A unitary heat pump air conditioner having a heat exchanger with an integral receiver and sub-cooler.

The disclosure relates to a unitary heat pump air conditioner (100) having a plate type hot-side heat exchanger assembly (102), a cold-side heat exchanger assembly (110), and electrically driven compressor (112) and coolant pumps (114, 116). The plate type hot-side heat exchanger assembly (102) includes a plurality of plates (120) stacked and hermetically sealed between an upstream end plate (126) and a downstream end plate (128), defining a condenser/chiller portion (103) having a first coolant passageway (124a), a sub-cooler portion (106) having a second coolant passageway (124b), and a refrigerant receiver (19) portion sandwiched between the condenser/chiller portion (103) and the sub-cooler portion (106). The first coolant passageway (124a) and the second coolant passageway (124b) are in non-contact thermal communication with the refrigerant passageway (122).