Chill the ESCO Air Conditioning Exam 2026 – Cool Your Way to Certification!

When a refrigerant system is completely empty, you need a carrier gas to create pressure for leak testing rather than relying on the refrigerant alone. A trace amount of refrigerant is used, but the pressure comes from a compressible gas such as air or nitrogen. This lets you pressurize the system to a test level and observe for leaks with a tracer or soap test without dumping large amounts of refrigerant into the atmosphere. Using oxygen would be unsafe and reactive with oils/refrigerants, and a vacuum cannot create the needed pressure. The idea is to employ a compressible gas to generate the pressure required for leak checking.