A halide torch is a flame-based leak detection tool that changes color in the presence of refrigerant, producing a distinctive reaction from green (no leak) to yellow or blue (leak detected). The torch heats a copper element within a sampling tube, and refrigerant vapors contacting the heated copper create the color change. Halide torches have been used in HVAC service for decades but are increasingly restricted due to safety concerns.
Operation and Limitations
The torch requires a fuel cartridge and produces an open flame, creating fire and explosion hazards in certain environments. The color change is subjective and depends on proper torch temperature, making results inconsistent in field conditions. Halide torches are incompatible with A2L refrigerants and many newer refrigerants, limiting their usefulness in modern systems. EPA and HVAC industry guidance increasingly discourages their use.
Historical Role and Modern Alternatives
Halide torches were industry standard before electronic detectors became prevalent. They require skill to operate safely and interpret correctly, with operator fatigue affecting detection reliability during extended use. Modern electronic and ultrasonic detectors have replaced halide torches in professional practice due to superior safety, accuracy, and compatibility with all refrigerant types. Their use is now limited primarily to legacy systems and specific training contexts.