ENVIRONMENTALLY SAFE
REFRIGERANT SERVICE TECHNIQUES
FOR TYPE I - SMALL APPLIANCE
A/C & REFRIGERATION TECHNICANS

A Self Study Course for EPA 608 Type I Certification
in the Proper Use of Refrigerants, Including
Recovery, Recycling, and Reclamation

Written by: Robert P. Scaringe
Edited by:  Erik Thomas

Fifteenth Edition
July 2009

© Copyright 1998-2009
ALL RIGHTS RESERVED
by
Mainstream Engineering Corporation, 200 Yellow Place, Rockledge, Florida 32955

Except as permitted by Sections 107 and 108 of the 1976 United States Copyright Act, no part of this publication may be reproduced or distributed in any form, or by any means, or stored in any database or retrieval system, without the prior written permission of the copyright owner.

Information contained in this work has been obtained by Mainstream Engineering Corporation from sources believed to be reliable. However, neither Mainstream Engineering Corporation nor its author guarantee the accuracy or completeness of any information published herein, and neither Mainstream Engineering Corporation nor its author shall be responsible for any errors, omissions, or damages arising out of the use of this information. This work is published with the understanding that Mainstream Engineering Corporation and its author are supplying information but are not attempting to render engineering or other professional or technical services. If such services are required, the assistance of an appropriate professional should be sought.

PREFACE

The information in this course is intended for educational purposes only. Procedures described are for use only by qualified air conditioning and refrigeration service technicians. This training course is not a substitute for any equipment Manufacturer's Operator Manual.

Take safety precautions when using all HVAC equipment. Improper use of HVAC equipment can cause explosion and serious personal injury. Always read the entire Manufacturer's Operator Manual before turning on any equipment for the first time. Use extreme caution when working with refrigerants; hoses may contain liquid refrigerant under pressure. Use only approved refillable storage cylinders. Do not overfill any storage cylinder beyond its rated capacity. Always wear safety glasses. Protect the skin from flash freezing. Never turn on any equipment if you do not understand its operation. Where procedures described in this manual differ from those of a specific equipment manufacturer, the equipment manufacturer's instructions should be followed.

Do not leave any refrigerant recovery or recovery-recycling machine ON and unsupervised. All refrigerant recovery and recycling devices are to be used by trained refrigeration technicians only. Again, misuse of refrigerant recovery and recycling devices can cause explosion and personal injury.

Technical and legislative information presented in this book is current as of the date of the manual's latest publication. Due to rapidly advancing technology and changing regulations in the refrigerant recovery and recovery-recycling field, no representation can be made for the future accuracy of the information. Visit the EPA's Internet Home Page at http://www.epa.gov for the latest details.

Mainstream Engineering Corporation assumes no liability for the use of information presented in this publication. This information is presented for educational purposes only. Manufacturer's Operator Manuals must be consulted for the proper operation of any piece of equipment. The content of this course is limited to information and service practices needed to contain, conserve, and re­use refrigerants, and to prevent their escape into the atmosphere. This manual is not intended to teach air conditioning-refrigeration system installation, troubleshooting, or repair. Refrigeration technicians should already be well versed in these areas prior to taking this self-study course.


EPA EXAMINATION INFORMATION

EPA Examination Details

Since November 14, 1994, the EPA must certify refrigerant technicians. Only certified technicians can purchase CFC and HCFC refrigerants. At this time you do not need to be certified to purchase HFCs but you are required to recover HFCs. Mainstream is approved by the EPA as a certifying agency for Section 608 TYPE I, II, III, and Universal Exams as well as Section 609 Motor Vehicle A/C Technician Exams. Mainstream also offers other training and certification exams including R-410A Service Techniques, Preventative Maintenance Certification, and Indoor Air Quality Certification. Information on these non-EPA training and certification programs is also available on the www.epatest.com website.

The Type I exam consists of 25 Core questions and 25 specific Type I questions for a total of 50 multiple choice questions. Mainstream does not make-up the questions, the questions have been prepared by the EPA.

Technicians can take the certification exams as many times as necessary (passing grade for the open-book exam is 84% in both sections, that is, 21 of 25 correct in each section). For technicians using this Type I Open-Book format the core questions must be repeated in a proctored environment if other certifications (such as Type II, Type III, or Universal) are later desired.

Technicians receiving a passing grade on the Type I (small appliance) examination are certified to recover refrigerant during the maintenance, service, or repair of refrigerators and freezers designed for home use, room air conditioners (including window air conditioners and packaged terminal air conditioners), packaged terminal heat pumps, dehumidifiers, under-the-counter ice makers, vending machines, and drinking water coolers which are fully manufactured, charged, and hermetically sealed in a factory with five pounds or less of refrigerant. Only Type I or Universal certified technicians can recover refrigerant from these units. With Type I certification you will be allowed to purchase refrigeration in any size container except for CFC-12 which can only be purchased in containers of 20 pounds or more.

If you wish to purchase CFC-12 in containers holding less than 20 pounds of refrigerant, such as one pound cans, or to purchase refrigerant from automobile wholesalers then Section 609 Motor Vehicle certification is required. Only Section 609 Certified Motor Vehicle A/C (MVAC) technicians can purchase CFC-12 in containers of 20 pounds or less. Furthermore, automotive wholesalers will typically only honor 609 MVAC certification cards. The Section 609 Motor Vehicle Certification exam is a 25 question open book exam, also available from Mainstream on the internet (www.epatest.com)

Any technician with an Open Book Type I certification must retake the Core Section of the exam in a proctored environment (closed-book) if they are seeking additional certifications such as Type II, Type III or Universal.

Refrigerant Purchase Restrictions

 

Allowed to Purchase*

Certification Type

CFCs

HCFCs

HFCs

None

No

No

Yes

608 Type I

20+ lb container

20+ lb container

Yes

608 Type II

20+ lb container

20+ lb container

Yes

608 Type III

20+ lb container

20+ lb container

Yes

608 Universal1

20+ lb container

20+ lb container

Yes

609 MVAC

Yes2

Yes2

Yes2

1Universal certification is simply possessing a Type I, Type II, and Type III certification
2Container can be any size but must be purchased from an automotive supply house, which
typically will only sell R-12, R-134a, and replacement blends for R-12
* Individual Wholesaler's rules may be more restrictive than the EPA requirements.
Contact your local supply house for more information.

Serviceable Systems

 

Systems/Appliances

Certification Type

Small1

High/Very High Pressure2

Low Pressure3

Motor Vehicle

None

No

No

No

No

608 Type I

Yes

No

No

No

608 Type II

No

Yes

No

No

608 Type III

No

No

Yes

No

608 Universal4

Yes

Yes

Yes

No

609 MVAC

No

No

No

Yes

1Small Appliances (packaged terminal air conditioners) containing 5 lbs or less of refrigerant
2High-pressure and very high-pressure appliances including split systems and all other non-automotive
systems not covered under the category of unitary small appliance or low pressure appliance.
3Low-pressure appliances such as chillers
4Universal certification is simply possessing a Type I, Type II, and Type III certification


Refrigerant Recovery

 

Permitted to Recover*

Certification Type

CFCs*

HCFCs

HFCs

None

NONE*

NONE*

NONE*

608 Type I

Small Appliance

Small Appliance

Small Appliance

608 Type II

High/Very High

High/Very High

High/Very High

608 Type III

Low

Low

Low

608 Universal1

All above

All Above

All Above

609 MVAC

MVAC Only

MVAC Only

MVAC Only

1Universal certification is simply possessing a Type I, Type II, and Type III certification
*All refrigerants are required to be recovered. Only certified technicians are permitted as per the table above.

 

Study Hints

We recommend you read this entire manual first and then use the interactive testing software on the CD to practice taking a simulated exam. When you can successfully pass the practice exams you are ready to sit for the actual open-book exam. If you are receiving failing scores on the practice exams, then I suggested you consider practicing more before talking the actual exam! To study for one particular section of the exam, please refer to the following section-by section topic review:

The Core Section of the EPA Section 608 exam concentrates on the general knowledge of all types of refrigeration systems. Questions in this section relate to topics throughout the book. Carefully read each section and be sure to review the subsection titled "Review Notes" at the end of each section. Pay special attention to topics relating to EPA Regulations, especially the Clean Air Act, Montreal Protocol and shipping and safety requirements, the basics of refrigeration systems and techniques, all aspects of ozone depletion, replacement refrigerants and oils, the three R's: Recover, Reclaim and Recycle, and recovery, leak detection and dehydration techniques.

The Type I Section of the EPA Section 608 exam concentrates on safety and recovery requirements and techniques for unitary small appliances with five pounds or less of refrigerant. Carefully review the subsection titled "Review Notes" at the end of each section.

 


TABLE OF CONTENTS

PREFACE
EPA EXAMINATION INFORMATION
INTRODUCTION
DEFINITIONS
SECTION I: Refrigerants Past, Present, and Future
                 MOLECULAR STRUCTURE AND TERMINOLOGY
                           CFCs
                           HCFCs
                           HFCs
                 THE REFRIGERANT DESIGNATION NUMBERING SYSTEM
                 REPLACEMENT REFRIGERANTS
                 DISPOSABLE REFRIGERANT CYLINDERS
                 REFILLABLE CYLINDERS
                 REFRIGERANT SAFETY
                 REVIEW TOPICS
SECTION II: The Basics of Ozone Depletion
                 STRATOSPHERIC OZONE
                 HEALTH AND ENVIRONMENTAL EFFECTS
                 GLOBAL NATURE OF THE PROBLEM
                 REVIEW TOPICS
SECTION III: Regulations 
                 OBJECTIVES
                 INTRODUCTION
                 EARLY CONTROLS ON CFCs
                 THE MONTREAL PROTOCOL 
                 CLEAN AIR ACT AND SUBSEQUENT AMENDMENTS
                 REVIEW TOPICS
SECTION IV: Refrigerant Conservation and Containment
                 BASIC VAPOR-COMPRESSION REFRIGERATION PRINCIPLES
                 REVIEW TOPICS
SECTION V: Recovery, Recycling, and Reclamation
                 REFRIGERANT PROCESSING OPTIONS
                 REFRIGERANT SPECIFICATIONS
                 REFRIGERANT RECOVERY METHODS
                 RECOVERY/RECYCLING SYSTEMS
                 SAFETY PRECAUTIONS
                 REVIEW TOPICS
SECTION VI: Proposed EPA Rule Changes
                 PROPOSED EPA RULE CHANGES
                 TECHNICIAN CERTIFICATION
                 CONVERSION FACTORS

 


 

Table 1. Tank Color Coding for Common Refrigerants
Table 2. Pressure/Temperature Saturation Relationship for Common Refrigerants
Table 3. Pressure/Temperature Saturation Relationship for Replacement Refrigerant Blends


INTRODUCTION

On November 14, 1994, the U.S. Environmental Protection Agency (EPA) implemented the Clean Air Act, which requires certification of personnel who work with refrigerants. Air conditioning and refrigeration personnel today are in a position of increasing responsibility, both to implement procedures resulting from refrigerant regulations and to provide answers to customers' questions and technical problems. Safety continues to be a primary concern when using both new and familiar methods and equipment.

Some users of this manual will also be aware of additional information that is not included here. The intent is to present a course concentrating on practical, basic information that is most needed, and that can be readily applied on the job with the most effective results.

This manual is in a continual state of evolution and re-writing, partly because of changing EPA regulations and partly because of information feedback from technicians in the field. If you believe sections of this manual require improvement or that additional information should be added, please write to us and we will consider your suggestions for future editions. In the past, we have received very useful comments and suggestions from refrigeration technicians in the field, and to all those who have helped in the past, we owe a sincere debt of gratitude. Suggestions on the improvement of this course or any Mainstream product are always welcome. For suggestions related to this course, please write to Robert P. Scaringe, Ph.D., P.E., Refrigeration Certification Program, Mainstream Engineering Corporation, Pines Industrial Center, 200 Yellow Place, Rockledge, Florida 32955 or e-mail your comments to rps@mainstream-engr.com.

It is also suggested, that you read the last section titled Proposed New Changes, to get an idea of the direction the EPA is heading in terms of regulatory changes.

DEFINITIONS

Appliance: Any device that contains and uses a refrigerant and that is used for household or commercial purposes, including any air conditioner, refrigerator, chiller, or freezer. EPA interprets this definition to include all air-conditioning and refrigeration equipment except units designed and used exclusively for military purposes.

Azeotrope: A blend of two or more components whose equilibrium vapor phase and liquid phase compositions are the same at a given pressure. These refrigerants are given a 500 series ASHRAE designation and behave like a single refrigerant. They can be charged as a liquid or vapor.

CFC-12: dichlorodifluoromethane, (R-12).

Class I Refrigerant: CFC refrigerants such as R-12.

Class II Refrigerant: HCFC refrigerants such as R-22 and R-124.

Compound: A substance formed by a union of two or more elements in a definite proportion by weight.

Disposal: The process leading to and including any of the following:

(1) The discharging, depositing, dumping, or placing of any discarded appliance into or on any land or water.

(2) The disassembly of any appliance for discharging, depositing, dumping, or placing of its discarded component parts into or on any land or water.

(3) The disassembly of any appliance for reuse of its component parts.

Fractionation: The separation of a liquid mixture into separate parts by the preferential evaporation of the more volatile component.

Halocarbon: A halogenated hydrocarbon containing one or more of the three halogens: fluorine, chlorine, and bromine. Hydrogen may or may not be present.

HCFC-22: chlorodifluoromethane, (R-22).

HFC-134a: 1,1,1,2,-tetrafluoroethane, (R-134a).

High-Pressure Appliance: (prior to March 12, 2004, referred to by the EPA as higher-pressure appliance) An appliance that uses a refrigerant with a liquid phase saturation pressure between 170 psia and 355 psia at 104°F. This definition includes but is not limited to appliances using R-410A, R-22, R-401B, R-402A/B, R-404A, R-407A/B/C, R-408, R-409, R-411A/B, R-502 and R-507A.

Hydrocarbon: A compound containing only the elements hydrogen and carbon.

Hygroscopic: Affinity for water, so hygroscopic oils are oils that readily absorb moisture.

Isomer: One of a group of substances having the same combination of elements but arranged spatially in different ways.

Leak Rate: The rate at which an appliance is losing refrigerant, measured between refrigerant charges or over 12 months, which ever is shorter. The leak rate is expressed in terms of the percentage of the appliance's full charge that would be lost over a 12-month period if the current rate of loss were to continue over that period. The rate is calculated using the following formula:

(Refrigerant added / Total Charge) x (365 days/year/D) x 100%
where D = the shorter of: # days since refrigerant last added or 365 days

Low-Loss Fitting: Any device that is intended to establish a connection between hoses, appliances, or recovery/recycling machines, and that is designed to close automatically or to be closed manually when disconnected to minimize the release of refrigerant from hoses, appliances, and recovery or recycling machines.

Low-Pressure Appliance: (definition unchanged by the EPA's March 12, 2004 rule change) An appliance that uses a refrigerant with a liquid phase saturation pressure below 45 psia at 104°F. Evacuation requirements for the low-pressure category apply to these appliances. This definition includes but is not limited to appliances using R-11, R-113, and R-123.

Major Maintenance: Maintenance, service, or repair that involves removal of the Service or Repair appliance compressor, condenser, evaporator, or auxiliary heat exchanger coil.

