Copper tubes in air conditioners...quick questions..need ur help urgently.. hey there.. I have an assignment where I have to choose a material and research about.. anyway, I chose to talk about copper tubes in air conditioners..My question is.. what is the function of this tube? What is the most distinctive characteristic/property that makes manufacturers choose copper to be used in the manufacturing of these tubes? Finally, I read that an amount of phosphorus(P) or silver(Ag) is added to the copper.. Why is phosphorus/silver added to the copper? I appreciate ur help coz by answering these questions I'll understand so many things, and ill be able to finish my assignment.. Need ur help!! plz..!! Thanks in advance..