Good morning, first of all I would like to give my regards to you by the wonderful site you have and also by such detailed information! Last year, I did some "refrigeration" installations using Copper and Aluminium (for the different tubes). These tubes must be in contact to provide efficient "heat" absorption from one to another and so I put a plastic shrink-wrap involving them. Last week one of the installations had a fault and analyzing the situation I notice that there was pitting corrosion in the aluminium tube. So my question is, is possible that only by putting together Aluminium (99%) and Copper (more noble) we can have a pitting process? I notice that this happened only in the points of the tubes that are colder. Perhaps in these points we have some condensation/humidity that accelerates the process? Could also be that the shrink-wrap is not well close and lets pass some air and of course, oxygen will accelerate the process? I need to fix this installation but I have some doubts how to do it better. Please can you give me an answer ASAP. Thanks a lot. Best regards Paul