At work at the fertilizer plant I work at they have air operated bin vibrators on the two load out bins to shake loose any fertilizer that sticks to the walls. They have maybe a 3 hp unit supplying the air. The chap I work under is fairly lazy and doesn't do the proper maintenance on the compressor he should be, namely draining the water out. Twice in the 5 years the plant has been in operation they vibrators have quit working because they became plugged up with water and the bit of oil from the cylinder walls in the head that makes it by the rings. When the repairman opened the pet cock you wouldn't believe how much gunk came out. I think it may have been a couple of 4 liter pails worth.Our climate is obviously very different to yours. In my business we used a compressor all day long, air was reticulated to each bench. The compressor had a label saying to drain the tank each. In the weeks after getting this compressor we opened the drain tap each day but not a drop came out. Even checking it around monthly, still nothing came out so we stopped the procedure. After retiring and leaving the business to my son which he closed after about three years when the cost of a new superior VCR was less than the cost of a major repair.
After it closed I was given the compressor and the first thing that I did was open the drain and STILL not a drop came out. Never in use did any water come out of the air drivers or blowers.