Part 2 - Systems other than self-contained low charge systems

In Australia, any person who carries out work that involves handling a scheduled refrigerant, or a component of refrigeration and air conditioning (RAC) equipment with a risk of scheduled refrigerant being emitted, must ensure that they and/or any of their employees who handle scheduled refrigerant are appropriately licensed under the Ozone Protection and Synthetic Greenhouse Gas Management Regulations 1995 (the Regulations).

Such work activities include decanting of scheduled refrigerant, and manufacturing, installing, commissioning, servicing and modifying RAC equipment that contains, will be charged with, or will be manufactured incorporating any scheduled refrigerant, whether or not refrigerant is present. It also includes decommissioning RAC equipment in which scheduled refrigerant is present.

Apprentices and other trainees working with refrigerant and RAC equipment must hold a trainee licence and work under the supervision of a fully qualified licence holder. A person or company must also be appropriately authorised to acquire, possess, or dispose of bulk scheduled refrigerant.

Refrigerant Trading Authorisation holders and some Refrigerant Handling Licence holders must include their permit number on advertising, invoices, receipts and quotes, as detailed in their permit conditions.

Other relevant national licensing scheme conditions are referred to in the relevant section of this code. Permit holders must comply with the conditions of their permit. Conditions may be added or changed as outlined in the Regulations. For further details on the Australian licensing system, see www.dcceew.gov.au or www.arctick.org.

In New Zealand, any person who carries out work including the manufacturing, installation, servicing, modifying, or dismantling of any RAC equipment which contains, will be charged with, or will be manufactured incorporating any refrigerant, must ensure that they and/or any of their employees who carry out refrigerant charging or recovery,possess a refrigerant filler and handler training and certification.

In New Zealand, it is a legal requirement that any person who fills gas containers with gases under pressure, must be trained and hold a current, approved filler compliance certificate. This applies to all gases under pressure, including air. The Refrigerant License Trust Board operates under the name Refrigerant License New Zealand (RLNZ) and provides refrigerant filler and handler training and certification for HVAC&R practitioners in New Zealand.

For more details on filler certification see www.irhace.org.nz and www.rlnz.org.nz.

Any person who carries out work including the manufacturing, installation, servicing, modifying, or dismantling of any RAC equipment which contains, will be charged with, or will be manufactured incorporating, any scheduled refrigerant, must ensure that they and/or any of their employees who handle scheduled refrigerantare provided with a copy of this code and work to the standards set out herein.

The Australian Ozone Protection and Synthetic Greenhouse Gas Management Act 1989 prohibits conduct that results in (or is likely to result in) the discharge of a scheduled substance to the atmosphere. See section 45B of the Australian Act for more details.

Examples of such discharges may include:

• venting refrigerant directly or indirectly to atmosphere
• charging refrigerant into equipment with known or suspected leaks
• using refrigerant to flush refrigerant pipework clean internally
• using refrigerant as the pressure medium during leak tightness testing
• using refrigerant to clean heat exchanger fins or coils.

Systems must not be charged with a higher global warming potential (GWP) refrigerant than the refrigerant the equipment was designed to use (the design refrigerant), unless the design refrigerant was an ozone-depleting hydrochlorofluorocarbon (HCFC). To do so is an offence under the Australian Regulations.

Systems that were not designed to operate with scheduled refrigerants must not be charged with a scheduled refrigerant.

See Australian regulations 2AAA, 111A, 135 and 141, including for information on when this prohibition does not apply.

All refrigerants used in RAC equipment must have been classified according to AS/NZS ISO 817 (See Appendix B).

Under AS/NZS ISO 817 refrigerants are assigned to one of four flammability classes: 1, 2L, 2 or 3. Flammable refrigerants include A2L, A2, A3 and B2L refrigerants (see Appendix B).

Flammable scheduled refrigerants are currently either Class A2L (common) or Class A2 (uncommon).

It should be noted that lubricant/refrigerant mixtures may be flammable, even if the refrigerant is classified as non-flammable.

Manufacturers and suppliers include additional safety information in the installation and service manuals for RAC equipment using a flammable scheduled refrigerant. Technicians should follow these instructions.

For more information on the duties associated with flammable refrigerants refer to the Heads of Workplace Safety Authorities (HWSA) Flammable Refrigerant Gases Position Paper and the AIRAH Flammable Refrigerants Safety Guide.

Systems should be designed to optimise the amount of refrigerant required. The designer should always aim to minimise the specific refrigerant charge, i.e. the ratio of design refrigerant charge mass to system design heating or cooling capacity (kg/kW).

Design parameters that affect refrigerant charge include:

• system architecture
• selection of refrigerant type
• diameters and lengths of pipes
• sizing of receivers
• the technology of the expansion device
• the technology of the heat exchangers employed.

The maximum refrigerant charge limits of design standards must be complied with.

Refrigerant charge limit (RCL) is the maximum amount of refrigerant allowed in a product or system to reduce the risks of toxicity, asphyxiation and flammability hazards.

AS/NZS 60335 standards contain RCLs for particular products, and AS/NZS 5149.1 Tables A.1 and A.2 contain RCLs for systems.

Refrigerant charges are restricted according to the level of risk posed based on the toxicity/flammability class, the occupancy category, the application (human comfort or other) and whether the system is above or below ground.

Practical limits, used for simple calculations for non-toxic and non-flammable refrigerants, are based on the RCL or historically established charge limitations.

Alternative provisions such as system valving, ventilation, detection and alarm can be used in accordance with the design standards to modify the RCL allowed in some circumstances.

There are applicable refrigerant charge limits specified for all refrigerants and, for air conditioners that use flammable refrigerants, corresponding minimum room sizes specified. Manufacturers and suppliers include additional safety information in the installation instructions for air conditioners using a flammable refrigerant. Technicians should follow these instructions.

Considering the number of variables and the complexity of the required calculations for air conditioners that use flammable refrigerants, AS/NZS 60335.2.40 mandates that the manufacturer performs the calculations and that the installation instructions clearly show the resulting minimum floor area into which the air conditioner can be installed. Air conditioning installations must conform to those application limits.

For residential or light commercial air conditioning using a flammable refrigerant, the RCL is specified in AS/NZS 60335.2.40. The common rule of thumb calculation of 20 per cent room volume, previously used for A1 refrigerants, is not applicable for systems using a flammable refrigerant. The allowable charge of flammable refrigerant takes into consideration variables such as the room floor area, height of the air conditioner, type of air conditioner, characteristics of the particular refrigerant, the level of ventilation and the application of risk mitigation devices, for example detectors, sensors, alarms, etc.

For installation of split system ducted air conditioners, the maximum refrigerant charge limits are particularly important. The smallest room the system serves dictates the maximum refrigerant charge in the system that can be safely installed. Ducted indoor units pose an additional hazard if the indoor unit is located in a confined space where, if a refrigerant leak occurs, the refrigerant could pool or become trapped, exceeding RCL levels.

For air conditioners using a non-flammable A1 refrigerant, the maximum refrigerant charge or minimum room volume is calculated using AS/NZS 5149.1.

All lubricants used should be compatible with the refrigerant and equipment, as indicated by the refrigerant/equipment manufacturer’s specifications.

Designers should ensure manufacturers’ specifications for refrigerants and lubricants are complied with.

