In this study, instead of gasketed or brazed plate heat exchangers, which are used in various fields of application, a direct metal sintering method is used to design a heat exchanger with its original geometry and with different geometries. Studies of heat exchangers found in published literature were reviewed, and the thermal behaviors of the proposed unique designs were examined. Usually heat exchangers using this design do not use channel spacing angles of 30-45-60-75 degrees for the plate ducts. The thermal behaviors of the fluid-circulating systems were analyzed using ANSYS FLUENT software, and they used the boundary conditions found in the literature for this design. Heat transfer between the heat exchanger channels and channel walls was calculated. The analyses results show that an increase in the amount of heat transfer surface area and also an increase in surface roughness increased the amount of positive heat transfer.