Residential Systems and Domestic Appliances
3.1 Types of Systems
Residential systems include central air conditioning or split
systems under 17.6 kW (5 tR) of capacity, window air
conditioners, heat pumps, and central dehumidifiers.
The general principles which underlie Section 2,
Commercial/Industrial Systems, are also applicable to residential
systems.
Appliances includes plug-in residential refrigerators,
freezers, window air conditioners, and dehumidifiers. Appliances
are generally very reliable systems but proper procedures in
manufacturing and refrigerant recovery are essential.
3.2 Equipment and
Systems Design
3.2.1 Compressor
To prevent leaks and emissions, the compressor should be
mounted on the unit's frame in such a way as to prevent vibration
and stress on connecting tubing. The compressor should be
accessible and removable for leak testing and repairs.
3.2.2 Isolating Valves
Isolating valves should be provided to permit compressor
removal and replacement without losing the refrigerant charge. A
suitable permanent valve for a recovery connection should be
provided on all appliances.
3.2.3 Condensers and
Evaporators
Condensers and evaporator coils should be designed and mounted
in a way that will prevent vibration. Only welded non pre-charged
line sets should be used to attach the evaporator and the
condensing unit together. Quick connects are not a dependable
leak-free permanent connection and as such their use (except for
temporary use) should be discontinued by January 1, 1996.
3.3 Equipment
Manufacturing
The equipment manufacturing process should verify that systems
are leak-free before charging with refrigerant. The reuse of
trace gas mixtures used for leak testing systems should be
implemented.
Fugitive emissions should be captured using the best available
technologies from the evacuation and dehydration process.
Isolation valves should be used to isolate the compressor,
condenser, and evaporator on larger residential systems. All
systems should have access valves for the recovery of
refrigerants.
3.3.1 Elimination of Emissions in
Manufacturing
Elimination of emissions should be established by:
- verifying the system is leak-free before charging with
refrigerant;
- leak testing after run-in;
- checking the carton for damage before shipment; and
- checking the carton for refrigerant leakage.
The unit may be repaired and recharged using the original name
plate sticker. If a depot or retail store finds a refrigerant
shortage, they should leak test the unit and apply a repair
sticker indicating the sealed system has been opened.
3.3.2 Cleanliness of Systems
Systems should be absolutely clean to reduce the risk of
refrigerant contamination. Key personnel should be conversant
with refrigerant technology and familiar with all aspects of the
manufacturing process, especially those related to emission
prevention.
3.3.3 Labels
Labels on equipment are essential to prevent accidental
addition of improper oils or refrigerants during servicing.
Labels should be permanent and displayed prominently. Information
should include:
- equipment manufacturer,
- refrigerant type CFC, HCFC, HFC, or blend,
- ASHRAE Refrigerant Number,
- ASHRAE Safety Designation,
- refrigerant quantity,
- refrigerant oil type, quantity, and viscosity,
- ozone-depleting potential, and
- global warming potential.
See Appendix B for examples.
3.4 Installation
and Servicing
3.4.1 General Servicing
All service persons should have an environmental awareness
course card. Installation and Servicing personnel should be
qualified and knowledgeable about the equipment they are
servicing or installing. Proper location and installation
procedures are important.
Equipment should be located so that leak testing and
maintenance are not impeded.
3.4.2 Bolt-on Access Valves
Bolt-on access valves cannot be used other than as a tool that
must be removed before the service person leaves the job site, or
the repair shop. These valves may be used to evacuate systems
before disposal.
3.4.3 Leak Testing and Repair
The following procedures are recommended and approved before
repairing leaks and replacing components in systems.
- Verification that the unit is genuinely short of charge,
before opening the closed loop.
- The system should be thoroughly leak checked before and
after servicing, using the best available technology,
e.g., an electronic leak detector, capable of detecting
leakage rates of less than 14 g (0.5 oz) per year. If a
leak is found, the unit should be evacuated and repaired.