To ensure all the refrigerant and oil circulated within the system stays clean and moisture-free, provisions should be made for removing moisture, solids, and oil from the refrigerant using sufficiently sized strainers, filters, and dryers.

Refrigerant dryers must be compatible with the refrigerant and lubricant used in the system.

Replaceable dryers should be used on all systems. For larger systems these should be replaceable core dryers. A moisture-indicating liquid line sight glass installed with the dryer is recommended. Full flow filter dryers should be used in preference to bypass dryers.

The shaft seals in open compressors must be:

• compatible with the compressor, oil and refrigerant used in the system
• capable of containing any pressure or vacuum that may be attained during both operation and any shut down periods.

Lack of lubrication can cause seal mating surfaces to dry out and adhere. Subsequently, dry starting can cause damage to the seal faces. To avoid this, large systems must have a separate oil pump to lubricate the compressor bearings and shaft before start-up.

Superior shaft seals that do not rely on carbon faces should be used to prevent leakage of refrigerant. The provision of double shaft seals is advantageous.

Where a carbon seal is used, soft versus hard face combinations should be used, where the soft face material is mechanical carbon, while the hard face can be a ceramic or other non-wearing material.

The compressor must be mounted on a solid foundation, and/or anti-vibration mountings to avoid leaks caused by vibration.

Pipeline connections to the compressor must be supported in accordance with AS 4041 and AS/NZS 5149.2 to avoid unacceptable stresses that could lead to fracture and leakage.

The inclusion of a gas muffler or equivalent to reduce gas pulsation is recommended, especially on large capacity systems.

Eliminating vibration in the suction and delivery refrigerant pipelines connected to the compressor will also minimise the potential for leaks.

Service valves should be fitted to both the suction and discharge sides of the compressor to minimise refrigerant discharge during service work, in all systems except those that are hermetically sealed.

Where compressor service valves are not installed, pump out capability with isolating valves must be provided for system servicing.

Multiple compressors should be fitted with independent isolation valves where practical.

Oil equalising lines between compressors should be fitted with isolation valves that allow for the removal of individual compressors without the loss of refrigerant.

Consideration should be given to potential over-pressurisation and component failure resulting in refrigerant loss from inadequate pressure relief methods and location of service/isolation valves, especially on systems with external refrigerant oil cooling.

All systems should be designed with materials selected to minimise the risk of corrosion.

Sacrificial anodes, cathodic protection systems or other anti-corrosion measures should be provided where it is necessary to reduce corrosion and protect against electrolytic action.

The system should be designed to avoid excessive fluid velocity through the heat exchangers, which can cause vibration and erosion failures.

Anti-vibration mountings, vibration eliminating pipework connections and mufflers are recommended, as vibration transferred from compressors or other equipment can cause heat exchanger tubing failure.

Where cooling water quality is poor, for example with sea water or bore water:

• The tube plate and tube materials appropriate to the type of water should be selected to minimise corrosion.
• Facilities for flushing and/or drainage must be fitted, since reduced or inactive water flow may lead to serious corrosion problems.
• Treatment and filtration methods should be designed to avoid corrosion or erosion failure. and
• Galvanised surfaces should be passivated before use (with no system load) to prevent premature corrosion.

All pipelines must be designed so that the number of joints is kept to the practical minimum.

Provision must be made for thermal movements in the pipework, and loops/anchors incorporated to account for expansion and contraction of long runs of piping.

Trombone bends or spring hangers should be specified for large pipelines (75mm diameter or above).

Piping in refrigerating systems must be designed to minimise the likelihood of liquid hammer (hydraulic shock) damaging the system.

Refrigerant pipelines must be designed in accordance AS 4041 and AS/NZS 5149.2.

Refer to AS 4041 to determine the class of piping and the requirements associated with that class. Scheduled refrigerant pipelines are generally characterised as Class 3 pipelines under AS 4041.

Pipework must have sufficient flexibility to accept structural movement during earthquakes, in accordance with AS 4041.

Pipe sizing (particularly for liquid services and larger plant) should minimise the potential for liquid hammer, which can result in component and pipework failure.

Piping material should be assessed for compatibility with the refrigerant being used, and preference should be given to materials that have a higher resistance to corrosion/environmental effects.

The fixings of plant, pipework and fittings should be designed to resist wind, seismic vibration and other loads that may be imposed on them during their life.

Welding, brazing or another permanent hermetic sealing method is recommended for joining refrigerant pipelines, since these methods offer increased resistance to pressure, temperature and vibration stresses.

Flared, screwed, or flanged connections should be avoided.

Pipelines must be welded or brazed to flanges wherever possible.

Where flanged joints are used, attention must be given to the selection of gaskets, joining materials and joint design to withstand the pressures and temperatures involved and the effects of exposure to the refrigerant/oil mixtures.

Mechanical crimped connections should only be used with solutions designed specifically for RAC equipment and rated to appropriate pressures in accordance with AS/NZS 5149.2.

Vibration is a major source of fatigue on piping systems and is the cause of many leaks.

Pipelines must be designed to minimise breakage due to vibration.

Pipe penetrations through structures should be designed to prevent rubbing on pipelines due to vibration.

Lines to fitted gauges, high-pressure and low-pressure cut-outs and oil safety switches etc., must be designed to minimise breakage due to vibration.

Care should be taken where vibration loops are created on small lines to prevent pipes rubbing through, and to support the weight and forces developed in the vibration loop.

Liquid line solenoids fitted for the purpose of system control should be sited as close to the evaporator as practical to reduce the effect of liquid hammer.

The use of flexible refrigerant hose should be kept to the practical minimum.

Refrigerant flexible hose should comply with ISO 13971.

Flexible hose connections should incorporate ‘O’ ring seals or flared fittings to ensure minimum leakage of refrigerants.

Flexible hoses should only be used for instrument and oil connections, with preference for stainless instrument lines on larger systems.

Consideration should be given to maximum working pressure of flexible lines for high-pressure refrigerants.

Valves with welded or brazed connections must be used where the valve size exceeds 18mm outside diameter.

Isolation/service valves must be fitted to all systems to:

• minimise the danger and loss of refrigerant
• enable the pump down and isolation of major components and equipment
• assist in the servicing and maintenance of plant.

Refrigeration pipework systems must be designed so that liquid refrigerant cannot be trapped between isolation valves without pressure relief.

Where gauges are fitted, isolation valves must be installed to minimise the chance of refrigerant loss during servicing or replacement.

Where valves with removable packing are used, they must have retained or captive spindles, and facilities for tightening or replacement of the gland packing under line pressure.

The system must be designed to enable valves that use packing (e.g. expansion valves, service valves and packed line valves) to retain leakage from the spindle gland and to remain capped at all times, unless being opened or closed.

The use of Schrader valves should be kept to the practical minimum.

Schrader valves fitted to the system must be sealed with a cap when not in use to prevent loss of refrigerant.

The specification should include a requirement for all valves to be capped. The valve cap should be attached to the valve to prevent its loss when uncapped.

Systems must have relief devices selected for the refrigerant and the operating conditions of the system. Relief devices must be of the type that automatically reset after activation.

Safety cut-out devices or switches must not be capable of being isolated from the system in normal operation.