Medium-Pressure Appliance: (prior to March 12, 2004, referred to by the EPA as high-pressure appliance) An appliance that uses a refrigerant with a liquid phase saturation pressure between 45 psia and 170 psia at 104°F. R-114 appliances are at the low-pressure end since the saturation pressure of R-114 at 104°F is slightly above 45 psia. This definition includes but is not limited to appliances using R-12. R-114, R-124, R-134a, R-401C, R-406A and R-500.

Mixture: A blend of two or more components that do not have a fixed proportion to one another and that no matter how well blended, still retain a separate existence (oil and water for example).

Motor Vehicle Air Conditioner (MVAC): Mechanical vapor compression refrigeration equipment used to cool the driver or passenger compartments of any motor vehicle. This definition is NOT intended to encompass the hermetically sealed refrigeration system used on motor vehicles for refrigerated cargo or the air conditioning systems on passenger buses. Section 609 certification is required for working on MVAC systems while either Section 608 Type II or Section 609 certification is required for MVAC-like A/C systems (e.g. farm equipment and other non-roads vehicles). Section 608 certification is required for working on hermetically sealed refrigeration systems used on motor vehicles for refrigerated cargo or the air conditioning systems on passenger buses. Due to the similarities between MVAC and MVAC-like appliances, EPA recommends that technicians servicing MVAC-like appliances consider certification under Section 609. Note that buses using CFC-12 or HFC-134a to cool the driver are MVACs, however buses using HCFC-22 are not MVACs or MVAC-like appliances, but rather high-pressure equipment covered under Type II of the section 608 test. Therefore if you service service both the drivers AC system (MVAC) and the passenger AC system both a 609 MVAC and a 608 certification are required. Likewise if your service the AC system for the cab of a truck (MVAC) as well as the refrigerated cargo container then again, you need both a 609 MVAC and a 608 certification.

MVAC-Like Appliances: Mechanical vapor compression, open-drive compressor appliances used to cool the driver's or passenger's compartment of a non-road vehicle, including agricultural and construction vehicles. This definition excludes appliances using HCFC-22 refrigerant or their substitutes, such as R-410a or R-407. The regulations implementing Sections 609 and 608 treat MVACs and MVAC-like appliances (and persons servicing them) slightly differently. A key difference is that persons who service MVACs are subject to the Section 609 equipment and technician certification requirements only if they perform "service for consideration", while persons who service MVAC-like appliances are subject to the equipment and technician certification requirements set forth in the Section 608 and 609 regulations regardless of whether they are compensated for their work.

Another difference is that persons servicing MVAC-like appliances have the option of becoming certified as Section 608 Type II technicians instead of becoming certified as Section 609 MVAC technicians under subpart B. Persons servicing MVACs do not have this choice. They must be certified as Section 609 MVAC technicians if they perform the AC service for compensation.

Non-Azeotropic Refrigerant: A synonym for zeotropic, the latter being preferred though less commonly used descriptor. Zeotropic: blends comprising multiple components of different volatilities that, when used in refrigeration cycles, change volumetric composition and saturation temperatures (exhibit temperature glide) as they evaporate (boil) or condense at constant pressure. These refrigerants are given a 400 series ASHRAE designation.

Normal Charge: The quantity of refrigerant within the appliance or appliance component when the appliance is operating with a full charge of refrigerant.

Opening an Appliance: Any service, maintenance, or repair on an appliance that could be reasonably expected to release refrigerant from the appliance to the atmosphere unless the refrigerant were previously recovered from the appliance.

Person: Any individual or legal entity, including an individual corporation, partnership, association, state, municipality, political subdivision of a state, Indian tribe, and any agency, department, or instrumentality of the United States and any officer, agent, or employee thereof.

Process Stub: A length of tubing that provides access to the refrigerant inside a small appliance or room air conditioner that can be resealed at the conclusion of repair or service.

PSIA: The absolute pressure in pounds per square inch, where 0 PSIA corresponds to 29.9 inches of mercury vacuum and 14.7 PSIA corresponds to 0 PSIG (pounds per square inch gauge).

PSIG: The gauge pressure in pounds per square inch, where 0 PSIG corresponds to atmospheric pressure (14.7 PSIA). A positive PSIG value indicates the pressure in pounds per square inch above the ambient pressure.

Reclamation: To reprocess refrigerant new product specifications, that is to at least the purity specified in the ARI Standard 700, Specifications for Fluorocarbon Refrigerants, and to verify this purity using the analytical test procedures described in the Standard.

Recovery: To remove refrigerant in any condition from an appliance and to store it in an external container without necessarily testing or processing it in any way.

Recovery Efficiency: The percentage of refrigerant in an appliance that is recovered by recycling or recovery equipment.

Recycling: To extract refrigerant from an appliance and to clean refrigerant for reuse without meeting all of the requirements for reclamation. In general, recycled refrigerant is refrigerant that is cleaned using oil separation and single or multiple passes through devices such as replaceable-core filter driers, which reduce moisture, acidity, and particulate matter.

Refrigerant: Any class I or class II substance used for heat transfer purposes, or any substance used as a substitute for such a class I or class II substance by any user in a given end-use, except for the following substitutes in the following end-uses:

ammonia in commercial or industrial process refrigeration or in absorption units

hydrocarbons in industrial process refrigeration (processing of hydrocarbons)

chlorine in industrial process refrigeration (processing of chlorine and chlorine compounds)

carbon dioxide in any application

nitrogen in any application

water in any application

Self-Contained Recovery: Recovery or recycling equipment that is capable of removing refrigerant from an appliance without the assistance of components contained in the appliance.

Small Appliance: Any of the following products that are fully manufactured, charged, and hermetically sealed in a factory with five pounds or less of refrigerant: refrigerators and freezers designed for home use, room air conditioners (including window air conditioners and packaged terminal air conditioners), packaged terminal heat pumps, dehumidifiers, under-the-counter ice makers, vending machines, and drinking water coolers.

System Dependent Recovery Equipment: Recovery equipment that relies upon the compressor in the appliance and/or the pressure of the refrigerant in the appliance.

Substitute: Any chemical or product substitute, whether existing or new, that is used by any person as a replacement for a class I or II compound in a given end-use.

System-Dependent Recovery: Recovery equipment that requires the assistance of recovery components contained in an appliance to remove the refrigerant from the appliance.

Technician: Any person who performs maintenance, service, or repair that could reasonably be expected to release refrigerant into the atmosphere, including but not limited to installers, contractor employees, in-house service personnel, and in some cases, owners. Technician also means any person disposing of appliances except for small appliances.

Very High-Pressure Appliance: (definition unchanged by the EPA's March 12, 2004 rule change) Appliance An appliance that uses refrigerants with a critical temperature below 104°F or with a liquid phase saturation pressure above 355 psia at 104°F. This category includes but is not limited to appliances using R-13, R-23, R-503.



SECTION I: Refrigerants Past, Present, and Future

 

MOLECULAR STRUCTURE AND TERMINOLOGY

Except for ammonia and a few other substances, most refrigerants currently in use are compounds containing carbon, fluorine, usually chlorine, and sometimes hydrogen, bromine, or iodine. When a refrigerant is referred to as a "CFC", the refrigerant contains Chlorine, Fluorine, and Carbon. When a refrigerant is referred to as a "HCFC", the refrigerant contains Hydrogen, Chlorine, Fluorine, and Carbon. When a refrigerant is referred to as a "HFC", the refrigerant contains Hydrogen, Fluorine, and Carbon. When bromine is present in place of all or part of the chlorine, the capital letter "B" after the designation for the parent compound shows the presence of the bromine (Br), for example "R-13B1". Compounds containing bromine are sometimes referred to as "BFCs" if they contain Bromine, Fluorine, and Carbon (no chlorine). That is, R-13B1 is also known as BFC-13B1. Similarly a compound such as R-30B1, which contains Hydrogen, Bromine, Chlorine, Fluorine, and Carbon, is sometimes referred to as a "HBCFC", so R-30B1 is HBCFC-30B1.

CFCs

The refrigerants heard about the most are the chlorofluorocarbons (CFCs). As the name says, these refrigerants consist of chlorine, fluorine, and carbon, thus the abbreviation "CFC". Since they contain no hydrogen, CFCs are chemically very stable, even when released into the atmosphere, but since they contain chlorine, CFCs are damaging to the ozone layer high above the Earth's surface. The ozone layer shields the Earth from excessive ultraviolet solar radiation.

The combination of these two characteristics gives CFC refrigerants a high ozone-depletion potential (ODP), and has made these refrigerants the target of legislation that has reduced their availability and use. Thus, manufacture of CFC refrigerants was discontinued after December 31, 1995. R-12 is a CFC and often referred to as CFC-12.


HCFCs

A second category of refrigerants which are currently available are the hydrochloro-fluorocarbons (HCFCs). Although they contain chlorine which is damaging to the ozone layer, they also contain hydrogen which makes them chemically less stable when they enter the atmosphere. These refrigerants decompose when released in the lower atmosphere so very little ever reaches the ozone layer. HCFCs, therefore, have a lower ozone-depletion potential. HCFC-22 also know as R-22 has been in widespread use for many years. Most residential and small commercial air conditioning systems use HCFC-22.


HFCs

Hydrofluorocarbon (HFC) refrigerants contain no chlorine at all. Although these refrigerants have an ozone-depletion potential of zero, they probably still contribute to the global warming problem. Two new HFC's that are replacing CFC-12 and HCFC-22 are HFC-134a (1,1,1,2-Tetrafluoroethane CF3CH2F) and HFC-410A (HFC-32 &HFC-125). Mandatory recovery is required for all refrigerants (including HFC's) before opening or disposing of appliances, because of their potential to cause global warming. No "drop-in" substitute refrigerants are available for any equipment category.

THE REFRIGERANT DESIGNATION NUMBERING SYSTEM

Because the chemical names of typical refrigerants are long and complex, DuPont developed a method of referring to refrigerants by number . The DuPont numbering system was released for general use in 1956 and has become an industry standard. A complete discussion of the number designation and safety classification of the refrigerants is presented in ASHRAE Standard 34-1992.

Briefly, the method of designating a refrigerant by number is as follows. (Note that the numbering system begins on the right.)

First digit on the right = Number of fluorine atoms
Second digit from the right = Number of hydrogen atoms plus one
Third digit from the right
= Number of carbon atoms minus one
   (not used when equal to zero)
Fourth digit from the right
= Number of unsaturated carbon-carbon bonds in the compound
   (not used when equal to zero)

When bromine is present in place of all or part of the chlorine, the same numbering rules apply except that the capital letter "B" after the designation for the parent compound shows the presence of the bromine (Br). The number following the letter "B" shows the number of Bromine atoms present.

The lower-case letter that follows the refrigeration designation refers to the form of the molecule when different forms (isomers) are possible, with the most symmetrical form indicated by the number alone. As the form becomes more and more asymmetrical, the letters a, b, and c (lower case) are appended (for example, HFC-134a).

If all of the carbon bonds are not occupied by fluorine or hydrogen atoms, the remainder are attached to chlorine.

Because the structure of a refrigerant, whether CFC, HCFC, or HFC, has become so important, it is often referred to in this way (for example, R-12 is CFC-12; R-22 is HCFC-22; R-134a is HFC-134a.) Thus, their chemical structure and their relative ozone-depletion potential are highlighted.

Example 1. CHClF2

Number of F atoms = 2
Number of H atoms + 1 = 2
Number of C atoms - 1 = 0

The refrigerant in Example 1 is designated HCFC-22. Since carbon has four bonds and the total of F and H = 3, there is one Cl atom.

Example 2. CCl2FCClF2

Number of F atoms = 3
Number of H atoms + 1  = 1
Number of C atoms - 1  = 1

The refrigerant in Example 2 is designated CFC-113. Since two carbon atoms connected together have six bonds remaining and the total of F and H = 3, there are three Cl atoms present.

Example 3. The Designation of Refrigeration Isomers

Isomer Formula
CFC-216 CF3CCl2CF3
CFC-216a CF2ClCF2CF2Cl
CFC-216b CF2ClCFClCF3
CFC-216c CFCl2CF2CF3

REPLACEMENT REFRIGERANTS

EPA concerns about depletion of the Earth's protective stratospheric ozone layer and the effect of CFC on this depletion have resulted in a halt in CFC production since December 31, 1995. According to the EPA, recent ozone depletion studies indicate that the current situation is far worse than originally thought. HCFC refrigerants such as R-22 are currently scheduled for phase-out by the year 2030. However, this too will probably be accelerated before the year 2030 is actually reached. Azeotropes such as R-502 are, of course, also affected.

As stated in the last section, mixtures or blends of refrigerants can exhibit a distinct boiling point or they can exhibit a boiling range. When a refrigerant mixture exhibits a distinct boiling point, that is it behaves as a single "new" refrigerant, it is designated as an azeotropic blend and is given a 500 series ASHRAE designation. When the refrigerant mixture has a boiling range it is referred to as a non-azeotropic or zeotropic refrigerant and is given a 400 series ASHRAE designation.

Key considerations for any new refrigerant are chemical stability in the system, toxicity, flammability, thermal characteristics, efficiency, ease of detection when searching for leaks, environmental effects, compatibility with system materials, compatibility with lubricants, and cost. In general, HCFC-123 is intended to replace CFC-11, and HFC-134a has replaced CFC-12 in most applications and HFC-410A is replacing HCFC-22 in many applications.

HFCs such as R-134a do not lead to ozone depletion but do contribute to global warming due to the greenhouse effect. So refrigerant recovery and recycling are here to stay regardless of the new refrigerants developed. Recycling also makes sense economically because of the cost of the new refrigerants and taxes on the more traditional refrigerants.

Briefly, for the short term, heavy reliance will probably be placed on continued use of HCFC-22 until it is no longer allowed. As an HCFC, R-22 has only a small fraction of the ability of the CFC refrigerant to destroy stratospheric ozone. However, R-22 does contribute to global warming. Mandatory recovery is required for all refrigerants (including HFCs) before opening or disposing of appliances, because of their potential to cause global warming.

Manufacturers are beginning to offer HFC-410A air conditioning and heat pump systems as an alternative to HCFC-22 units. The EPA has established the phase out of the HCFC-22 with no production or importing beginning in 2020. However, manufacturers of air conditioning equipment must phase out the use of HCFC-22 in new equipment by January 1, 2010. In general, existing R-22 systems will probably be converted to R-407C, however new air conditioning equipment is being designed to operate on R-410A. Both R-407C and R-410A are non-azeotropic HFC refrigerant blends. Non-azeotropic blends (400 series) means that they experience a temperature glide during evaporation and condensation. In contract, a pure refrigerant or an azeotropic (500 series) refrigerant blend has a single boiling point temperature at a given pressure. However, as discussed below R-410A is a near azeotropic refrigerant.

No "drop-in" substitute refrigerants are available for any equipment category. This means that some changes in a system's equipment or materials of construction are always necessary when converting the equipment to using a replacement refrigerant. An existing refrigerant cannot simply be removed from a system and replaced with another. Usually the changes involve replacement of incompatible seals and changes in lubricant. Filter/dryers, compressors, and seals that are compatible with CFCs, HCFCs, and HFCs have been developed.

