I think I do not understand the concept of a closed system and yet a constantly running compressor or a recharge??? Is this the gas in the system (it's nitrogen right???) leaking out? I think the idea was to use an inert gas that doesn't change in volume during temperature fluctuations. Anyways I am sold on the functionality and ride quality of the a/s but I just don't feel like I understand the system in total. Coils I understand VERY WELL...they are basically springs made of metal...