[cscott672]

OP,
I am NOT an electrician, but have had similar success with the T5 HO bulbs and fixtures. I put three 4ft/4bulb high-bay fixtures in one garage mounted 13ft up that was 900sqft. For the new shop I used the 8ft 4bulb units mounted every 15ft at 12ft ht. Plenty of light. I think I replaced basically 2 fixtures for 1 and got more light/coverage than previous T8s. S