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Compact LED grow lamp

The description for this section of the forum states 'Show off your inventions', so here goes...
 
I needed a compact LED grow lamp with decent output and thought why not build one. Winter where I am is not too tough, but still just cold enough that over wintering is best advised. And always good to get off to a flying start with small plants as opposed mere sprouts. By decent output I was thinking something commercial grade.
 
Here's the result:
 
led_lamp_1_600x450.jpg
  
led_lamp_2_600x450.jpg

 
led_lamp_4_600x450.jpg

 
Power: 180 W
Luminous flux: 22500 lm
Colour: 5700 K
PPFD: 336.5 μmols-1m-2 (@ 1 m, measured)
Efficiency: 40%
Size: 300 mm x 200 mm x 100 mm
 
 
But the real indicator: the seedlings / plants loved it!  :dance:
 
Inside the case is a big aluminium heatsink and a small board with the connectors (from the PSU, and to the LED board and the fans). Thus the two fans at either end draw air through the unit and over the heatsink.
 
As for airflow over the power supply, sure - more airflow to cool is always better, but there was not easy way to incorporate it without making the unit quite a bit larger. There were also limitations regarding the enclosure possibilities. Even so, the unit runs at about 40 °C on the external surface.
 
If I did it again it'd likely be a little different. The unit is good as a concentrated light source, but it can also be useful to have a wider light distribution. So more LEDs and spread out over a wider surface area - we'll see if I build it up.
I'd also put some more smarts into it, allowing for in-built timer, WiFi access (of course! Why not?), etc.
 
nice.chili said:
I used 25x Cree XLamp MHD-E LEDs - got them as samples from Cree (so a nice price!). They have some newer similar units now with higher output, etc. Really a matter of how big a power supply is practical.
 
Another 'if I did it again': as KAOS mentions in http://thehotpepper.com/topic/58028-how-to-build-an-led-growlight, I think I would change to either 5000 K (or maybe even 4000 K LEDs). It appears not to be as simple as red vs. blue...
 
I grew all my pepper starts this year under 3500k cree cxb 3590 s your spectrum is probably too much blue
 
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