Abstract An improved design of the refrigeration unit that provides enhanced airflow distribution inside the refrigerated container is proposed by numerically analyzing the airflow patterns in the refrigerated container with several design models of the refrigeration unit. Fifteen different models have been considered by changing effective dimensions and design parameters of the refrigeration unit, which play a major role in affecting the airflow patterns inside the refrigerated container. The numerical simulation of the airflow inside the refrigerated container is performed by considering the pressure drop and flow characteristics in the refrigeration unit. The pressure drop in the refrigeration unit is obtained by modeling the evaporator coil of the refrigeration unit as a porous medium. Results show that the improved design of the refrigeration unit provides significantly higher jet velocity, higher vertical velocity distributions, improved Coanda effect, higher mass averaged velocity, and reduced areas of dead zones in the container compared to the base case refrigeration unit. The mass averaged velocity in the refrigerated container with the improved refrigeration unit is 33.66% higher than that of the base case refrigerated container.