It's normal and isn't ice. The air con condenses all that nasty humidity (water vapour) out of the air. That pipe is where the water ends up (well, it ends up on the ground, actually) and on a muggy day there can be rather a lot of it. If you remember, my car looked as if it had wee'd itself. Perhaps it was expressing its opinion of the landlady and her "cluttered-up" car park.