The fan maybe loud but its doing its job. You would have another problem if it didn't. Just replace the int. fan with a quiet version of X-db level and that has the same rpms & size as the old(if availabe, check laptop vendors, service centers), but can you do that. The laptop cooler setup is only 2ndary in nature and they may cause some noise as well. The smaller the fan is and the higher the rpms, expect noise. The only real noiseless solution are heat tubes and if yours wasn't so equipped then expect fan noise, sorry. DO NOT attempt to reduce the level the int. fan kicks-in at X-temp setting or run in reduced level unless you want the cpu to be slower if so equipped. The laptop cooler can provide a level of possible nonhi-speed fan operation if the high x-temp isn't reached but that also depends on the surrounding ambient temp, so if you're in a well A/C'ed room it helps as well as the cooler.

tada -----Willy Happy