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Hydrocarbon Refrigerants Training Presented by Refrigeration Service Engineers Society
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Transcript of Hydrocarbon Refrigerants Training Presented by Refrigeration Service Engineers Society
Hydrocarbon Refrigerants TrainingPresented by
Refrigeration Service Engineers Society
1. Uses of Hydrocarbons as Refrigerants2. HC Regulations and Standards3. Refrigerant Properties and Safety4. The Refrigerant Cycle5. System Components6. Servicing Procedures
Topics to Cover
• 1900’s - HCs used in infancy of the refrigeration industry;• 1930’s - CFCs developed (non-flammable), HC use
reduces;• 1970’s - Ozone depletions by CFCs discovered;• 1980 - HFC and HC start to replace CFCs;• 2000 - Launch of HC ice cream cabinets;• 2005 - Over 50,000 HC cabinets in use in Europe.
History of Hydrocarbons as Refrigerants
Must follow recommended safety practices when working with these approved flammable refrigerants
R-600a-IsobutaneR-290-Propane R-441A-Flammable blend
Why use Flammable Refrigerants?
The Montreal ProtocolReduces CFC and HCFC Production
EPA Approves Use of HCs through the Significant New
Alternatives Policy (SNAP)
Low Global Warming Potentials (GWP) Less than 3
Zero Ozone DepletingPotential (ODP)
Technician servicing procedures need to change with the introduction of flammable refrigerants
• HCs already used worldwide;• Over 80 million domestic refrigerators in use worldwide;• HCs also used in commercial appliances-bottle coolers, chest freezers,
commercial refrigerators;• Also used in split system and portable AC systems in use, however not
yet approved in USA
• R-600a and R-441A – New Household Refrigerators and Refrigerator/Freezers-57 grams (2.0 ounces) Equipment Constructed following UL250-Current Edition
• R-290 – New Retail Food Refrigerators Freezers-150 grams (5.3 ounces) Equipment Constructed following UL471-Current Edition
Applications and Limits
R-600a-IsobutaneR-290-Propane R-441A-Flammable blend
Common Regulator AgenciesEPA NFPACSA ECISO IECASHRAE UL
Ultimately the technician is responsible for knowing the local regulations
Understanding HC Regulations
Keeping Up with Regulations
http://www.epa.gov/ozone/snap/regulations.html
• HCs allowed for use in only new systems under the SNAP approved program;
• NO RETROFITTING allowed in the USA (retrofitting is allowed in other countries).
Unauthorized Applications
• Before servicing equipment look for MATCHING refrigerants equipment labels (the unit and compressor)
• If the compressor and refrigerant match then it should be acceptable to service the system
• If the labels do not match assume the system has been retrofitted and– STOP work on this system immediately– Contact the owner– Inform owner of system violations– Refuse to service– Offer to replace system with approved systems
Unauthorized Refrigerants
• Be an qualified refrigeration technician;• Be familiar with the safety precautions for flammable refrigerants;• Be familiar with the information provided by other sources, such as the
manufacturers of the system equipment, component manufacturers, and refrigerant suppliers.
EPA Further Information Statement
Identification Labeling
• Compressors and systems will have labels identifying the type of flammable refrigerant.
• UL 250 and 471 require labeling as part of the SNAP approval
"DANGER- Risk of Fire or Explosion. Flammable Refrigerant Used. Do Not Use Mechanical Devices To Defrost Refrigerator. Do Not Puncture Refrigerant Tubing."
Further Labeling Requirements
Labeling attach on or near any evaporators
Evaporator Labeling Requirements
"DANGER- Risk of Fire or Explosion. Flammable Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture Refrigerant Tubing."
Further Labeling Requirements
Attach near the machine/compressor compartment
Machine/Compressor Labeling Requirements
“CAUTION- Risk of Fire or Explosion. Flammable Refrigerant Used. Consult Repair Manual/Owner’s Guide Before Attempting To Service This Product. All Safety Precautions Must be Followed."
“CAUTION- Risk of Fire or Explosion. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used."
Further Labeling Requirements
Attach on the exterior of the refrigerator
Exterior Labeling Requirements
“CAUTION- Risk of Fire or Explosion Due To Puncture Of Refrigerant Tubing; Follow Handling Instructions Carefully. Flammable Refrigerant Used."
Further Labeling Requirements
Attach near any and all exposed refrigerant tubing
Near Refrigerant Tubing Labeling Requirements
All of these markings shall be in letters NO LESS than 6.4 mm (1/4”) high.
