A laundry dryer comprising: a casing supporting a drying chamber for receiving a load to be dried; a process air conduit in communication with the drying chamber where a process air stream is apt to flow and including an air duct; and a heat pump having a heat pump circuit in which a refrigerant can flow, said heat pump circuit including a first heat exchanger where the refrigerant is cooled off and the process air stream is heated up, and a second heat exchanger where the refrigerant is heated up and the process air is cooled off; wherein said first and/or second heat exchanger is thermally coupled to the process air conduit to perform heat exchange between said refrigerant flowing in said heat pump circuit and said process air stream; wherein said first and/or second heat exchanger (31; 32) further comprises a heat exchanger module (10; 10'), said module including: an inlet header (5; 5') to direct a flow of said refrigerant into said module; an outlet header (6; 6') to discharge said refrigerant from said module; and a plurality of heat exchange layers (8, 8') fluidly connecting said inlet (5; 5') to said outlet header (6; 6') to enable said refrigerant to flow from said inlet to said outlet header and/or vice versa, wherein said layers (8, 8') are stacked one on top of the others in a stacking direction and each heat exchange layer including a plurality of channels; and wherein said plurality of heat exchange layers (8; 8') is at least partially arranged inside said air duct; and wherein said stacking direction is perpendicular to a direction of flow of said process air inside said air duct; characterized in that the inlet header and/or the outlet header of said module (10, 10') is located outside said air duct, said inlet and outlet headers (5, 6) having a longitudinal extension in said stacking direction. a casing supporting a drying chamber for receiving a load to be dried; a process air conduit in communication with the drying chamber where a process air stream is apt to flow and including an air duct; and a heat pump having a heat pump circuit in which a refrigerant can flow, said heat pump circuit including a first heat exchanger where the refrigerant is cooled off and the process air stream is heated up, and a second heat exchanger where the refrigerant is heated up and the process air is cooled off; wherein said first and/or second heat exchanger is thermally coupled to the process air conduit to perform heat exchange between said refrigerant flowing in said heat pump circuit and said process air stream; wherein said first and/or second heat exchanger (31; 32) further comprises a heat exchanger module (10; 10'), said module including: an inlet header (5; 5') to direct a flow of said refrigerant into said module; an outlet header (6; 6') to discharge said refrigerant from said module; and a plurality of heat exchange layers (8, 8') fluidly connecting said inlet (5; 5') to said outlet header (6; 6') to enable said refrigerant to flow from said inlet to said outlet header and/or vice versa, wherein said layers (8, 8') are stacked one on top of the others in a stacking direction and each heat exchange layer including a plurality of channels; and an inlet header (5; 5') to direct a flow of said refrigerant into said module; an outlet header (6; 6') to discharge said refrigerant from said module; and a plurality of heat exchange layers (8, 8') fluidly connecting said inlet (5; 5') to said outlet header (6; 6') to enable said refrigerant to flow from said inlet to said outlet header and/or vice versa, wherein said layers (8, 8') are stacked one on top of the others in a stacking direction and each heat exchange layer including a plurality of channels; and wherein said plurality of heat exchange layers (8; 8') is at least partially arranged inside said air duct; and wherein said stacking direction is perpendicular to a direction of flow of said process air inside said air duct; characterized in that the inlet header and/or the outlet header of said module (10, 10') is located outside said air duct, said inlet and outlet headers (5, 6) having a longitudinal extension in said stacking direction.