Final answer:
An oil-less refrigerant recovery unit is a device used in refrigeration systems that does not rely on oils to remove heat from a cold reservoir. It uses a nontoxic and relatively inexpensive refrigerant, such as CO₂, to extract heat without any input of work.
Step-by-step explanation:
An oil-less refrigerant recovery unit is a device used in refrigeration systems that does not rely on oils to remove heat from a cold reservoir.
Instead, it uses a nontoxic and relatively inexpensive refrigerant, such as CO₂, to extract heat without any input of work.
This refrigerant can be easily recovered by reducing the pressure and collecting the resulting gas.