DISPOSABLE REFRIGERANT CYLINDERS

Size and Color Codes

New virgin refrigerant for use by air conditioning and refrigeration service personnel are usually packaged in disposable containers. Disposables are manufactured in three sizes: 15-, 30-, and 50-pound capacities and should never be refilled. New disposable containers use a check valve and cannot be refilled. Refrigerant manufacturers voluntarily color code cylinders for their chlorofluorocarbon products. Table 1 lists the color-coding for common chlorofluorocarbon refrigerants; however, the shade of color may vary somewhat among manufacturers.


Table 1. Tank Color Coding for Common Refrigerants

 
CFC-11 orange
CFC-12 white
HCFC-22 green
CFC-113 purple
CFC-114 dark blue
HFC-134a light blue
CFC-500 yellow
CFC-502 Orchid (purple)
R-717(ammonia) Silver
R-401A light purple
R-401B yellow-brown
R-401C blue-green
R-402A light green-brown
R-402B green-brown
R-404A orange
R-407C medium brown
R-410A pink

Regulations

Disposable cylinders are manufactured to specifications established by the U.S. Department of Transportation (D.O.T). The D.O.T. has regulatory authority over all hazardous materials in commercial transportation.

Hot-weather recovery operations can result in very high storage-tank pressures and therefore disposable cylinders should never be refilled or used as a recovery tank. Rust, dents, and other damage can significantly reduce the burst pressure of disposable cylinders.

Transportation of refilled D.O.T. 39 cylinders is illegal and subject to a penalty of a fine up to $25,000 and five years imprisonment. The use of a refilled D.O.T. 39 cylinder also violates OSHA workplace regulations and may violate state laws.

Safety

Every cylinder is equipped with a safety-relief device that will vent pressure from the cylinder before it reaches the rupture point. Cylinders can become over-pressurized for several reasons. However, the primary cause is overheating. When a cylinder ruptures, the pressure drop causes the liquid refrigerant to flash into vapor and sustains the explosive behavior of the rupture until all the liquid is vaporized. The rupture of a refrigerant cylinder containing liquid refrigerant that flashes into vapor is far worse than the rupture of a compressed-air cylinder under the same pressure.

If a refrigerant cylinder reaches a full-of-liquid (no vapor space) condition, the internal pressure rises very rapidly under minor increases in temperature. If the safety valve is not able to vent this rapid increase in pressure, the cylinder will explode. Safety valves are very important. Never tamper with a cylinder safety device.

Hazards of Reuse

Disposable cylinders are manufactured from steel. Rust can eventually weaken the cylinder to the point where the cylinder wall can no longer contain the compressed refrigerant. Consequently, cylinders must be stored and transported in dry environments. Cylinders exhibiting extreme rust should be emptied of contents and properly discarded.

Disposal

Disposable cylinders should be emptied of all contents using a refrigerant recovery device. Once emptied the cylinder's valve should be opened to allow air to enter, and the cylinder should be punctured with the valve still open (rendered useless). Used cylinders can be recycled with other scrap metal. Never leave used cylinders with any residual refrigerant either outdoors or at a job site. The internal pressure of a cylinder with one ounce of liquid refrigerant is exactly the same as a full cylinder. An abandoned cylinder will eventually deteriorate and can explode if the cylinder wall weakens. Never refill a disposable cylinder.

REFILLABLE CYLINDERS

Refillable cylinders, also referred to as "recovery cylinders" or "recovery tanks", are now available for the transportation of refrigerants used in the air conditioning and refrigeration industry. These refillable cylinders are used for the same refrigerants as the disposable cylinders. In addition to disposable and returnable cylinders, refillables also are regulated in their design, fabrication, and testing by the D.O.T. for use in transportation of refrigerants.

Recovery cylinders are painted yellow in the shoulder area and 12 inches down the side; the manufacturer paints the remainder of the cylinder body gray.

D.O.T. Requirements

Refillable cylinders satisfy the requirements of either 4BA or 4BW specifications, Ref. 49 CFR 178.51 and 49 CFR 178.61, respectively. The 4BA cylinder is comprised of two deep-drawn carbon-steel heads welded together with one girth seam; the 4BW cylinder is comprised of two separate heads on opposite ends of a center cylindrical section.

The 4BA cylinders are generally sized for refrigerant capacities of 50 lb. or less, with the most widely used sizes being 15-lb., 30-lb., 37-lb., and 50-lb., respectively. The design pressure is typically 340 psig for the 15-lb. and 30-lb. unit, 302 psig for the 37-lb. unit, and 400 psig for the 50-lb. unit. Newer tanks which can accommodate R-410A must be rated for at least 400 psig. Recovery tanks rated for 400 psig are available in 15, 30, and 50 pound sizes but not every recovery tank is rated for these higher pressures. Be careful, and read the nameplate, only use recovery tanks rated for at least 400 psig with R-410A.

WARNING: According to the American Society of Mechanical Engineers Pressure Vessel Code, the pressure rating must be 285 psig or higher for R-407C and 400 psig or higher for R-410A. Do not use any storage or recovery tank with a maximum pressure rating less than 400 psig for R-410A. Recovery tanks for R-410A should be specified as DOT 4BA400 or 4BW400.

Cylinder Re-testing

The use of various refrigerants in cylinders that are exposed to the environment is reason for concern. Although the interior of these cylinders must be void of moisture, the exterior cannot avoid it. Thus, corrosion can and does occur, as well as damage due to mishandling. These are a few of the reasons why cylinders must be re-tested at five-year intervals.

The valves should be examined regularly, especially the relief valve. Check to be sure that nothing is obstructing the relief valve and that no visual deterioration or damage has occurred to the cylinder. If any damage is visible, empty the cylinder and have the tank repaired. NEVER use a cylinder with a faulty pressure-relief valve or with obvious structural impairments.

REFRIGERANT SAFETY

ASHRAE Safety Classification of Refrigerants

As stated earlier in this section, the ASHRAE standard on Refrigerant Number Designation also includes a Safety Classification of Refrigerants. Specific product safety information is always available from the manufacturer, and by law a Material Safety Data Sheet (MSDS) must accompany the delivery of all chemicals. The newer ASHRAE 34a-1992 standard includes two alphanumeric characters. The capital letter (either A-Non-Toxic or B-Toxic) indicates the toxicity and the numeral (1-non-flammable, 2-slightly-flammable, 3-highly-flammable) denotes the flammability.

Health Hazards

Skin or eye contact with fluorocarbon refrigerants can result in irritation and frostbite. Although the toxicity of traditional fluorocarbon refrigerants is low (due to their chemical stability), the possibility of injury or death always exists in unusual situations and if they are deliberately misused. The vapors are several times heavier than air. Good ventilation must be provided in areas where high concentration of the heavy vapors might accumulate and exclude oxygen. Inhalation of concentrated refrigerant vapor is dangerous and can be fatal. Exposure to levels of fluorocarbons above the recommended exposure levels can result in loss of concentration and drowsiness. Cases of fatal cardiac arrhythmia have been reported in humans that were accidentally exposed to high levels. The exposure levels for some of the new replacement refrigerants may be lower than for those with which you may be familiar. Less-stable compounds can break down more easily and can potentially form harmful substances within the body. Treat replacement refrigerants with care!

First Aid

If refrigerant vapor has been inhaled, remove the victim to fresh air. If the victim is not breathing, give artificial respiration. If breathing is difficult, give oxygen. Avoid stimulants. Do not give adrenaline (epinephrine) because this can complicate possible effects on the heart. Contact a physician.

In the case of eye contact, flush eyes promptly with plenty of water for at least 15 minutes. Contact a physician. Flush exposed skin with warm water (not hot) or use other means to warm the skin slowly.

Other Hazards

Most halogenated compounds will decompose at high temperatures such as those associated with gas flames or electric heaters. The chemicals that result under these circumstances always include hydrofluoric acid. If the compound contains chlorine, hydrochloric acid will also be formed, and if a source of water (or oxygen) is present, a smaller amount of phosgene will be formed. Fortunately, the halogen acids have a very sharp, stinging effect on the nose and can be detected by odor at concentrations below their toxic level. These acids serve as a warning that decomposition has occurred. If they are detected, the area should be evacuated until the air has been cleared of decomposition products. Some replacement refrigerants have lower exposure limits, so read the manufacturer's warnings carefully and take the precautions seriously.

 

REVIEW TOPICS

- Chlorofluorocarbon (CFC) refrigerants are so named because they contain the elements Chlorine, Fluorine, and Carbon.

- CFCs have the highest ozone depletion potential (ODP) and are the most harmful to stratospheric ozone.

- Hydrochlorofluorocarbon (HCFC) refrigerants contain Hydrogen, Chlorine, Fluorine, and Carbon.

- Hydrofluorocarbon (HFC) refrigerants contain Hydrogen, Fluorine, and Carbon. R-134a, also known as HFC-134a, a chlorine-free refrigerant.

- HFC refrigerants cause no harm to stratospheric ozone; they have a zero ODP. They do however contribute to global warming (like any refrigerant) and cannot be vented.

- Oils that will be used with most HFC-134a refrigeration and HFC-410A air conditioning applications are ester-based synthetic (POE) oils.

- The synthetic lubricant presently used with ternary blends is alkylbenzene.

- Ester-based synthetic oils cannot be mixed with other oils.

- A non-azeotropic (or azeotrope) refrigerant blend, sometimes referred to simply as a blend refrigerant, has a range of boiling points or condensing points throughout the evaporator and condenser, respectively; the terms used to describe this are "temperature glide" or "gliding-temperature."

- A compound pressure gauge for the low side of a refrigeration system measures pressure in psig and vacuum in inches of mercury.

- Refrigerant will travel to a compressor's crankcase because of the difference between the oil and refrigerant's vapor pressure.

- A binary blend is a two-part mixture and a ternary blend is a three-part mixture.

- When transporting cylinders containing used refrigerant, the D.O.T. requires that you attach D.O.T. classification tags.

- On a typical gauge manifold set, the high pressure gauge is color coded red and the low pressure gauge is color coded blue.

- The high pressure gauge on a service manifold set has a continuous scale, usually calibrated to read from 0 to 500 psig. This does not mean the gauge set is actually rated for use up to 500 psia. Typical ratings on older gauge sets and/or hoses is only 340 psig. When using R-410A you must use a gauge set rated for at least 800 psig (with a 4,000 psig burst pressure on the manifold and the hoses).

- Containers designated "refillable" by DOT must be used to transport recovered pressurized refrigerant to meet safety requirements.

 

 

SECTION II: Stratospheric Ozone Depletion

Stratospheric Ozone

Ozone is a gas, slightly bluish in color, with a pungent odor. It consists of three atoms of oxygen in each molecule. The oxygen we breathe contains two atoms in each molecule. Chemically, oxygen is O2, and ozone is O3. The "ozone layer" consists of ozone in the stratosphere, high above the Earth at an altitude of between 7 and 28 miles. It is formed by ultraviolet light (UV) from the sun acting on oxygen molecules. The ozone layer absorbs and scatters ultraviolet light from the sun, thus preventing harmful amounts of ultraviolet light from reaching the Earth. For this reason, it is often referred to as the Ozone Shield or the Earth's Protective Shield.

Atmospheric Ozone

Ozone is also found at times in the lower atmosphere where we breathe it. Here it is caused by ultraviolet radiation from the sun acting on smog and air pollutants on hot summer days. This situation should not be confused with the protective ozone layer in the stratosphere. Ozone at ground level is a harmful pollutant; in the stratosphere it is a protective shield.

 

Depletion of Stratospheric Ozone

In June 1974, Professor Sherwood Rowland and Dr. Mario Molina of the Department of Chemistry at the University of California at Irvine first proposed the theory that certain chlorine-containing compounds could pose a threat to the ozone layer above the Earth. The Rowland-Molina theory states that CFCs would ultimately cause damage to the ozone layer, which protects the Earth from harmful levels of ultraviolet radiation from the sun. What follows is a summary of the current theory held by the EPA.

Refrigerants that contain chlorine but not hydrogen are so stable that they do not break down in the lower atmosphere not even one hundred years or more after being released. These chemicals gradually float up to the stratosphere, where the chlorine or bromine reacts with ozone, causing it to change back to oxygen.

The "Ozone Hole" is a thinning in the ozone layer over Antarctica and occurs during the Antarctic spring season (autumn in the Northern Hemisphere). It occurs over the Antarctic continent due to its unique climate. Powerful winds encircle Antarctica during its winter, isolating the continent from warmer winds that would otherwise migrate from lower latitudes on the Earth's surface, and the continent is in darkness during the winter. These two effects combine to produce the coldest temperatures on Earth, colder than the Arctic.

The stratosphere is normally too dry to form clouds, except at the bitterly cold temperatures reached during the Antarctic winter. At these frigid temperatures, clouds of ice and nitric acid, called "polar stratospheric clouds" (PSCs), form in the stratosphere over the continent of Antarctica. Chemical reactions take place on the surfaces of these clouds, converting chlorine and bromine from forms that do not react with ozone to other, less stable forms that readily break up in the presence of sunlight and destroy ozone.

Both cold temperatures and sunlight are critical to the ozone depletion process. So in the spring, when the sun again rises and when the PSCs are still present, the Antarctic ozone hole is found. As the sun warms the region in the spring, the clouds dissipate.

This area is being carefully monitored for the degree to which the ozone thins because it has been found to lead to ozone depletion in other parts of the world as well. Significantly reduced ozone levels were detected in 1985, and high chlorine levels were found in 1986. Since that time, aircraft flights through the stratospheric ozone layer and ground-based instruments have indicated that the ozone depletion problem may be more serious than initially thought.

When ozone depletion occurs, more UV radiation penetrates to the Earth's surface. Moreover, because of the long atmospheric lifetimes of CFCs, it will take many decades for the ozone layer to return to past concentrations. As stated earlier, bromine-containing compounds, which are contained in typical Halon fire extinguishers, react the same way as chloride atoms in destroying the ozone. In the years since the ozone-depletion theory was first proposed, substantial scientific research has supported the general concern that an increased concentration of chlorine and bromine in the stratosphere poses substantial risks of ozone depletion, which results in harm to both human health and the environment. The EPA states that each chlorine atom has the ability to destroy 100,000 ozone molecules in the stratosphere.

The CFC refrigerants and the halons have been assigned factors that represent their relative ability to destroy stratospheric ozone, called the Ozone Depletion Factor, or Ozone Depletion Potential (ODP). This scale is based on CFC-11 having been assigned a factor of 1. CFC-12 has an ODP of 1, HCFC-22 has an ODP of 0.05, and HFC-134a has an ODP of 0.Note that the bromine-containing halons have factors many times those of the CFC refrigerants.


HEALTH AND ENVIRONMENTAL EFFECTS

Since it shields the Earth from much of the damaging part of the Sun's radiation, the ozone layer is a critical resource safeguarding life on this planet. Should the ozone layer be depleted, more of the Sun's damaging rays would penetrate to the Earth's surface. Some scientists have claimed that each 1% depletion of ozone increases exposure to damaging ultraviolet radiation by 1.5-2%. EPA's assessment of the risks from ozone depletion focus on the following areas:

   - Increase in skin cancers
   - Suppression of the human immune response system
   - Increase in cataracts
   - Damage to crops
   - Damage to aquatic organisms
   - Increases in ground-level ozone
   - Increased global warming

 

 

GLOBAL NATURE OF THE PROBLEM

Stratospheric ozone protection is a global problem. CFCs and halons are used in many nations, and because of their long atmospheric lifetimes, they become widely dispersed over time. As a result, the release of these chemicals in one country will adversely affect the stratosphere above other countries and therefore the health and welfare of their citizens. To protect the ozone layer from damage that may be caused by CFCs and halons, an international solution is critical.

