Air conditioner for a vehicle with cold accumulator

A second vaporizer (4) is integrated in a separately created circuit (5) with storage (8) for a refrigerating storage medium, e.g. a salt solution. The storage is designed with a double cylinder and two chambers (13,14). It also has a flexible membrane (10) as a partition between the two chambers. An independent claim is also included for a method for operating an air-conditioning unit for a motor vehicle.