A refrigerant condenser assembly for a motor vehicle air-conditioning system, comprising - an inlet opening for the introduction of a refrigerant, - an outlet opening for the discharge of a refrigerant, - cooling tubes for conducting a refrigerant, - two collecting tubes for fluidically connecting the cooling tubes, - a collecting tank having at least one flow transfer opening via which the collecting tank is fluidically connected to the cooling tubes and/or to the collecting tube, wherein the collecting tank is arranged at a first longitudinal side of the refrigerant condenser assembly, - wherein the cooling tubes have a superheat region for cooling the vaporous refrigerant, a condensation region for condensing the refrigerant, and a supercooling region for cooling the liquid refrigerant, wherein, in the supercooling region, at least two cooling tubes as a first supercooling parallel portion are charged with the refrigerant in parallel in terms of fluid conduction, the refrigerant flowing out of the first supercooling parallel portion issues into a first supercooling intermediate flow duct, and the first supercooling intermediate flow duct issues into at least two cooling tubes as a second supercooling parallel portion, wherein, in the supercooling region, the second supercooling parallel portion issues into a second supercooling intermediate flow duct and the second supercooling intermediate flow duct issues into at least two cooling tubes as a third supercooling parallel portion, such that the outlet opening is arranged on a second longitudinal side of the refrigerant condenser assembly, wherein, upstream of the first supercooling parallel portion as viewed in the flow direction of the refrigerant, at least two cooling tubes as a first parallel portion are charged in parallel in terms of fluid conduction, the refrigerant flowing out of the first parallel portion issues into a first intermediate flow duct, and the first intermediate flow duct issues into at least two cooling tubes as a second parallel portion and the second parallel portion issues into a second intermediate flow duct and the second intermediate flow duct issues into the collecting tank, characterised in that the sum total of the flow cross-sectional areas of the cooling tubes of a supercooling parallel portion (14, 16, 18) is less than the product of 0.7 or 0.5 or 0.3 or 0.1 and the sum total of the flow cross-sectional areas of the cooling tubes of the respective parallel portion (19, 21, 23), and wherein the cooling tubes are formed as flat tubes and corrugated fins are arranged between the flat tubes. - an inlet opening for the introduction of a refrigerant, - an outlet opening for the discharge of a refrigerant, - cooling tubes for conducting a refrigerant, - two collecting tubes for fluidically connecting the cooling tubes, - a collecting tank having at least one flow transfer opening via which the collecting tank is fluidically connected to the cooling tubes and/or to the collecting tube, wherein the collecting tank is arranged at a first longitudinal side of the refrigerant condenser assembly, - wherein the cooling tubes have a superheat region for cooling the vaporous refrigerant, a condensation region for condensing the refrigerant, and a supercooling region for cooling the liquid refrigerant, wherein,