 

REVIEW TOPICS

- Ozone in the stratosphere above the Earth consists of molecules containing 3 oxygen atoms (O3).

- Chlorine and bromine in refrigerants cause stratospheric ozone depletion.

- The EPA states that each chlorine atom has the ability to destroy 100,000 ozone molecules in the stratosphere.

- CFCs are chemically very stable; they do not dissolve or break-down in water (so they are not removed by rain). Because of this chemical stability, CFCs are able to reach the stratosphere.

- CFCs have the highest ozone depletion potential (ODP) and are the most harmful to stratospheric ozone.

- R-134a, also known as HFC-134a, is a chlorine-free refrigerant.

- HFC fluorocarbon refrigerants cause no harm to stratospheric ozone, and have a zero ODP.

- The ozone layer protects the Earth from ultraviolet radiation from the sun. Skin cancer, increased cataracts, and damage to crops are just some of the results of damage to the Earth's ozone layer.

- Actual measurements of CFCs in air samples from the stratosphere are positive evidence that CFCs are in the stratosphere.

- Chlorine in the stratosphere is believed to come primarily from CFCs rather than from natural sources such as volcanoes. The rise in the amount of chlorine measured in the stratosphere over the past 20 years has been shown to match the rise in CFCs over the same period. Samples of air taken from the stratosphere over erupting volcanoes show that volcanoes contribute only a small quantity of chlorine to the stratosphere when compared to CFCs.

- The existence of chlorine monoxide in the upper stratosphere indicates that the ozone layer is being destroyed.

- Capturing and eliminating the use of chlorofluorocarbons is being done in the United States to stop damage to the stratospheric ozone layer.

- When addressing consumer complaints regarding additional service expense caused by recovery efforts, the technician needs to explain to the customer that recovery is necessary to protect human health and the environment.

 

SECTION III: Regulations

INTRODUCTION

There is tremendous confusion in the refrigeration industry as to what the current regulations are. This chapter will attempt to provide the background for the regulations and to summarize the regulations in the last section, "Clean Air Act and Subsequent Amendments." If you suspect further changes in the law call the EPA Information hot-line at 800-296-1996.

The Montreal Protocol Regulations are not U.S. laws, but rather an agreement (Treaty) between nations to follow some rules. Each nation that agrees with the Montreal Protocol (termed signatory nations) must pass its own laws to enforce the protocol ideals. U.S. laws that apply to refrigeration technicians in the United States are part of the U.S. Clean Air Act and subsequent revisions to the Clean Air Act. EPA proposed rulings are rules proposed by the EPA to enforce the Clean Air Act. The EPA proposes the rules, and then, after public comment, refines these rules. Some people incorrectly assume that the proposed rulings are law; they are not. Many of the proposed rules have been modified after public input, including input by equipment manufacturers and technical groups. The actual laws that must be followed concerning stratospheric ozone protection (including venting, recovery, recycling, equipment certification, technician certification, disposal, record keeping, and enforcement). EPA Final Rule Summaries are published in the Federal Register and posted on the EPA website.

EARLY CONTROLS ON CFCs

During the early 1970s, CFCs that were used as aerosol propellants constituted over 50% of total CFC consumption in the United States. Following concerns initially raised by the Rowland-Molina theory in 1974, the EPA and the Food and Drug Administration in 1978 banned the use of CFCs as aerosol (spray can) propellants in all but a few essential (mostly medical) applications. Two new factors brought CFCs back into public concern in 1986. One was the connection between CFCs and the theory of global warming, or the greenhouse effect. The other was new scientific evidence that CFCs deplete stratospheric ozone and that a "hole" had developed in the ozone layer over Antarctica.

THE MONTREAL PROTOCOL

Recognizing the global nature of the problem, on September 16, 1987, in Montreal, Canada, 24 nations and the European Economic Community (EEC) signed the Montreal Protocol on Substances that Deplete the Ozone Layer. Most of the major CFC and Halon producing and consuming nations signed this agreement. Other nations, including the then Soviet Union, indicated that, following further consultations at home, they might possibly become signatories. On August 1, 1988, the U.S. EPA enacted the provisions of this agreement into regulations for the United States.

CLEAN AIR ACT AND SUBSEQUENT AMENDMENTS

The 1990 Amendments to the Clean Air Act were signed by former President Bush on November 15, 1990. The amendments establish a National Recycling and Emissions Reduction Program to regulate the use and disposal of substances, including CFCs and HCFCs, which are harmful to humans and the environment. Title VI of this program is titled Stratospheric Ozone Protection; Section 608 of Title VI contains the National Recycling and Emission Reduction Program. Title VII is titled Provisions Relating to Enforcement. Final EPA regulations were published on May 14, 1993 and most recently revised with the EPA's March 12, 2004 rule change..

The objectives of this program are to reduce the use and emissions of abusive substances to the lowest achievable level and to maximize the recapture and recycling of such substances. In addition, the amendments establish new standards for safe disposal of these substances and new federally mandated certification procedures for those engaged in servicing refrigeration systems. The EPA regulations also require that new refrigeration and air conditioning appliances are equipped with a servicing aperture, or similar device, to facilitate recapture of refrigerants during service and repair.

The amendments also affect personnel repairing or servicing an appliance or industrial process refrigeration. Under the statute, HVAC service personnel or any other individual may not "knowingly vent or otherwise knowingly release or dispose of any substance used as a refrigerant in such appliance in a manner which permits such substance to enter the environment." "De minimis" releases associated with good-faith attempts to recapture and recycle or safely dispose of any such substance shall not be subject to prohibition set forth in the preceding sentence. In other words, if you are attempting to minimize refrigerant losses, any minimal losses associated with recovery and recycling are allowed. This prohibition became effective July 1, 1992. The penalties and fines for violating the EPA provisions can be severe. The EPA is authorized to seek various levels of legal redress against any person who violates the above prohibitions.

   - The EPA is authorized to obtain an injunction against the offending parties prohibiting them from discharging refrigerants into the air.

   - The EPA may impose a $32,500-per-day penalty on the offender with the approval of the U.S. District Court. In addition, the EPA may seek to have criminal penalties and prison terms not exceeding five years assessed against any person who knowingly releases refrigerants into the atmosphere, and criminal fines and imprisonment may be assessed against any person who makes a false material statement or representation in any report, notice, or application required by the EPA.

   - Criminal fines and penalties may also be assessed against any person who negligently or knowingly releases into the ambient air a hazardous air pollutant and who, as a result of the release, places another person in imminent danger of death or serious bodily injury. In the case of an intentional discharge, the prison term may be a maximum of 15 years.

   - Finally, to encourage others to report violations of the act, the EPA is authorized to pay awards of up to $10,000 to any person who furnishes information that leads to a criminal conviction of another person for violation of the above prohibitions.

Since November 14, 1994, all HVAC service personnel must be fully trained in recommended service and repair procedures and techniques applicable to appliances containing refrigerants. In addition, since July 1, 1992 XE "July 1, 1992" , all individuals (service personnel, equipment owners, etc.) should be using their best efforts (good-faith procedures) to ensure that they do not permit inadvertent discharge of refrigerants into the atmosphere. A fine can be as much as $32,500 per day and per occurrence.

Refrigerant Production Phase-out--The Current Law

The restrictions on production and consumption of ozone-depleting substances under the Clean Air Act and all its amendments essentially match those of the revised Montreal Protocol. The phase-out schedule for the most common refrigerants is detailed below.

- Reduce CFCs from 1986 production levels by
          
1994 75% Reduction (Production 25% of 1986 levels)
          1995 75% Reduction (Production 25% of 1986 levels)
          1996 Total Phase Out (Zero Production) 

- Reduce HCFC from 1989 production levels by
          1996 (allow 100% of 1989 ODP levels for HCFC + 3.1% of 1989 ODP levels for CFC)
          2010 65% reduction (35% of 1996 level)
          2015 90% reduction (10% of 1996 level)
          2020 99.5% reduction (0.5% of 1996 level)
          2030 Total Phase Out (Zero Production)

- Hydrobromofluorocarbons (HBFC) Phased Out by 1996

Prohibition on Venting

Effective July 1, 1992, Section 608 of the Clean Air Act prohibits individuals from knowingly venting ozone-depleting compounds used as refrigerants into the atmosphere when maintaining, servicing, repairing, or disposing of air conditioning or refrigeration equipment. Some types of releases are permitted under the prohibition.

- Technicians releasing "de minimis" quantities of refrigerant in the course of making good faith attempts to recapture and recycle or safely dispose of refrigerant are not subject to the prohibition.

- Refrigerants emitted in the course of normal operation of air conditioning and refrigeration equipment, as opposed to during the maintenance, servicing, repair, or disposal of this equipment, are NOT subject to the prohibition. Thus, emissions due to leaks and mechanical purging, which occur during normal operation of equipment, are permitted under the prohibition. However, the EPA is requiring the repair of substantial leaks on systems that are normally charged with more than 50 pounds of refrigerant (after June 14, 1993). Furthermore, substantial leaks on systems that are normally charged with more than 50 pounds of refrigerant must be repaired within 30 days after discovery of the leak.*

For the industrial process and commercial refrigeration sector, a 35% leakage rate or more (35% loss of charge/year) on a system with a normal charge of more than 50 pounds is defined as a substantial leak, while for all other refrigeration systems with a charge of 50 pounds or more, a substantial leak is defined as a leakage rate of 15% (15% loss of charge/year).

* Note: There is a proposed rule change, See the section titled: "Proposed EPA Rule Changes" near the end of this manual.

- Mixtures of nitrogen and R-22 (and only R-22-nitrogen mixtures) that are used as holding charges or as leak test gases are not subject to the prohibition because in these cases, the ozone-depleting compound is not used as a refrigerant. However, a technician may not avoid recovering refrigerant by adding nitrogen to a charged system. Before nitrogen is added, the system MUST be evacuated to the required level. Otherwise, the refrigerant-nitrogen mixture will be considered a refrigerant, and its release will be a violation of EPA regulation and subject to fine. Similarly, pure CFCs or HCFCs released from any appliance, hardware, or device, is presumed to be a refrigerant, and their release will be a violation of EPA regulations and subject to fine. When changing refrigerant being used on a recovery or recycling device, the refrigerant in the recovery or recycling machine must be recovered and cannot be vented into the air. Then evacuate the unit. Typically, filters also have to be changed.

- Mixtures of nitrogen and any other CFC or HCFC, except HCFC-22, are subject to the prohibition on venting. That means it is illegal to vent them into the atmosphere.

- Since November 15, 1995, HFCs and other refrigerants with a zero ozone depletion factor (ODP) are also subject to the restriction on venting because they are "greenhouse gases," meaning they contribute to the global warming problem and must be recovered. All refrigerants must be recovered.

- Small releases of refrigerant that results from purging hoses or from connecting or disconnecting hoses to charge or service appliances will not be considered violations of the prohibition on venting. However, recovery and recycling equipment manufactured after November 15, 1993, must be equipped with low-loss fittings.

Evacuation Requirements of Small Appliances

Since July 13, 1993, technicians have been required to evacuate air-conditioning and refrigeration equipment to established vacuum levels. When using recycling and recovery equipment manufactured on or after November 15, 1993, 90% of the refrigerant from the small appliance must be recovered if the compressor on the appliance is operational, and 80% of the refrigerant must be recovered if the compressor is not operational. When using recycling and recovery equipment manufactured before November 15, 1993, 80% of the refrigerant from the small appliance must be recovered.


Exceptions to Evacuation Requirements

The EPA has established limited exceptions to its evacuation requirements for 1) repairs to leaky equipment and 2) repairs that are NOT major and that are not followed by an evacuation of the equipment to the environment.

NOTE: "Major" repairs are those involving removal of the compressor, condenser, evaporator, or auxiliary heat exchanger coil.

1. Repairs to Leaky Equipment

     If, due to leaks, evacuation to the levels required are not attainable or would substantially contaminate the refrigerant being recovered, persons opening the appliance must

     a) isolate leaking from non-leaking components wherever possible;

     b) evacuate non-leaking components to the levels required; and

     c) evacuate the leaking components to the lowest level that can be attained without substantially contaminating the refrigerant. However, this level cannot exceed 0 psig.

2. If evacuation of the equipment to the environment is not to be performed when repairs are complete, and if the repair is NOT major, then the appliance must

     a) be evacuated to at least 0 psig before it is opened if it is a high- or very high pressure appliance; or

     b) be pressurized to 0 psig before it is opened if it is a low-pressure appliance. Methods that require subsequent purging (e.g., nitrogen) cannot be used.

Key EPA Dates to Remember

- January 1, 1992 - Mandatory use of certified recycling equipment when servicing automotive (not commercial/residential/industrial) air conditioning.

- July 1, 1992 - Prohibition against venting during refrigeration/air conditioning service, repair, and disposal.

- June 14, 1993 - Owners of equipment containing more than 50 pounds of refrigerant with substantial leaks must have such leaks repaired within 30 days after discovery. For the industrial process and commercial refrigeration sector, a 35% leakage rate or more (35% loss of charge/year) is defined as a substantial leak, while for all other refrigeration systems with a charge of 50 pounds or more, a substantial leak is defined as a leakage rate of 15% (15% loss of charge/year).

- July 13, 1993 - Safe Disposal Requirements go into effect.

- July 13, 1993 - All persons opening appliances (except for small appliances and motor vehicle A/C) for maintenance, service, or repair, and all persons disposing of appliances, except for small appliances, must have at least one piece of certified, self-contained recovery equipment available at their place of business.

- August 12, 1993 - Owners of recycling and recovery equipment must have certified to the EPA that they have acquired such equipment and are complying with the rule.

- August 12, 1993 - Reclamation Requirements to ARI-700 went into effect. Refrigerant that transfers ownership must be certified to ARI-700 purity before it can be recharged into a system of another owner. Regardless of whether the refrigerant is sold or given to the second owner, it must be certified to ARI-700 purity. Refrigerant may be returned to the appliance from which it was recovered or to another appliance owned by the same person without being recycled or reclaimed.

- November 15, 1993 - All manufactured appliances must be equipped with a service aperture or process stub. Appliances (except small appliances) manufactured after November 15, 1993, must be equipped with a service aperture. Small appliances manufactured after November 15, 1993, can be equipped with either a process stub or a service aperture. The major purpose of this requirement is to make it easier to recover refrigerant. A service aperture or process stub is used when adding or removing refrigerant from the appliance. A process stub service port is a straight piece of tubing that is entered using a piercing access valve.

- November 15, 1993 - All recycling and recovery equipment manufactured must be certified to ARI 740-1993.

- November 15, 1993 - Low-Loss Fittings are required.

- November 14, 1994 - Mandatory Technician Certification. Refrigerant sales restrictions in effect.

- November 15, 1995 - Prohibition on venting any refrigerants, went into effect. This is due to the greenhouse global warming effect of vented refrigerants.

- December 31, 1995 - CFC Production Ban went into effect. No production or importation of new CFC's. All CFC's must come from recovery, recycling, and reclamation.

- January 29, 1998 - Persons servicing MVAC-like appliances have the option of becoming certified as Section 608 Type II technicians instead of becoming certified as Section 609 MVAC technicians under subpart B. Persons servicing MVACs do not have this choice.  They must be certified as Section 609 MVAC technicians if they perform the AC service for compensation.

