A heat pump laundry dryer comprising: a. a casing supporting a drying chamber for receiving a load to be dried; b. a process air conduit in communication with the drying chamber where a process air stream is apt to flow; c. a heat pump having a heat pump circuit in which a refrigerant can flow, said heat pump circuit including a condenser where the refrigerant is cooled off and the process air stream is heated up, and an evaporator where the refrigerant is heated up and the process air is cooled off; said condenser and evaporator being 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; characterized by said condenser and evaporator (31; 32) including one or more heat exchanger modules, said heat exchanger modules being located in an air duct of the process air conduit, said condenser comprising a first heat exchanger module and said evaporator comprising a second heat exchanger module, each module (10; 10') including ▪ an inlet header (5; 5') to direct a flow of said refrigerant into said module (10, 10'); ▪ an outlet header (6; 6') to discharge said refrigerant from said module (10, 10'); 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; said layers (8; 8') being stacked one above the others in a predetermined stacking direction (Z; Z') and each layer (8; 8') including a plurality of channels (7; 7'); wherein said first and said second heat exchanger modules (10,10') are mounted adjacent one to the other and a first heat exchange layer of the first module and a second heat exchange layer of the second module are separated by a gap (g) in a direction incident to said stacking direction (Z, Z'), said first and said second heat exchanger modules (10, 10') including a plurality of fins arranged on both said first and said second heat exchange layers (8, 8') and extending through said gap (g). a. a casing supporting a drying chamber for receiving a load to be dried; b. a process air conduit in communication with the drying chamber where a process air stream is apt to flow; c. a heat pump having a heat pump circuit in which a refrigerant can flow, said heat pump circuit including a condenser where the refrigerant is cooled off and the process air stream is heated up, and an evaporator where the refrigerant is heated up and the process air is cooled off; said condenser and evaporator being 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; ▪ an inlet header (5; 5') to direct a flow of said refrigerant into said module (10, 10'); ▪ an outlet header (6; 6') to discharge said refrigerant from said module (10, 10'); 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; said layers (8; 8') being stacked one above the others in a predetermined stacking direction (Z; Z') and each layer (8; 8') including a plurality of channels (7; 7');