I have built several rigs with Vero 29 SE C Bin COBs and I love them. I recently tried a couple HLG QB 288 v2s and really like them. You can get the v1 quantum boards right now for $47, but they are out of stock of both 3000K and 4000K. The v2s are what I am testing, but they are $89 for the board and a Slate 2 heatsink that can handle up to 150w each (closer to 175 max from my testing, but I keep mine between 150-160).
So, at 30 watts a square foot and 64 square feet, you will need 13 QBs. There’s no thermal adhesive or anything needed, so it would just be the packages and drivers you need. Use an HLG-150-54A per light so you can tune the dimming and power consumption. They run $40-ish per driver, so including wire, power plugs, and the kit, you’re looking at $140 for 150 watts or 93.3 cents a watt. Total for 13 would be $1677-ish. For 50 watts per square foot, you will need 22 lights at $3080.
For the Vero 29 SE COBs, you can run 4 C bin COBs per HLG-480H-C1750A, so I would do 2 drivers with 4 COBs each for a total of eight COBs per fixture. Running fewer cobs on the driver will reduce efficiency. So, for 64 square feet at 30 watts per square foot, you will need 2 fixtures with two drivers and eight cobs on each; totaling 1909.6 watts. The actual wattage for this comes to 29.84 watts per square foot. For 64 square feet at 50 watts per square foot, you will need three fixtures with two drivers and four COBs per driver plus a fixture with one driver and four COBs. This would total 3341.8 watts.
Keep in mind that running these at this high of a drive will mean active cooling. I use the Arctic Alpine 64 plus CPU coolers since they can handle this wattage easily, but Arctic appears to have quit making them. The closes you can get now is the Arctic 12 CO, thought you might want to check that first since the pad is nowhere near as large as it was on the 64 plus. You can get them on Amazon for about $11.99. So 20 COBs from Arrow with 10 BXRC-40G10K0-C-73-SE 4000K ($273.50) and 10 BXRC-30G10K0-C-73-SE 3000K ($259.60), plus 20 Arctic Alpine 12 CO coolers from Amazon ($239.80), plus 3 APV-16-12 drivers for the fans ($17.70), plus $80 in wiring and power cords, plus about $150 in angle aluminum, plus $10 in screws, comes out to $1031-ish.
Now… it gets more complex…
A Vero 29 SE at 1750 mA will throw about 18.375 lumens or 153.9 lumens per watt. This means a Vero 29 setup with 3341.8 watts will output about 514,285 lumens, equaling 498.8 lumens per dollar to build. The quantum board setup at 50 watts per square foot will output about 168 lumens per watt. This means the QB setup with 3300 watts will output about 554,400, equaling 180 lumens per dollar… BUT… each light is outputting about 25,200 lumens, which means your 20 COBs are putting out as much light as about 20 QBs, even though the wattage is lower… so in reality, you could cut the QB build down to 20 lights at $2800 and 3000 watts. This would mean you would be using 341.8 watts less power. This in turn means you would be using 8.2 kWh less power per day and 254.3 kWh less per month. The average power rate in the USA is 12 cents per kilowatt-hour, so you would be saving $30.52 per month. At that rate, the cost difference would be recouped in 5.59 years. This all depends on where you live though… for example in California, the average power rate is 18.32 cents per kWh, so that would be a savings of $46.59 a month and would take 3.6 years to recoup the cost and start saving money. And the worst case scenario, Hawaii… they charge 32.09 cents per kWh, so it would save $81.60 a month and only take about two years to become more cost saving. So, it really depends on location and if you plan to stick with it long term.
I know I went down a rabbit hole here, but it’s something to think about.
