Question

Why must recycled refrigerant be checked for air?

Answer 1

Air is the main contaminant in recycled refrigerant.

Effects :

Excess air more than allowable amounts, can cause the system to operate at pressures that are higher than normal.

This can result in noisy system operation and loss of air conditioning performance.

Air is not a good heat transfer medium, as refrigerant and higher pressures also mean higher condenser temperatures, which can also degrade system performance.