Transcript RSES HC Refrigerants

Hydrocarbon Refrigerants
Training
Presented by
Refrigeration Service
Engineers Society
Topics to Cover
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Uses of Hydrocarbons as Refrigerants
HC Regulations and Standards
Refrigerant Properties and Safety
The Refrigerant Cycle
System Components
Servicing Procedures
History of Hydrocarbons as
Refrigerants
• 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.
R-290-Propane
R-600a-Isobutane
R-441A-Flammable blend
Must follow recommended safety practices when working
with these approved flammable refrigerants
Why use Flammable Refrigerants?
The Montreal Protocol
Reduces CFC and HCFC Production
Low Global Warming
Potentials (GWP) Less than 3
EPA Approves Use
of HCs through the Significant New
Alternatives Policy (SNAP)
Zero Ozone Depleting
Potential (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
Applications and Limits
R-290-Propane
R-600a-Isobutane
R-441A-Flammable blend
• 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
Understanding HC Regulations
Common Regulator Agencies
EPA
CSA
ISO
ASHRAE
NFPA
EC
IEC
UL
Ultimately the technician is responsible for
knowing the local regulations
Keeping Up with Regulations
http://www.epa.gov/ozone/snap/regulations.html
Unauthorized Applications
• 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 Refrigerants
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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
EPA Further Information Statement
• 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.
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
Further Labeling Requirements
Evaporator Labeling Requirements
"DANGER- Risk of Fire or Explosion. Flammable Refrigerant Used.
Do Not Use Mechanical Devices To Defrost Refrigerator. Do Not
Puncture Refrigerant Tubing."
Labeling attach on or near any evaporators
Further Labeling Requirements
Machine/Compressor Labeling Requirements
"DANGER- Risk of Fire or Explosion. Flammable Refrigerant Used.
To Be Repaired Only By Trained Service Personnel. Do Not
Puncture Refrigerant Tubing."
“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."
Attach near the machine/compressor compartment
Further Labeling Requirements
Exterior Labeling Requirements
“CAUTION- Risk of Fire or Explosion. Dispose of Properly In
Accordance With Federal Or Local Regulations. Flammable
Refrigerant Used."
Attach on the exterior of the refrigerator
Further Labeling Requirements
Near Refrigerant Tubing Labeling Requirements
“CAUTION- Risk of Fire or Explosion Due To Puncture Of
Refrigerant Tubing; Follow Handling Instructions Carefully.
Flammable Refrigerant Used."
Attach near any and all exposed refrigerant tubing
Further Labeling Requirements
Letter Sizing
“CAUTION- Risk of Fire or Explosion Due To Puncture Of
Refrigerant Tubing; Follow Handling Instructions Carefully.
Flammable Refrigerant Used."
All of these markings shall be in letters NO
LESS than 6.4 mm (1/4”) high.
Further Labeling Requirements
Service Access &Tubing Painting
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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
Liability
• Working with any refrigerant carries a certain liability
• Check with your insurance carrier before with HC refrigerants
ASHRAE Refrigerant Ratings
Increasing
Flammability
SAFETY GROUP
Higher Flammability
Lower Flammability
No Flame
Propagation
A3
A2
A2L*
A1
B3
B2
B2L*
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
Flammability and Ignition
Sudden release of refrigerant can result in proper
concentrations for:
Flash Fire • Sustained Fire • Explosion
Ignition Sources
• Temperatures greater than 460°C or 860°F;
• Flame from a match;
• Torch including halide leak detectors.
Ignition Sources
Electric sparks from:
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Light and Socket Switches
Unsealed Relays and Overloads
On Off switches
Contactors
Pressure Switches
Defrost Timers
Thermostats
Vacuum Pump Switches
Electronic Leak Detectors
Upper and Lower
Explosive (Flame) Limits
LEL -Lower Explosive Limits
R290-2.1%
R600a-1.8%
UEL-Upper Explosive Limit
R-290-9.5%
R600a-8.5%
MSDS
Material Safety Data Sheets
• Required to be availability to
all employees
• Also required to be available
to local Fire Departments
CHECK WITH THE AUTHORITY HAVING
JURISDICATION (AHJ) FOR LOCAL REGULATIONS
Cylinder Safety
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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 Transport
• 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 Storage
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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.
Check the local Authority Having Jurisdiction
Brazing Requirements
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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.
Rated Equipment
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Flammable gas leak detectors and monitors;
Personal safety monitors.
Confined Space
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
Refrigerant Cycle
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 Used
Condenser Evaporator Metering Device Lubricants Gaskets,
Seals, O-rings
Always Use Approval Components When Replacing
Servicing Procedures
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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
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Use standard evacuation and pressure testing procedures
Use standard recovery methods
Use standard charging methods (weigh in)