Outdoor air design conditions selection for underground railway direct evaporative cooling ventilation and cooling system

For the direct evaporative cooling technology applied in the public area of the underground railway station, outdoor air design conditions have a direct influence on the equipment selection. However, the existing norms and standards lack precise values. Analyses several current calculating approaches, compares the actual statistics of the meteorological data collected from different areas, and determines a relatively appropriate method for this issue: the summer evening nearly twenty years the average annual peak load while not guaranteed thirty hours wet bulb temperature to determine the average temperature in the same time air dry bulb temperature.