 

Record Keeping Requirements

Technicians must keep a copy of their proof of certification at their place of business.

Wholesalers who sell HCFC, CFC and HFC refrigerants must retain invoices that indicate the name of the purchaser, date of the sale, and quantity of refrigerant purchased.

Reclaimers must maintain records of the names and addresses of persons sending them material for reclamation and the quantity of material sent to them for reclamation. This information must be maintained on a transactional basis. Within 30 days after the end of the calendar year, reclaimers must report to the EPA the total quantity of material received by them for reclamation that year, the mass of refrigerant reclaimed that year, and the mass of waste products generated that year.

Reclamation

Refrigerant recovered and/or recycled can be returned to the same system or other systems owned by the same person without restriction. However, since August 12, 1993, the EPA requires that if the refrigerant changes ownership, it will have to be cleaned to the ARI-700 standard of purity AND be chemically analyzed to verify that it meets this standard. This process is referred to as reclamation, and refrigerant meeting these conditions is referred to as being reclaimed.

Several important points need to be made concerning this regulation.

First, a refrigerant is considered "reclaimed" if and only if it is certified to meet the purity standards of ARI-700. In other words, if tests on the purity of the refrigerant show the refrigerant is clean (to ARI-700 standards), it is referred to as reclaimed, no matter what process if any, was used to clean it.

Second, the refrigerant cannot be transferred from any appliance owned by one person (person here means a person, corporation, partnership, or any other legal entity) to an appliance owned by a different person; it cannot be sold or given free to a second person. The refrigerant must be certified to meet the purity requirements of ARI-700 before it can legally be put in a second owner's equipment (except recovery, recycling, and reclamation equipment). Some technicians have wrongly believed that refrigerant can be transferred into a different owner's equipment if it was not sold. This is not correct; refrigerant cannot be transferred to a new owner unless it is certified pure (to ARI-700). This rule does not apply to automotive applications; they have to meet SAE (Society of Automotive Engineers) purity standards. In other words, if tests on the purity of the refrigerant show the refrigerant is clean (to ARI- 700 standards), it is referred to as reclaimed, no matter what process, if any, was used to clean it. This rule does not apply to automotive applications; they have to meet SAE (Society of Automotive Engineers) purity standards.

Equipment Certification

The EPA has established a certification program for recovery and recycling equipment. Under this program, the EPA requires that equipment manufactured on or after November 15, 1993, be tested by an EPA-approved testing organization to ensure that it meets EPA requirements. All recovery equipment now manufactured is required to have a certification label showing that the unit is EPA approved. Recovery equipment intended for use with small appliances must be tested under either ARI-740 or Appendix C of the EPA Final Rule (May 14, 1993). The agency is requiring recovery efficiency standards that vary depending on the size and type of air-conditioning or refrigeration equipment being serviced, and since July 13, 1993, technicians have been required to evacuate air-conditioning and refrigeration equipment to established vacuum levels. For small appliances, when using recycling and recovery equipment manufactured on or after November 15, 1993, 90% of the refrigerant from the small appliance must be recovered if the compressor on the appliance is operational, and 80% of the refrigerant must be recovered if the compressor is not operational. When using recycling and recovery equipment manufactured before November 15, 1993, 80% of the refrigerant from the small appliance must be recovered.

Technician Certification

Since November 14, 1994, the EPA has required that all individuals handling refrigerants be certified. Four types of section 608 certification are available. Only certified technicians can purchase refrigerants.

Technicians receiving a passing grade on the EPA Type I (small appliance) examination are certified to recover refrigerant during the maintenance, service, or repair of packaged terminal air conditioners with 5 pounds or less of refrigerant. Only Type I or Universal certified technicians can recover refrigerant from these units.

Technicians receiving a passing grade on the Type II (medium-pressure, high-pressure and very high pressure) examination are certified to recover refrigerant during the maintenance, service, or repair of medium, high and very high-pressure equipment (Medium-Pressure CFC-12, CFC-114, HFC-134a, CFC-500, High-Pressure HFC-410A, HCFC-22, CFC-502, Very-High Pressure CFC-13, CFC-503, as well as the other 400 Series Replacement Blends). Only Type II or Universal certified technicians can recover refrigerant from these units.

Technicians receiving a passing grade on the Type III (low-pressure appliance) examination are certified to recover refrigerant during the maintenance, service, or repair of low-pressure equipment (CFC-11, HCFC-123). Only Type III or Universal certified technicians can recover refrigerant from these units.

Technicians receiving a Universal Certification are certified to recover refrigerant during the maintenance, service, or repair of small appliances, medium, high and very high-pressure equipment, and low-pressure equipment. That is, they are certified to work on any type of air conditioning and refrigeration equipment except motor vehicle air conditioning.

Type I, II, and III certification exams consist of 25 core questions and 25 specific Type I, II, or III questions, for a total of 50 multiple choice questions for each type of certification. The Universal certification exam consists of 25 Core questions, 25 Type I questions, 25 Type II questions, and 25 Type III questions, for a total of 100 multiple-choice questions.

For technicians using the Type I open-book formats only, the exam is open-book, but the passing grade is 84% instead of 72% and the core questions must be repeated in a proctored environment if other certifications are required later.

Currently the certification has no expiration date; however, if EPA regulations change after a technician becomes certified, the technician is responsible for complying with any changes in the law. Visit www.epatest.com for the latest updates and changes in EPA regulations.

Mainstream is approved by the U.S. EPA as a national certifying agency for section 608 Type I, II, III, and Universal and section 609 Motor Vehicle Air Conditioning exams in all cities throughout the United States. Mainstream also offers Preventative Maintenance, R-410A, and Indoor Air Quality training. These open-book training and certification programs are available at our website www.epatest.com.

Reclaimer Contractor Certification

Reclaimers are required to return refrigerant to the purity level specified in ARI Standard 700 and to verify this purity. The laboratory protocol set forth in the same standard must be used. In addition, reclaimers must release no more than 1.5% of refrigeration during the reclamation process and must dispose of wastes properly. Since August 12, 1993, reclaimers must certify to the Section 608 Recycling Program Manager at EPA headquarters that they are complying with these requirements and that the information given is true and correct. The certification must also include the name and address of the reclaimer and a list of equipment used to reprocess and analyze the refrigerant (to ARI-700 standards).

Safe Disposal Requirements

Small Appliances that typically enter the waste stream with the charge intact (motor vehicle air conditioners, household refrigerators and freezers, and room air conditioners) are subject to special safe-disposal requirements.

Under these safe disposal requirements, the final person in the disposal chain (e.g., a scrap metal recycler) is responsible for ensuring that the refrigerant is recovered from the equipment before final disposal of the equipment. However, persons "upstream" could remove the refrigerant and provide documentation of its removal to the final person if this were more cost-effective.

The equipment used to recover refrigerant from appliances prior to their final disposal must meet the same evacuation performance standards as other recovery equipment, but this disposal-related equipment does not need to be tested by a laboratory to verify it meets ARI 740 standards. This means that self-built equipment is allowed as long as it meets the evacuation requirements. For motor vehicle air conditioning and motor vehicle-like systems, the requirement is 102 mm (4") of mercury vacuum; and for small appliances, 90% of the refrigerant from the small appliance must be recovered if the compressor on the appliance is operational, and 80% of the refrigerant must be recovered if the compressor is not operational.

Hazardous Waste Disposal

Recycled or reclaimed refrigerants are not considered hazardous under federal law. In addition, used oils contaminated with CFCs are not hazardous providing that:
   - they are not mixed with other waste;
   - they are subjected to recycling or reclamation (to remove trapped refrigerant); and
   - they are not mixed with used oils from other sources.

Used oils that contain CFCs after the CFC reclamation procedure, however, are subject to specification limits for used oil fuels if these oils are destined for burning. Individuals with questions regarding the proper handling of these materials should call the EPA's RCRA hotline at 800-424-9346 or 703-920-9810.

CFC Refrigerant Tax

The 1990 federal budget contained provisions for federal excise taxes on new production, floor stocks, and imports of CFCs and halons. The taxes were effective January 1, 1990, and apply to CFCs 11, 12, 113, 114, and 115. The original excise tax was amended in 1991 to include methyl chloroform, carbon tetrachloride, and other CFCs regulated by the amended Montreal Protocol and Title VI of the Clean Air Act. The Energy Policy Act of 1992, Section 1931 of Public Law 102-486, revised and further increased the excise tax (in effect since January 1, 1993). The government's intent is to provide additional financial incentives to increase recycling and to promote shifting-away from these substances. This excise tax is imposed when the CFC is sold or used by the manufacturer or importer. Recycled and reclaimed refrigerants are exempt from the tax. A floor tax also applies to anyone holding 400 lbs or more of the regulated CFCs.

The tax payment must be deposited with Form 8109, Federal Tax Deposit Coupon, at an authorized depository or a Federal Reserve Bank. In addition, a return must be filed on Form 720, the Quarterly Federal Excise Tax Return with the Environmental Tax Form 6627 attached. Contact an accountant or the IRS for further details.

Enforcement

Since July 1, 1992 the EPA has been responding to tips reporting venting. Under the Clean Air Act and subsequent revisions, the EPA is now authorized to assess fines of up to $32,500 per day per violation for any violation of the Act. In addition, the EPA may pay an award, not to exceed $10,000, to any person who furnishes information or services that lead to a criminal conviction or a judicial or administrative civil penalty assessed as a result of a violation of the act. These dollar amounts are maximum figures and are not necessarily the amount that will be assessed or paid in all cases.

Some contractors are circulating advertisements about the Clean Air Act requirements that may be misleading. The EPA will report such misleading advertisements to the Federal Trade Commission.

Further Information

For information concerning regulations related to stratospheric ozone protection, please call the EPA Stratospheric Ozone Hotline: 800-296-1996 (10am-4pm eastern) or visit their web site: http://www.epa.gov/.  

 

REVIEW TOPICS

- Capturing and ultimately eliminating the use of chlorofluorocarbons is being done in the United States to stop damage to the stratospheric ozone layer.

- State and local governments may establish laws that contain stricter regulations than the Clean Air Act/EPA regulations.

- July 1, 1992 - The Clean Air Act calls for the phase-out of CFC/HCFC production, prohibits CFC/HCFC venting, and requires the EPA to set standards for recovery, recycling, and reclamation of refrigerants.

- Disposing of disposable cylinders is accomplished by assuring that all refrigerant is recovered, that the cylinders are rendered useless, and then recycling the metal.

- Before you dispose of any appliance containing a refrigerant, you must recover the refrigerant.

- Violations of the Clean Air Act include falsifying or failing to keep records required by the EPA, the knowing release of refrigerant or refrigerant substitutes during the maintenance, service, repair, or disposal of appliances, and failing to reach required evacuation levels before opening or disposing of appliances.

- Whenever possible to avoid unnecessary venting of refrigerant, systems should be leak checked with pressurized nitrogen before charging.

- Service technicians who violate Clean Air Act provisions can be fined, lose their certification, and face federal charges and fines.

- An award of up to $10,000 may be paid to any person supplying information that leads to a penalty against a technician who is intentionally venting refrigerant.

- Violation of the Clean Air Act, including the knowing release of refrigerant during the maintenance, service, repair, or disposal of appliances, can result in fines up to $32,500 per day per violation. This fine was originally $25,000, then increased to $27,500 and with the most recent rule change increased to the current fine amount of $32,500. Some older paper exams might still use the $25,000 or $27,500 fine, you should choose the most correct answer.

- As of December 31, 1995, CFCs can no longer be legally manufactured or imported into the United States. Supplies of CFC refrigerant for equipment servicing can ONLY come from recovery, recycling, and reclamation.

- Recovery of refrigerants is necessary to provide adequate refrigeration supplies for service applications after the production bans, as well as to prevent venting to the atmosphere and the resulting ozone depletion.

- Since July 1, 1992, to knowingly release CFC or HCFC refrigerants during the service, maintenance, repair, or disposal of appliances is illegal.

- November 15, 1995, the EPA determined that venting substitute refrigerants poses a threat to the environment. Venting of substitutes for CFC and HCFC refrigerants, including HFC-134a, is now illegal.

- Chlorofluorocarbons, hydrochlorofluorocarbons, hydrobromofluorocarbons (HBFCs) and halons are all controlled by the Montreal Protocol.

- Under EPA regulations, reclaimed refrigerant must meet ARI-700 standards for purity before it can be resold.

- "Self-contained" (active) recovery devices can capture liquid and/or vapor refrigerant without the assistance of components in the air conditioning or refrigeration equipment.

- "System-dependent" (passive) recovery devices are so named because they depend on components of the system; that is, they capture refrigerant with the assistance of components in the air conditioning or refrigeration equipment they are emptying.

- All devices used for refrigerant recovery must meet EPA evacuation standards.

- Equipment covered by the EPA regulations includes all air conditioning and refrigeration equipment containing and using CFC, HCFC, and HFC refrigerants.

- Electronic/ultrasonic testers are assumed by the EPA to be the most effective method for locating the general area of small leaks.

- EPA regulations define a "small appliance" as one manufactured, charged, and hermetically sealed at the factory and containing 5 pounds or less of refrigerant.

- EPA rules require the capture of 80% of refrigerant from a small appliance sealed system with a non-operating compressor whether the technician is using a system-dependant (passive) process or a self-contained (active) process.

- It is permissible to use a passive recovery device to recover refrigerant from a domestic refrigerator or other small appliances.

- When checking for non-condensables in a recovery cylinder, the technician should allow the temperature of the cylinder to stabilize to room temperature before taking a pressure reading because comparisons to a pressure-temperature chart are only valid if both the pressure and temperature of the refrigerant are stable and known.

- All recovery devices manufactured before November 15, 1993, for use with small appliances must be capable of recovering 80% of the refrigerant whether or not the compressor is operational.

- Small appliance recovery equipment manufactured after November 15, 1993, must be certified to be capable of recovering 90% of the refrigerant when the compressor is operative or 80% when the compressor is inoperative.

- Recovery equipment manufactured after November 15, 1993 that is used during maintenance, service, or repair must be certified by an EPA-approved laboratory.

- Since November 14, 1994, technicians servicing refrigeration hardware must be certified in refrigerant recovery.

- Since November 14, 1994, the sale of CFC and HCFC refrigerants has been restricted to technicians certified in refrigerant recovery.

- At this time you don't need to be certified to purchase HFCs however you are required to recover HFCs.

- Before beginning any type of refrigerant recovery procedure it is always necessary to know the type of refrigerant that is in the system.

- When servicing a small appliance for leak repair, it is not mandatory to repair the leak, but do so whenever possible.

- Since November 15, 1993, refrigerant recovery devices must be equipped with low-loss fittings, which are fittings that are used to connect the recovery device to an appliance and which can be either manually closed or which closes automatically when disconnected to prevent loss of refrigerant from hoses.

- All appliances (except small appliances) manufactured after November 15, 1993, must be equipped with a service aperture. Small appliances manufactured after November 15, 1993, must be equipped with a process stub. The major purpose of this requirement is to make it easier to recover refrigerant. The service aperture or process stub is used when adding or removing refrigerant from the appliance. For small appliances, this process-stub-type of service port is a straight piece of tubing that is entered using a piercing access valve.

- Technicians receiving a passing grade on the Type I (small appliance) examination are certified to recover refrigerant during the maintenance, service, or repair of packaged A/C or refrigeration equipment with five pounds or less of refrigerant. Only Type I or Universal certified technicians can recover refrigerant from these units. Neither Type I or Universal certified technicians are certified to recover refrigerant from MVAC equipment.

