Which of the following refrigeration systems/appliances would it be permissible to use a passive recovery device for refrigerant recovery?

Using a passive recovery device for refrigerant recovery is permissible for a domestic refrigerator. Passive recovery devices rely on gravitational force to collect refrigerants without the use of mechanical systems, making them suitable for smaller, self-contained appliances like domestic refrigerators. Such refrigerators typically have a limited amount of refrigerant, which makes the use of passive recovery devices practical and efficient.

In contrast, larger systems such as commercial freezers or chiller systems generally contain significantly more refrigerant and require more robust recovery methods. These systems are designed for higher pressure and greater refrigerant volume, which necessitates the use of active recovery devices that can safely and effectively extract refrigerants under various conditions.

Vacuum pumps are not typically used for refrigerant recovery; instead, they are employed to create a vacuum in a system before repairs or after maintenance to remove moisture and air. This further illustrates why passive recovery devices are specifically viable in smaller applications, as opposed to larger, more complex refrigeration systems or vacuum technology.