Yeah, there is a fan in each POD. I forget if it's 80mm or 92mm (think it's 80mm, but I ordered four Noctua of both sizes for two different projects at the same time). I ran the fan power cord outside the Norco PODs when I upgraded the fans. Right now all four fans are connected to one fan header on my MB. So, the fans in all for PODS run at higher speed even if just one drive is hot.
A lot better than full speed 24/7 like the original wiring, but far from optimal. And as I said, IPMI tools (and possibly MB) only allows for two fan speed controls; CPU and other. Therefore, my chassis fan speeds are all based on the tempo of the hottest hard drive as well. I'd really like to at least get the chassis and POD fans separated, but it would be so nice if each POD had its own control and all the chassis fans were on another.