I noticed that the top and back exhaust fans on P180 can have such a noticeable increase in noise when switching from Low to Med. (even though it says Low is 25dB and Med is 28dB). Anyway, I changed the back exhaust to panaflo, but panaflo cannot be placed on the top because it's too thick (only 25mm is allowed, 38mm won't do). Same with the front fan. It seems all panaflo fans are 38mm thick. I just want to know what are the best 25mm thick fans that are quiet and can move decent amount of air.