Fans in Horizontal Orientation

[Genem]

I've heard that fans are optimized to run vertically rather than horizontally. I'm wondering because I've recently acquired a Coolermaster 690, and 120mm are certainly more expensive than 80mm, I wondered if it was okay to just bolt in some Yate Loons into the horizontal holes, or if I should get something else?

 

[Arcygenical]

I run my fans horizontally... Yate loons too.

 

[Genem]

I heard that the sleeves in the Yate Loons don't work well horizontally.

 

[Dangman]

Yate Loons are sleeve bearing fans, which either wear out faster or doesn't perform as well when placed horizontally. Ball Bearing fans perform well horizontally or vertically.