[exmadscientist]

Do not use 24V fans for anything, if you have any control over it.

24V fans in general are poorly stocked. 24V 4-wire PWM fans are, these days, more or less special order items. There are thousands of 12V 4-wire PWM fans in stock at Mouser and Digi-Key. There are less than a dozen 24V 4W fans in stock, and most of those are sizes you probably don't want.

I'm a consulting EE these days. One of the jobs I get to do is clean up designs that aren't working. We always flag these fans when we see them... then nothing gets done because they're "available enough"... then when build time comes we can't source the fans because the "stock item" is completely out of stock and all possible substitutes are out of stock. But 12V versions are available.

So, yeah, stick to 12V fans whenever possible (or 5V for the little guys). Also genuinely never use AC fans, but that's a different story.

[balfirevic]

> 24V fans in general are poorly stocked.

I'm guessing the same holds for 48V fans?