Question about Icy Box Ib-3810u3

Replacing the fans is easy and is recommended, as the original fans are rather loud.
I bought and fitted these fans at the time and am very happy with them.
be quiet! Shadow Wings Mid-Speed (140 mm, 1 x)
Unfortunately, they no longer seem to be on sale. I would therefore use another 140mm fan with a 3-pin connector that is also quiet.

Yes, I've replaced mine, I got a noctua unless I'm mistaken (it's a bit dated) - just make sure you get a 140mm three-pin.
Digging around, I see these two fans in my order history "very shortly after" I bought this case:
Noctua Nf-a14 Uln (140 mm, 1 x)
be quiet! Ailes d'ombre 2 (140 mm, 1 x)

Both are very good.

Replacing the fans is easy and is recommended, as the original fans are rather loud.
I bought and fitted these fans at the time and am very happy with them.
be quiet! Shadow Wings Mid-Speed (140 mm, 1 x)
Unfortunately, they no longer seem to be on sale. I would therefore use another 140mm fan with a 3-pin connector that is also quiet.