Relief devices for liquid services must not discharge directly into the atmosphere.

Safety componentry/solutions should be assessed for integrity of operation in accordance with AS/NZS 4024 to mitigate risk of safety system failure.

Fail-safe electrical and/or mechanical protection and isolation must occur before any critical or maximum allowable pressure can be exceeded.

Unnecessary operation of the pressure relief device must be avoided, by providing an adequate safety margin between the normal high-pressure cut-out setting of the system and the relief device setting.

It is recommended that where relief devices are activated, they will not result in release of the total refrigerant charge.

Relieving the high-pressure side into the low-pressure side involves several risks.

High side pressure relief devices must not discharge into the low-pressure side of the system unless provisions are made so that the system is not affected by increased downstream back pressure. The designer should ensure that this pressure does not exceed the vessel’s maximum allowable pressure.

Alternatively, the low-pressure side must have a pressure relief valve with sufficient capacity to protect all connected vessels, compressors and pumps simultaneously subjected to excess pressure.

Refer to AS/NZS 5149.2 for guidelines on pressure relief to atmosphere from the low-pressure side.

For systems with a refrigerant charge greater than 300kg, an indicating device must be provided to indicate when the pressure relief device has discharged.

Installing a rupture disc between the equipment and the relief valve will protect the valve from corrosion and resetting problems. Where a rupture disc is utilised in this manner, an indicator system must be installed to indicate whenever the disc has ruptured and permitted refrigerant to contact the relief valve.

All refrigeration systems that have a liquid receiver or condenser/receiver combination should have at least the capacity to hold the refrigerant charge of the largest group of evaporators to be pumped out for service at any one time.

The system should be designed so that the entire charge can be contained in the high-pressure receiver when the receiver is no more than 80% full, by volume.

The receiver vessels must be designed to contain the pressure at ambient conditions at pump down without the relief valve discharging (see AS 1210).

Auxiliary receivers must be installed to accommodate system expansion for safety and operational requirements.

Refrigerant receivers in systems containing more than 100kg of group A1 refrigerant, or 25kg of group A2 refrigerant, and which can be isolated, must be provided with a liquid level indicator to show at least the maximum refrigerant level.

Systems containing a one-piece condenser/receiver need not contain a separate receiver if the condenser shell is:

• large enough to contain the pumped down refrigerant charge
• fully isolated by shut off valves
• protected by a pressure relief valve in accordance with AS/NZS 5149.2.

All refrigeration systems that do not have a liquid receiver as part of their design must be fitted with permanently installed access valves for pumping out the system (i.e. capillary expansion or other critical charge designs).

Flooded and pump-recirculated systems must be fully isolatable with shut off valves and protected by a pressure relief facility in accordance with AS/NZS 5149.2.

Systems may be exempted from having a receiver, provided the evaporator or liquid accumulator/separator (or both) can contain the entire refrigerant charge.

Flooded systems must have service valves to allow the transfer of the entire refrigerant charge to approved storage vessels without the loss of refrigerant. See AS 1210 for approved storage vessels and refrigerants.

Service valves must be fitted to compressors and major items of equipment to allow the connection of a pump down unit for the removal of refrigerant before service or repair operations.

AS/NZS 5149.3 requires that detectors must be installed where the RCL of the refrigerant can be exceeded in the occupied space if a leak occurs. Detectors must be refrigerant specific and located where a refrigerant leak will concentrate. Triggers to actuate alarms, shut-off valves and emergency ventilation systems in machinery rooms are specified, including:

• 19.5% oxygen content (for human respiration)
• 25% of the lower flammability limit (LFL) of the refrigerant
• Half or less of the AS/NZS ISO 817 RCL concentration of the refrigerant.

Leak detection systems can also be required by design standard AS/NZS 5149.1 as part of the appropriate measures that must be applied if the quantity limit with minimum ventilation (QLMV) value is exceeded.

The appropriate measures that must be provided include:

• ventilation (natural or mechanical)
• safety shut-off valves
• safety alarms

and these measures must be initiated by a refrigerant gas detection device.

Indirect leak detection involves observation of parameters such as temperatures and pressures in the refrigerating system to ascertain whether there is a shortage of refrigerant. This can be especially useful if parts of the plant are inaccessible or located outdoors (where a hand-held leak detector may not function well).

Indirect detection can detect slow leaks over time and leaks where the RAC equipment is placed in a well-ventilated environment. If a leak is detected indirectly, it will often be necessary to use direct measurement methods to identify the exact location.

Installation, operation and maintenance instructions must be provided with each new system, component, or sub-assembly, detailing the correct methods and recommended procedures for installation, operation, and maintenance that:

• prevent the deliberate emission of scheduled refrigerant
• minimise the potential for accidental emission of scheduled refrigerant.

Installation, operation and maintenance instructions must be provided in accordance with the applicable standard:

• AS/NZS 5149.2 – Clause 5.4 Marking and Documentation
• AS/NZS 60335.2.24, AS/NZS 60335.2.40, AS/NZS 60335.2.89 – Section 7 Marking and instructions
• AS/NZS 60335.2.40 – Annex DD Requirements for installation, service, maintenance and repair, and decommissioning manuals of appliances using flammable refrigerants.

The installer must follow the installation instructions and provide the operation and maintenance instructions with the completed system.

Instructions must encourage the owner to pass on operation and maintenance procedures for the system to the purchaser if the system is sold and is to be reinstalled.

The manufacturer’s instructions for installation should be followed if the system is factory matched and the manufacturer has supplied instructions with the system.

If the manufacturer’s instructions are followed, the installation is exempt from the requirements of this section.

The relevant parts of this section of this code must be complied with if there are any installation procedures not covered by the manufacturer’s instructions.

Installation of all other systems, or systems where the manufacturer’s instructions are not supplied, must comply with this section of this code in its entirety.

Refrigerant pipe must not be exposed to external sources of excessive heat such as furnace rooms or boilers.

The exposure of refrigerant pipe or insulation to direct sunlight should be minimised.

Refrigerant pipe must not be installed where it can be walked on or mechanically damaged, unless protected from mechanical damage.

Piping with detachable joints not protected against disconnection must not be located in public hallways, lobbies, stairways, stairway landings, entrances, exits, or in any duct or shaft that has unprotected openings to these locations.

The position of any equipment, cables or piping that may already be in place must be ascertained before any holes are drilled or penetrations made in the building to avoid possible damage and leakage of refrigerant.

All penetrations must conform to the requirements of the Australian National Construction Code/Building Code of New Zealand, where applicable.

Pipe should be cut with a pipe cutter and de-burred using the correct tool. When cutting pipe, the opening should be facing down.

Metal filings must not be left in pipework after cutting, as they can cause damage to shaft seals, compressor bearings and windings in hermetic and semi-hermetic compressors.

All copper pipes must be bent with the correct-sized pipe bender or bending spring.

When pre-insulated pipe is bent (e.g. pair coil pipes) the following procedure must be used:

1. Split the insulation and cut away from around the pipe.
2. Bend the pipe using the correct-sized bender or insert a copper bend using brazed connections.
3. Replace the insulation, or insulate the bend, and seal the joins using adhesive and tape.

After pipework has been fixed in position, oxygen-free nitrogen (OFN) must be passed through the system to remove any oxygen before brazing or silver soldering joints.