- Leak testing using ODS and releasing them to the
atmosphere is an unacceptable practice and is illegal in
most provinces.
- In the case of an non-repairable leak, the refrigerant
should be recovered and the owner should dispose of the
equipment in accordance with the appropriate Municipal
By-laws or provincial regulations. All refrigerant and
oil should be recovered.
If there is a repairable leak, the following procedures are
recommended:
- The service person will attach an access entry valve if
necessary, and evacuate the system.
- A permanent access entry valve is brazed onto the
refrigeration system before the closed loop is punctured.
This should be done in accordance with CEASA procedures.
- Small systems will then be sweep charged using the
appropriate CEASA procedure.
NOTE: Do not use ODS for the leak test.
- After a leak testing and repair, the sweep charge is
recovered.
- The unit is recharged to the proper operating level.
The following alternate methods are recommended for larger
equipments:
- Standing Vacuum test 75 µm for 15 minutes. The system is
then repaired and recharged.
- Standing pressure test at 1034 kPag (150 psig) of dry
nitrogen for 24 hours. The system is then repaired and
recharged.
NOTE: Charging cylinders are tools and not approved storage
vessels and cannot be used to store or transport refrigerant
.
The unit should be isolated to contain the refrigerant or have
the refrigerant recovered until the service is completed when
repairing leaks and replacing components on residential systems.
Leak repair of a residential split system, usually entails
removing a maximum of four to five pounds of refrigerant which
should be recovered for reuse. Epoxy should not be used to repair
leaks, as it may fail or loosen after several months service.
Brazing or welding is preferred.
3.4.4 Recovery, Reuse, Recycling, and
Reclamation
Recovery, reuse, recycling, reclamation of refrigerant is the
only acceptable practice today. Venting of refrigerant into the
atmosphere during manufacturing, installation, or servicing is
unacceptable. Typical and nontraditional recovery systems such as
resin adsorption technology are now available to recover
refrigerant.
Refrigerant Recovery. There are three acceptable
methods of recovering refrigerants from residential systems and
appliances.
- The Active Recovery Method (recovery machine and an
approved recovery cylinder). Typical active recovery
equipment consists of two basic types. Type one is
capable of refrigerant recovery only. The quality of the
refrigerant removed for reuse or storage is exactly the
same as was in the system being emptied.
The second
type of equipment (recovery/recycle) not only recovers
refrigerants similar to type one, but also improves the
refrigerant quality by removing particulate matter,
moisture, and refrigerant oil. The material stored or
returned to the system is of superior quality to that
removed by type 1.
- The Passive Recovery Method uses a specially designed
industry approved plastic recovery bag (for domestic
refrigerators and freezers only). The bag has been
designed to recover 672 g (24 oz) of R - 12 or R-500, or
560 g (20 oz) of R-22 or R-134a and is reusable and
recyclable.
The recovered refrigerant is then
transferred to an industry approved recovery cylinder for
reclaiming back at the shop.
- The Adsorption Recovery Method uses resin in a cylinder.
The cylinder is then sent back to the supplier to have
the refrigerant reclaimed. Because this cylinder is not
under pressure it can be transported without special
labelling under the Transportation of Dangerous Goods
Act .
Standards for Recycled Refrigerants . Service
organizations should ensure that the recycled refrigerant quality
meets the appropriate industry standard of purity, unless the
refrigerant is being returned to the same system.
Recycling Equipment Maintenance . Follow the
recovery/recycling equipment manufacturers' maintenance
instructions using the prescribed filter and cleanup procedures.
This equipment service includes such things as emptying oil
containers, changing compressor oil, changing filters and dryers,
checking equipment and hoses for leaks. This will ensure that the
level of quality of final recycled refrigerant is in accordance
with the equipment manufacturers' certified claim.
3.5 Refrigerant
Cylinders
3.5.1 Approved Refrigerant Container
The designed maximum working pressure and carrying capacity of
the refrigerant recovery container should not be exceeded. The
working pressure is stamped on the cylinder.
