Code of Practice to eliminate halocarbon emissions from refrigeration and air conditioning systems: chapter 4

4.0 Servicing

• 4.1 System Start-up
• 4.2 Preventative Maintenance
• 4.3 Inspection
• 4.4 Leak Testing
• 4.5 System Repair
• 4.6 Recovery, Reuse, Recycling and Reclaiming of Refrigerants
• 4.7 Cleaning
• 4.8 Charging
• 4.9 Sealants
• 4.10 Handling and Storage of Refrigerants
• 4.11 Release Reports
• 4.12 Record Keeping
• 4.13 Conversion of a System to an Alternate Refrigerant (Retrofit)
• 4.14 Shut Down
• 4.15 Decommissioning
• 4.16 Disposal of Refrigerant

4.1 System Start-up

Before starting the system, the technician should be familiar with the manufacturer's installation, operating and maintenance manuals, this code of practice, and all applicable regulations and standards. The objective of the start-up is to verify that all components and controls are in working order through functional performance testing. The following are good practices:

• Ensure that the system meets all specification requirements.
• Verify the installation of all components of the system, including piping, piping connections, anchors, hangers, vibration insulators and insulation.
• Ensure proper labeling of the system and its components.
• Confirm that electrical systems are properly wired. If operating on three-phase electrical power, confirm that the system shuts down if any one of the phases is opened.
• Ensure that mechanical room safety features and ventilation are adequate.
• Check and test all the system controls, detectors and actuators.
• Compile test results and prepare a final commissioning report upon completion of system start-up.
• Create the service log for this system.

Refer to Section 4.8-Charging and to the manufacturer's charging instructions to complete the commissioning. If the system is pre-filled, follow the manufacturer's instructions for start-up.

4.2 Preventative Maintenance

Developing and implementing a preventive maintenance plan for all the air conditioning and refrigeration assets will benefit the environment and prolong the life of the system. The following should be considered in developing and implementing a preventive maintenance plan:

• Include an inventory of all refrigerants and cooling systems.
• Identify what records are to be created, how often they are to be updated and where they need to be kept.
• Ensure that the system's service log is accessible so that technicians can retrieve its tombstone and historical performance data.
• Ensure that the qualified technician possesses the proper environmental awareness certificationbefore performing work that may lead to a refrigerant release.
• Include scheduled inspections and maintenance procedures.
• Include scheduled leak tests in accordance with the Federal Halocarbon Regulations, 2003.
• Include regularly scheduled calibrations of test equipment in accordance with the manufacturer's recommendations.
• Include the tracking of servicing and repairs to identify trends in system performance.
• Establish a system for tracking complaints and maintenance calls to monitor the performance of the system's instrumentation and control systems.
• Ensure that contractors are made aware of the preventive maintenance plan.
• Identify the resources needed to carry out the planned preventive maintenance programs.
• Ensure that immediate steps are taken to stop refrigerant release.
• Calibrate test equipment such as test gauges, weigh scales and refrigerant detectors in accordance with the manufacturer's instructions.
• Review the system's log periodically and in relation to past work orders to identify trends and to take appropriate action.
• Leak-test systems with a history of leakage or frequent air purge regularly. Note that spindle gland-packing nuts on valves do not require tightening unless they are leaking.
• Replace filter-dryer cores when the filter and/or desiccant are no longer viable.
• Regularly inspect and flush evaporators to minimize corrosion problem.
• Purge trapped gases in condensers and evaporators periodically.
• Clean the evaporator air-side surfaces and drain the condensate pans to prevent the build?up of microbial growth. Condensate pans could have biocide pucks placed in them to prevent the growth of bacteria in the pans and drain lines. Biocide pucks may be considered if recommended by the system manufacturer.
• Lubricate rotating shaft at the seals on large open compressor systems during shutdown.
• Replace saddle valves by welded-in access valves or have the tube puncture welded shut if it was used as a tool during servicing.
• Use dry nitrogen as a welding blanket during welding or brazing; do not use refrigerant.
• Use caution not to overheat pipes when welding or brazing because it may cause scaling on the inside.
• Replace a defective motor with a more efficient one.
• Replace the neoprene packing glands in Schrader valves when they become deteriorated. The valve stem in these valves can be replaced without evacuating the system.
• Cap Schrader valves to prevent dirt entering and to help prevent leaks from a faulty valve. Metal caps with rubber inserts are preferred since they provide a good seal.
• Use Schrader valves to attach gauge manifold test sets.
• Examine all piping and fittings for cleanliness and corrosion.
• Inspect visually and confirm the tightness of the mechanical joints before performing a nitrogen pressure test.
• Tighten flanges evenly and to the manufacturer's torque setting.
• Replace caps that cover gauge points and leak-test after service.
• Use safe working practices and personal protective equipment. The following hazards can cause injuries (not an exhaustive list):
  • discharge of high-pressure refrigerant from burst hoses,
  • hot parts of automotive engine compartments,
  • generation of harmful gases by exposing halocarbon refrigerant to an open flame,
  • danger of explosion when exposing hydrocarbon refrigerant to an open flame,
  • opening valves too quickly,
  • leaving refrigerant recovery equipment on and unsupervised,
  • overfilling cylinders.
• Update the system's service log.

