depending on the space still available in the server room and ammout of $ you company is willing to spend additional insulation and sound proofing the room would help this could raise productivity by allowing employees to focus on work versus the noise coming from your serve or if your able to spend large sums of $ the update your servers to newer more efficent models with higher processing speeds this will take some time so your bus. will be temporaroly be down.
Is it too loud outside the room or inside? special sound baffles, (looks like foam packing), on the walls would help absorb the sound so that it does not resonate in the room. That could get costly though and won’t help with the huge amount of heat that you are creating.
What I would do is look into virtualizing your environment, (VMWare, Virtuozzo, etc.). Usually servers don’t utilize the amount of processing power they have and sit idle a lot. This is a great way to consolidate a lot of servers down to a few. This would cut your utility and cooling bills in half and drop the noise down considerably.
When deploying new servers you can cut the build time down to nothing by having a generic VM image. Say you want to build a new Windows Server 2003 server. If you have a generic image already built for Server 2003, (which in fact is what I am building right now), in VMWare all you have to do is use the VMWare console to make a copy of it, boot it and change the name of the server and you are up and running. when building windows servers make sure that you run an app called NewSID to generate a new unique SID for the server instance. Then install your apps and you are done. And to go even further than that, VMWare has aquired a company called Thinstall that virtualizes the applications so you could use those on the virtual server and not have to install any apps either, (except core apps like antivirus). Check them out at www.vmware.com and www.thinstall.com. VMWare has released their VMWare Server product for free so this is a great way to start. There is also a P2V, (physical to virtual), program that you can get for free that will convert your existing physical servers to a virtual image so that you will not have to rebuild your current servers.
If you use a backup program like StorServer that licenses their backup software by CPU and not by server OS you would NOT have to buy another backup license since it is running on the same hardware as your original backup software license. More money saved!