What type of nozzles must be directed during FREON PDIs?

The correct answer focuses on the specific configuration required during the Pressure Differential Inspection (PDI) of FREON systems. Directing two nozzles towards the waste bin and one towards the water heater is essential to ensure proper pressure checks and functionality of the FREON system. This setup allows for effective circulation and assessment of the cooling system, which is critical for safety and performance in the aircraft operations.

This configuration ensures that any potential leaks are detected efficiently, as positioning the nozzles in this manner facilitates the monitoring of the pressure differentials necessary to assess the integrity of the systems involved. Additionally, directing nozzles towards the water heater plays a role in checking temperature regulation, which is vital during PDI protocols.

In terms of the other options, directing nozzles towards the exit, the cockpit, or only towards the ceiling does not align with the established protocols for ensuring comprehensive monitoring and testing of the FREON systems. Properly assessing the systems requires a targeted approach that maximizes the effectiveness of the inspection process.