- Technicians receiving a Universal Certification are certified to recover refrigerant during the maintenance, service, or repair of small appliances, high-pressure equipment, and low-pressure equipment. That is, they are certified to work on any type of air conditioning and refrigeration equipment except motor vehicle air conditioning.

- EPA Section 608 Certified technicians (Type I, II, III or Universal) are certified to purchase refrigerant in any size container except for CFC-12, which may not be purchased in containers less that 20 pounds. Recently the EPA has changed their stance on barring 608 certified technicians from purchasing any refrigerant in containers less than 20 pounds to barring 608 technicians from purchasing CFC-12 in containers less than 20 pounds. The exam questions used by Mainstream (and also used by all other testing companies) are supplied by the EPA, therefore in some older EPA exams you may be asked a question regarding the smallest container of refrigerants that can be sold to a 608 technician. Assume they are referring only to CFC-12.

- EPA Section 609 Motor Vehicle A/C (MVAC) Certified technicians can buy refrigerant in any size container, however they can only purchase refrigerant that is used in MVAC systems. For example, HCFC-22 is not used in MVAC systems and therefore cannot be purchased by 609 technicians.

- Type I, II, and III certification exams consist of 25 Core questions and 25 specific Type I, II, or III questions for a total of 50 multiple choice questions.

- Universal certification exams consist of 25 Core questions, 25 Type I questions, 25 Type II questions, and 25 Type III for a total of 100 multiple-choice questions.

- Technicians can take any of the certification exams as many times as necessary (passing grade per section is 72%, that is, 18 of 25 correct in each section). When retaking the exam, only the sections failed need to be repeated. If a technician taking a Universal Exam, fails to pass all sections, but passes the Core Section and at least one other section, a certification card for the types passed will be issued.

- Currently, the certification has no expiration date. However, if EPA regulations change after a technician becomes certified, the technician is responsible for complying with any future changes in the law.

- Accurate pressure reading of the refrigerant inside a recovery cylinder is necessary to determine if excessive air or other non-condensables are in the cylinder.

- After recovering refrigerant from a sealed system, if nitrogen is used to pressurize or blow debris out of the system, the nitrogen can be vented because air is about 80% nitrogen.

- When you check system pressures to determine the performance of a refrigerant, use equipment such as hand valves or self-sealing hoses to minimize any refrigerant release.

- When filling a charging cylinder, the refrigerant that is vented off the top of the cylinder must be recovered.

- Appliances containing refrigerant can be evacuated to atmospheric pressure instead of sub-atmospheric pressures when leaks in the appliance make evacuation to the EPA-prescribed level unattainable because air would be drawn into the recovery device from the surroundings. However, the appliances must always be evacuated to at least 0 psig.

- System-dependent recovery equipment CANNOT be used when the appliance contains over 15 pounds of refrigerant.

- When using a passive recovery device to recover refrigerant into a non-pressurized container from a system with an inoperative compressor it may be necessary to heat the compressor and strike it with a rubber mallet.

- When installing any type of access fitting onto a sealed system the fitting should be leak tested before proceeding with recovery.

- Only one access valves on the high side of the system are needed to evacuate the refrigerant on a sealed system that has a completely restricted capillary tube.

- To avoid the removal of liquid when drawing vapor from a sealed refrigeration system using a self-contained (active) recovery device that cannot handle liquid refrigerant, you should draw vapor from the high-side service port.

 

SECTION IV: Refrigerant Services Practices

Basic Vapor-Compression Refrigeration Principles

It is not the intent of this lesson to teach basic refrigeration theory; however, a simple discussion of the basic cycle is useful for describing the effects of non-condensable gases, moisture, and contaminates on the refrigeration system.

The most basic vapor-compression refrigeration system consists of four major components: compressor, evaporator, condenser, and expansion device. Actual practical hardware contains many other critical components for reliable, trouble-free operation, such as a control system, high-pressure and low-pressure safety controls, liquid receiver, accumulator, oil separator, crankcase pressure regulator, etc., but the four basic components are all that is needed to illustrate the point of this section.

Refrigerant adsorbs energy (provides cooling) as it evaporates, that is, as it boils and turns from liquid to vapor. For pure refrigerants, if the refrigerant evaporates at a constant pressure, then evaporation occurs at a constant temperature while both liquid and vapor are present. Likewise, refrigerant rejects energy (gives off heat) as it condenses from vapor to liquid. For pure refrigerants and azeotropic mixtures, if the condensation occurs at a constant pressure, then the condensation will occur at a constant temperature until all the vapor has condensed to a liquid. Therefore, for evaporation or condensation, the temperature and pressure are related by the pressure/temperature saturation curve. Table 2 presents saturation temperature/pressure data for CFC-11, CFC-12, HCFC-22, HFC-134a, CFC-500, CFC-502, and CFC-503. Table 3 presents temperature/pressure data for the new blends.

NOTE: A point of confusion regarding pressure units appears to frequently occur. When discussing pressure in PSI (pounds per square inch), PSIG means pounds per square inch gauge and PSIA means pounds per square inch absolute. The two numbers differ by approximately 15 psi. A refrigeration gauge normally reads in units of PSIG, that is, in normal air it will read a pressure of zero. However an absolute gauge would read a pressure of about 14.7 PSIA in this same location. In refrigeration, we typically talk about pressure above ambient in terms of PSI (with the ambient being at zero PSI so it would be more correct to refer to the pressure in PSIG.) Likewise we normally use inches of mercury to discuss vacuum levels with 29.9 being a complete vacuum (0 PSIA). Some of the new saturation charts for refrigerants are using the absolute pressure instead of the combination of gauge pressure and vacuum in inches of mercury. To convert PSIA to PSIG simply subtract 14.7 (or round to 15) from the PSIA reading to get the PSIG reading. For example 14.7 PSIA is 0.0 PSIG; normal atmospheric pressure, 164.7 PSIA can be referred to as 150 PSIG. As a simple rule of thumb to convert inches of mercury (the symbol for mercury is Hg) to PSIA, simply divide the value in inches of mercury by 2 and subtract it from 15 to get the approximate PSIA reading. For example 5" Hg is about 12.5 PSIA (actually it is 12.2 PSIA), 10" Hg is about 10 PSIA (actually it is 9.8 PSIA), and finally 15" Hg is about 7.5 PSIA (actually it is 7.3 PSIA).

If a technician has an unknown refrigerant in a recovery cylinder, and both liquid and vapor are present in the recovery cylinder, the refrigerant type can be verified by comparing the pressure and temperature with the saturation pressure/temperatures curves for the various refrigerants. For example, suppose the unknown refrigerant has a tank temperature of 80F and a tank pressure of 86 psig; referring to Table 2, the refrigerant in the tank is HFC-134a. Similarly, for the same tank temperature, the pressure would have to be 1.5 psig if the refrigerant was CFC-11, 84 psig if the refrigerant was CFC-12, 144 psig if the refrigerant was HCFC-22, 102 psig if the refrigerant was CFC-500, and 161 psig if the refrigerant was CFC-502. This technique will only work if the unknown refrigerant is pure and not contaminated with other refrigerants or non-condensable gases. If the refrigerant is known, but the measured pressure is above the saturation pressure (and both liquid and vapor are present in the tank), then the refrigerant is contaminated with either non-condensable gases or another refrigerant. If recovery of some vapor from the top of the tank removes or reduces this pressure discrepancy, then the problem was non-condensable gas, which was removed by the recovery operation. Non-condensable gases will add to the refrigerant's partial pressure resulting in an increased total system pressure for the mixture. Similarly, if the refrigerant is known, but the measured pressure is below the saturation pressure (and both liquid and vapor are present in the tank), then the refrigerant is contaminated with another refrigerant. If the pressure and temperature of the unknown refrigerant does not agree with any of the known refrigerants and recovery of vapor from the recovery tank does not improve the problem, then the recovery tank most likely contains two or more refrigerants mixed together, and this mixture cannot be recycled or reclaimed but must be destroyed at considerable expense (it must be incinerated by an EPA-approved waste processing facility).

A brief discussion of the operating vapor-compression cycle is helpful to indicate other potential refrigeration problems in real systems. In the basic cycle, slightly subcooled refrigerant leaves the condenser at high pressure and flows into the liquid receiver if one is present. The refrigerant then enters the throttling device (capillary tube, TXV, etc.) where the pressure is dropped. It then enters the evaporator as a two-phase mixture (liquid and vapor) and evaporates or boils at low temperature, adsorbing heat. Slightly superheated refrigerant vapor exits the evaporator and enters the suction line accumulator, if one is present (used to trap any transient liquid slugs). The refrigerant vapor then enters the compressor where the pressure and temperature are increased as the compressor compresses the refrigerant vapor. The vapor leaving the compressor is superheated, and the compressor discharge is the hottest point in the cycle. This refrigerant is cooled and condensed in the condenser where heat is rejected, and the refrigerant is condensed to liquid. Refrigerant actually leaves the condenser slightly subcooled (subcooled liquid) to assure condensation has been complete. Any non-condensable vapors in the system will be unable to condense in the condenser and will appear as gas bubbles in the condensed liquid stream. These non-condensables may collect in the condenser and displace refrigerant from the condenser heat exchanger, thereby reducing the effective surface area of the condenser.

Any water in the system will most likely freeze in the expansion valve because this is the point where refrigerant is cooled by the evaporation occurring as a result of the sudden pressure drop, and the expansion device also represents the smallest passageway in the overall system. This is the reason why filter-driers are typically located just upstream of the expansion device.


Table 2. Pressure/Temperature Saturation Relationship for Common Refrigerants

  Pressure[psig]
Temperature [°F] CFC-11 CFC-12 HCFC-22 HCFC-123 HFC-125 HFC-134a HFC-410A CFC-500 CFC-502 CFC-503
-20 27.0a 0.6 10.1 27.7a 20.0 3.7a 26.2 3.2 15.3 161.0
-15 26.5a 2.4 13.2 27.4a 24.1 0.0 31.0 5.4 18.8 177.0
-10 26.0a 4.5 16.5 26.9a 28.6 1.9 36.3 7.8 22.6 194.0
-5 24.5a 6.8 20.1 26.4a 33.4 4.1 42.0 10.4 26.7 212.0
0.0 27.70a 9.2 24.0 25.8a 39.6 6.3 48.4 13.3 31.1 230.0
10.0 23.1a 14.6 33.8 24.4a 50.4 11.6 62.4 19.7 41.0 271.8
20.0 21.1a 21.0 43.0 22.7a 64.0 18.0 78.7 27.2 52.5 318.5
30.0 18.6a 28.5 54.9 20.8a 79.6 25.6 97.4 36.0 65.6 370.6
40.0 15.6a 37.0 68.5 18.0a 97.4 34.5 118.8 46.0 80.5 428.2
50.0 12.0a 46.7 84.0 14.9a 117.6 44.9 143.2 57.5 97.4 491.7
60.0 7.8a 57.7 101.6 11.0a 140.4 56.9 170.7 70.6 116.4 561.0b
70.0 2.8a 70.2 121.4 6.6a 166.0 70.7 201.8 85.3 137.6
80.0 1.5 84.2 143.6 1.2a 192.6 86.4 236.5 101.9 161.2
90.0 4.9 99.8 168.4 2.5 226.4 104.2 275.4 120.5 187.4
100.0 8.8 117.2 195.9 6.1 261.7 124.3 318.5 141.1 216.2

a Indicates a vacuum in inches of mercury.
b Critical point @ 67F.


Table 3. Pressure/Temperature Saturation Relationship for Replacement Refrigerant Blends


 
R-401A
R-404A
R-407C
R-410A

Temperature
(F)

Liquid Phase Pressure (psig)

Vapor Phase Pressure (psig)

Liquid Phase Pressure (psig)

Vapor Phase Pressure (psig)

Liquid Phase Pressure (psig)

Vapor Phase Pressure (psig)

Liquid Phase Pressure (psig)

Vapor Phase Pressure (psig)

-50
14*
18*
0
0
3*
11*
5
5
-40
8*
14*
5
4
3
5*
11
11
-30
2*
9*
10
10
8
2
18
18
-20
3
2*
17
16
14
6
26
26
-10
7
3
25
24
21
12
36
36
0
13
7
34
33
29
19
48
48
10
19
13
44
43
40
28
62
62
20
27
20
57
55
51
38
79
78
30
36
27
71
69
65
50
97
97
40
46
36
87
85
80
63
119
118
50
58
47
105
104
98
79
143
143
60
71
59
126
124
118
97
171
170
70
86
73
149
147
141
117
202
201
80
103
88
175
173
166
141
237
236
90
122
106
204
202
194
167
275
274
100
143
126
237
235
225
196
319
318
110
167
148
273
270
260
229
366
365
120
193
172
312
310
299
266
419
418
130
221
200
356
354
341
307
478
477
140
253
230
404
402
387
352
543
541
150
286
263
457
455
437
402
614
613

* Indicates a vacuum in inches of mercury.


REVIEW TOPICS

- Since December 31, 1995, CFCs can no longer be manufactured or imported into the United States, and supplies of CFC refrigerant for equipment servicing can ONLY come from recovery, recycling, and reclamation.

- After the production bans, recovery of refrigerants is necessary in order to provide adequate refrigeration supplies for service applications, as well as to prevent venting to the atmosphere and the resulting ozone depletion.

- Since July 1, 1992, it has been illegal to knowingly release CFC or HCFC refrigerants during the service, maintenance, repair or disposal of appliances.

- Since November 15, 1995, it has been illegal to vent substitutes for CFC and HCFC refrigerants.

- The equipment covered by the EPA regulations includes all air conditioning and refrigeration equipment, as well as any other equipment containing and using refrigerants.

- The component of a refrigeration system that changes a high-pressure vapor to a high-pressure liquid is the condenser.

- The state of the refrigerant entering the compressor of a refrigeration system is low-pressure superheated vapor.

- The component that changes a low-pressure vapor to a high-pressure vapor is the compressor.

- Because the refrigerant flow is used for cooling in a hermetic compressor, the compressor must never be operated when the system is evacuated (or when there is a dehydration vacuum in the system). Due to the absence of refrigerant, there will be no cooling; this leads to rapid motor burn out.

- Oil foaming may occur in the compressor of a refrigeration system.

- Remember always recover or recycle refrigerant, keep systems tight, and find and repair leaks.

- Electronic and ultrasonic testers are assumed by the EPA as the most effective method for locating the general area of SMALL leaks.

- After evacuation, a failure of the system to hold a vacuum indicates that a leak exists in the system or that trapped refrigerant and/or water may be boiling off. If the internal pressure rises above ambient pressure, boil-off is occurring because a leak would not raise the pressure above ambient pressure.

- When evacuating a system, the use of too large of a vacuum pump could cause trapped water to freeze.

- The system vacuum gauge should be connected as far as possible from the vacuum pump.

- Vacuum lines (hoses) should be equal to or larger than the pump intake connection, and they should be as short as possible.

- A system is not dehydrated until a vacuum gauge (not the inaccurate manifold low-pressure gauge) shows you have reached and HELD the required finished vacuum with the system isolated from the vacuum pump.

- The final system vacuum level is measured with the system isolated and the vacuum pump turned off.

