A method of manufacturing a three-way heat exchanger for use in a desiccant air conditioning system, comprising the steps of: (a) forming a plurality of plates, each plate including at least one liquid desiccant supply port, at least one liquid desiccant drain port, at least one heat transfer fluid supply port, and at least one heat transfer fluid drain port, each plate further including one or more features defining a liquid desiccant region on one side of the plate in fluid communication with the at least one liquid desiccant supply port and the at least one liquid desiccant drain port, each plate further including one or more features defining a heat transfer fluid region on an opposite side of the plate in fluid communication with the at least one heat transfer fluid supply port and the at least one heat transfer fluid drain port, each plate also including a plurality of holes at an upper end thereof in fluid communication with the at least one liquid desiccant supply port for distributing liquid desiccant across the liquid desiccant region, each plate also including features defining a liquid desiccant flow restriction at each of said holes to increase uniformity of liquid desiccant distributed across the liquid desiccant region; (b) attaching a membrane to said one or more features of each of said plates defining the liquid desiccant region to cover the liquid desiccant region; and (c) attaching the plates together in a stacked manner with alternate plates being reversed such that the membrane on each plate faces the membrane on an adjacent plate and defines an air stream gap between the membranes, such that the heat transfer fluid region on each plate is connected to the heat transfer fluid region on an adjacent plate, and such that the liquid desiccant supply ports of the plates are in sealed fluid communication, the liquid desiccant drain ports of the plates are in sealed fluid communication, the heat transfer fluid supply ports of the plates are in sealed fluid communication, and the heat transfer fluid drain ports of the plates are in sealed fluid communication. (a) forming a plurality of plates, each plate including at least one liquid desiccant supply port, at least one liquid desiccant drain port, at least one heat transfer fluid supply port, and at least one heat transfer fluid drain port, each plate further including one or more features defining a liquid desiccant region on one side of the plate in fluid communication with the at least one liquid desiccant supply port and the at least one liquid desiccant drain port, each plate further including one or more features defining a heat transfer fluid region on an opposite side of the plate in fluid communication with the at least one heat transfer fluid supply port and the at least one heat transfer fluid drain port, each plate also including a plurality of holes at an upper end thereof in fluid communication with the at least one liquid desiccant supply port for distributing liquid desiccant across the liquid desiccant region, each plate also including features defining a liquid desiccant flow restriction at each of said holes to increase uniformity of liquid desiccant distributed across the liquid desiccant region; (b) attaching a membrane to said one or more features of each of said plates defining the liquid desiccant region to cover the liquid desiccant region; and (c) attaching the plates together in a stacked manner with alternate plates being reversed such that the membrane on each plate faces the membrane on an adjacent plate and defines an air stream gap between the membranes, such that the heat transfer fluid region on each plate is connected to the heat transfer fluid region on an adjacent plate, and such that the liquid desiccant supply ports of the plates are in sealed fluid communication, the liquid desiccant drain ports of the plates are in sealed fluid communication, the heat transfer fluid supply ports of the plates are in sealed fluid communication, and the heat transfer fluid drain ports of the plates are in sealed fluid communication.