Philips EnduraLED MR16 dimmable LED bulb 10W/35W

[ergodic]

I just picked up one of the dimmable 10W Philips EnduraLED bulbs that Home Depot is now selling for about $25.

 

The bulb caught my eye because of the 10W / 435 Lumen rating printed on the package. All my ceiling lights are Elco 12V 50W halogen floods with the MR16 (GU5.3) 2-pin base. The Elco fixtures are dimmable with almost anything, very efficient, have a large selection of trims, and work well with Insteon. The Ushio MR16 bulbs I use have about 800 lumen rating and cost about $5-$6@, so this LED seems to be getting in the range.

 

The Philips spec sheet is here:

 

http://www.usa.lighting.philips.com/pwc_li/us_en/connect/tools_literature/downloads/Technical%20specs_10WMR16.pdf

 

There is a great deal to like about this bulb and in a lot of ways I see it as is a real advance. It is listed as a 35W equivalent, but subjectively it appears as bright or brighter than the 50W halogens. Part of that is color temperature: it is listed as "warm" at 2700K, but it is still noticeably bluer than the halogen even at full brightness. I run the halogens with a 95% top-set to extend their life (in four years I've never replaced one), so the color temp. difference there is even a little more obvious.

 

There are four (presumably 2.5W) LEDs with lenses arranged concentrically around the rim. No diffusers. The optics designers have done their work here: the flood beam spread is surprisingly even and appears about the same width as the halogen. Physically, the bulb a little taller than a typical MR16, but you can dispense with the UV glass which gets back a lot of that.

 

In terms of dimmability, it caused no interference with Insteon that I could detect. The bulb dims down to about 10% before shutting off and there isn't much hysteresis. But there are still problems: As you dim it up, there is a brief and annoying flash when comes on. Second, the dimming curve isn't nearly as linear as the halogen. At 10% it appears to be about 1/2 brightness. It isn't as bad as with other LEDs I've tested, but it still seems better pulse circuitry and compensation is called for.

 

The other dimming problem - one that is the really tough nut for all LEDs - is that the color temperature of the light doesn't change as you dim it. You probably wouldn't want to mix these bulbs with halogen or incandescent. (In the interest of full disclosure, I need to say that I detest CFLs and CCFLs in all their incarnations. Even in the newest ones the light quality is dreadful. That apart from the fact that breaking or disposing of one is a near-toxic spill and the "dimmable" ones are to me a bad and overpriced joke.)

 

The other big issue I found when I disassembled this bulb: a thin little 30mm fan mounted above the LED. Now 10W is real heat - it's no high-temp halogen, but put your hand up near this bulb and you'll feel it. And that heat has to be dissipated somehow. But speaking from long experience, small fans are a Bad Idea because they fail. It's a shame that Philips couldn't have vented and heat-sinked this nice bulb for passive cooling or arranged a piezoelectric cooler, or something as durable as the LEDs. Worse, the fan is soldered into the PCB making replacement quite difficult. This I have to see as simply stupid design. The bulb is trivial to disassemble with just two little screws and making the fan replaceable with a connector and an overheat cutoff would cost almost nothing. I assume this is the reason for the "6 year" life listing. But if a fan like this lasts 6 years in operation I'll eat one.

 

So: is it a winner? I'm not sure. I see this bulb as a clear step forward in price-performance. But there is obvious room for improvement. It is somewhat expensive but I think quite reasonable given what it is, and the price of course is certain to come down. And this is a very nice bulb with an overall pleasing light. Certainly if it came down to this or any sort of fluorescent, there'd be no contest as far as I'm concerned.

 

But that **** fan is the deal-breaker for me. Until something better is done there, I'm not biting.

[Brian H]

I agree fans are a problem.

I have an EvoLux S LED bulb and it has a fan in it.

Now that is has about a year of use. The originally quiet fan now sounds like a growling beast.

[supercargo]

Thanks for the great write up, ergodic. You hit on all the major points that keep me from being super excited about LED lighting (not that I don't use it to cut down on power consumption), most people don't seem concerned with the lack of color temperature shift that comes with dimming LEDs. My ideal light would be a variable color temp light which was "always on" but had built in Insteon control so that all of the dimming could be handled on the DC side. This would get rid of poor dimming curves and poor behavior at low brightness as well.