All the blower fans for part cooling I've seen rotate counter-clockwise when viewed from the intake side. I'm looking to replace mine on an Ender 3 with something stronger, and one of the worst parts of the stock design is that it's offset by about 20 mm versus the nozzle position, requiring awkward duct paths that reduce the flow to get uniform coverage around the newly extruded material. A fan that rotates in the opposite direction, with air exiting on the right-hand size when viewed from the intake side, would be exactly right. Are there such models available, and if so, what is the right terminology to search for them by? Or is there a simple way to modify a fan to reverse its direction?
They exist, but maybe only for industrial use and not so compact. Look for "clockwise".
You could carve the back side of a normal blower with some openings (make a grid out of it) and obstruct the original inlet (or leave both open...).
Commenting on the idea of changing the air holes, that could work for either the intakes OR the outputs, depends on how the fan is built. The exit port might be easier to cut out with a dremel or something, then tape over the old exit hole. The intake zones tend to be large and any kind of obstruction rather than a fully open face would not be recommended.