The invention relates to a heat exchanger for a refrigerant dryer such as a compressed air refrigerant dryer comprising at least one first inflow surface element, past which a fluid to be dried such as compressed air can flow during operation of the heat exchanger, and comprising at least one second inflow surface element, past which a refrigerant fluid can flow as required during operation of the heat exchanger, wherein the first and second inflow surface elements are or can be coupled at least in some areas to at least one cold store chamber that is provided for filling with a cold accumulator medium, and wherein the first and/or second inflow surface element(s) (is) are connected to at least one heat transfer element which extends into the cold store chamber, e.g. penetrates the cold store chamber.