This is the third window unit I've purchased for this particular room and, it is by far the best. It's very quiet; no rattle. And the quiet 'hum' is consistent; no loud power-up when the system switches from fan ot colling. Very nice. And the cooling seems to radiate throughout the room. My last unit seemed cold only when standing right infront of the vents. This is the best window air conditioner I've ever owned.