4.3 Inspection

A frequent walk-around is a simple, cost-effective manner of minimizing cooling system failures and refrigerant releases. The following verifications on cooling systems should be considered as applicable to each particular system:

• Inspect systems regularly according to manufacturer's specifications, or at least twice a year if no specifications exist.
• Check the sight glasses for the proper levels of fluids. Bubbles in the refrigerant can be an indication of low refrigerant levels or leaks in the system.
• Ensure that the levels on gauges and settings on thermostats and other sensors and controls are within acceptable ranges.
• Confirm that filter-dryer cores and/or desiccant are still viable.
• Listen to the sound of the compressor and condenser fan for deviations from the norm.
• Note any unusual vibrations.
• Check for leaks from rotating shaft seals, O-rings, mechanical connections and rusting components.
• Examine the system for indications of oil leakage.
• Check the piping and fittings for indications of damage or corrosion.
• Ensure that the condenser is clean and that the air flow to and from it is unimpeded.
• Ensure that the air around the condensing unit is not hotter than the ambient air.
• Check the belts on open belt-driven compressors for wear, damage and tension. Worn or damaged belts, misalignment or over-tensioning can cause compressor shaft seal and front-end bearing failure, resulting in leaks. Confirm V-belt is not too tight.
• Ensure that the evaporator coil is not iced up and that the condensate pan drain is functioning. A build-up of ice may indicate problems with the electric or hot gas defrost cycle, or that the compartment is open too long or too often without a vinyl curtain to isolate the compartment from the occupied space.
• Ensure that the system guards are in place and not loose.
• Ensure that area signs are in place.
• Ensure housekeeping in the area is good.
• Confirm that the air quality monitor in the mechanical room is functioning.
• Look for indications in the occupied areas that zones are being over- or under-cooled (for example, louvres sealed shut or improvised deflectors).
• Check the refrigerator and freezer doors for proper seal.
• Inspect the refrigerant storage area (see Section 4.10 - Handling and Storage of Refrigerants for details).
• Update the system's service log after inspection.

4.4 Leak Testing

While an annual leak test shall be done in accordance with the regulations, the manufacturer's recommendations should be considered as part of the organization's preventive maintenance plan. It is essential to perform a leak test at least once a year and in accordance with applicable regulations, policies and manufacturer's specifications. If the system has a history of leakage, more frequent leak tests should be considered. Small sealed packaged units like window air conditioners, water coolers, vending machines and domestic refrigerators do not need a regular leak-testing program.

When to perform leak tests

As prescribed in the Federal Halocarbon Regulations, 2003, leak tests must be carried out:

• before charging a system with refrigerant (new system, after repairs or after it has been out of service),
• after initial start-up (see Leak-Testing Procedure below for details),
• when a leak is suspected, and
• when parts or replacement parts are to be installed.

Leak-Testing Procedure

In a normal situation, the high and low sides of the system equalize on shutdown. The static pressure normally is enough to locate leaks.

On larger hot-gas type systems, the low-pressure side could be pressurized before leak-testing the evaporator, heat exchanger, thermostatic expansion valve or solenoid valve by short-circuiting hot gas to the low-pressure side. The pressure cannot exceed the pressure of the relief devices.

On sub-atmospheric systems, the evaporator water temperature can be raised a few degrees to facilitate leak testing.