OFN must be purged continuously through the system during the operation to eliminate oxidation (scaling), a common cause of choked dryers, blocked expansion valve strainers, dirty oil and compressor failure.

The OFN pressure must be at minimal gauge pressure during brazing, to eliminate the possibility of pin hole leaks forming in the solder.

The use of flare connections must be kept to the practical minimum. Their use is restricted by AS/NZS 5149.2 for some refrigerant/system types.

Flared joints must only be used with annealed pipe and on pipe sizes not exceeding 20mm outside diameter. Care should be taken not to flare piping that has been work hardened.

Flaring of joints is not a simple task and the correct tool, suitable for the refrigerant type and pipe wall thickness being applied, must be used.

Pipe must be cut with a pipe cutter and de-burred using the correct tool.

A suitable refrigerant-compatible lubricant must be used on the flare threads, flare sealing surfaces and between the back of the flare and the nut to avoid tearing the flare when tightening the nut.

For single-flare connections of copper tubes, the torque and conditions outlined in AS/NZS 5149.2 must be applied, see Table 4, or the manufacturer’s instructions used.

The flare nut must be tightened with the designated torque by means of an appropriate torque wrench and spanner.

The torque used to tighten the nut must not exceed the manufacturer’s instructions.

Stainless welds for refrigerant lines must be purged with an appropriate inert gas (nitrogen or argon) during the process to prevent internal contamination.

Any welded pipework connections should be completed in accordance with AS 4041 and AS 3992.

The use of flanged connections must be kept to the practical minimum.

The correct type and grade of gasket material must be used, that is:

• suitable for the operating temperatures and pressures in the relevant part of the system
• compatible with the relevant refrigerant and oil.

Flanged connections must be arranged so that the connected parts can be dismantled with minimum distortion stress of the piping.

Flanges should be evenly tightened, applying the ‘opposites’ rule in three or more gradual passes until the flange is seated correctly.

Compression/crimped fittings must be installed following the manufacturer’s preparation and fitting instructions.

All burrs must be removed from pipe ends before connecting.

Valve cores must be tightened to the manufacturer-recommended torque using a purpose designed tool.

Valve cores should be removed when brazing the fitting.

Pipework and fittings must be adequately supported according to their size and service weight, to prevent movement and failure.

The selection of pipework support materials should take into account surrounding atmospheric conditions to prevent premature wear and corrosion.

Where galvanised clamps are used, copper pipe must be protected from chafing and corrosion.

Pipework must be fixed at regular intervals according to the outside diameter.

The maximum spacing for supports should not exceed the recommendations of AS/NZS 5149.2 (see Table 5 and 6).

AS/NZS 5149.2 Table 5 - Recommended maximum spacing for copper pipe supports

AS/NZS 5149.2 Table 6 - Recommended maximum spacing for steel pipe supports

These are recommended maximum spacings and additional support may be needed to account for components, vibration and thermal expansion, as specified by the designer or manufacturer.

Good support throughout the system means not only fewer leakage problems, but better operation and offers the following additional advantages:

• no pipework sagging and eventual cracking
• good oil-handling characteristics
• no bad effects from vibration
• longer service life for the piping
• less chance of liquid hammer damage.

The clearance around the piping must be sufficient to allow:

• routine maintenance of insulation, vapour barrier, and components
• checking of pipe joints
• repairing of leaks.

Pipework should undergo visual and non-destructive testing post installation in accordance with AS 4041 to verify its integrity.

Compressors must be in a clean, dry and serviceable condition when installed.

The technician must ensure that no foreign matter enters the suction side of the compressor during the initial run-in period.

Shaft alignment must be within the compressor manufacturer’s specifications.

Compressor drive belts, when fitted, must not be over tensioned, as this can lead to premature bearing wear and shaft seal failure.

Condensing units must be secured in accordance with the manufacturer’s instructions to prevent any movement.

This test applies to site assembled systems and not to manufactured systems or components.

Warning: When pressure testing at high pressures with oxygen-free nitrogen (OFN), the pressures are high enough to cause serious injury or death. Nitrogen is an asphyxiant.

Systems or parts of systems must be leak tightness tested to ensure that they are leak free before being charged with refrigerant.

The leak tightness test must be completed:

• at initial system commissioning
• after the system is moved, altered, or a change in use has occurred
• after the system is repaired
• after a change in refrigerant type
• when a refrigerant leak or low refrigerant charge is known or suspected
• after system standstill for longer than two years.

OFN (Oxygen-free nitrogen) – high purity <10ppm moisture content.

Note: The use of standard grade nitrogen is unsafe because of the possibility of sufficient oxygen to cause an explosion at high pressure.

Tracer gas – OFN with a small percentage of <5% hydrogen (tracer) or 10–30% helium (tracer) gas added, to improve the sensitivity of detection. Specific detectors for hydrogen or helium are used to pinpoint the leak.

Warning: For safety reasons 5% hydrogen must not be exceeded.

Note: With the use of a suitable electronic leak detector, using tracer gas (H₂/N₂) offers far more sensitive and accurate leak detection than when using pure OFN.

Leak detectors – A variety of technology is available for leak detection:

• Electronic leak detector – gas detector designed and calibrated for the gas being detected (recommended).
• Ultrasonic leak detector – electronic detectors designed to detect the sound of leaking gas.
• UV additives – fluorescent additives that reveal the location of leaks using a UV light.
• Proprietary leak detection spray – commercial non‐corrosive spray purpose-designed for leak testing.

All equipment should be used in accordance with the manufacturer’s instructions. The use of an electronic leak detector is recommended, with leak detection spray limited to point source leak verification.

Systems containing flammable refrigerants require the use of a leak detector designed specifically for combustible gases. Traditional halide leak detectors can create a spark and must not be used for flammable refrigerants.

The detection equipment should be calibrated periodically. The sensitivity of portable gas detection devices should be at least 5g per year.

For initial system commissioning the test pressure must be at the maximum system operating pressure and:

• lower than any pressure limiting device setting and any pressure relief device setting
• never greater than the maximum allowable pressure (PS).

When testing a repair or component replacement the test pressure must be:

• above 25% and below 90% of the maximum system allowable pressure (PS)
• lower than any pressure limiting device setting and any pressure relief device setting.

The leak-detection procedure must take into account the response time of the equipment and the maximum distance between the leak and the leak-testing equipment. The following steps are recommended:

1. Evacuate the system, recovering any refrigerant where applicable.
2. Connect the OFN cylinder to the system or isolated section under test.
3. Pressurise the system in stages.
4. Check for leakage and pressure loss at every pressure increment increase.
5. When the maximum system allowable pressure has been reached, isolate the system from the nitrogen cylinder and record the system pressure and ambient temperature.
6. Monitor the system pressure for the required test duration, 1 hour or 24 hours.
7. If there is any drop in pressure (pressure adjusted for changes to ambient conditions in accordance with the ideal gas laws) then all leaks must be identified.
8. While the system is holding the test pressure all potential leakage points must be tested with a leak detector. Check the whole system. The first leak found may not be the only leak.
9. If a leak is identified, the OFN must be vented, the leak repaired and the leak tightness test procedure repeated.

The detection equipment should be used in accordance with the manufacturer’s instructions.

