ReLED Solid State Replacements for Fluorescent Tubes

ReLED Systems offers this solid-state LED lamp that fits into standard fluorescent fixtures, offering a longer service life (ten years, they say) and better power efficiency. Their first product, the "Re-LT5," fits into "virtually any existing 28W luminaire design."

I didn't see any price spec on their site, but I think we can presume these aren't going to be cheap.

Product Page [ReLEDSystems.com via Gizmag]

[#1 posted by Daniel Rutter , November 13, 2007 6:21 AM]

You're probably right that they're pricey, but they don't have to be terribly expensive, because (like a lot of other LED lights) they're not very powerful.

The PDF "cutsheet" says that the four foot "tube", which is the same size as a 40 watt fluoro, only has eight LEDs in it. It also says that the LEDs are Luxeon K2s, so that'll only be three watts per LED unless they're overdriving them, for a total of 24W.

The very newest and shiniest Cree and Seoul Semiconductor LEDs now have lumens-per-watt figures that're better than compact fluorescent lamps, and up there with a lot of straight fluoros. K2s are a bit older and not quite as good, though, so the total light output of these tubes is probably only about half that of an equivalent fluoro.

There are a number of other factors, of course. Ordinary straight fluoros emit half of their light upwards into a not-nearly-100%-efficient reflector, for instance; all of the light from the LED "tubes", in contrast, goes down.

Oh, and it would appear that the LED lamps aren't actually drop-in replacements for standard tubes. They're the same size and shape, but note the box next to the tube in the picture - that's a replacement for the fluorescent ballast, because the LED tubes apparently have "low voltage wiring", instead of the current-limited mains voltage that runs fluoros.

And fair enough, too - an LED lamp able to run from a standard fluoro ballast (and not get blown up by the "starter" kick...) would be a fairly perverse item. But that knowledge doesn't make rewiring your roof any more fun.

(A more common example of this problem is the compact fluorescent replacements for halogen downlights. They run from mains voltage, which is good; simple, and more efficient. But if you want to use them, that means you can't just plug them into sockets that 12V downlights were running from a moment ago. You have to go into the roof and rip out the downlight transformers, and then you have to put stickers in the sockets or something that warn people not to plug 12V lights in there any more.)

[#2 posted by Anonymous , November 13, 2007 10:28 AM]

http://www.everled.com/everled-tr/

A fluorescent tube replacement that uses the original ballast and is not absurdly expensive.

Looks cool, I've never seen one in person before.

[#3 posted by dculberson , November 14, 2007 11:39 AM]

A standard good-quality T8 tube is 32 watts, puts out an unbelievable amount of light, and has a lifespan in the 24,000 hour range. The Luxeon K2 has a 70% lumens-maintenance life of 50,000 hours. The cost of a single F32T8? Approximately $1.50.

Summary:

(8) K2's puts out a max of 1,120 lumens (140 lumens each) consuming 24 watts and costing a lot. Lifespan 50,000 hours, requires rewiring.

(1) F32T8 puts out a max of 3,200 lumens consuming 32 watts costing about $1.50. Lifespan 24,000 hours, no rewiring.

A savings of 25% energy usage, at a cost of (likely) a hundredfold replacement cost and a 65% decrease in light output. Great deal.

Granted, the T8 will send more light up, but that's frequently not "wasted" light. Even if it is, the lumen output is so much greater that the net effective light output is still higher.

[#4 posted by Joel Johnson , November 14, 2007 1:27 PM]

DCulberson: Marry me.

[#5 posted by dculberson , November 14, 2007 3:03 PM]

Joel: I'll keep you in mind for the next time I'm single. ;-)