The goal of this paper is to establish the optimal operating regime of the observed perforated plate air/water heat exchanger in a wide range of parameters. The experimental investigation was carried out in a package of three perforated plates which were placed in the experimental chamber and heated by hot water. A fan with the variable air volume flow was connected to the experimental chamber, so the air flow rates varied from 100 to 300 m 3 /h, while the water flow varied from 0.03 to 0.06 m 3 /h. The thermocouples were attached to the surface of the middle perforated plate in the package along its upwind and downwind sides, as well as at the inlet and outlet of the chamber and between the perforated plates. During each experiment, the readings of thermocouples were recorded alongside with the air and water volume flow and temperatures of water at the inlet and outlet of the chamber. In order to predict the performance of the observed perforated plate heat exchanger, NTU-Effectiveness analysis was performed on the basis of the experiment results and analytical relations. Experimental results showed that the effectiveness of the perforated plate heat exchanger can be calculated the same as for the concentric tube counter flow. At the end of the paper, the optimal operating point in the range of varied parameters was determined.