It is best practice to use a combination of techniques e.g. an electronic detector to test an area and leak detection spray to identify and verify the exact location of the leak.

When the system has met the acceptance criteria the OFN must be evacuated and the system charged with refrigerant in accordance with Section 6.

When the system has not met the acceptance criteria, and a leak has not been found, the test must be repeated using more sensitive leak detection, e.g. using a tracer gas to improve detection or a specialised UV leak detection dye.

Leak tightness test pressure must be held for:

• 24 hours for initial system commissioning tests, and
• 1 hour when testing a repair or component replacement.

The system must be observed over a period of time, relative to the size of the system, to ensure that no pressure drop occurs, having due regard to temperature variation throughout the system.

For joints, equipment and components assembled at the installation site, all potential leakage points must be tested with detection equipment with a capability of 5g per year of refrigerant or better, with the equipment in standstill and under operation or under a pressure of at least the standstill or operational conditions.

For refrigerants with global warming potential (GWP) > 150, the AS/NZS 5149 acceptance criterion for this test is that no leaks are detected when using detection equipment with a capability of 10⁻⁶ Pa·m³/s or better, for example, a helium sniffer.

For refrigerants with GWP < 150, the AS/NZS 5149 acceptance criterion for this test is that no leaks are detected when using detection equipment with a capability of 10^–3Pa·m³/s or better, for example, application of a leak detection spray to the outer surface.

Any leak detected at this level of sensitivity must be repaired and retested.

Repairs must be carried out and verified before the system is charged with refrigerant.

Repairs must not be made with the system pressurised.

Repairs must be carried out in accordance with Clause 9.9.

After the repairs have been completed, the system or affected parts of the system must be leak tightness tested to ensure that the repair is leak free.

The manufacturer’s instructions for evacuation should be followed if the system is factory matched and the manufacturer has supplied instructions with the system.

If the manufacturer’s instructions are followed then the evacuation procedure is exempt from the requirements of this section.

The relevant parts of this section of this code must be complied with if there are any evacuation procedures not covered by the manufacturer’s instructions.

Evacuation of all other systems, or systems where manufacturer’s instructions are not supplied, must comply with this section of this code in its entirety.

1. Evacuate the system to at least 500 microns/67Pa absolute.
2. Isolate the vacuum pump from the system.
3. Allow the system to stand for 60 minutes. Ensure that vacuum is maintained below 600 microns/80Pa absolute.
4. If the gauge rises by 100 microns or more, then there is a leak or moisture in the system.
5. Test for leaks if the vacuum is not maintained.

1. Evacuate the system to at least 4,500 microns/600Pa absolute.
2. Break vacuum with oxygen-free nitrogen (OFN).
3. Allow the system to stand.
4. Purge OFN through the pipework.
5. Re-evacuate the system, pulling the second vacuum to at least 4,500 microns/600Pa absolute and repeat the process using OFN to break the vacuum.
6. Re-evacuate the system for a third time, pulling the third vacuum to 500 microns/67Pa absolute.
7. On the third re-evacuation, isolate the vacuum pump from the system.
8. Allow the system to stand for 60 minutes to ensure the vacuum is maintained below 600 microns/80Pa absolute.
9. If the gauge rises by 100 microns or more, then there is a leak or moisture in the system.
10. Test for leaks if the vacuum is not maintained.

At installation, a clearly readable identification plate must be located near or on the refrigerating system. The identification plate must contain at least the following data:

• the name or identification of the installer or manufacturer
• the model, serial number, or reference number
• the year of manufacture

Note: The year of manufacture can be part of the serial number, and all information can be part of the identification plate of the equipment and can be coded.

• the number designation of the installed refrigerant type, in accordance with AS/NZS ISO 817
• the refrigerant charge
• the maximum allowable pressure, high- and low-pressure sides
• when flammable refrigerants are used, the flame symbol (ISO 7010 W021).

Whenever the type of refrigerant and/or lubricant in a system is changed, see Section 11, the technician must clearly label the system with:

• the number designation of the new replacement refrigerant, in accordance with AS/NZS ISO 817
• the refrigerant charge
• the maximum allowable pressure, high- and low-pressure sides
• when flammable refrigerants are used, the flame symbol (ISO 7010 W021)
• name of technician, licence number (Australia only) and service organisation
• date of service
• whether any ultraviolet dye has been added.

Whenever the type of lubricant in a system is changed (other than when it has been pre-charged into a replacement compressor by its manufacturer), the technician must also clearly label the system with:

• the lubricant type.

Pipe markers should also be utilised in accordance with AS 1345, accurately indicating refrigerant, especially for plants with lines external to plantroom.

The manual should include:

• the purpose of the system and a description of the machinery and equipment
• a refrigerating system schematic diagram and electrical circuit diagram
• instructions concerning the starting, stopping, and standstill of the system
• instructions concerning the disposal of operating fluid and equipment
• precautions to be taken to prevent freezing at low ambient temperatures or by normal reduction in the system pressure/temperature
• precautions to be taken when lifting or transporting the systems or parts of the systems
• information displayed on the documentation at the operating site, if necessary, in its entirety.

The manual must include:

• a reference to protective measures, first aid provisions, and procedures to be followed in the event of emergencies, e.g. leakage, fire, explosion
• the instructions concerning the handling of refrigerant and the hazards associated with it
• the instructions concerning the function and maintenance of safety, protective, and first aid equipment, alarm devices, and pilot lamps.

The manual must include:

• the causes of the most common defects and measures to be taken, e.g. instructions concerning leakage detection by authorised personnel and the need to contact competent technicians in the event of leakage or breakdown
• the maintenance instructions for the entire system with a time schedule for preventive maintenance with respect to leakage
• the instructions concerning the charging and discharging of refrigerant
• the logbook and guidance for the use of the logbook, where applicable.

The manufacturer’s instructions for commissioning should be followed if the system is factory matched and the manufacturer has supplied instructions with the system.

If the manufacturer’s instructions are followed then the commissioning is exempt from the requirements of this section.

The relevant parts of this section of this code must be complied with if there are any commissioning procedures not covered by the manufacturer’s instructions.

Commissioning of all other systems, or systems where manufacturer’s instructions are not supplied, must comply with this section of this code in its entirety.

Regular leak tests, inspections and checking of the safety equipment should be carried out.

The system instruction manual (see AS/NZS 5149.2) must include the maintenance instructions for the entire system with a time schedule for preventive maintenance with respect to leakage.

AS/NZS 5149.4 requires that preventive maintenance be carried out in accordance with the system instruction manual.

All systems should be regularly inspected in accordance with AS/NZS 5149.4, Section 5.2 Maintenance and AIRAH l DA19 – HVAC&R maintenance – Compliance level maintenance.

The general operating conditions should be checked once a week, including system pressures where readings are displayed, refrigerant sight glass, etc. The condition of condensing equipment should be checked once a week. For air cooled equipment, the condition of the condenser coil should be observed.

A regular inspection program should ensure that the protection offered by the sacrificial anode or other protection where fitted is maintained and that the heat exchangers stay clean and scale-free.

