You guys hit it from every angle
I have appreciation for commercial lamps builders (like A51) providing us what I cannot, a relatively large quanitity of darn good lights that can make HPS growers start to wonder. But in all honesty, before COBs were available and I was limited to small single die LEDs, I chose cheapo HTG HPS kits rather than building a large DIY LED or buying a commercial LED. I was limitied to using LED for veg. So my thesis is,
large COBs are the game changers. So what we growers need now is a quality commercial lamp that uses COBs.
Here is how it went down. Before COBs I was using red/deep red//warm white/blue. This setup stomped my 600W HPS watt for watt, but maybe too tedious to build on a large scale.
-Luxeon ES deep blues, 700mA, 55% minimum, $2.80/PAR W for top bin on stars
-Cree XPE reds, 700mA, 41% minimum, $6.30/PAR W for top bin on stars.
-Luxeon ES deep reds, 38% minimum, $5.60/PAR W for top bin on stars.
-Cree XTE 3000K, 700mA 33% minimum and cost $4.51/PAR W rare R3 bin on stars.
So the XTE whites were the weakest link, although they were the very best option at the time. But then COBs became available, HUGE improvement in efficiency and cheaper. Faster and easier to assemble the lamps.
-CXA3070 3000K Z2 bin, 700mA, 42.6% minimum, $3.36/PAR W.
Then the AB bins came out:
CXA3070 3000K AB bin, 700mA, 49% minimum $3.34/PAR W.
And what should thrill the commercial lamp builders and buyers:
-Vero 29 3K, 2.4A, 37% typical, $0.94/PAR W (if these can be mass produced, adios HPS).
For comparison, here are the very best single die warm white LEDs currently:
Cree XML2 3K T4, 700mA, 38.9% minimum, $4.85/PAR W
Cree XPL 3K U6, 700mA, 42.7% minimum, $5.23/PAR W
Cree XML2 3K T4, 2A, 30.1%, $2.51/PAR W
Cree XPL 3K U6, 2.1A, 32%, $2.40/PAR W
So as you can see,
COBs are like a diffferent type of growing lamp. Once this catches on, it does not seem that there will be any single die based lamp that will be able to compete.
Also, so far it seems that warm whites work great on their own, so no worries about color mixing. The COBs stand up to the abuse of high heat very well. In my heatsink tests, even with the heatsinks running too hot to touch (57C, 135F), the COBs only lose 8-12% of their output. When we run them at more reasonable temps, 35C we only lose ~3%.