Leak-testing procedure typically includes the following steps:

• Conduct a visual check for leaks by inspecting sight glasses and look for staining or traces of oil.
• Leak-test using any one or a combination of the following methods:
  • using a fluorescent dye that is compatible with the refrigerant and oil,
  • using a bubble test with a soap and water solution for larger leaks,
  • using water immersion tests for parts that have been removed.
• Common areas where leaks occur in systems:
  • piping connection,
  • Schrader valves,
  • compressor gaskets,
  • rotating shaft seals,
  • control bellows.
• Use an electronic leak detector sensitive to the refrigerant in use and with a suitable minimum detection level (when selecting this method).
• Ensure that the mechanical room is not contaminated with refrigerant before leak-testing a system.
• Test under the connectors because refrigerants are heavier than air.
• Shield the area (for example, use a tarp) when leak-testing out-of-doors in windy conditions.

4.5 System Repair

Identify the location of the leak and carry out the leak-testing procedure using best practices. Before initiating a repair, consult the system's maintenance record to determine if there is a history of leaks, which could indicate that other measures have to be considered.

System repair procedure typically includes the following steps:

• Isolate the section of the system that needs repair, if possible.
• Recover the refrigerant from the leaking portion or the entire system into the system's receiver, which could be the condenser or auxiliary receiver; otherwise, pump it into a suitable approved storage container.
• Repair the leak:
  • Tighten the piping connection if the leak is due to a loose mechanical connection.
  • Repair Schrader valves using tools that allow replacement of the valve core while the system is under pressure if the valve is leaking.
  • Brazing or welding is usually preferred for leak repair of piping.
  • Replace components that have rusted or leaking casings.
• For larger systems, conduct the standard test:
  • a standing vacuum test to 75 mm Hg (3 in Hg) for 15 minutes, or
  • a standing pressure test at 1034 kPag (150 psig) of dry nitrogen for 24 hours.
• Charge the unit to the proper operating level (see Section 4.8 - Charging).
• Run the unit in accordance with the manufacturer’s instructions (4 to 48 hours) and carry out another leak test.
• Update the service log and leak-test notice according to the applicable regulations to record the details of the work performed.
• Change or modify the equipment labels if needed.

Note that if the leak cannot be repaired, the refrigerant has to be recovered and the system disposed of in accordance with applicable regulations.

4.6 Recovery, Reuse, Recycling and Reclaiming of Refrigerants

In accordance with applicable regulations, refrigerant removed from a cooling system may be:

• reused,
• recycled,
• reclaimed, or
• disposed of.

It is prohibited to vent refrigerants to the atmosphere in Canada. The recovery equipment is expected to be in good working order before use. If applicable, the extraction efficiency has to meet the standards set for the jurisdiction in which the work is performed. In the absence of standards, remove as much refrigerant as possible. As a rule of thumb, 90% of the refrigerant can usually be recovered if the compressor is operational; otherwise, 80% could be recovered.

If not contaminated, the recovered refrigerant can be reused in the same system.

Refrigerant Recovery Methods

There are two acceptable methods of recovering refrigerants from cooling systems: active recovery and adsorption recovery. There are two types of active recovery: Type 1 active recovery equipment simply recovers the refrigerant. The refrigerant is returned to the same system or a similar system in the organization. Type 2 active recovery and recycle equipment recovers refrigerants and improves their quality by removing particulate matter, moisture and oil. The refrigerant is of superior quality to that removed by Type 1. This method usually will not remove ultraviolet dyes and sealants. The adsorption recovery method transfers the refrigerant to a container with resin, which is then sent to the supplier to reclaim the refrigerant.

Recovery Equipment

Select the appropriate recovery equipment for the planned work and consider the following best practices:

• The equipment has been serviced by:
  • emptying oil containers,
  • changing compressor oil,
  • replacing dryers,
  • replacing internal filters before each service job, and
  • checking equipment including hoses for leaks.
• The equipment meets recovery standards for extraction efficiency.
• The equipment is not cross-contaminated with other refrigerants.
• The equipment is intended for the type of refrigerant being processed and will clean the refrigerant to meet the required specifications (for recovery and recycling equipment).

