Comment by 15155
1 day ago
110VAC "LED bulbs" are not the same thing as the LEDs on a PCB in a DC motor ceiling fan.
"LED bulbs" die because they have to rectify 110VAC (hot) into LEDs (hot) into an enclosure that was designed for incandescents.
In a proper enclosure, with cooling (it's a fan), they will actually live their fully-stated lifetime - assuming the fan's upstream power supply makes it.
There are LED lamps rated for enclosed fixtures. If you buy and use them in enclosed fixtures, your lamps will last longer.
A recessed can or “upside down” ceiling fan globe with an open bottom is technically an enclosed fixture since heat rises.
> A recessed can or “upside down” ceiling fan globe with an open bottom is technically an enclosed fixture since heat rises.
Typically fans with built-in LED downlights are engineered to actually dissipate heat - and they have a much larger area to do it in. Edison-format bulbs are inherently space-constrained.
> In a proper enclosure, with cooling (it's a fan), they will actually live their fully-stated lifetime - assuming the fan's upstream power supply makes it.
But in an "old school" hardware, you'd then replace the bulb and get a new "lifetime" out of it, here you have to throw everything away.
An AC motor has basically nothing inside that can fail (maybe the capactitor, but that can be replaced), and can work for a hundred years and more if properly maintained (mostly cleaned).
On average ~6 hours per day (living room with night owls living there), is ~2000 hours per year... 5 years at 10.000hours expected lifetime for the leds, 10 if the stated lifetime is 20k hours... that's not really that long.
You can replace parts that don't come in nice detachable sockets.
Lightbulbs came in sockets because they were meant to fail. First by accident, later intentionally. They were also quite breakable because they were made of glass. LED lights don't have these problems unless they're designed to. Which is the meta-problem - how do you know which ones are planned obsolete?
Forcing an LED system into a lightbulb from factor has quality and cost implications though. A good LED light has a separate power brick inside the enclosure. Which is what you see in these fan lights.
I build lights with cob modules with phosphor (bridgelux), and unless I screw up the thermal interface, I get many years out of modules that cost < $5 each. one thing is that the thermal paste is too fiddly for most people, voltage/current tends to drift around and 0.5V is a big difference here. mechanically they tend to use a couple different form factors, but not 100%. the 10 watt units I had been using were bigger than the 15w I use now, and the mounting spacing went from 0.75 to 0.71
I would hope that at least some of this would get standardized over time
> An AC motor has basically nothing inside that can fail
Let me know how the non-replaceable sealed bearing packs in these AC or DC fans fare after 10,000 hours.
In a proper/high-end DC fan, the bearings are failing before any motors or LEDs.
Regardless, in a Big Ass Fans Haiku, the downlight is a completely separate/replaceable module - and it isn't going to fail before the bearings or motor.
Edison screw LED bulbs are the inferior design by every objective measure.
> Let me know how the non-replaceable sealed bearing packs in these AC or DC fans fare after 10,000 hours.
...your AC-powered ceiling fans are failing (or even "just" substantially degrading) after a little under fourteen months? What garbage are you buying?