The technician should review the maintenance records to check where leaks have been found previously. The technician should complete a visual inspection of the operating system including, but not limited to, identifying any:

• visible oil or dust stains on joints, components or insulation
• movement or stresses due to vibration or thermal expansion
• signs of corrosion, thermal stress, wear or metal to metal contact points
• unusual level of noise or vibration from the system.

The technician should assess the system/refrigerant operating temperatures and pressures and compare against the manufacturer’s data and operation instructions to determine whether the refrigerant charge is low.

For systems with fixed-speed compressors, measuring pressure readings coupled with air and refrigerant temperatures allows technicians to assess charge levels against manufacturer data.

For systems with variable speed compressors, diagnostic analysis can involve running the system at maximum output and measuring temperature difference (ΔT) across the heat exchanger at steady state or measuring delivered capacity, which requires measuring ΔT (heating), ΔH (cooling) and airflow.

Some systems have on-board diagnostics for automatic leak detection.

Where diagnostic analysis indicates a low refrigerant charge, a leak tightness test must be performed.

Various methods may be used for leak inspection, e.g. electronic leak detectors, ultrasonic leak detectors, proprietary leak detection spray, or ultraviolet fluorescent additives. Electronic leak detectors must be specific to the refrigerant type, see Clause 4.9.3.

• Using a leak detector, assess all joints and components on the system for leakage, with a focus on common leakage points and any areas identified in the visual survey.
• Follow the leak detector manufacturer’s instruction for leak detection.
• The results of the in-service inspection should be recorded.

Where a leak is detected, all refrigerant must be removed from the system or affected section, and the leak repaired.

Where a leak is suspected but not detected, all refrigerant must be removed, and the system (or affected section) must be leak tightness tested.

The following areas should be individually assessed with a leak detector:

• joints – flare joints, mechanical joints and flanges, brazed joints, catalyst cured joints
• valves – Schrader valves, service valves, manual valves, pressure relief valves/devices, expansion valves, line tap valves
• evaporators and condensers – corroded areas, return bends, valves and joints
• seals – shaft seals (open compressor), compressor gaskets, seals on replaceable driers and filters, seals on gauge points, seals on caps
• other – capillary tubes, control bellows, O rings and pressure switches.

Access valves should have their caps refitted.

The low-pressure side of a system must be placed under a positive pressure before leak testing the evaporator, heat exchanger, expansion valve, solenoid valve, and other components.

Pressure build up in the low-pressure side of the system must not exceed the maximum design conditions during testing.

Negative pressure systems can, if not controlled correctly during testing, burst the rupture disc.

The test pressure must comply with AS/NZS 5149.1 when leak testing.

Tube-piercing valves or equivalent devices must only be used to gain temporary access to the system where there is no other means of access in order to remove refrigerant. They must be removed prior to the completion of service.

The technician should ensure that the condenser is clean and serviceable.

If the system has electric defrost, the compressor should be switched off and the defrost cycle initiated without pumping down the system to increase the system pressure.

The charging and/or temporary gauge lines and connecting lines and/or flexible hose should be evacuated using a vacuum pump to less than 5,000 microns to eliminate air intake.

AS/NZS 5149.4 requires that each refrigerating system be subjected to preventive maintenance with respect to leakage in accordance with the system instruction manual, including the frequency of in-service leakage inspections.

In the absence of instructions in the operating manual, the recommended frequency of in-service leakage inspections of AS/NZS 5149.4 should be followed.

AS/NZS 5149.4 Recommended in-service leak inspection frequency

The best practice approach to in-service leakage inspections is currently reflected in the European Union (EU) F-Gas regulations, where the frequency is based on tonnes of CO₂ equivalent of the refrigerant charge, and whether a fixed refrigerant leak detection system is fitted.

The tonnes of CO₂ equivalent (tCO₂e) of a refrigerant charge is calculated by multiplying the mass of refrigerant charge in tonnes by the global warming potential (GWP) of that refrigerant.

The EU regulations also mandate inspection frequencies for HFO refrigerants, based on refrigerant charge mass.

European Union (EU) F-Gas regulation – Leak inspection frequency

For systems with separate oil pumps, these pumps should be run at least once a month.

On systems where a separate oil pump is not fitted, the shaft should be rotated at least once a week to ensure the seal is kept lubricated.

If a system is to be shut down for more than one month the system should be:

1. pumped down
2. all necessary valves closed to prevent the escape of refrigerant
3. suitably labelled.

If this is not possible, the system should be run once a week for at least half an hour in order to ensure that mechanical seal faces, bearings, etc. have a continuous oil film on their surfaces. This procedure could prevent seal failure occurring over a long period of shutdown.

If, after any shut down period of more than one month:

• the oil pump has not been run, or
• on compressors with no oil pump, if the shaft has not been rotated periodically,

the shaft seal must be thoroughly inspected, lubricated and leak tested before starting any maintenance.

Negative pressure systems can be under a vacuum and could draw in air and moisture both while operating and when they are off.

A method of pressurising the system and controlling the pressure to between 0.3kPa and 2.0kPa gauge should be implemented when the system would otherwise equilibrate at a vacuum when not operating.

Once a week the compressor should be stopped and the shaft seal checked for excessive oil leakage.

The seal must be checked with a refrigerant leak detector if oil leakage is found, opening the compressor only.

This minimises the quantity of refrigerant that might be lost due to any minor leak on the low-pressure side of the system and refrigerant that might leak through the shaft seal.

The compressor should not be allowed to pump the suction pressure into a vacuum.

A slight positive pressure is necessary to prevent air and moisture from being drawn into the system through minor leaks and through the now unmoving shaft seal.

Replacement of components or changes to the refrigerating system should be ordered and carried out by a competent person.

System components should be replaced with parts that are more leak-resistant or have a reduced number of potential leak sources.

An equivalent replacement ‘O’ ring seal should be used each time an ‘O’ ring connection is remade.

Repairs on refrigerant containing components should be carried out in the following order, where applicable:

1. recovery of refrigerant, emptying and evacuation
2. disconnecting and safeguarding of the components to be repaired
3. cleaning and purging (e.g. with OFN)
4. carrying out the repair
5. testing and checking of the repair (pressure test, leakage test, functional test)
6. evacuating and recharging with refrigerant.

Following any repair, all safety, control and measurement devices as well as alarm systems must be checked to verify operation.

Where not in the open, the area must be adequately ventilated before breaking into the system or conducting any hot work.

Systems, or the isolated section of the system, must be evacuated and purged with OFN prior to any hot work.

If the system contains any refrigerant, or any other gas under pressure, it must not be broken into by means of cutting or breaking pipework.

A portable leak detector should be considered when completing cut-in tasks for toxic or flammable fluids.

Where repair work requires brazing or de-brazing or any hot work, all refrigerant must be recovered from the system, or isolated (by means of shut off valves) in a part of the system remote from the repair.

OFN must then be purged through the system both before and during the brazing process.

As many parts of the system as practical must be isolated.

All scheduled refrigerants including contaminated refrigerant must be fully recovered.

The recovery cylinder must not be over-filled, as per AS 2030.5, see Clause 13.4.

Contaminated refrigerant must not be recovered in the same cylinder as clean/reusable refrigerant.

Flammable scheduled refrigerants must be recovered into appropriately labelled cylinders.

When the system is empty and at atmospheric pressure, the faulty component parts should be removed and the system capped off. Small systems should be taken to a workshop with appropriate facilities for cleaning and reinstating.