Refrigerant Recovery Containers

Recovery containers are grey and yellow, and when they are used to recover a refrigerant, they are labeled to identify the refrigerant they contain. Generally, they are not identifiable by the designated ASHRAE refrigerant colour. There are various types of containers: 1) Recovery drums are grey with a yellow cover and are used for liquid refrigerants; 2) Recovery cylinders are grey with a broad yellow band on the top and have a two-way liquid/vapour valve. 3) Ton tanks are also grey with a broad yellow band around the end and are used to recover larger quantities of refrigerant from cooling systems to facilitate the reuse of a refrigerant following servicing. 4) Molecular sieve or resin adsorption containers are not pressure cylinders and are approved by Transport Canada. Recovery containers may be exposed to contaminants that could compromise their integrity. The Transportation of Dangerous Goods Act has specifications for refrigerant recovery containers.

Refer to Section 4.10 - Handling and Storage of Refrigerants for more information on refrigerant containers.

Recovery Procedure

A recovery procedure typically includes the following steps:

• Bring system to room temperature.
• Ensure that the recovery containers used are appropriate and are in good condition. Pressure vessels are the preferred type of recovery container for all types of refrigerants, including liquid.
• Fill the recovery container with only one type of refrigerant (do not mix refrigerants).
• Place the recovery container on a portable weigh scale to avoid overfilling.
• Allow a vapour space equal to 10% of the drum height when filling a drum with a low-pressure refrigerant if using a recovery drum for a liquid refrigerant.
• Ensure that the designed maximum working pressure that is stamped on the cylinder or ton tank is never exceeded during recovery, even temporarily.
• Consider that the weight-carrying capacity of a recovery container may be influenced by certain factors. Refrigerant/oil mixtures have a lower density than refrigerant alone, and therefore the weight-carrying capacity of a recovery container will be reduced. A good rule of thumb is:
  • not to exceed 80% of the maximum net weight capacity, stamped on the upper portion of a recovery cylinder, for ambient temperatures of around 21°C (70°F); or
  • not to exceed 60% of the maximum net weight capacity if the temperatures could reach 49°C (120°F).
• Supervise the whole recovery operation; do not leave equipment unattended.
• Bond the recovery container to the recovery equipment before transferring the refrigerant (refrigerants that are flammable).
• Open valves slowly on the recovery cylinder or ton tank.
• Label the recovery container to indicate the type of refrigerant, including any information about additives that may be contained in the recovered refrigerant (for example, ultraviolet dye or sealant).
• Track the weight of the recovered refrigerant.

Under the Federal Halocarbon Regulations, 2003, if the system will be disposed of, it has to be labeled to indicate that the refrigerant has been removed. If the recovered refrigerant is contaminated, the container should be sent to be reclaimed or disposed of in accordance with applicable regulations.

It is best practices to warm the system using the oil sump heater or with indirect heat to recover refrigerant from oil before it is removed. Open flame cannot be used. Oil in the crankcase can also be heated to vaporize residual refrigerant. For low-pressure systems, the evaporator temperature can be raised using hot water.

4.7 Cleaning

Repairing a system after it has been contaminated by a hermetic compressor failure or conversion of systems from HCFC/mineral oil to HFC/polyolester oil typically includes a thorough cleaning by flushing. Older servicing equipment may not be compatible with new refrigerants, and therefore new hoses, seals and O-rings may be necessary.

Generally, the procedure is as follows:

1. Test for leaks.
2. Remove refrigerant.
3. Remove oil.
4. Flush system.
   • Use procedures recommended by the manufacturer.
   • Use a non-ozone-depleting flushing agent approved for the refrigerant and oil being cleaned.
   • Use a liquid flushing agent from a pressurized container, since flushing agents in open containers can be contaminated with the moisture in the air. Biodegradable flushing agents with boiling points in the order of 85 to 90°C (185 to 195°F) work efficiently and thoroughly.
   • Flush system until the flushing agent is contaminant free. Note that flushing will remove both the refrigerant and oil.
5. Remove flushing agent.
   • Draw a vacuum to 500 mm Hg (20 in Hg) to ensure that the entire flushing agent has been removed.
6. Change components.
   • Conversion kits may be available, particularly for domestic systems. Dismantle the system one section at a time and change components as necessary. Consider replacing the filter-dryer. It is best practice to replace any removed gaskets with new ones that are compatible with the refrigerant and oil.
7. Reassemble system.
8. Test for leaks.
9. Charge.
   • Charge the system immediately with refrigerant and oil using the approved procedures, or seal if not in use to prevent atmospheric contamination (refer to Section 4.8 - Charging).
10. Test for leaks.
    • Run the system for the recommended time and perform another leak test.

