CXB3070 3K AD @ 1.4 = 49.8W * .48 = 23.9 PAR W * 4 = 96 PAR W
CXB3590 3K CB @ .7A = 48.9W * .517 = 25.3 PR W * 2 = 50.6 PAR W
So your total is 146.6 PAR W emitted. You could apply -10% for lenses/reflector/scatter losses so 132 PAR W. If you have a 3X3 tent that is 14.7 PAR W/ft² or:
14.7 * 4.66umol/s/PAR W * 10.7 = 733 PPFD.
The way I look at driver efficiency, if you are using HLG-120H or 185H series, it cant get any better, 94% and power factor corrected. The best HPS competitors claim 95% efficient ballast so they are in the same ball park but if the COB system can achieve the same yield with half the wattage, the HPS ballast losses are twice the COB driver losses and will affect system efficiency.
Thanks Supra ... very clear answer.
so...based on discussions here and some of your own grows accomplished with 15PAR W/ft² i see i'm in the right range
( regarding the 14.7 PAR W/ft²). i thought about driving the CXB3590 @ max 1.4ma for 2-3 weeks in middle flowering... to help the buds fatten up ( i don't know if that makes sense???)
i would have 1.4A=103.94W * 0.3957 = 41.15 PR W * 2 = 82.3 PAR W
which would bring the total to 178 PAR W - 10% losses = 160 PAR W .
finally i would have in my 3x3 tent around 17.8 PAR W/ft² ...
sincerely i don't think it will make much difference and probably i will just let them finish like this, this round.
maybe i'll try this next time and see what kind of difference it may have to go from 14.7PAR W/ft² to 17.8 PAR W/ft² ...
learning is fun with you guys.
thank u.