No, it's fan is not constantly noisy. I'm using four of those QSC Digital Cinema amps. I'm sitting only 6 feet away from them and only after a few minutes of operation, the fan speed slows down and I don't hear any of the 3 DCA 1222s. The only fan that I can hear when there's no music being played is the one on the DCA 1824, the 4 channel amp that drives my surround speakers. Since it has to keep cool 4 output stages in the same size chassis, it is a little noisy.
Anyways, who sits less than 6 feet away from the power amps? Also, when there's music being played, any fan noise and all other noises such as air conditioner, refrigerator etc are masked. With either of the 2 channel DCA 1222 or the 1622, the fan noise should not be a concern.