Took a while to find a clear picture since most industrial applications put radial fans in boxes...



They suck axially from the center (so from inside the wheel, if there is a blanking plate on the outside), and blow radially - outward from the vanes.

It would NOT be hard for a sheetmetal shop to build a pair but you'd have to make decisions about what kind of vane angle you want, etc. It would be simple to start with true radial vanes - pointing striaght out from the axle...

K