A refrigeration trailer having a transportation refrigeration system comprising: an enclosure, and at least two compartments (22, 24) within said enclosure to be conditioned to two distinct temperatures; at least two refrigeration circuits (26, 28), with a refrigeration circuit associated with each of said at least two compartments (22, 24), and a first of said at least two refrigeration circuits (26, 28) including a first compressor, a first evaporator, and a first expansion valve, and a second of said at least two refrigeration circuits including a second compressor, a second evaporator, and a second expansion valve; and characterised by said first and second refrigeration circuits (26, 28) utilizing a common condenser, with first inlets into said condenser from said first circuit connected to a first flow passage and second inlets from said second circuit connected to second flow passages, and first and second outlets (38, 50) connected to said first and second flow passages, and said first and second flow passages staggered in a direction perpendicular to a flow passage across said condenser wherein said condenser is a round tube and plate fin heat exchanger; wherein said round tube and plate heat exchanger has a dimension parallel to a flow path of refrigerant across said heat exchanger; wherein said first and second inlets (35, 48) being at one end of said dimension, and said first and second outlets (38, 50) also being at said one end of said dimension, with said first and second flow passages passing across said dimension from said first and second inlets (35, 48), respectively, to a bend and then extending back across said dimension to said outlets (38, 50). an enclosure, and at least two compartments (22, 24) within said enclosure to be conditioned to two distinct temperatures; at least two refrigeration circuits (26, 28), with a refrigeration circuit associated with each of said at least two compartments (22, 24), and a first of said at least two refrigeration circuits (26, 28) including a first compressor, a first evaporator, and a first expansion valve, and a second of said at least two refrigeration circuits including a second compressor, a second evaporator, and a second expansion valve; and characterised by said first and second refrigeration circuits (26, 28) utilizing a common condenser, with first inlets into said condenser from said first circuit connected to a first flow passage and second inlets from said second circuit connected to second flow passages, and first and second outlets (38, 50) connected to said first and second flow passages, and said first and second flow passages staggered in a direction perpendicular to a flow passage across said condenser wherein said condenser is a round tube and plate fin heat exchanger; wherein said round tube and plate heat exchanger has a dimension parallel to a flow path of refrigerant across said heat exchanger; wherein said first and second inlets (35, 48) being at one end of said dimension, and said first and second outlets (38, 50) also being at said one end of said dimension, with said first and second flow passages passing across said dimension from said first and second inlets (35, 48), respectively, to a bend and then extending back across said dimension to said outlets (38, 50).