In Fig. 5 the effect of vertical port centre is shown. The heat transfer increases with the increase of the vertical port centre distance as the area of thermal plate is increased. But due to the increase of the vertical port centre distance with constant width of plate, the frictional pressure drop will also increase due to increase in the flow length. Therefore, the overall pressure drop will be increased. In this case, there is a compromise between heat transfer and pressure drop. Heat transfer can be maximized under the allowable limits of pressure drop.