I have a split unit AC in my sons room and it some time blows out ice. What could be the problem ?

The evaporator is running to cold allowing ice to form. If the outside temperature is to low this can happen.

Cold air,, very cold and damp air

A name and model number might help

Wish I lived in a area where I would be running the a/c it was 4 below zero this morning when I got up

Did you find what the problem was as I am having the same thing now... little ice chunks on my rug and the air isn't as "chilled" as usual