- Always isolate the system and relieve the vacuum on the vacuum pump (by loosening the hose connections, for example) before turning the pump off. Otherwise vacuum pump oil may be drawn out of the vacuum pump and into the lines or system.

- During dehydration of a refrigeration system, the refrigeration system can be heated to decrease dehydration time.

- Whenever a technician is working with any unknown solvents, chemicals, or refrigerants, the technician should always review the material safety data sheets, which by law should be shipped by the manufacturer with these compounds.

- Refrigerant vapors or mist in high concentrations should not be inhaled because they have been demonstrated to cause heart irregularities or unconsciousness in some people. Note warnings on the packaging. Refrigerants are heavier than air and can displace the air in a room, leaving no breathing air and leading to asphyxia. In most refrigerant accidents where death occurs, the major cause is oxygen deprivation.

- When pressurizing a refrigeration system with nitrogen, always use a pressure regulator and never charge with liquid nitrogen (only charge with nitrogen vapor).

- When corrosion build up is found within the body of a relief valve, the valve must be replaced, NOT repaired.

- Never use oxygen or compressed air to leak-check hardware because some refrigerants, including R-410A, when mixed with air or oxygen, can explode.

- Approved refrigerant recovery cylinders can be identified by yellow tops and gray bodies. It is a good idea to paint a color-stripe around the cylinder to indicate the type of recovered refrigerant contained inside and to utilize two recovery cylinders (one clean recycled, one dirty not recycled) for each refrigerant used by the technician. Reusable refrigerant containers that are under high pressure (above 15 psig at normal ambient temperature) must be hydrostatically tested and date stamped every five years.

- The MOST IMPORTANT reason NEVER to heat a refrigerant storage or recovery tank with an open flame is that the tank may explode and seriously injure people in the vicinity.

- When servicing a small appliance for leak repair, it is not mandatory to repair the leak but do so whenever possible.

- You can determine safe pressure for leak testing a system from the low-side test-pressure data-plate value.

- Refrigerant recovery devices must be equipped with low-loss fittings, which are fittings that are used to connect the recovery device to an appliance and which can be manually closed or which close automatically when disconnected to prevent loss of refrigerant from hoses.

- All appliances must be equipped with a service aperture or other device that is used when adding or removing refrigerant from the appliance. For small appliances, this service port is typically a straight piece of tubing (process-stub) that is entered using a piercing access valve. The major purpose of this requirement is to make it easier to recover refrigerant.

- A standard vacuum pump can only be used as a recovery device in combination with a non-pressurized container.

- After installing and opening a piercing access valve, if the system pressure is 0 psig do not begin the recovery procedure because all the refrigerant has leaked out, and the air and moisture in the system would contaminate the recovery tank's refrigerant.

- Sulfur dioxide, methyl chloride, and methyl formate, which are refrigerants used in some refrigerators built before 1950, should not be recovered with current recovery hardware. Likewise, ammonia, hydrogen, and water may be present in refrigerators used in small appliances in campers or other recreational vehicles and should not be recovered with current recovery devices.

- Piercing-type valves are recommended for use only on copper and aluminum tubing. Solderless piercing valves are not recommended, they leak over time.

- According to the EPA, a refrigerant leak detector should be used daily to check for leaks on a recovery device.

- Small amounts of refrigerant have no odor. When a pungent odor is detected during a sealed system recovery and/or repair, a compressor burn-out has likely occurred.

- AFTER recovering refrigerant from a sealed system (but never before recovering the refrigerant), if nitrogen is used to pressurize or blow debris out of the system, the nitrogen can be vented because air is predominantly nitrogen.

- When you check system pressures to determine the performance of a refrigerant, always use equipment such as hand valves or self-sealing hoses to minimize refrigerant release.

- When filling a charging cylinder, refrigerant that is vented off the top of the cylinder must be recovered.

- At high temperatures (i.e., open flames, glowing metal surfaces, etc.), R-12 and R-22 can decompose to form hydrochloric and hydrofluoric acids.

- If moisture remains in an operating refrigeration system, acid will form.

- If a large leak of refrigerant occurs, such as from a filled cylinder in an enclosed area, and no self-contained breathing apparatus is available, then the area should be vacated and ventilated.

- When first inspecting a hermetic system known to be leaking, you should look for traces of oil because this is an excellent indication of leaks.

- The rotating shaft seal on an open-type compressor is likely to leak if the unit is not used for several months. Operating the unit for a short period of time monthly will significantly reduce the leakage.

- When a refrigerant leak check trace gas becomes absolutely necessary, only HCFC-22 refrigerant can be used as the trace gas. Never use any other refrigerant as the trace gas. Use only a small quantity of the trace gas in combination with nitrogen to pressurize the system and inspect for leaks. Never use air or oxygen to pressurize the trace gas.

- Remember, always recover or recycle refrigerant, keep systems tight, and find and repair leaks

- The EPA suggests evacuation of a system as a method of dehydration.

- Dehydrating a refrigeration system is done to remove water and water vapor.

- While servicing an A/C system, if a technician discovers that a CFC refrigerant was added to an HFC system, the technician should recover the mixed contaminated CFC/HFC refrigerant into a separate tank since this refrigerant cannot be reused and must be destroyed at an approved facility. (It is typically impossible or much too expensive to reclaim.)

- Long hoses between the unit and the recovery machine should not be used because they cause excessive pressure drop, increased recovery time and increased emissions.

- There is no such thing as over-evacuation.

- Turn on the defrost heater on a frost-free refrigerator to vaporize any trapped liquid. This will speed the recovery process and ensure that all refrigerant has been removed.

- When using recovery cylinders and equipment with Schraeder valves, it is critical to inspect the Schraeder valve core for bends and breakage, cap the Schraeder ports to prevent accidental depression of the valve core and replace a damaged Schraeder valve core to prevent leakage.

- When a new system has been assembled and is ready for testing, the first thing that you should do is pressurize the system with an inert gas and leak check.

- If a system is opened for servicing, the filter drier should always be replaced.

- When evacuating a vapor compression system, the vacuum pump should be capable of pulling a vacuum of 500 microns (which is 0.5 mm of mercury). One mm of mercury = 0.039 inch of mercury = 1,000 micron.

- Non-condensables in a refrigeration system result in a higher discharge pressure.

- Every refrigerating system and refrigerant cylinder must be protected by a pressure-relief device. Never connect a pressurized gas to a system without a pressure relieving device in either the downstream system or line.

- Refrigerant is added to a centrifugal machine through the evaporator charging valve.

- Technician certification should ensure that the technician knows how to handle refrigerant in a safe manner without exhausting it to the atmosphere.

- A passive system-dependent recovery device captures the refrigerant in a non- pressurized container or recovery bag. A passive recovery device can be used on systems with operative or inoperative compressors.

 

SECTION V: Recovery, Recycling, and Reclamation

 REFRIGERANT PROCESSING OPTIONS

Recover and Destroy

In some instances, a refrigerant is so badly contaminated or mixed with other refrigerants that effective reclaiming of these refrigerants is impossible. Because the stability of CFCs has made them difficult to destroy, this is an expensive option. Yet sometimes because of contamination with other chemicals, the reclamation and separation of refrigerants from their contaminates is impossible.

Once refrigerants are mixed, they can never be used again. The only option is to destroy the refrigerants, and the only method is incineration an expensive option. CFCs are difficult to destroy because of their inherent stability and the release of fluorine during the incineration process. The incineration process must be able to contain the released fluorine. Always send refrigerant to an authorized treatment facility for destruction. Even waste oils containing high amounts of refrigerant can be harmful and destructive.

Recover and Reuse Without Processing

In many instances, the refrigerant in a system is still in good condition. This refrigerant can be removed from the system, and the repair or maintenance performed on the system and the refrigerant can be transferred back into the unit. For a small system, many technicians return recovered refrigerant back into a system without any processing or testing.

Recover and Recycle

When conditions of a system indicate that the refrigerant is deficient, the refrigerant may need to be processed to remove contaminants. Recycling machines can remove non-condensable gases, oil, acid, and water and can typically purify a refrigerant to the purity levels of new refrigerants. However, these fluids are not reclaimed unless they are tested and meet ARI-700 purity requirements. Recycling without purity testing works best in small operating appliances where the amount of refrigerant and the value of the equipment do not warrant a hundred-dollar investment in refrigerant test data and ownership of the refrigerant is not changing.

Refrigerant recovered and/or recycled can be returned to the same system or other systems owned by the same person without restriction. However, since August 12, 1993, the EPA has required that if the refrigerant changes ownership, then the refrigerant has to be cleaned to the ARI-700 standard of purity AND chemically analyzed to verify that it meets this standard. This process is referred to as reclamation (not recycling), and refrigerant meeting these conditions is referred to as being reclaimed.

Recovered or recycled refrigerant cannot be transferred from an appliance owned by one person (person here means a person, corporation, partnership, or any other legal entity) to an appliance owned by a different person. That means, it cannot be sold or given free to the second person. The refrigerant must be certified to meet the purity requirements of ARI-700 before it can legally be put in to a second owner's equipment (except for a transfer into a second owner's recovery, recycling, and reclamation equipment). Some technicians have wrongly believed that they could transfer the refrigerant into a different owner's equipment if it was not sold. This is incorrect;refrigerant cannot be transferred unless it is certified pure to ARI-700 Standards. This rule does not apply to automotive (MVAC and MVAC-like) applications; they have to meet SAE (Society of Automotive Engineers) purity standards.

Reclamation

The EPA requires that if refrigerant changes ownership, then the refrigerant has to be cleaned to the ARI-700 standard of purity AND chemically analyzed to verify that it meets this standard. This process is referred to as reclamation, and refrigerant meeting these conditions is referred to as being reclaimed.

First, a refrigerant is considered "reclaimed" if, and only if, it is certified to the purity standards of ARI-700. In other words, if tests on the purity of the refrigerant show the refrigerant is clean (to ARI-700 standards), it is deemed reclaimed no matter what process, if any, was used to clean it. Refrigerant that is tested and meets ARI-700 purity standards meets the same purity standards as virgin refrigerant, and can be used in any application where virgin refrigerant is used without limiting manufacturers' warranties.

 

REFRIGERANT SPECIFICATIONS

Mobile and stationary systems have different refrigerant specifications. The Society of Automotive Engineers (SAE) has developed standards for the recycling of refrigerants (SAE J-1991) that can be returned to mobile air-conditioning systems. The Air Conditioning and Refrigeration Institute (ARI) has developed the ARI-700 standard for new or reclaimed refrigerants used in stationary equipment that will maintain the equipment warranties and ensure compliance with the manufacturers' standards for air conditioning and refrigeration equipment.

REFRIGERANT RECOVERY METHODS

Recovering refrigerant is the first step in preventive maintenance or repair of equipment. Simply put, recovery means transferring the system's refrigerant into a refillable refrigerant cylinder. Recovered refrigerant may require further processing before it can be returned to the system. Only commercially available recovery equipment that has been certified (by an independent laboratory test approved by the EPA) to meet ARI-740 performance standards should be used for recovery or recycling.

A variety of designs are currently available. Some remove refrigerant in vapor form (and condense it in the recovery machine), they are very slow. Others remove liquid and vapor but do not separate the system's oil from the refrigerant. When the oil is not removed, the refrigerant cannot be reused reliably because the quantity of oil introduced into the refrigerant is unknown. Finally, the best recovery method removes both liquid and vapor, and separates the system's waste oil.

The fastest method to remove refrigerant from a system is to take it out in the liquid state. In the liquid state it occupies a smaller volume per pound of refrigerant. Large systems may have a liquid receiver where most of the charge is collected.

The slowest method of removing refrigerant is to remove it as a vapor. When recovering refrigerant as a vapor, a recovery or recycling unit can remove the vapor faster if the hoses and valve ports are not restricted and if a greater pressure difference can be created. The warmer the system, the warmer and more dense the vapor, which allows the compressor in the recovery unit to transfer more refrigerant in a minute. As pressure in the system is reduced, the vapor becomes less dense, and the unit capacity is reduced. More time is required as the system's pressure drops. For example, when removing CFC-12 from a system, if saturated vapor is removed at 70 psig, only 0.482 cubic feet of refrigerant vapor must be removed to remove 1 lb. of refrigerant. When pressure in the system is reduced to 20 psig, 1.147 cubic feet of vapor must be removed to remove 1 lb. of refrigerant. When the pressure is reduced to 0 psig refrigerant is still in the system, however 2.54 cubic feet of refrigerant vapor must be removed to remove 1 lb. of refrigerant. The recovery/recycle unit slows down as the refrigerant pressure drops because the compressor's volumetric pumping rate is a constant.

Under ARI-740 performance standards, recovery and recycling units are evaluated for liquid and vapor recovery from a standard test stand. These recovery rates are useful for comparison of individual units but do not exactly reflect the recovery rates attainable in actual practice because of different hose lengths, system temperatures, and internal system restrictions. Nevertheless, because of the greater density of liquid refrigerant, the liquid recovery rate is faster than the vapor recovery rate.

Typically, liquid refrigerant cannot be allowed to enter the compressor of a recovery unit because compressor knocking and damage will occur. Different manufacturers use varying methods to prevent this from occurring. However, even on those systems that can accommodate direct liquid input into a recovery unit, faster recovery rates are usually obtained if a push-pull liquid recovery method is used. For small appliances, the total quantity of refrigerant is quite small (less than 5 pounds) and the push-pull method is not recommended because the time to change hoses (between push-pull and direct recovery) will exceed the time saved by the more efficient recovery. A push-pull recovery only removes liquid refrigerant and must be followed by a direct vapor recovery to reach the required evacuation levels.

A push-pull method of removing refrigerant is accomplished by connecting the liquid line fitting on the system to a liquid line fitting on the recovery tank. The suction line of the recovery unit is connected to the vapor fitting on the recovery tank, and a connection is then made from the discharge (outlet) of the recovery unit back to the system. When the unit is started, vapor is drawn out of the recovery tank from the vapor port of the tank and condensed in the recovery unit. A very small amount of liquid is then pushed back into the system where it flashes to a vapor to build pressure and push more liquid from the system and into the recovery tank. A sight glass in the liquid line between the system and liquid-connection of the recovery tank is useful for monitoring the liquid recovery. When no more liquid is being recovered, the recovery unit is reconnected for direct vapor recovery. In spite of the fact that the push-pull recovery method is faster, there is time associated with changing the hose connections between push-pull liquid and direct vapor recovery. Mainstream recommends direct vapor recovery if the system contains less than 2-3 lbs. of refrigerant and push-pull liquid recovery is recommended for larger quantities. Check with your recovery equipment manufacturer for recommendations concerning your specific unit.

Remember, when the liquid is removed, it contains oil. In a push-pull configuration, this oil will be trapped in the recovery cylinder, whereas in direct liquid recovery, it will be trapped in the recovery unit's oil separator (assuming your recovery unit has an oil separator). There is no requirement for a recovery or recycling machine to have an oil separator.

Always follow the manufacturer's specific instructions while using their recovery, recycling, and any other equipment; they know the capabilities of their equipment. When using tanks that do not have an internal liquid-level control, the operator must monitor the weight of the external tank (using a refrigerant scale) and only fill this tank to 80% of its rated full-tank capacity. Overfilling a tank can cause the tank to rupture (as the tank heats during the day, the liquid contained in the tank has no room for expansion).

