Experimental research on performance of direct evaporative outdoor air handling units

Designs and establishes a new test rig of direct evaporative outdoor air handling units independently, tests and analyses the influence of compressor operating frequency on cooling capacity, dehumidification, capacity, input power of the compressor, energy efficiency ratio (EER), as well as air pressure drop of evaporator, condenser and refrigerant side of the direct evaporative outdoor air handling units. The results show that the performance of the outdoor air handling units is the best when the frequency of the compressor is 40 Hz and the air face velocity of the evaporator is 1.87 m/s under nominal condition, and the optimal EER is 2.89; While under dehumidifying condition, the optimal EER is 3.11 when the frequency of the compressor is 40 Hz and the air face velocity of the evaporator is 2.07 m/s, reaching to the best performance.