Now there's an interesting thought:
Comparison of construction cost.
Here are some known values for a 400w, HID, HPS (400w, High Intensity Discharge, High Pressure Sodium):
400w Ballast/Core Kit: $102.00 (no housing, no factory cords/connectors)
C400s51/ALTO HPS lamp: $16.00 (standard, commercial, otc lamp)
LU64AC - ducted reflector: $80.00
Completed fixture: $198.00 each (assembly required)
you left out a few other items, like electrical connectors, fan to run the air cooled
hood, and other assorted tools. for ease of calculations, i will leave out the cost
of crimp connectors and liquid tape, which would be the same for both projects.
the duct fan would add ~$50 to the cost of the 400w HPS though.
Vero 29 $ 30.00
Meanwell LPF-90-48 $ 43.00
Arctic 11 plus heatsink/fan $ 10.00
Fan power supply $ 17.00
Pico EZ mate connectors $ 2.00
Cost for a finished COB $102
You would need 3 of these units to equal a 400w HPS in terms of square footage
and finished yield. That would make the cost comparison approximately
400w HPS $250
Next is electrical considerations.
400w hps draws .4kW/hr x 12 hrs= 4.8 kw per flowering day
210w COB draw .21kW/hr x 12 hrs= 2.52 kw per flowering day
if we assign a cost per kWhr of .25 cents, the HPS costs $1.20 per day
if we assign the same cost per kWhr for the COB, cost is $0.63 per day
that does not take into account the extra power consumed by the duct fan in the
HPS air cooled hood setup. the setups would need the same wattage for canopy
fans, so that cost is left out of the equation.
Though the COB costs about $56 more, the return of investment (hereafter abbreviated
ROI) would be ~98.25 days. That means that on the 99th day, you would have actually
saved money if you chose the COB. if your energy cost is higher than .25 cents per
kilowatt hour, then the ROI would be faster. if your energy cost is lower than .25 cents
per kilowatt hour, then the ROI would be longer.
Edited by kcmoxtractor, 29 September 2014 - 08:52 PM.