When using a passive system-dependent recovery process, when should both high and low side access be used?

In a passive system-dependent recovery process, both high and low side access should be used when the compressor does not run. This scenario is critical because the recovery process relies on the pressure differential within the system to effectively remove refrigerant. When the compressor is non-operational, relying solely on low side access may not provide sufficient pressure to draw out the refrigerant, particularly if the refrigerant is in a liquid state and is located in the high side. By accessing both the high and low sides, technicians can facilitate better refrigerant recovery by balancing the pressure and allowing more complete removal.

Using a high side access in conjunction with low side access ensures that any refrigerant trapped in the high side can be evacuated, which is particularly important when dealing with larger refrigerant charges or systems that have complex refrigerant routing. This method helps in minimizing the amount of refrigerant left in the system during recovery, adhering to environmental regulations and ensuring efficiency in the recovery process.