A nonpressurized refrigerant recovery container such as the
molecular sieve or resin adsorption container is approved by
Transport Canada. These containers are not pressure cylinders.
Disposable cylinders should not be used. Low pressure
refrigerants are normally shipped in drums which may be
returnable or nonreturnable.
3.5.2 Refrigerant/Oil Mixtures
Refrigerant/oil mixtures have a lower density than refrigerant
alone. Fill refrigerant recovery containers with mixture only to
80% by weight of the allowable pure refrigerant weight.
3.5.3 Contaminated Refrigerant
If contaminated refrigerant is decanted into a refrigerant
container, corrosion may occur. This container should be sent to
the reclaimer or disposed of as hazardous waste as soon as
possible.
3.5.4 Refrigerant Container Belonging to a
Third Party
Refer to Section 2.9.3 of this report.
3.5.5 Cross-contamination of Refrigerant
M ixing of different refrigerants should be avoided. The
receiving container should have been used previously only for the
refrigerant that is being transferred into it.
3.6 Conversion
of Systems to Alternate Refrigerants
In future it will become necessary to convert some CFC systems
to alternate refrigerants. This is environmentally desirable as
the alternates have very low, or zero ODP values.
3.6.1 Basics of Conversion
The basic principles for conversion are the same as those for
commercial equipment described in Section 2.8.1.
Ensure the new refrigerant has a zero or very low ODP and is
thermodynamically efficient. It is also important that it is
compatible with all system components and parts, including the
lubricant oil. Parts that are not compatible must be replaced.
3.6.2 Recommended Procedure
Remove all refrigerant using recovery/recycling equipment and
put recovered refrigerant in an approved recovery container.
Warm the system with indirect heat to recover refrigerant from
oil, then remove oil. Flush system if necessary using procedures
recommended by the manufacturer. Change components as necessary.
Reassemble the system and evacuate to 75 µm of Hg. If there are
any leaks use an approved tracer gas and an electronic leak
detector.
After the system is leak free, recharge with the new
refrigerant and recommended oil. Recheck for leaks. Operate
systems for 4 to 8 hours and recheck for leaks.
3.6.3 Surplus Used Refrigerant
Used refrigerant should be returned to the supplier or
manufacturer for credit, reclamation, or disposal or it should be
sent to an independent reclamation centre. Reclaimed material
should meet or exceed ARI-700 purity standards for refrigerant to
be reused (see Appendix A).
3.7 Handling
of Used Refrigerant
Refrigerant removed from working equipment may be:
- reused,
- recycled,
- reclaimed and returned to the supplier, or
- disposed of as hazardous waste.
Ensure that recycling equipment is intended for the type of
refrigerant being processed and will clean the refrigerant to
meet prescribed specifications, i.e., ARI 700 latest edition.
Refrigerant that cannot meet the prescribed purity specifications
must be returned to the supplier for reclamation or disposal
using environmentally acceptable methods of destruction.
3.7.1 External Agencies
An external agency that reclaims used refrigerants should
ensure that the equipment it uses is functioning properly and the
reclaimed refrigerant meets the prescribed purity specifications
as defined in ARI 700 latest edition (verified by laboratory
analysis).
3.7.2 Destruction Facilities
Facilities are presently available with limited capability to
destroy mixtures of refrigerant that cannot be reused, recycled,
or reclaimed. These mixtures should be returned to the
manufacturer.
Refrigerant that has been contaminated by foreign or toxic
materials (excluding oil) must be sent to a hazardous waste
disposal centre.
3.8 Disposal
of Appliances Containing Refrigerants
The disposal of appliances that contain refrigerant should be
handled with care and brought to a pre-assigned site for the
recovery of the refrigerant and oil.
Alternatively, have the refrigerant removed first, depending
on the Provincial regulations. Equipment should be labelled
indicating that all CFC/HCFC/HFC has been removed.
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