Rapid Fire AIT Practice Exam

In HVAC systems, nitrogen is commonly used to purge copper lines. The primary reason for using nitrogen is its inert nature, which means it does not react chemically with the materials in the HVAC system. Purging with nitrogen helps to remove moisture and contaminants from the copper pipes before refrigerant is introduced, thus preventing any potential reactions that could lead to corrosion or system failure.

Using nitrogen for purging also helps to ensure that the copper is free of debris, oils, or other substances that could interfere with the efficiency and effectiveness of the refrigerant. This is crucial for maintaining the integrity and performance of the HVAC system. Furthermore, nitrogen is readily available and cost-effective, making it a practical choice for HVAC technicians.

Using gases like oxygen or hydrogen could introduce significant risks. Oxygen can react with copper and lead to oxidation, while hydrogen poses risks of flammability. Argon, though inert like nitrogen, is less commonly used for this specific application and is typically more expensive. Hence, nitrogen is the preferred gas for purging copper in HVAC systems due to its safety, effectiveness, and economical nature.