Question : Problem: Quiet fans for server

I have a server that currently has four fans all of them are YSTECH FD128032HB.  This fan runs at 4400 RPM, pushes 47CFM, and is 45db loud and measures 80x80x32mm.

Anyone know of any fans that will push around 47CFM that are considerably more quiet?

Thanks

Answer : Problem: Quiet fans for server

you can contact Zalman, or Papst :  they are leading in the fan world !
http://www.zalman.co.kr/eng/main.asp
http://www.ebmpapst.us/