In this study, the performance of a small - sized wave heat exchanger to be applied to the white smoke reduction system was experimentally confirmed. The heat transfer rate, drain and pressure drop were measured according to the air flow rate, water flow rate and relative humidity change of the wave heat exchanger for two kinds of pitch numbers. A constant temperature and humidity calorimeter and a constant temperature water bath were used to measure the performance of the wave heat exchanger. The heat transfer rate and drain increased gradually with changes of water flow rate. Case 2 showed more than 50% higher heat transfer rate and drain than Case 1. The increase of air heat transfer rate and drain according to air flow rate was greatly increased when the number of pitches was the same or increased, unlike the result of water flow rate change. In the temperature visualization using a thermal imaging camera, it can be seen that as the water flow rate and the number of pitches increase, the heat transfer becomes more effective in Case 2.