Which technique is commonly used to clean refrigerant before returning it to the HVAC system?

The technique of filtration through driers and oil separators is essential in maintaining the efficiency and longevity of HVAC systems. When refrigerant is recovered from a system, it may contain contaminants such as moisture, oil, and debris. These contaminants can adversely affect the performance of the system and lead to issues such as premature wear, decreased efficiency, or even system failure.

Driers play a key role in removing moisture and any acids that may have formed due to refrigerant breakdown. They contain desiccants that absorb moisture from the refrigerant, ensuring that the system operates smoothly when the refrigerant is returned. Additionally, oil separators eliminate excess lubricating oil that could circulate with the refrigerant and cause charge imbalances or compressor damage.

This filtration process is particularly vital because introducing dirty refrigerant back into an HVAC system can create serious operational issues. The technique thus ensures that the refrigerant is clean, dry, and free of particles, making it optimal for efficient operation of the system. Other methods listed, such as heating and condensing or flushing with water, are not standard practices for cleaning refrigerant before returning it to the system.