Which evacuation method involves charging a system with nitrogen to absorb moisture?

The method that involves charging a system with nitrogen to absorb moisture is known as the triple evacuation technique. This method is utilized to ensure that the refrigeration system is free of moisture and non-condensables before being charged with refrigerant.

In the triple evacuation process, the system is first evacuated to remove most of the air and moisture. After that, nitrogen is introduced to the system to push out any remaining moisture. The system is then evacuated again to remove the nitrogen along with any absorbed moisture. This process often involves repeating the evacuation steps multiple times to ensure complete moisture removal.

This technique is particularly effective because nitrogen is non-reactive and can safely absorb moisture without causing any harm to the system components. It helps in achieving a deeper vacuum and ensures the integrity of the refrigerant system, thus avoiding potential issues like reduced efficiency or compressor damage due to moisture.

In contrast, the other methods listed may not involve the use of nitrogen or may have different applications and benefits, which are not aimed at moisture absorption in the same manner as the triple evacuation process.