Stuart just emailed to ask how many times I stuck my head into the fans while installing the fluorescent lamps. The answer is zero. I had stuck my head into the fan blades and ripped them out soon after. It was pretty dramatic. My head hit the spinning blade, setting the fan into an odd orbit and striking the garage door. The strike caused the blade to skew, creating a mean shimmy, which led to splinters of fan blades flying everywhere. Each strike against the aluminum garage door, clanged out, causing my dogs to flee in horror. Argh! The fans worked great on previous layouts, but the layouts were never this high off the ground.