A set of reflector spots (replacing 45W halogen bulbs) all in recessed ceiling fixutres in one specific location within the house failed within a few months of one another.
Another spot in the kitchen, in an exposed can, failed within a year or so. It was located directly over the sink.
I suspect moisture / condensation as issues in both, as the ceiling cans have minimal insulation between them and the roof, and the kitchen fitting would be exposed to steam / vapour coming off the sink.
Other than that, a couple of stick-style closet bulbs have failed, also apparently electronics. And one fixture in the garage which seems to have been physically struck.
That's over roughly a decade's experience and roughly 30 bulbs / fixtures. Far better than incandescent or even CF bulbs. Though still not quite meeting expectations.
I think the biggest difference is that these downlights have separate driver modules and a short wire to the lamp itself, which must make the thermal aspect a lot easier to manage. This also puts the electronics up out of the condensation.
The bulb in a regular socket in the bathroom on the other hand has the driver electronics there in the bulb, being heated by the lamps, so they're getting a lot hotter, and also it's there in the steam from the shower etc.
I'd suspect that in/near the fan might reduce condensation / humidity. Lavatory moisture is no joke.
I haven't bought a Cree product since then no matter how cheap Costco marks them.
They were, for sure. However, in 2019 they were sold to another company and I do not know what may have changed since. All of my Cree lights pre-date that.
> I had one of their CFLs
Cree was founded entirely on the premise of creating LED lighting, I am pretty sure they have never done CFLs.
There’s only a few bulbs I’m aware of that follow this pattern. The Philips Dubai Lamp takes this to an extreme. A 60W equivalent uses only 3W. Other 60W eq. LEDs tend to be ~3x that. All that heat has to go somewhere.
I just picked up a 40W eq. bulb from IKEA that has double the normal amount of LED strands- they’re unusually long, too. It also uses about half the power of the LED bulb it replaced. I expect it to last quite a long time.
Heat is a primary killer of many electronic things, including LED bulbs and their constituent parts.
And LEDs -- the diodes themselves -- do tend to become more efficient (in terms of lumens produced per Watt of input) when not pushed to their extreme operational limits.
And it is definitely possible to create a longer-lasting, more-efficient LED bulb.
It's absolutely trivial to do this, even: To start, just add more LEDs, reduce their individual RMS current, improve heat sinking and dissipation, and use better capacitors.
But it does cost more to do these things, and regular consumer products are all built down to a price.
This isn’t some weird surprising tendency. The forward voltage (the amount of energy needed to shove each electron through the LED) increases with current, approximately according to the Shockley equation. The external quantum efficiency (photons out per electron in) is no more than 1, and tends to get lower at higher current [0]. The wavelength of the emitted photons is pretty much constant. So you get the best efficiency when the current, and hence voltage, is low.
Incandescent bulbs, in contrast, don’t have a meaningful quantum efficiency, and they produce a more useful spectrum as they get hotter.
[0] There’s a ton of detail here, for example https://www.degruyter.com/document/doi/10.1515/nanoph-2018-0...
Approachable explanations like this are a huge part of the reason I hang out here.
This may or may not be the only thing in play for that much of a difference, but my absolute favorite thing about LEDs is that their power consumption vs brightness is not 1:1, so taking an LED to 50% brightness will use <50% power. (So then doubling the number of LEDs means you will always get more brightness or less power or I suppose both if you split the difference.)
The IKEA bulb’s rated at 450 lm, 2700k, 90+ CRI. It uses 2.8W. Both are dimmable and I suspect the IKEA bulb has a higher R9 value.
The RAB bulbs have a weird stair step warm-then-cool when turning on and off. They also have a huge non-linearity when dimming. That makes the Philips version more desirable, but they’re 2700k.
Shitty light, and they consistently averaged a shorter lifespan than cheap incandescents across two houses. Nope. Done with that tech forever.
Here in Japan, ceiling lights have a standardized socket[0] so ceiling lamp fittings are easily user-replaceable without people being stuck with old bulb fittings, and so ceiling LED lamps are not fitted as bulbs but typically a large flat metal plate with the LEDs mounted to it[1], which results in fantastic cooling and good lifespan.
[0] https://www.garageland.jp/wpimg/hikkakeceiling_topimg.jpg
[1] https://kensroom.c.blog.ss-blog.jp/_images/blog/_bda/kensroo...
Edit: Our apartment was built in 1998, at the height of "CCFLs are the future", and the hallway lights are all recessed "G24q" bulbs, which I had never heard of before.
There were supposed to be the CCFL-native replacement for Edison screw bulb sockets, where instead of having to build the CCFL ballast into each bulb, it was external in the ceiling socket, increasing longevity and decreasing the cost of the bulbs themselves.
We have yet to need to replace any of them, a much longer lifespan than I've ever had from one of those CCFLs with the ballast embedded in the base of the Edison bulb. With a less-compromised ballast they also work much better (light quicker, less affected by temperature)
Don't get me started on blinding LED headlights. It's so hard to see on the road at night these days.
See https://FlickerSense.org for a PhD scientists personal account, and, https://LEDStrain.org forum full of people that get migraines, dizziness, eyestrain and headaches from LED lights and other forms of flicker like temporal dithering.