When you say you're not worried about temp's, does that mean you're not venting the light itself at all? Obviously there is some heat generation, is it seriously no more than the LED's you used? For a newcomer to growing, this unit seems attractive, in that it's relatively low consumption AND quite stealthy (not to mention looks a lot like simple "plug and play"), going by initial reports. If no venting is needed and the results are good, which they appear to be, NICE! And to be fair, once you've committed to paying for high quality lighting, $500 is pretty reasonable for a central light considering the competition for stealthy alternatives to HPS (AT600 - for a 3 x 3 or 4 x 4 runs $2500 or $2800-ish shipped to Europe and even with A51's where 3 or 4 units is probably the equivalent in terms of coverage you're looking at $1500 to $2000 + shipping). All of a sudden, a couple of these are an interesting prospect for a 4 x 8 area with a few LED/CFL side lights perhaps, again, assuming they are as easy and stealthy as they appear at first glance! Would you recommend these for a novice grower?
I shall pray to the herb spirits that your harvest is a fruitful and delicious one.
(sorry to go off on a selfish tangent! Your buds do look rather frosty and tantalizing!)
EDIT: Sorry, forgot to ask; is it noisy at all?
Hey Heavy, thanks for the comments/questions. I was running up to 700W of LED's in this 4x9.5x7'H room through the fall/winter/spring. Now it's fall again and I'm running 2 of the LEC's pulling 760W @120v at the wall (about 690W if you run them on 220v) with no change in equipment, just a 4" inline intake from the furnace/air conditioner for fresh air and 4" inline exhaust (w/carbon filter once they get 3-4 weeks into flowering). Both running at the lowest setting on variable controllers. No different than when I had the LED's. Of course they generate some heat but in comparison to the LED's it's like 2F difference and still keeps me peaking at 84F during lights-on (perfect imo). In comparison to hps, there is no comparison for heat, my son runs hps and he's always fighting with temps, particularly through the summer (although he's just about to pull the trigger on 6 of these!).
For a 4x8, 3 or 4 of these would cover the 4x8 well, they're more suited for 3 to 3.5' depth so like 3 of them would cover off 3.5x9-10' nicely. Not sure what you mean by stealthy but I've recently posted a pic showing both units, they don't take much room and you want to run them about 20-22" above the canopy to avoid any leaf burn/discolouration. As far as recommending them yeah, for a novice grower even better, set them up and forget about them, you can concentrate on other things . An no, there is no separate cooling required for the hoods, I just have a couple of fans for circulation and the inline fans for incoming/exhaust. The Sun Systems units don't have cooling in the hoods other than a couple of vents on the ends and you can touch them after a 12 hour cycle and they're barely warm.
It really is a great option if you have at least say 6' of height in your room/tent. I'd consider DIY COBs or high end LED's like Apache or A51 as the comparison for efficiency, output and heat generation. I wish I had found these before spending a few months getting next to nothing from cheap Chinese LED panels. Cheers.
EDIT: Forgot your noise question. Quieter than LED's, no hum, no fan noise, nothing, the circulation/inline fans in the room make more noise than anything.