While this sort of explains the noisy PS5 situation, it’s not a nice answer. Generally, fans with more blades perform more efficiently, which means they can operate more quietly. But it’s not a nice thing to discover that, having been lucky enough to buy a PS5 to begin with, you need to be lucky enough to get one with a better fan.
On one hand, when you do get your console, you can just pop off the side panel and find out if you got doubly lucky. On the other, if you end up not being lucky enough, there’s pretty much nothing you can do besides endure whatever noise levels you end up with. After all, the number of consoles available are scarce enough as it is. And if it’s not overheating, it’s probably not reason enough for Sony Interactive Entertainment to accept a fan replacement request.