Further Labeling Requirements
“CAUTION- Risk of Fire or Explosion Due To Puncture Of Refrigerant Tubing; Follow Handling Instructions Carefully. Flammable Refrigerant Used."
Letter Sizing
• The refrigerator or freezer must have red, Pantone® Matching System (PMS) #185 marked pipes, and other devices through which the refrigerant is serviced, such as any service port;
• This color must be present at all service ports and where service puncturing or otherwise creating an opening from the refrigerant circuit to the atmosphere might be expected (e.g., process tubes).
• The color mark must extend at least 2.5 centimeters (1”) from the compressor and must be replaced if removed, repaint if necessary
Further Labeling Requirements
Service Access &Tubing Painting
• Working with any refrigerant carries a certain liability• Check with your insurance carrier before with HC refrigerants
Liability
SAFETY GROUP
Increasing Flammabili
ty
Higher Flammability A3 B3Lower Flammability A2 B2
A2L* B2L*No Flame Propagation A1 B1
Lower Toxicity
Higher Toxicity
Increasing Toxicity
A2L and B2L are lower flammability refrigerants See ASHRAE Standard 34 for full Details Refrigerant Safety Group Classification
ASHRAE Refrigerant Ratings
Sudden release of refrigerant can result in proper concentrations for:
Flash Fire • Sustained Fire • Explosion
Flammability and Ignition
• Temperatures greater than 460°C or 860°F;• Flame from a match;• Torch including halide leak detectors.
Ignition Sources
Electric sparks from:• Light and Socket Switches• Unsealed Relays and Overloads• On Off switches• Contactors• Pressure Switches• Defrost Timers• Thermostats• Vacuum Pump Switches• Electronic Leak Detectors
Ignition Sources
LEL -Lower Explosive LimitsR290-2.1%R600a-1.8%
UEL-Upper Explosive LimitR-290-9.5%R600a-8.5%
Upper and Lower Explosive (Flame) Limits
Material Safety Data Sheets• Required to be availability to
all employees• Also required to be available
to local Fire Departments
MSDS
CHECK WITH THE AUTHORITY HAVING JURISDICATION (AHJ) FOR LOCAL REGULATIONS
• Never store or expose to temperatures above 125°F (52°C);• Never apply open flame;• Never heat with water or heat blanket above 110°F (43°C);• Never refill single trip cylinders;• Never exceed refillable limits;• Never remove labels;• Never smoke near flammable refrigerant cylinders.
Cylinder Safety
• Department of Transportation Division 2.1 Classification-Flammable Gas– Transport in upright position– Label vehicle as carrying flammable gas– Inventory vehicle contents
• Some jurisdictions require– Storage in explosive proof cabinets– Venting of cabinet to exterior
Check the local Authority Having Jurisdiction
Cylinder Transport
• Store in a locked cage;• Store at ground level;• Store away from air intakes;• Keep ignition sources away
from area;• Limit access;• Install combustible gas
monitors.
Cylinder Storage
Check the local Authority Having Jurisdiction
• Recover refrigerant;• Ventilate the area;• Wear personal protection
equipment (PPE);• Check brazing equipment for
leaks and proper pressure settings;
• Purge with inert gas while brazing (Nitrogen);
• Only trained and qualified personal should be brazing.
Brazing Requirements
• Flammable gas leak detectors and monitors;• Personal safety monitors.
Rated Equipment
All refrigerants in confined space have inherent dangers.Remember to:
• Use a combustible gas detector and /or monitor• Ventilate area and clear the area of any potential LEL or
UE;• Eliminate alll sources of ignition
Confined Space
Basic cycle is the same as it is for CFCs, HCFCs, & HFCs
Refrigerant Cycle
What is different• Additional safety requirements• Monitor area and prevent possible ignition sources• Ventilate area when required• Using tubing cutting to remove refrigeration components – do
not use a torch
Refrigerant Cycle
Generally Same Components UsedCondenser Evaporator Metering Device Lubricants Gaskets,
Seals, O-rings
Refrigerant Cycle
Always Use Approval Components When Replacing
• Use only spark proof equipment-like a brass screwdriver,• Use non-ignitable type detectors such as UV additive, liquid detection
solution, electronic leak detectors for flammable gasses or ultra sonic leak detectors
Servicing Procedures
• Use standard evacuation and pressure testing procedures• Use standard recovery methods• Use standard charging methods (weigh in)
Servicing Procedures