Aux 2 Unit 9 Refrigerant Under/ re-charge, leaks, trouble shooting Q5 Answer

  1. State THREE different methods used to detect a refrigerant gas leak, explaining EACH method.(10)

Three Methods of Refrigerant Gas Leak Detection

  1. Soap Solution Method
    • Principle: A soap and water solution is applied to joints, valves, or suspected leak points. Escaping refrigerant gas creates visible bubbles.
    • Advantages: Simple, inexpensive, and effective for locating leaks at accessible joints.
    • Limitations: Cannot be used in inaccessible areas or with very small leaks.
  1. Electronic Leak Detector
    • Principle: A portable electronic “sniffer” detects halogenated refrigerant vapours in the atmosphere. The detector gives an audible or visual alarm when refrigerant is sensed.
    • Advantages: Highly sensitive, can detect very small leaks, suitable for enclosed spaces.
    • Limitations: Requires calibration and can give false alarms if exposed to other vapours.
  1. Halide Torch Test (for halogenated refrigerants)
    • Principle: A flame (usually propane or butane) passes over a copper element. When refrigerant vapour is drawn into the flame, it changes colour (e.g., to green/blue).
    • Advantages: Provides quick indication of leaks with older refrigerants (e.g., R-12, R-22).
    • Limitations: Cannot be used with modern non-halogenated refrigerants; flame hazard makes it unsafe in confined or flammable areas.