      Small systems:

    • Recheck for leaks after 4 to 8 hours of operation.

      Other systems:

    • Recheck for leaks after 24 to 48 hours of operation (refer to Section 4.4 - Leak Testing).
11. Document.
    • Label the system and update the service log (refer to Section 4.12 - Record Keeping)

Other systems

Auxiliary receivers or specially approved ton tanks may be used to recover larger quantities of refrigerant from cooling systems to facilitate the reuse of the refrigerant charge after servicing. It is best to clean each section of a system separately. Consider taking the component to be cleaned off-site.

4.8 Charging

Generally, the procedure is as follows:

• Ensure that each section of the system is leak-tested.
• Ensure that the system is clean and free of moisture. If necessary, flush the system (refer to Section 4.7 - Cleaning).
• Ensure that charging equipment materials are compatible with the refrigerant.
• Pressure-test charging equipment (hoses and gauge manifolds) using dry nitrogen before attaching to the system.
• Install either self-reseating or isolation valves placed at 15 to 30 cm (6 to 12") of the end of the charging lines.
• Use quick disconnect fittings with one-way valves.
• Install a fresh filter-dryer in the system.
• Weigh refrigerant container to determine the quantity of refrigerant in the container.
• Ensure that refrigerant containers are not connected to a system at a higher pressure.
• Add refrigerant slowly to pressurize the system one section at a time.
• Leak-test each section before proceeding to the next. If there is a leak in any section, the refrigerant should be recovered and the leak repaired before proceeding further (refer to Section 4.4 - Leak Testing).
• Measure the amount of refrigerant charged using an appropriate scale or a volumetric charging device.
• Adjust the refrigerant charge to the correct pressure settings as indicated by the system manufacturer. Note that the charge of refrigerant in systems assembled with pre-charged components may need to be adjusted.
• Collect purge gas using appropriate technologies. Non-condensable fluids such as air from the lines can be recovered using conventional or adsorption technology.
• Label the system with weatherproof, permanent labels indicating the date, refrigerant type and charge, and oil type and quantity. If an ultraviolet dye has been added to the charge, include this information on the label as well.
• Place one label on the compressor above the weld line, one on the back of the cabinet just above the compressor compartment, and, if applicable, another just inside the refrigerator door by the model/serial number.
• Update the log, note the full charge and type of refrigerant and oil, and whether an additive was added, and note the type and quantity.

4.9 Sealants

When added to a refrigerant, a sealant may slow a leak in a system, but it will not completely fix it. The sealant will seep out of any small holes or cracks along with the refrigerant and, on contact with air, will solidify and seal the hole. Sealants only work when the system is operating.

Because a sealant will continue to do its job on subsequent small holes and cracks, it may conceal the deterioration of a component of a system and lead to a large leak in the future. Therefore, sealants should only be considered for the following:

• In emergencies on mobile systems.
• In small package systems such as vending machines, ice cream display cases and water coolers.
• In remote, unattended locations.

Before using a sealant:

• Determine if the leak is small.
• Determine that the leak is on the low-pressure side. Usually, sealants do not work if the leak is on the high-pressure side.
• Consult the manufacturer of the system and the supplier of the refrigerant to determine if the sealant is compatible with the system and the refrigerant.
• Consider using sealants with an ultraviolet dye, since this combination could reveal locations where formerly sealed leaks are located.

When adding a sealant:

• Ensure that the system is operating.
• Affix a label, weatherproof if located outside, to the compressor and above the compressor to indicate that a sealant has been added to the refrigerant.

4.10 Handling and Storage of Refrigerants

Various types of containers are used to store virgin or recovered refrigerants in the liquid or gas state. They vary in size, shape and pressure rating. Refrigerant containers can be colour-coded to identify which refrigerant or blend they contain. All refrigerant containers should meet the Canadian Transport Commission specifications under the federal Transportation of Dangerous Goods Act.

Containers for Refrigerants in the Liquid State

Drums can be used to store liquid refrigerants such as R-22. Some are returnable.

