HRAI ODP Refrigerant Handling key terms

A number comparing how strongly a substance destroys stratospheric ozone relative to CFC-11, which is set at 1.0. Higher values mean greater ozone damage per unit mass released.

Any chemical capable of breaking down stratospheric ozone, including CFCs, HCFCs, halons, carbon tetrachloride, methyl chloroform, and methyl bromide. Handling rules and phase-out schedules apply to these substances.

The thinning of the stratospheric ozone layer that shields life from ultraviolet radiation. It is caused mainly by chlorine and bromine released from synthetic chemicals that persist long enough to reach the stratosphere.

The natural layer of ozone gas roughly 15 to 35 kilometers above the earth. It absorbs most harmful ultraviolet light before it reaches the surface, protecting people, crops, and ecosystems.

High-energy light from the sun that ozone absorbs in the stratosphere. Increased surface exposure raises risks of skin cancer, cataracts, immune suppression, and damage to plants and marine life.

A fully halogenated compound containing chlorine and fluorine, once common as a refrigerant and propellant. CFCs have high ODP values and long atmospheric lifetimes, and their production is banned under the Montreal Protocol.

A compound containing hydrogen, chlorine, fluorine, and carbon, such as R-22. Because hydrogen makes them break down faster in the lower atmosphere, HCFCs have lower ODP than CFCs, but they are still being phased out.

A compound of hydrogen, fluorine, and carbon with no chlorine or bromine, so it has zero ODP. However, many HFCs are potent greenhouse gases and are subject to separate controls.

A newer class of unsaturated refrigerant with zero ODP and very low GWP because it breaks down quickly in the atmosphere. Some HFOs are mildly flammable and may be blended with other fluids.

Bromine-containing chemicals used mainly in fire suppression. Bromine is far more destructive to ozone than chlorine, so halon production is banned and handling is tightly controlled.

The international treaty adopted in 1987 that schedules the phase-out of ozone-depleting substances. Its amendments add controls, including the Kigali Amendment covering hydrofluorocarbons.

An amendment to the Montreal Protocol that sets schedules for reducing production and use of high-GWP hydrofluorocarbons. It links refrigerant handling rules to climate protection as well as ozone protection.

The timeline in regulations that limits or bans production and import of a controlled substance by specified dates. Technicians must know which refrigerants may no longer be sold or used for servicing.

A fluid used in a cooling system that absorbs heat by evaporating at low pressure and releases heat by condensing at high pressure. Its chemical class determines ODP, GWP, and safety requirements.

A mixture of two or more refrigerants formulated to achieve desired properties. Zeotropic blends change temperature as they evaporate or condense, so they must be charged as liquid and not topped off with a different blend.

A blend whose components behave as a single fluid, boiling and condensing at one constant temperature at a given pressure. It can be charged as vapor without changing composition.

A blend whose components boil at different temperatures, producing a temperature glide during phase change. Leaks and vapor charging can shift its composition, so liquid charging is normally required.

The difference between the bubble point and dew point temperatures of a zeotropic blend at a given pressure. It affects superheat and subcooling calculations and must be considered when charging or diagnosing performance.

The separation of a blend's components when vapor leaks from a system or when vapor is used for charging. The remaining liquid becomes richer in the less volatile component, changing performance and safety characteristics.

A number expressing how much heat a gas traps over a set period compared with carbon dioxide, which is set at 1. It guides refrigerant selection and regulatory limits on high-impact fluids.

The rule that forbids intentionally releasing refrigerant to the atmosphere during service, repair, or disposal. Recovered refrigerant must be captured and processed instead of being allowed to escape.

Removing refrigerant from a system and storing it in an external container without necessarily cleaning it for reuse. Recovery is required before opening a system or disposing of equipment.

Cleaning recovered refrigerant on site by removing oil, moisture, and particulates so it can be reused in the same equipment. Recycling does not restore the refrigerant to new-product purity specifications.

Processing recovered refrigerant at a certified facility to restore it to purity standards set for new product. Reclaimed refrigerant is tested and documented before it may be sold or used in another system.

A refillable pressure vessel built and marked specifically for holding recovered refrigerant. It must be DOT-approved, never filled above its rated capacity, and labeled with the refrigerant it contains.

The maximum safe amount of refrigerant a recovery cylinder may hold, usually 80 percent of its volume by weight of water capacity. Overfilling risks hydrostatic rupture when the cylinder warms.

A pressure vessel used to store or transport virgin refrigerant. It must be kept upright, secured, away from heat, and fitted with a valve cap and appropriate pressure-relief device.

Adding refrigerant to a system in liquid form, which is required for zeotropic blends to preserve their intended composition. It is often done into the liquid line or receiver with the system running.

The process of adding refrigerant to a system to reach the correct operating charge. It may use weight, superheat, subcooling, or sight-glass methods depending on the equipment design.

The temperature of refrigerant vapor above its saturation temperature at the measured pressure. It is used to verify charge and expansion-device performance and to protect the compressor from liquid return.

The amount by which liquid refrigerant is cooled below its saturation temperature at the measured pressure. It indicates how much liquid is stored in the condenser and is a key charging check.

Water that enters a refrigeration system and can form acids, sludge, and ice blockages. It must be prevented with proper evacuation and removed with filter-driers, especially in systems using newer refrigerants.

Pulling a vacuum on a system to remove air and moisture before charging. It is verified with a micron gauge and is required after any repair that opens the refrigerant circuit.

An instrument that measures deep vacuum in microns of mercury, used to confirm that evacuation has removed moisture and non-condensables. It is far more precise than a standard manifold gauge.

An evacuation method that alternates deep vacuum with dry nitrogen pressure to break up trapped moisture and air. It is used when a system has been exposed to the atmosphere for an extended time.

Air or another gas that will not condense at normal system pressures and temperatures. It raises head pressure, reduces efficiency, and must be removed by proper evacuation and recovery procedures.

A device containing desiccant and a filter that removes moisture, acids, and particles from the refrigerant stream. It is replaced whenever a system is opened or contamination is suspected.

The chemical reaction of moisture, refrigerant, and oil that creates acidic compounds which corrode metal and degrade insulation. Acid tests and filter-driers are used to detect and control it.

Failure of a compressor motor winding or mechanical parts, often producing acidic residue and debris that spread through the system. Cleanup requires recovery, flushing, and multiple filter-drier changes.

A safety rating such as A1, A2L, A2, or A3 that describes a refrigerant's burning characteristics and lower flammability limit. It drives handling, ventilation, and ignition-source controls.

A mildly flammable refrigerant class with low burning velocity and low toxicity. Systems using A2L fluids require charge limits, leak detection, ventilation, and no ignition sources during service.

The use of electronic detectors, pressure tests, or visual methods to find refrigerant leaks. Leaks must be repaired promptly because they release ODS or greenhouse gases and degrade performance.

A specification such as AHRI Standard 700 that sets limits on moisture, oil, and non-condensables in reclaimed refrigerant. It is used to certify that reclaimed product matches new-refrigerant quality.

Records that must accompany recovered refrigerant when it is transported, including the refrigerant type, quantity, and destination. Proper paperwork demonstrates compliance with handling and transport rules.

The credential required by regulation before a person may service equipment containing ozone-depleting refrigerants. It confirms knowledge of recovery, recycling, and safe handling practices.