Quiet Fans?

I'm building a PC for a friend and he mentioned how he wants the quietest fans possible. They would be used for overall case cooling and 4 fans needed for push pull water cooling since we're using the Corsair H100i. I don't know much about case fans, when I built my systems I just used the fans that came with the case and just bought the same kind off of amazon and they were pretty quiet already. I heard the Noctua fans are the quietest but are butt ugly, but I want to hear your opinions first. Thanks!

Noctua fans certainly aren't the prettiest things to look at but they will definitely makeup for it with their performance and noise level. Although I have not personally owned any Noctua fans, I know many that have and they have not a single complaint about them as far as performance goes. I might even be buying a few of them myself at some point for a radiator. Unless theme is a big design point for your build, go for the Noctuas.

I second noctuas.  I have 2 in my case and I cant hear them, at all.  Like at all.  Not to mention if you add the low noise adapters, good god it would be quiet.

Noctua's are probably the best, good alternatives are bequiet! fans if you really don't want the beige and purple ugliness, but they are significantly harder to find.

most cheapo fans are insanely quiet, if you need static pressure noctuas are some of the best, for airflow they kindof suck

Since you need those fans for radiators, I would go for the Noctua NF-P12 fans. People say the aesthetics aren't good but if you use LOTS of Noctua fans within a build it can come quite fashionable. If beige cases were a trend like the old days then Noctua would be the brilliant match! Hope this helped!

Noctua's are great fans, but there are options out there. How about the Air Penetrators from Silverstone?

http://www.silverstonetek.com/product_fan.php?tno=5&area=en

Everyone has said Noctua in this post, and I agree with all of them.

If you can find them Gentle Typhoon AP-13 or AP-12.They are designed with radiator acoustics in mind.

They aren't being made anymore but they are a good alternative to noctua fans.You could undervolt AP-14 or AP-15 fans but scythe fans have motor noise when undervolted.

Another alternative to Noctua would be Noiseblocker fans.Both e-loops and blacksilentpro are good and quiet radiator fans.They have a unique blade design.

Seems like noctuas are the best choice. Thanks everyone!