The present research is to develop a homogenous mathematical model to simulate capillary tube-suction line heat exchanger (CT-SL HX) based on the fundamentals of conservations of mass, momentum and energy with comprehensive experimental result validations. The computer model is fully validated by 72 experimental data with error bands of +/- 15%, +/- 2 degrees C and +/- 35% on the mass flow rate prediction, the suction pipe outlet temperature, and the heat exchange estimation respectively. The results suggest that the internal diameter of the capillary tube, and the heat-transfer length of the CT-SL HX have demonstrated an apparent impact on the capillary tube outlet conditions and heat transfer across the segment.