HVAC - EPA Certification Practice Exam

What is required when performing recovery on a unit with a receiver/storage tank?

1. Place refrigerant in the condenser

2. Begin recovery with liquid line entering evaporator

3. Only recover vapor phase refrigerant

4. Isolate the receiver first

The correct answer is: Begin recovery with liquid line entering evaporator

When performing recovery on a unit with a receiver or storage tank, beginning recovery with the liquid line entering the evaporator is essential for efficient refrigerant recovery. This method allows for the movement of refrigerant from the high-pressure liquid side of the system into the recovery unit. Starting with the liquid line ensures that the liquid refrigerant is removed from the system first, which can help prevent liquid slugging in the recovery equipment. Liquid refrigerant is denser and contains more refrigerant mass than vapor, allowing for a more effective and quicker recovery process. This approach also helps in minimizing the potential for contamination with oil and moisture, both of which are more prevalent in vapor form, leading to a more streamlined recovery operation. Using this method can lead to quicker recovery times and reduce the risk of pressure imbalances within the system, which could ultimately protect the equipment and ensure safety protocols are followed.