10Watt Triple Cree P4 House Light

LEDite

Enlightened
Joined
Dec 6, 2002
Messages
324
Location
Dallas, TX
Well, I finally got my shipment of Cree P4's in.

Put this Triple P4 light together as a prototype 4" diameter can replacement:
triplep4.jpg

The three P4's are directly attached to the anodized heat sink with a special filled epoxy I made up.

Heat is a big issue in this 4" can downlight. I finally added a fan to lower the operating temperature of the LED's.

I then checked the actual wattage against a 14 watt compact fluorescent bulb.

The 14 watt CFL actually used 14 watts.
The LEDs & PS used 10 watts wo fan & 11 watts w/fan

Next I took some floor lighting shots with the exposure locked and the fixture 8' up.
The first one is the CFL and the 2nd the Triple P4:
cornercfl.jpg

cornerled.jpg


If CFLs are the most efficient commonly used light for a 4" can, then LED's have a promising future.

The PS is a switching type with UL approval.
The Crees are WD color bin (~6000K).

Larry Cobb
 
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2xTrinity

Flashlight Enthusiast
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Dec 10, 2006
Messages
2,386
Location
California
Re: 10Watt P4 House Light

Hmm... the CFL looks like it's probably the yellow 2700K variety. Lumen output looks like it's clearly higher for the CFL, but the LED looks like it would be a more useful as a task light. I still think a 3500, 4200, or 5000k CFL would be an advantage at this point, but that advantage may not last long.

For recessed can fixtures, those fluorescent retrofit bulbs have fairly inefficient reflectors as a lot of light gets bounced back into the tube. Dedicated CFL fixtures with external ballasts are much more efficient, as the ballast isn't cooking itself and the reflector is specially designed. However, those dedicated fixtures can be expensive -- it seems like soon LEDs will be able to dominate for recessed lighting as much smaller fixtures with diffusing optics, and even specially designed heatsinking could be implemented in a very smaller package for around the same price.

You have to love those current-regulated switching power supplies (I presume some sort of battery charger power supply). I'm in the process of using one right now from an old cell phone to make under-cabient accent lights for some pictures using Cree LEDs.
 

LEDite

Enlightened
Joined
Dec 6, 2002
Messages
324
Location
Dallas, TX
2xTrinity;

You are correct on the color, but useful lumens favor the LEDs.

The CFL probably has a 2700K color temp. The LEDs definitely have a higher color temp.

The CFL is a HD Commercial Electric rated @ 900 Lumens.

According to my calculations, the LEDs are outputing ~500 Lumens.

Larry Cobb
 
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