Containers for Refrigerants in the Gas State

A pressure vessel is a refrigerant container of a capacity of more than 28 litres (1 cubic foot). The designed maximum working pressure, carrying capacity and expiry of the pressure certification is stamped on the cylinder.

Refillable refrigerant cylinders can only be used by refrigerant manufacturers for virgin refrigerant and need to be visually inspected and re-qualified as stated in the applicable jurisdiction. Many of the refillable refrigerant cylinders sold in Canada are white with a label that is colour-coded and/or that indicates which refrigerant the cylinder contains. Disposable cylinders only have a one-way valve and are not appropriate for refrigerant in a gas state.

Refer to Section 4.6 - Recovery, Reuse, Recycling and Reclaiming of Refrigerants for information on refrigerant recovery containers.

Storage of Refrigerants and their Containers

Good practices for refrigerant containers usually include:

• protected from rusting,
• leak-free,
• stored upright and securely with all valves and bungs closed,
• manifolded only if there is no possibility of temperature differences existing between them that could result in refrigerant transfer and the danger of overfilling the coldest container. Where containers are manifolded, ensure that all containers are the same height to avoid gravity transfer between containers, and
• stored away from any source of heat or where temperatures could exceed 51°C (125°F).

Storage, handling and servicing areas are:

• smoke-free,
• fenced, labeled and protected from vandalism and weather,
• monitored when large quantities of refrigerant containers are stored, and
• well-ventilated, cool and dry, away from risk of fire, sources of direct heat and direct sunlight.

In addition to general handling and storage practices, fire protection requirements for refrigerants that are flammable have to be incorporated, including the following:

• Cylinders are to be stored at least 3 m (10 ft) from other buildings and be electrically grounded, and the grounding checked periodically for corrosion.
• All electrical equipment is appropriately rated.
• The area is labeled appropriately.

Handling and Transfer of Refrigerants

Handle refrigerant containers carefully, avoiding dragging, dropping and denting, and secure containers into place. When not in use, close container valves and screw on the valve outlet cover nut or cap.

Use a pump and weigh scale when transferring refrigerant in order to prevent releases and to prevent overfilling the container. A pressure differential can be established between the containers using a pump or by heating the discharge container under controlled conditions. The discharge container can be indirectly heated by warm water or forced warm air to a maximum of 49°C (120°F). Do not use direct heating, with the exception of plug-in charging cylinders (dial-a-charge). Avoid mixing refrigerants in one container. Ensure the container is colour-coded and labeled accordingly.

Handling procedures for refrigerants that are flammable are similar to those for other flammable substances:

• Ensure that handling is conducted in a well-ventilated area.
• Ensure that no ignition sources are within 3 metres.
• Ground and bond all components, including charging rigs and cylinders.
• Wear required personal protective equipment such as gloves, glasses and non-static clothing.

Storage and Shipping of Equipment

Consider storing and shipping systems with dry nitrogen or dry air (-40°C dew point) as a holding charge.

4.11 Release Reports

The Federal Halocarbon Regulations, 2003 and most Canadian jurisdictions have halocarbon release reporting requirements for cooling systems. Some require that releases over a certain weight, usually 10 kg(22 lb), be reported to the authorities.

• Owners must be familiar with the halocarbon release reporting requirements in their applicable jurisdictions.

4.12 Record Keeping

According to the Federal Halocarbon Regulations, 2003, owners have to maintain a service log to record the installation, servicing, leak testing, charging or other work on cooling system that could result in the release of a halocarbon. Records may also be kept on refrigerant storing containers. The service log has to be updated each time the system is serviced. Forms are available on Environment Canada's website. Ideally, an up-to-date service log would be kept close to the system. A copy can be attached to service contracts for background information on the history of servicing and preventive maintenance.

Consumption Reports

Some jurisdictions require annual reports of refrigerant consumption.

Record Retention

The Federal Halocarbon Regulations, 2003 and some jurisdictions require that owners keep, for a specified period of time, all service logs, notices, records and reports on the site where the cooling systems are located.

4.13 Conversion of a System to an Alternate Refrigerant (Retrofit)

One of the best ways to reduce the environmental impact of ozone-depleting substance releases is to convert the air conditioning or refrigeration system to a system that uses a refrigerant with a significantly lower, or zero, ozone-depleting potential.

Owners of multiple cooling systems should consider developing a long-term strategic plan to upgrade their air conditioning and refrigeration assets.

