When I mine this coin my fans ramp up and down I’m not sure which ones

I am trying out ravencoin mining and when i run either nbminer or t-rex miner, some fan in my system, haven't figured out what it is. ramps up and down and quiet for a bit then again. I don't think its my cpu fans nor the gpu, because when i goto afterburner and unlock it and up it to say 85% speed i still hear the fans going up and down and cpu hasn't increased in heat. could my psu be going up and down? and why is it only this coin. I tried eth using lolminer and it doesn't do this.