Tamina wrote:...
Not really, this is always the case even with smaller fans...
Not quite. The two types of fans are very different from each other. That large industrial fan's motor produces a bunch of heat, comparatively speaking, and the magnetically, "brushless motor" PC case fan has more efficiency, with less torque/hp.
Those look like direct-drive fans. No intervening transmission system. A smarter large fan would be a squirrel-cage type, like is used in most home air-movers in heating/AC units. You get pretty good efficiency, can have the motor outside the casing unit, and can move a lot of air. But... there's a lot more noise due to power transmission.
We really need to up the ante on moving heat. There are more ways to do it than air and liquids. At least, lots of different combinations we could use. Some of 'em... toxic. But, hey, anything for a few more fps, amiright?