Fans on amps.

Ive been checking out some posts about fans by amps but cannot find anything about them being good or bad for the amps. This is what I would like to know. Ok. I have a Krell Fpb 600 and I listen to my music about a 28-30 volume on my ARC Ref 6 which is pretty loud most of the time depending on recordings. Tonight I felt my amp like a lot of times and felt very hot like u could fry an egg on top. This is the normal with a few hrs of listening. Anyway I put a fan on the right side of amp and about a half hour later I checked the right side and was significantly cooler I mean like a night and day difference between the right and left top and heat sinks. I was wondering if adding 2 fans one on each side to cool the amp down would do more harm than good. Would I get more life out of the amp with fans ? Or are amps designed like that without using fans and just heat sinks to get rid of the heat. Btw my amp has plenty of ventilation as it is on the floor. Thanks.