Refrigerant

A refrigerant is the working fluid of a refrigeration or air conditioning system: a substance chosen because it changes between liquid and vapor at useful temperatures and pressures. As it evaporates it absorbs heat from the space or process being cooled, and as it condenses it rejects that heat somewhere else. The compressor and metering device drive this cycle continuously, so a single charge of refrigerant does its job over and over rather than being consumed like a fuel.

Because the fluid is sealed inside the circuit, a healthy system should keep essentially the same charge for its entire service life. Refrigerant that goes missing has not been used up; it has escaped. That single fact underlies most of Section 608. The regulation treats refrigerant as something to be contained, captured, and returned to service or destruction, never released, because many refrigerants damage the upper atmosphere or trap heat when they escape.

Refrigerants are grouped into chemical families with very different environmental profiles, and the regulatory treatment follows the chemistry. Chlorine bearing families deplete stratospheric ozone, while later replacements avoid chlorine but can still be potent greenhouse gases. A technician certified under Section 608 is expected to know which family a refrigerant belongs to and what obligations attach to handling it, which is why the exam's Core section leans so heavily on this vocabulary.

Related terms