How effective !!! ... Bump here and silently. I replaced my fan housing "Fratal Design R4" on the front by 2 ventilos "Noctua NF-A14 PWM" and I do not hear them at all. They are considerably quieter than the original fan. I placed it on the side and it makes an infernal noise. I'll quickly replaced by another "Noctua NF-A14 PWM" because it is a necessity to have a fan on the side to cool the Adaptec controller that controls the disks 8 of my NAS. The case is very well soundproofed and have equipped these new fans "Noctua NF-A14 PWM" is a treat for the ears but especially for the PC, as they are fearsome of efficiency.