Hi guys,
I've been reading and absorbing as much as possible. Lots of great info here for the aspring DIYer. I need some validation prior to clicking the checkout button(s). Please bear with me, I'm presenting all details.... I've got basically two questions. Is my light level appropriate, and what driver selection that I've listed is most appropriate? It's long winded, sorry. Also, does dimming provide similar energy savings to using lower-powered drivers?
I'm looking to light my 3x2 grow area with 8x Vero 18s because the price is good on them, and they're efficient at 127lm/w. I'm trying to determine appropriate driver options before making my purchase. I'm looking for advice. For the record, I'm used to a 400w HPS bulb in my area, at around 45,000 lumens (e.g. not a new bulb) and how it performs. I'm looking for better coverage, and reduced electrical costs, since I (may be) plan to move to perpetual autos - meaning 18 hours/day, instead of 12 - so reducing the electrical bill will be important.
I'm looking at 8 of these these 3500k Vero 18s:
http://www.digikey.com/product-detail/en/BXRC-35E4000-F-03/976-1156-ND/3913133
These should be appropriate for both flowering and vegging - considering my planned autos... in the following configuration:
View attachment 3370635
My calculations are are follows (had trouble formatting, sorry):
amps, volts, watts, lumen %, lumens, lumens/w
0.35, 27.10, 9.49, 35.00%, 1,372.00, 144.65
0.47, 27.70, 12.91, 46.92%, 1,839.16, 142.46
0.70, 28.40, 19.88, 70.00%, 2,744.00, 138.03
1.05, 29.50, 30.98, 100.00%, 3,920.00, 126.55
1.40, 30.40, 42.56, 129.34%, 5,070.00, 119.13
2.10, 31.60, 66.36, 185.71%, 7,280.00, 109.70
At their intended level of 1050ma, they put out 3920 lumens each, so I'd have 31360 LED lumens of output (5227lm/sqft) compared to what I'm used to at 7500lm/sqft with my HPS. Now, I hear (without fully understanding) that LED has improved spectrum, and I'll certainly have better coverage - so I'm hoping that this apparent decrease in power will not reduce yields or quality. That brings me to my first question:
1. Is this the appropriate level of light for my space using LED? I see people using quite a bit less.
2. What's the best way to drive it? I can use a single expensive 200w driver, running two strings in parallel, but I'll be at 700ma. I can run 8 drivers but they are normally inefficient. I can run 2 expensive 200w drivers (one per string), but that's spendy. What would you guys do?
Thanks!