When using a passive system-dependent recovery process, you should access both the high and low side of the system for the refrigerant recovery if _____________.

• A. The system's compressor does not run.
• B. The compressor runs normally.
• C. The system is completely empty.
• D. Non-condensables are present.

Answer: (A)

Passive system-dependent recovery relies on the refrigerant’s own pressure to move from the high side to the low side into the recovery device, so the system must be off. With the compressor not running, you can access both sides and let the natural pressure difference push refrigerant into the recovery cylinder without any mechanical pumping. If the compressor is running, this passive flow doesn’t work reliably, and you’d use an active recovery method instead. The other situations don’t establish the necessary condition for passive recovery—the key point is that the compressor must be off to allow safe, bidirectional access to both sides for recovery.