Correct me if I'm wrong here. For what I know, it doesn't "help" cooling. I mean, yes but no. All it does, it allows you to manually control fan(s) speed.
It may be a good idea if you have many (loud) fans, and need improved cooling/air circulation under heavy gaming/processes. You just crank the fans up at full level, thus, improving cooling.
But when your computer is just idling or doing basically basic tasks (web surfing, text processing, file sharing, etc) and don't want loud fan noise, you just turn them down a little, or even shut some off, for softer sound level.