I have two on my VOS32 and it is very LOUD. It does not bother me though, I already have tons of fans so it all kind of blends into this soothing hum. That's just me though, you may be really bothered by them. They do work very well, however. At 7200 RPM or so, they move some serious air for a little 60mm fan. If you are not sure about the noise, I would try them first. If it bothers you, I would return them for the YS Techs that Klosters metioned. They are very nice fans too, and much quieter.