# Home Depot selling CREE downlights



## AquaNeko (Jul 26, 2009)

http://news.cnet.com/8301-11128_3-20013898-54.html?part=rss&subj=news&tag=2547-1_3-0-20

Yah the lumens arn't all there and LED's are expensive if you buy it commerically made but if you made it yourself I'm sure you could get more lighting out of it but then again you'd need to heatsink it good. Come to think of it. It would be interesting if when you turned the light on it turned on a water pump that water cools the light and that water goes back to a fish tank or hot water tank.


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## waj8 (Jun 30, 2010)

Cree is always getting in the news, but it looks like hype to me. How many lumens per watt including the power supply? If they are efficient they won't need cooling. Color temp. also not that useful.


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## AquaNeko (Jul 26, 2009)

Not sure if you know but LED's are different then halogen/incandecent/HID/CFL in that they are rearward heat vs forward heat in the mentioned other lighting. This why you need a lot of heatsinking as MC-E's are 4 dies on the LED thus 4 times the heat even on say 1W which I think is ~100lm @ 1W but I could be wrong as I'm thinking back on the Cree Q5's which were about 105lm @1W.


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## buffalo (Mar 6, 2010)

2700 k not enough i would say for reef lighting u need to start around 6000k (prefer 6500K).
When it comes to LEDs i say wait a while. Many people spending lots making their own or buying over priced units without really knowing what the long term results are using LEDs. When i say long term i mean as short as 2 yrs. Do a search for results of changing to LEDs for a reef tank.


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## Zebrapl3co (Mar 29, 2006)

Just keep in mind that LED isn't always what it's cracked up to be. It's mostly hype.
I've touch and experiment with more LED that most people. 2700K is a joke. The light is so yellow that it washes away most of the other colour spectrum. It's like walking around in a world of black and white. If you want to know what it feels like being colour blind that's a very good way to go about it.
Plus, the bigest problem with LED is that they are very spot focus. Yes, it's true that while you are under that 1 or 2 foot radius, it's 40 Watts or what have you. But any where outside of that 2 feet radius it's more like 20 watts and the further you are away from that spot, the less you can see with clarity.
Plus, the orginal definition of the life of an LED is when it reach 1/2 life. That means it's brightness declimes as it age. And when it's brightness is 1/2 of it's initial brightness. It's consider a dead bulb.
Many manufacturer ofcourse don't comply with this definition, their end time is went the bulb stops lighting up. This ofcourse can take eons, some might last more than 10 years. But it's brightness ofcouse, is 1/10 th or even less from it's original brightness.
Anyway, long story short. Don't expect your LED light to remain as bright for more than 2 years. Calculate that back to see how much you would save and you will have the real figure. Because chances are, your LED will have gone down hill and still burns just as much wattage, but offer a significantly less brightness.
But then again, we've been doing the same thing with flourescent light anyway ... so I'll stop babling.

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## AquaNeko (Jul 26, 2009)

Well those are more for home recessed ceiling lights or under counter lights. LED's depending what you're doing with them may not be as bright or are bright with benefits. I come from a MTB night riding culture. For us LED vs HID's have IMHO made a balance right now. A lot more lighting is coming out as LED's because when you're turning on/off HID's it shortens the life of the bulb where as with a LED you can turn it on/off a lot, instant on no warm up time, current controlled brightness, and shock proof.

Often easy to just upgrade later a few years down the road by removing the old LED and finding another one that is brighter and of same voltage specs and soldering that one on.

http://forums.mtbr.com/showthread.php?t=631642


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