New Design for LED Bulb Handles Heat w/o Heavy Heat Sink

[kristopher]

Three views of same bulb:

Philips LED bulb with rad design set for January arrival
Dec 17, 2013 by Nancy Owano

(Phys.org) —Netherlands-based Philips' SlimStyle LED bulbs will be arriving on January 2 at Home Depot stores, and the SlimStyle appears to be a promising newcomer in lightbulbs, with a flat design, energy-saving benefits. and ease of use for consumers. Intended as a replacement for 60- watt incandescents, SlimStyle is highly efficient; it uses only 10.5 watts, yet still puts out 800 lumens.

This lightbulb is shaped such that a string of LEDs are arranged into a horseshoe shape that arc out from the base. The shape is not just about grabbing attention; the technical advantage is that the SlimStyle does a good job in dispersing heat and does away with the need for heavy heat sinks. In a GigaOM report on the SlimStyle, a Philips spokeswoman e-mailed comments about the bulb's design "The flat surface," she said, "helps conduct heat away from the LEDs, eliminating the need for the heavy aluminum heat sinks associated with LED bulbs. This eliminates the cost of the bulb, while still delivering omnidirectional light."

Illumination in Focus further reflected on the significance of the design: "Philips has once again created an LED-based retrofit lamp with a novel shape that still delivers an omnidirectional beam that the company expects to win Energy Star certification. The design looks somewhat akin to a doughnut on top of an Edison base although there is only a flat area rather than a whole in the center of the doughnut. The solid-state lighting (SSL) design enabled a new approach to thermal management that does not rely on a visible metal heat sink."

Chris Davies, meanwhile...

http://phys.org/news/2013-12-philips-bulb-rad-january.html#ajTabs

[TreasonousBastard]

1. Cost? Lumens per watt? Color?

[kristopher]

2. Have you bought an LED lately?

Brightness and color concerns are a thing of the past.

The cost has also dropped substantially. I just bought some 60W replacement bulbs for about $7 each and some 40W replacements for about $6 each at a big box retailer.

Since the heat sink solution also decreases material usage, I hope the approach will continue the trend in price reduction.

[TreasonousBastard]

3. I'm currently writing the lighting specs for a building...

being renovated and I was in lighting sales and design for a few years a while back. So I'm not an expert, but I do have some place to start. And I do have a mix of CFL and LED lighting at home. I really liked halogens before CFLs got religion, but those are all retired along with some spectacular electric bills.

It's the cost of this lamp I question. The Philips HUE is a more interesting LED lamp, but it's over 40 bucks each and we would need at least 50 of them. And the lumens per watt for current LED lamps and CFLs are identical, so it's down to light quality and cost. And then there are some LED arrays I've seen that require a ballast at additional cost and complexity.

Color concerns are far from a thing of the past. I'm looking for 3,000-3,500K with a CRI around 90 and haven't found any LEDs that fit that spec while there are plenty of fluorescent tubes that do. Even a few CFL's come close. They could make them, but manufacturers haven't bothered yet. I might have to settle for some LEDs in ceiling fixtures where changing them would be dangerous. Then the irony is that we would be tempted to change them anyway when better ones came out.

Eventually LEDs will be the standard, but not just yet.

[kristopher]

4. I see. Your needs are out of the mainstream; I thought it was a holdover view from the past

This and all of the others are designed to replace common incandescents and I doubt that will change anytime soon. I would think the current range of choices will persist until the market is pretty well saturated as manufacturers focus on reducing costs.
Good luck.

[TreasonousBastard]

5. Truth is, I prefer natural color at home, too...

which is why I liked halogen before the better LEDs and CFLs came out. They were a little cooler and much brighter than your typical incandescent, but they cost a bundle, and burned out too fast.

Between LEDs and newer CFLS that don't take forever to warm up and are dimmable, we've got stuff that will last until the next discovery.

[cprise]

6. Same here: 2700K doesn't do it for me

I also prefer the 3000-3500K range and have been waiting for high-CRI LEDs tuned that way.

Can you recommend some good fluorescent brands of light bulbs?

[TreasonousBastard]

7. Unfortunately, some asshole bought Duro-Test and put them out of business, but...

if you see any Duro-Test or Luxor tubes still around, grab them. They made all sorts of stuff over there in their NJ factory including excellent 3,000K, 3,200K and 5,000K tubes. I lit photo studios with the 3200K that wouldn't spoil the photofloods.

Anyway, there's not much out there outside of specialty markets. GE, Sylvania, and Osram always made good stuff, but I think Sylvania is out of it now and the other two may be shedding the market nowadays. Osram is tough to find retail. Philips is still in it, but I never liked their stuff much-- always a little too green no matter what the specs said.

A couple of local lighting shops refuse to talk fluorescent and even give me funny looks when I mention CRI so I've been off to Home Depot and Lowe's as the last resort. Lowe's is hopeless for larger prices and less information but the Borg has a couple of Philips and GE tubes that are mid to high 80's CRI and that's the best I've seen so far. Looking online becomes a joke after a while, so when we get closer to actually doing something I'm going to have a long talk with an electrician and see what his sources are. They all charge pretty much the same, so the job goes to the guy with the answers.

[Iterate]

8. The wholesale houses should work with you.

It wouldn't take much to get an account, or just pay cash over the counter. If you can concentrate your buys with one that's linked with your preferred manufacturer, special orders wouldn't be a problem. With the contractor who's done the coolest lighting job in town, or even an architect who includes lighting design, a phone call can get you a contact and at least their eyes won't glaze over when you say CRI. Those are the people who meet monthly with the company reps.

[TreasonousBastard]

10. 'Tis a thought...

I'm not exactly in the boonies, but not that far from them that lighting designers are viewed with suspicion and architects think in terms of copses.

Thanks for the suggestion, though, and I will talk to one architect I know-- she's on both the town zoning board and our local Democratic committee.

It won't be a huge buy-- it's a small building and whatever we buy won't need replacing for years.

[cprise]

9. Thanks

I had high hopes for the newer Philips L-Prize and Cree LEDs, which are all at least 90CRI... but they're all 2700K. I anticipate they'll eventually bring out other color temps like they do with their other lines.

I bought a couple GE Halogen A type "energy saver" bulbs recently, knowing they don't save much energy. I intend to use them only in the cold months, and replace them with CFLs or LEDs when it gets warm.

[TreasonousBastard]

11. Yeah, the 2700 is to match all those 60 watt bulbs out there...

so it'll take a while to move on to others.

Those halogens are nice, though, aren't they? If only electricity was free...