I'd guess 12 nozzles (my leaky old cabinet has three nozzles per section, and these do a really good job of keeping things humid), with room for expansion? I guess it depends on whether you were planning on keeping things moist with the system or just keeping the humidity up, which is considerably different. 120 CFM seems like a good place to start, especially if they're strategically placed. I might go higher, in fact. Again as a point of reference, I probably have 60-70 CFM of movement in each section of my cabinet (2 60mm fans), though I wish my fan placement was a bit better.