Each system is equipped with an handling unit located over the room and complete with compressor unit and air condenser. Equipment complete Economizer device (liquid sub-cooling system) and heat gas recovery from Compressor Air will be distributed circular shape ducts. no p A series of dampers on the connecting ducts will control air flows, permitting alternative operation of the plant in first one then the other room, setting different environmental conditions in the two rooms. Each equipment will also include air renewal system for product oxygenation a