The efficiency of falling film heat transfer applied for absorber in the absorption cooling system, is significantly affected by the wettability and film thickness of the solution on the heat exchanger surface. The manufactured heat exchanger has several options such as bare tube type, floral type, and dimpled type. The dimpled-type heat exchanger also has different configurations with dimple depth and dimple spacing. This study focused on the solution hydrodynamics and wettability differences in axial and vertical directions among the mentioned heat exchanger configurations by utilizing the CFD for 3D simulation. The ICEM meshing and commercial ANSYS Fluent program were utilized to achieve precise results which was validated by the empirical observations from the experimental setup. For the real-case comparison modeling, fully wetted conditions on the heat exchanger and symmetry boundary conditions were adopted. The parametric analysis with different conditions according to the observation of the dynamics of the solution around the heat exchanger was carried out. It was found that the wettability of the floral tube was higher than those of the bare tube and dimpled tube depending on the surface configurations. It was also confirmed that the axial spreadability was not always directly related to the heat transfer efficiency improvement because both the conduction and convection must be considered for falling film heat exchanger. The floral tube formed the highest film thickness in the control group, resulting in the high thermal resistance and the lowest angular velocity, therefore the convective effect is not significant.