 lamp fixtures but they converted to 2 lamp T-8s on existing lamps but used reflectors that separates the 2 lights (in V or W shaped reflectors) That was when I first observed fixtures with one working light and one light out (which is typical in instant start ballast and lamps...having separate parallel wired lamps instead of series)
Oh and speaking of diffusers my old high school still had some old troffers from 1968 with clear diffusers. The subway system still has fixtures with white diffusers too and I believe some might be original when the system opened in the mid 50s. Those fixtures look modern but are old enough to have been preheat when installed.