So here's where I'm hung up on the idea that LEDs produce less heat than HID lighting.. True, if not vented, HID lights get extremely hot, however, how many of you are venting your LED panels?? For the nearly 3yrs of me growing exclusively w/ LED, my grow area temps were consistently higher than my current HID grow.. In fact, my grow box, w/ only 1 exhaust fan running, will see an average of mid-80's/26C+, which isn't as big a deal since plants grown under LED can have a higher leaf-surface-temperature, however w/ my HID set-up in my smaller tent, I have yet to see the temps exceed 80F.. Depending on the size of your area, you can get away without venting HID lights, so if that's an option, you may want to take it.. COBs are great, and I'm growing with some as we speak, however the cost, when compared to HID lighting is higher, if you want quality and equivalence.. I bought my Mars II panel for ~$200, used it for a couple years, and then converted it, but that came at a cost of about $275 for the COBs themselves, and then an additional $20 for supplies like thermal paste and kapton tape.. I just purchsed a 600w e-ballast (not eBay special), large enclosure and bulb for less than $225 and since I already had a scrubber and fan, there's no additional costs to me other than some small sections of piping and some clamps or duct tape..
