Experiments on dew-point indirect-direct evaporative cooling air conditioning unit

Develops the test bed, and tests the performances on separated and connected operation modes of each functional section. The result shows that the optimal ratio of secondary air rate to primary one for pre-cooling section and cooling section is 1.2 and 1.69 respectively within experimental range. The outlet air temperature on combination operation mode is lower than the inlet wet-bulb temperature, approaching the dew-point temperature.