Why is it important not to mix refrigerants when recovering?

Mixing refrigerants during recovery can lead to contamination, which can compromise the efficiency and performance of HVAC systems. It can also create safety hazards, as different refrigerants have varying properties and pressures. Additionally, contaminated refrigerants may be illegal to release into the environment, leading to potential fines and regulatory issues. Proper recovery ensures the integrity of the refrigerant and compliance with environmental standards.