.AixLib.Airflow.AirHandlingUnit.ModularAirHandlingUnit.Components.HeatRecoverySystem.PartialPressureDrop .AixLib.Airflow.AirHandlingUnit.ModularAirHandlingUnit.Components.HeatRecoverySystem.PartialPressureDropmodel PartialPressureDrop = Components.PressureDrop.BaseClasses.partialPressureDrop;