Scheduled refrigerant must not be used for flushing components.

WHS/OHS safety standards must be observed when handling solvents. Relevant Safety Data Sheets must be obtained and made available to the technician handling solvents.

The cleaning solvent should be pumped throughout the system until only clean solvent emerges. After ensuring the system has been thoroughly cleaned, caution should be taken to ensure no solvent residue remains in the system after purging.

All spent solvents must be disposed of in accordance with the Australian state and territory hazardous substance disposal regulations or the New Zealand Hazardous Substances (Health and Safety Reform Revocations) Regulations 2017,as applicable.

Each Australian state or territory has their own laws and policies, and relevant permits, licences and/or registrations that cover transporting, storing, treating and disposing of hazardous waste.

If it has been established after testing the refrigerant and oil for acidity that the system has only been locally contaminated by the burnout, moisture, or mechanical failure, and does not require the cleaning procedure outlined in Clause 9.12.2, then cleaning of the system by using purpose selected suction and liquid line filter dryers is an acceptable alternative.

When using this method all filters fitted must be capable of being replaced with a minimal loss of refrigerant to the atmosphere.

When cleaning is complete, the major component parts should be reassembled in the system with the replacement compressor.

It is recommended that a suction line filter/dryer (a burnout dryer) be fitted.

The system must be pressurised and strength and leak tested in accordance with Clause 8.2.

The system must then be evacuated prior to charging with refrigerant. Refer to Section 5.

A new dryer should be fitted while there is zero gauge pressure in the system. If triple evacuation is used, this should be done between the second and third stages. If deep evacuation is used, it should be done at the beginning of the process.

The system can then be recharged with refrigerant.

The system must not be recharged before the system has been fully leak tested, all identified leaks repaired and the system has been evacuated in accordance with Section 5.

Refrigerant used to recharge a system must meet the specification for new refrigerant set out by AHRI 700.

Because most lubricants are very hygroscopic and will absorb moisture from the air, they should not be exposed to atmosphere for any longer than is necessary.

The system should be recharged to the refrigerant quantity shown on the identification plate.

All scheduled refrigerant must be recovered from all parts of the system at the time of decommissioning.

Recovered refrigerant must be reclaimed or disposed of in accordance with Section 12.

The RAC equipment must be labelled stating that it has been decommissioned and emptied of refrigerant.

The label must be dated and signed.

Portable equipment is available for recovery of refrigerant in the field.

Refrigerant recovery equipment and recovery/recycling equipment must conform to AS 4211.3, ISO 11650 or AHRI 740. Refrigerant recovery units must be appropriate for the refrigerant being recovered.

Hoses, fittings and procedures used during recovery must be those which minimise the loss of refrigerant.

Recovery equipment should be used and maintained in accordance with the manufacturer’s instructions.

Tools and equipment must be rated for use with the appropriate flammability grade.

A2L and A2 refrigerants are generally not compatible with the following servicing tools used to work with A1 refrigerants, due to the flammable nature of the refrigerant:

• vacuum pumps
• recovery units
• refrigerant cylinders.

New or existing servicing tools must be assessed individually to ensure:

• they conform with relevant international/Australian/New Zealand Standards
• the manufacturer’s manual/specification states that it is designed for use with flammable refrigerants.

Cylinders used for recovery must conform with AS 4484, AS 2030.1 and AS/NZS 1200.

Refrigerant must not be recovered into an out-of-date recovery cylinder, i.e. the current date must not be later than the expiry date of the most recent test station stamp on the cylinder.

Note: Refrigerant/oil mixtures have a lower density than refrigerant alone and for this reason the carrying capacity of refrigerant cylinders will be reduced for refrigerant/oil mixtures compared to pure refrigerants.

The designed maximum safe working pressure of a refrigerant cylinder determined in accordance with AS 2030.5 must not be exceeded in any filling operation, no matter how temporary.

Particular care should be taken when recovering modern high-pressure refrigerants because their ambient pressures can be much higher than previous generation refrigerants.

Cylinders must only be used within the application for which they are designed. The recovery cylinder must be appropriate for the refrigerant being recovered. A2/A2L refrigerant must be recovered into A2/A2L specific cylinders with the correct design pressure ratings.

The permission of the owner of the cylinder must be obtained in advance if a refrigerant cylinder belonging to a third party (for example, a refrigerant manufacturer, wholesaler or hirer) is to be used as a temporary receiver. Where granted, the owner must be given the opportunity to carry out an internal inspection for corrosion and contamination immediately after such use, and the refrigerant cylinder must be labelled indicating such use.

Valves and non-return valves on refrigerant cylinders must not be tampered with without the permission of the owner.

Cross contamination of refrigerants and lubricants should not occur within the recovery equipment if the refrigerant is to be recycled or reused.

If contaminated refrigerant is decanted into a recovery cylinder, corrosion and contamination may occur.

If a cylinder is filled with contaminated refrigerant, an internal examination followed by cleaning should be carried out before it is reused.

Refrigerant suspected to be contaminated must be either disposed of or tested if it is to be re-used. If necessary, it may be recycled or reprocessed to ensure it complies with the provisions of AHRI 700 prior to re-sale or re-use.

Cross contamination of scheduled refrigerants with non-scheduled refrigerants must not occur within the RAC equipment or during the recovery process. Where these mixtures are encountered, they must be recovered by a competent technician. They must not be vented to the atmosphere and must be reclaimed.

Note: It is possible that non-design refrigerants and mixtures of refrigerants with a different safety classification have been incorrectly used as replacements for HFCs, HCFCs and CFCs or have been used to ‘top up’ a refrigerant charge in existing systems. There is a risk that the equipment in question was not appropriately redesigned and/or relabelled to indicate that a more hazardous (flammable and/or toxic) refrigerant has been used. As the operating pressures of these replacements and mixtures can be similar to those of the original design refrigerant, identification in the field can be extremely difficult.

When technicians encounter RAC equipment in the field that they are not familiar with, and where the refrigerant cannot be positively identified, they should treat the system as if it contained a flammable and toxic refrigerant. If the presence of a flammable or toxic refrigerant is suspected in a system that is not appropriately redesigned and relabelled, proper care should be taken to recover it. Only personnel trained in using equipment designed to recover these types of mixtures should perform this task.

Mixing different types of refrigerants during recovery may render large quantities of refrigerant unable to be recycled or reclaimed, as separation may be impossible.

In some cases the recycling of refrigerant involves simple cleaning processes using filters and driers that remove certain contaminants, such as moisture and particulate. The recycling process is more complicated for blended refrigerants, because preferential leakage or separation within the system may have resulted in a change of blend composition.

These refrigerant recycling cleaning processes can be carried out on site using portable equipment. Some refrigerant recovery units include cleaning (for recycling) stages.

Refrigerant recovery/recycling equipment must conform to AS 4211.3, ISO 11650 or AHRI 740.

Refrigerant reclamation must only be carried out at a specialist facility that reprocesses the refrigerant to a specification that is equivalent to the original refrigerant state.

Reclaimed refrigerant must be treated and processed so that it conforms to the AHRI 700 standard.

After reclamation, the refrigerant can be reused in any system designed for that refrigerant.

