Eich

Today is one of the few days in the past month where I ran the AC on Max Cold during lunch. I noticed that while the car is sitting at idle, the compressor sounds really loud. It has a very low-pitched grumble like the hum from a big subwoofer and it resonates through the interior of the car. Even outside the car, it is quite noisy.

Might this be normal or am I looking at compressor problems ?