A ram circuit for an aircraft includes a ram inlet housing, a ram outlet housing, a heat exchanger, a ram air fan, and a particle separator. The ram inlet housing includes a chamber and an inlet configured to receive air. The ram outlet housing is fluidly connected to the ram inlet housing. The heat exchanger is disposed between and fluidly connected to the inlet housing and the outlet housing. The ram air fan is disposed in the outlet housing and includes a motor with a cooling inlet. The particle separator includes an outer inlet and a clean air outlet. The outer inlet is configured to receive ram air from the chamber of the ram inlet housing and faces into a flow of air passing through the chamber. Clean air is discharged through the clean air outlet which is fluidly connected to the cooling inlet of the motor.