Ensure that a person knowledgeable in the cooling industry participates in the decision-making process. When deciding whether or not it is beneficial to retrofit a cooling system, owners can consider taking the following steps:

• Consult the system's manufacturer to assess the feasibility of a retrofit.
• Confirm that the cooling need is the same; if not, recalculate it.
• Assess the condition of the existing system.
• Perform a life-cycle cost analysis to determine if replacing the existing system with a more efficient one could result in a reduced cost over the life of the system.
• Consider the energy efficiency of the options being considered. While new refrigerants could match or come close to the existing refrigerant's cooling capacity, the efficiency of the system may decline.
• Consider that HCFC (including R-22) and blends containing HCFCs will only be allowed to be imported until 2020.

If it is determined that retrofitting the existing cooling system is the best alternative, consider the following in the selection of an alternate refrigerant and oil:

• Consult the system manufacturer and refrigerant manufacturers.
• Examine the ozone-depleting potential, global-warming potential and toxicity of the alternative.
• Consider the effects on efficiency.
• Examine the compatibility with all system components, for example, compatibility of the motor winding for hermetic systems.

Conversion of a system operating with CFC/HCFC refrigerant to HFC refrigerant may lead to:

• changing seals and gaskets,
• adjusting controls,
• changing to synthetic lubricants.

Conversion of a system operating with HFC refrigerant to hydrocarbons refrigerant may lead to:

• changing key components of the system,
• upgrading associated facilities to meet requirements for explosion proofing.

A conversion kit may be available from the manufacturer to assist in the conversion of a system. It may even be specific to the model and application. Retrofitting a system may be an opportunity for using improved components, such as high-efficiency motors or more efficient condensers.

Retrofit steps to follow:

• Use a certified technician to perform the retrofit.
• Leak-test the system and repair all leaks (see Sections 4.4 - Leak Detection and section 4.54.5 - System Repair).
• Recover refrigerant and oil (see Section 4.6 - Recovery, Reuse, Recycling and Reclaiming of Refrigerants).
• Clean and flush the system (see Section 4.7 - Cleaning).
• Perform the retrofit as instructed by the system manufacturer, remembering to replace the components that are not compatible.
• Leak-test the system.
• Charge the system (see Section 4.8 - Charging).
• Leak-test the system.
• Run the system for the recommended time and proceed with another leak test. Typically:
  • for small systems, operate systems for 4 to 8 hours and recheck for leaks,
  • for other systems, operate systems for 24 to 48 hours and recheck for leaks.
• Ensure proper handling and disposal of refrigerant (see Section 4.10 - Handling and Storage of Refrigerants).
• Label the system to indicate the type and amount of both new refrigerant and oil.

4.14 Shut Down

For a system greater than 19 kW(5.6 tR) that has to be shut down for more than six months, consider isolating the refrigerant in the system's receivers or removing it to approved storage containers.

Where a system has had its refrigerant removed, and that system may be used again in the future, it can be charged with dry nitrogen to help prevent its contamination. Note that ideally all the moisture would be remove from the nitrogen. Storing out of service small cooling systems inside a heated building should be considered.

4.15 Decommissioning

When decommissioning, putting out of service or disposing of equipment, the following steps need to be considered:

• Recover as much refrigerant and oil as possible from the cooling system before disposal (refer to Section 4.6 - Recovery, Reuse, Recycling and Reclaiming of Refrigerants).
• Store refrigerant in approved containers (refer to Section 4.10 - Handling and Storage of Refrigerants).
• Label the system to indicate that the refrigerant has been removed. Labels have to conform to the requirements of the applicable jurisdiction.
• Label refrigerant containers.
• Retain proof to show that the refrigerant and oil have been recovered from the cooling system.

Domestic appliances (for example, refrigerators) that contain a refrigerant should be handled with care and they may have to be brought to a pre-assigned site for the recovery of the refrigerant and oil. In some cases, the refrigerant can be removed first, in accordance with applicable regulations.

4.16 Disposal of Refrigerant

When a refrigerant is contaminated and can no longer be used, return it to:

• a refrigerant supplier or other approved facility to be recycled, reclaimed or destroyed, or
• a hazardous waste disposal center.

The oil has to be disposed of in accordance with provincial and territorial regulations. Note that blends can be returned to certain facilities.