Unwanted scheduled refrigerant must not be discharged to the atmosphere and must be returned to a supplier or collection agent for safe disposal.

In Australia, under the Regulations, unwanted scheduled refrigerant must be recovered and recycled or sent to an appropriately licensed facility for reclamation or disposal. A Refrigerant Trading Authorisation holder must accept any surrendered refrigerant or scheduled substance that appears to be intended for use in RAC equipment. They must also ensure that destruction of refrigerant is carried out only by the operator of a refrigerant destruction facility.

See refrigerantreclaim.com.au for more information.

In New Zealand all refrigerant importers are required to accept refrigerant back under product stewardship requirements. Locations that accept returned refrigerant in New Zealand include A Gas NZ Ltd, Patton NZ Ltd and RefSpecs NZ Ltd.

For additional locations that accept returned refrigerant in New Zealand, visit coolsafe.org.nz.

Scheduled refrigerant must be recovered from all refrigerating systems before their disposal.

All domestic and commercial refrigerator and freezer cabinets should have any locks removed or rendered inoperative upon removal from service. Doors, drawers and/or lids should be removed or otherwise rendered safe and inaccessible where refrigerators and freezer cabinets are stored or removed from service and left in any public place or any other place where children could have access.

In Australia, it is a legal requirement that any person who handles a scheduled refrigerant, including a person filling cylinders, must hold a Refrigerant Handling Licence.

In Australia, refillable containers must be used for the storage of scheduled refrigerant.

In New Zealand, it is a legal requirement that any person who fills gas containers with gases under pressure, must be trained and hold a current, approved filler compliance certificate. This applies to all gases under pressure, including air.

All refillable gas cylinders approved for filling in New Zealand must be stamped with a record number, normally done at the time of manufacture. The record number is in the form of LAB YYYY, or in the case of special cylinders, LAB YYYY SP. The inspection interval for refrigerant cylinders in New Zealand is every 5 years from date of manufacture.

The maximum gross weight must not be exceeded when filling refrigerant cylinders. The cylinder must not be used if the maximum gross weight is not marked on the cylinder. The cylinder supplier should determine the maximum gross weight in accordance with AS 2030.5.

The maximum gross weight is a function of the internal volume of the cylinder, refrigerant composition and oil content and temperature.

The safe fill capacity (SFC) is the quantity of liquid refrigerant that can be safely added to a storage cylinder without causing undue stress on the cylinder. The SFC, expressed in kilograms, is determined by multiplying the water capacity (WC) stamped on the cylinder, expressed in litres, by the maximum fill ratio (FR) specified for the refrigerant in accordance with AS 2030.5, i.e.:

SFC = FR x WC

The FR is a number that is based on the refrigerant properties, cylinder material and design, temperature considerations and the safety factor or ullage, the vacant space between the top of the liquid refrigerant and the top of the cylinder. AS 2030.5 requires a minimum ullage of 3% at the mean bulk liquid temperature of 57 °C for refrigerants except high-pressure refrigerants such as carbon dioxide (R744). So, the FR can be obtained from refrigerant’s specific gravity or liquid density (ρ_liquid) expressed in kg/L at 57 °C, i.e.:

FR = 0.97 x ρ_{liquid@57 °C}

Calculated FR based on AS 2030.5 Clause 7.1.3 and tabulated FR from AS 2030.5 Table 4 for some refrigerants are listed in the following table.

Common scheduled refrigerant fill ratios (FR)

For recovered and recycled refrigerants the safe fill capacity formula from AS 4211.3 requires a minimum ullage of 20%, so the SFC calculation becomes:

SFC = 0.80 x FR x WC

Refilling a cylinder must only be undertaken with the permission of the cylinder owner.

Refrigerant must not be vented to the atmosphere from the receiving cylinder.

The receiving cylinder may be cooled in an operating refrigerator or freezer.

Warming of the discharging cylinder is permissible under controlled conditions to increase the rate of discharge of refrigerant during transfer.

Refrigerant cylinders must not be directly heated by flame, radiant heat or uncontrolled direct contact heat. Heating of cylinders using indirect forms of heating, e.g. controlled temperature air flow, must only be conducted where the control system is designed to be fail safe.

There are numerous hazards associated with the storage of refrigerant. These include asphyxiation in confined spaces due to leakage from refrigerant cylinders, and fire, which may overheat and explode refrigerant cylinders or decompose refrigerant into toxic substances.

Technicians should make reference to refrigerant manufacturer’s Safety Data Sheets when handling refrigerant cylinders.

Gauges should be removed from the cylinder for storage and transport.

Cylinders containing scheduled refrigerants must be stored in accordance with AS/NZS 4332.

Refrigerant must be stored securely with appropriate signage (to provide ready identification by emergency teams).

There are limits on the amount that can be stored and reference must be made to current local legislation.

In Australia, to meet their permit conditions, holders of a Refrigerant Trading Authorisation must:

• regularly check refrigerant containers in their possession for leaks
• implement a risk management plan for handling and storing refrigerant in their possession.

They must also keep records relating to:

• refrigerant purchase, sale, recovery and disposal
• checks, tests and maintenance of equipment and refrigerant containers/cylinders, including leak checks.

The refrigerant cylinder and its valve must be handled carefully to avoid mechanical damage.

When a refrigerant cylinder is not in use its valve must be closed, the valve outlet sealing cap put in place and the valve protected.

Cylinders must be leak tested every 3 months. Refrigerant leak detectors can be used for this purpose.

The contents of a leaking cylinder must be transferred to a recovery cylinder immediately. The leaking cylinder must be returned to the supplier.

In Australia, Refrigerant Trading Authorisation holders must ensure that refrigerant in their possession is handled in accordance with applicable standards by the holder of an appropriate licence, and keep records of these licensees.

In Australia, the Australian Code for the Transport of Dangerous Goods by Road and Rail (the ADG Code) provides detailed technical specifications and recommendations applicable to the transport of dangerous goods by road and rail.

The ADG Code covers the requirements for classification, packaging, marking and labelling of substances and articles that meet the United Nations classification criteria for dangerous goods. The ADG Code adopts the structure, format, definitions and concepts of the United Nations Recommendations on the Transport of Dangerous Goods Model Regulations while retaining Australian-specific provisions.

In New Zealand, the regulations for transporting dangerous goods on land are outlined in the Land Transport Rule: Dangerous Goods 2005. This rule, also based on the UN Dangerous Goods Model Regulations, covers various aspects related to dangerous goods, including packaging, identification, documentation, segregation of incompatible goods, transport procedures, and the responsibilities of those involved in transporting dangerous goods.

New Zealand Standard NZS 5433 provides detailed technical information to meet the requirements of the Land Transport Rule.

For transportation purposes, flammable scheduled refrigerants are classified as a Dangerous Goods Division 2.1 flammable gas under the Australian Dangerous Goods Code and therefore require additional handling and storage safeguards compared to Division 2.2 non-flammable gases (see also Appendix B). Cylinders for transport should be marked with the ADG Flammable Gas 2.1 Class Label (red diamond). Note that WHS regulations allow GHS pictograms to be substituted by the correct ADG class labels.

Refer to the AIRAH Flammable Refrigerants Safety Guide for additional details on transporting flammable refrigerants and a self-assessment tool for vehicle storage.