I have a 2014 Model S P85. At start up in the Summer (I live in Michigan), the fan will hum noticeably. But after about 10-15 minutes, as the car/battery cools down, the humming gets less until it goes away. Since the car is silent, this is noticeable. But I only get this less than half the year since I live in the frigid Midwest. And it's only for a few minutes. No biggee.