In the example shown the system consisted of a sub-atmospheric reverse Brayton cycle driven by an electric motor and augmented with water injection. The motor drives the turbo-compressor, the turbine of which draws ambient air into the system and expands cooled air into an air-to-air heat exchanger. Water is sprayed into the air stream entering the heat exchanger where it evaporates, adding to the cooling effect. The heat exchanger discharges into the compressor inlet, which compresses the air back to ambient pressure and exhausts it to atmosphere. Air from the fighting vehicle is drawn into the other side of the heat exchanger where it is cooled and returned to the vehicle through a water separator which removes any condensate. The condensate is collected and sprayed into the heat exchanger as previously described.   

Another type of air cycle cooling system consisted of a closed Brayton cycle as shown on test at the facilities of Southern California Edison during evaluation for use as a  cooling system in commercial applications in place of  more common vapor cycle systems.