When recovery of refrigerant first starts, in which phase is the refrigerant removed to save recovery time?

The correct choice is the liquid phase because recovering refrigerant in this state is the most efficient approach for saving recovery time. During the recovery process, refrigerants are typically stored either as a gas or a liquid in their respective containers. Liquids can be directly removed from the system, as they occupy less volume and can be pumped out rapidly compared to gases, which require compression and can take significantly longer to recover due to their lower density and the need for reducing pressures.

Using the liquid phase for recovery minimizes the time required to restore the system when compared to recovering refrigerants solely in their vapor or gas forms. While the vapor phase refers to refrigerant in a gaseous state, and the gas phase typically describes a less pressurized situation, these options are less efficient for recovery purposes. The solid phase is not applicable, as refrigerants do not solidify under normal operating conditions in refrigeration systems. Therefore, focusing on the liquid phase is critical for an effective and fast recovery process in HVAC operations.