 

RECOVERY/RECYCLING SYSTEMS

Two types of recycling equipment are currently being sold. The first is referred to as single pass and the other is multiple pass. Single pass recycling machines typically process refrigerant only once through filter-driers. Multiple pass machines recirculate the recovered refrigerant many times through filter-driers. Recirculation systems are, of course, more flexible and more effective because the amount of filtering can be controlled by the operator, and can be based on the results of moisture and acid tests, which are performed during recycling.

Recirculating and recycling are not interchangeable terms. Recycling machines do not necessarily recirculate the refrigerant (see above definitions). Recycling is the process; recirculating is one mechanism of recycling. There has been far more scrutiny of the appropriate use of recycled refrigerant with the advent of recycling machines.

A few guidelines are available to use when choosing recycling equipment and determining when to use it. The general rule is that refrigerant can be recycled when removed from a system and returned to that same system or another system owned by the same person. The forward of ARI-700-88, Standard for Fluorocarbon Refrigerants, states, "This standard does not apply where refrigerant captured from a particular system is returned on site to the same system." (The EPA has eased this requirement to be the same owner.)

Any person using recycling equipment should address a variety of issues. First, decide if the refrigerant will be returned to the same system. If the system is being dismantled, for example, other factors must be considered.

If the refrigerant is to be returned to the same system, the next issue is the condition of the refrigerant. When oil is separated from the refrigerant, a vast majority of the contaminants are also removed. Most refrigerant recycling machines use filter/dryers to remove any other moisture and acid as well as hard particles. Then, generally the refrigerant can be returned to the system. However, if the quantity of refrigerant contained in the system is significant the refrigerant should be tested for purity to ARI-700 standards by a testing laboratory.

A real problem exists when a burnout occurs in a hermetic compressor. A burnout is caused by an electrical failure inside the compressor of a refrigeration system. This electrical failure can be due to a variety of reasons and contamination of the refrigerant in this situation can range from mild to severe. However, oil is the real villain in a burnout. When dealing with a burnout, regardless of what kind of machine, use caution! The oil can be very acidic and toxic. Anyone who has been in contact with its distinctive odor, a classic symptom, can attest to that. The best approach is to keep the acid oil from ever reaching the recycling machine. Use a recovery or recycling system with initial oil separation to remove the waste oil, or if your recovery machine does not separate the incoming oil, use a dual-valve recovery tank as an oil-separator on the inlet line to the recovery system. Waste oil should be drained from the recycling or recovery machine during the recovery operation.

If any doubt exists as to the suitability of the refrigerant, do not return it to the system. Recycle the questionable refrigerant and have its purity tested. Always add new or reclaimed refrigerant if the amount of recycled refrigerant is not enough for correct system operation. Additional refrigerant will probably be needed every time the system has had a leak. Recycled refrigerant cannot be represented as new. No matter how clean the refrigerant or how sophisticated the recovery, recycling, or reclamation machine, the refrigerant must be tested and meet the purity standards of ARI-700 before it can be called reclaimed and sold or transferred (change ownership) into a refrigeration or air conditioning system of a different owner.

Even if the refrigerant is not changing ownership, use of refrigerant that is not certified to meet ARI-700 purity standards will invalidate the manufacturer's warranty. The refrigeration technician could be liable for damages arising out of introducing impure refrigerant into a system. Have the refrigerant tested; don't risk thousands of dollars in equipment and refrigerant costs to try to save on a $200 test. Obviously, for a small system, testing does not make economic sense and the technician must use good judgment. Technician experience is the best guide. Check for acid content with Mainstream's QwikCheck.

Recovering Refrigerant from Appliances

Recovering refrigerant from appliances may be an easier job than from larger systems because not as much refrigerant is involved. Small appliances contain less than five pounds of refrigerant and only 80% to 90% of the charge needs to be removed from appliances (see Section III).

Refrigerant bags are available for recovery of refrigerant from small appliances. These bags are plastic and will hold the charge of several refrigerators. The technician must have enough room in the service truck to haul the bag. When a bag is full, it may be taken to the shop and the refrigerant transferred into a recycling machine or into a reclaim cylinder.

SAFETY PRECAUTIONS

1. Always wear protective goggles when working with refrigerant. If liquid refrigerant gets in your eye, permanent blindness may result.
2. Do not allow refrigerant to come in contact with your skin. Refrigerant has a very low boiling point, which will cause frostbite.
3. All refrigerant handling, charging, and recycling operations should be performed in locations with adequate ventilation of at least four air changes per hour. Avoid prolonged breathing of the vapor. Prolonged inhalation of refrigerant is extremely dangerous; death can occur without warning.
4. Do not use a recovery unit in the vicinity of spilled or open containers of gasoline, thinners, or any other flammable liquid or vapor unless the equipment is expressly designed (explosion proof designs) for such environments. Do not operate where flammable vapor is present.
5. Do not leave any recovery or recycling machine on and unsupervised.
6. Do not attempt to fill any vessels, containers, cylinders, charging equipment, or storage tanks that are not D.O.T.-approved and equipped with a safety-vent valve. Do not transfer refrigerant to non-refillable cylinders.
7. Do not fill any storage tank or vessel with refrigerant beyond 80% of its capacity.
8. Do not disconnect or tamper with the electrical high-pressure, low-pressure, or liquid-level safety shut-off.

Guidelines for Filling Cylinders

   - Disposable cylinders may be used for shipment of original refrigerant only. They are never permitted for any further use.
   - OSHA (U.S. Occupational Safety and Health Administration) requires that compressed gas cylinders be used only by individuals who are trained in the proper handling and safe use of these cylinders.
   - Never mix one refrigerant (or gas) with another type of refrigerant. These mixtures may be very difficult to separate once they are mixed and consequently must be destroyed rather than reclaimed.
   - Use personal protective equipment, such as side-shield safety glasses, gloves, and safety shoes, when filling and handling cylinders.
   - Avoid skin contact with refrigerant.
   - Be aware that inhalation of high concentrations of refrigerant vapor is harmful and may cause heart irregularities, unconsciousness, or death. Because vapor is heavier than air, avoid low areas without suitable ventilation.
   - Exercise caution when moving cylinders. 

Cylinder Inspection

Prior to filling, a cylinder should be inspected for signs of damage, such as dents or corrosion. Do not fill a damaged cylinder.

A recovery cylinder should not be filled if the present date is more than five years past the test date that is stamped on the shoulder of the cylinder. The test date will look similar to the example below:

A1

12                  99

 23

The designation in the example above indicates that the cylinder was re-tested in December 1999 by re-tester number A123. If a cylinder is out of date, it must not be filled, promptly return it to the cylinder owner for re-testing by an approved test laboratory. As stated earlier in this text, liquid refrigerant will expand as its temperature increases. If the cylinder is overfilled, thermal expansion of the liquid could rupture the cylinder.

After filling, verify that all cylinder valves are closed properly and capped to prevent leaks during subsequent handling and shipment.

 

Shipping Procedures

The U.S. EPA does not characterize used refrigerants as hazardous waste. Most states share this view and, consequently, require no special procedures for used refrigerant shipments. However, any individual state may require special shipping procedures based on its own waste classification of used refrigerants. Shippers should contact the appropriate state agency to determine whether special state shipping instructions apply. The following information is intended as a guide, but is not complete for shipping used refrigerants that are classified as a hazardous waste.

All used refrigerant containers must be properly labeled, not just the ones you are planning to ship, and this regulation includes the yellow and gray recovery tanks. Cylinders and drums should be labeled prior to filling. Never fill a cylinder or drum that is not labeled for that material. Unlabeled containers in your truck could be dangerous and are illegal. In the event of an accident, most emergency personnel are instructed to avoid unidentified containers or cylinders, and to wait for a Hazardous Materials Response Team to arrive and identify the contents of the containers. This could cause unnecessary delays.

REVIEW TOPICS

- Disposing of disposable cylinders is accomplished by assuring that all refrigerant is recovered and that the cylinders are rendered useless (punctured), then recycle the metal.

- Before you dispose of any appliance containing a refrigerant, you must recover the refrigerant.

- Service technicians who violate Clean Air Act provisions can be fined, lose their certification, and face Federal charges.

- Violation of the Clean Air Act, including the knowing release of refrigerant during the maintenance, service, repair, or disposal of appliances, can result in fines up to $32,500 per day per violation.

- Recovery of refrigerants is necessary to provide adequate refrigeration supplies for service applications after the production bans, as well as to prevent the venting to the atmosphere and the resulting ozone depletion.

- Since July 1, 1992, to knowingly release CFC or HCFC refrigerants during the service, maintenance, repair, or disposal of appliances has been illegal.

- November 1995, the EPA determined that venting substitute refrigerants poses a threat to the environment. Venting of substitutes for CFC and HCFC refrigerants is illegal.

- Under EPA regulations, reclaimed refrigerant must meet ARI 700 standards for purity before it can be resold.

- "System-dependent" recovery devices are so named because they depend on components of the system. That is, they capture refrigerant with the assistance of components in the air conditioning or refrigeration equipment they are emptying.

- All devices used for refrigerant recovery must meet EPA standards.

- The equipment covered by EPA regulations includes all air conditioning and refrigeration equipment containing and using refrigerants.

- "Self-contained" recovery devices can capture liquid and/or vapor refrigerant without the assistance of components in the air conditioning or refrigeration equipment.

- The proper charging method for blended (non-azeotropic) refrigerants (400 Series) is to use a remove the charge from the cylinder as a liquid. Typical blends (except R-410A) will leak from a system in uneven amounts due to the different vapor pressures of the components, and therefore they should not be topped off. However, while R-410A is a blend (thus the 400 series designation), it behaves as a near azeotropic refrigerant, and can be topped off, unlike other 400 series refrigerants (R-410A should still be removed from the cylinder as a liquid.).

- Hygroscopic means affinity for water, so hygroscopic oils are oils with a high affinity for water.

- The center port on a three-port manifold is used for recovery, evacuation, and charging.

- Remember, always recover or recycle refrigerant, keep systems tight, and find and repair leaks.

- Recovered refrigerant can contain acids, oils and/or moisture.

- According to the EPA, an oil sample should be taken whenever the unit has had a leak or a major component failure.

- Recycling is defined as the cleaning of refrigerant for reuse by oil separation and single or multiple passes through moisture absorption devices.

- Reclamation is defined as processing refrigerant to a level equal to new product specifications as determined by chemical analysis (testing to ARI-700 standards).

- Recovery is defined as transferring refrigerant in any condition from a system to a storage container without testing or purifying the refrigerant in any way.

- When addressing consumer complaints regarding additional service expense due to recovery efforts, the technician needs to explain to the customer that recovery is necessary to protect human health and the environment, that recovery is required by federal law, that all professional service personnel are duty-bound to follow the law and protect the environment, and that there are substantial fines of $32,500/occurrence/day for anyone venting refrigerant.

- When recovering refrigerant, do not mix different refrigerants because the mixture will be impossible to reclaim. In cases where refrigerant cannot be reclaimed, it must be destroyed. Only one refrigerant type can be recovered into a cylinder at a time.

- A system is not dehydrated until a vacuum gauge shows that you have reached and HELD the required finished vacuum.

- During dehydration of a refrigeration system, the refrigeration system can be heated to decrease dehydration time.

- The system vacuum level is measured with the system isolated.

- After completing the transfer of liquid refrigerant between the recovery unit and the refrigeration system, be careful to avoid trapping liquid refrigerant between service valves of the refrigerant hose because pressure can build up in the line and burst the hose.

- Whenever working with any unknown solvents, chemicals, or refrigerants, always review the material safety data sheets, which by law should be shipped by the manufacturer with these compounds.

- Refrigerant vapors or mist in high concentrations should not be inhaled because they can cause heart irregularities or unconsciousness in some people. Note the warnings on the packaging. Refrigerants are heavier than air and can displace the air in a room, leaving no breathing air in the room (leading to asphyxia). In most refrigerant accidents where death occurs, the major cause is oxygen deprivation.

- Approved refrigerant recovery cylinders can be identified by yellow tops and gray bodies. It is a good idea to paint a color-stripe around the cylinder to indicate the type of recovered refrigerant contained inside, and to utilize two recovery cylinders (one clean recycled, one dirty not-recycled) for each refrigerant handled by the technician. Reusable containers for refrigerants that are under high pressure (above 15 psig at normal ambient temperature) must be hydrostatically tested and date-stamped every five years.

- All refrigerant tanks, including recovery tanks, should be labeled to show their contents.

- A refillable refrigerant cylinder must not be filled above 80% (by weight) of its full capacity.

- When transporting cylinders containing used refrigerant, D.O.T. requires D.O.T. classification tags be attached.

- Refrigerant cylinders should be stored vertically during shipping.

- Before transferring refrigerant to an empty cylinder, the cylinder should be evacuated.

- Small appliance recovery equipment manufactured on or after November 15, 1993, must be certified to be capable of recovering 80% of the refrigerant when the system's compressor has failed, or achieving a 4-inch vacuum under the conditions of ARI 740-1993.

- Small appliance recovery equipment manufactured on or after November 15, 1993, must be certified to be capable of recovering 90% of the refrigerant when the system's compressor is operational, or achieving a 4-inch vacuum under the conditions of ARI 740-1993.

- Since, November 14, 1994, technicians servicing refrigeration hardware must be certified in refrigerant recovery.

- Since November 14, 1994, the sale of CFC and HCFC refrigerants has been restricted to technicians certified in refrigerant recovery.

- The EPA may require technicians to demonstrate their ability to perform proper refrigerant recovery and recycling procedures. Failure to demonstrate proper procedures may result in revocation of the technician's certification.

- When servicing a small appliance for leak repair, it is not mandatory to repair the leak but do so whenever possible.

- Refrigerant recovery devices must be equipped with low-loss fittings that are used to connect the recovery device to an appliance and which can be manually closed or which close automatically when disconnected to prevent loss of refrigerant from hoses.

- All appliances must be equipped with a service aperture or other device that is used when adding or removing refrigerant from the appliance. For small appliances, this service port typically is a straight piece of tubing that is entered using a piercing access valve.

- An accurate pressure reading of the refrigerant inside a recovery cylinder is necessary to determine if excessive air or other non-condensables are in the cylinder.

- When a reclamation facility receives a tank of mixed refrigerant, it may refuse to process the refrigerant and return it at the owner's expense, or it may agree to destroy the refrigerant, but typically a substantial fee is charged.

- A standard vacuum pump can only be used as a recovery device in combination with a non-pressurized container.

- After installing and opening a piercing access valve, if the system pressure is 0 psig, do not begin the recovery procedure because all of the refrigerant has leaked out, and air and moisture in the system will contaminate the recovery tank's refrigerant.

- Because small amounts of refrigerant have no odor, when a pungent odor is detected during a sealed system recovery and/or repair, a compressor burn-out has likely occurred.

- After recovering refrigerant from a sealed system, if nitrogen is used to pressurize or blow debris out of the system, the nitrogen can be vented because air is predominantly nitrogen.

- When you check system pressures to determine the performance of a refrigerant, use equipment such as hand valves or self-sealing hoses to minimize any refrigerant release.

- When filling a charging cylinder, the refrigerant that is vented off the top of the cylinder must be recovered.

- D.O.T. Regulation 49 CFR requires the number of cylinders of each gas be recorded on the shipping document for hazard class 2.2, Nonflammable Compressed Gases.

- If a large leak of refrigerant occurs, such as from a filled cylinder in an enclosed area and no self-contained breathing apparatus is available, the area should be vacated and ventilated.

- Recovering refrigerant from a system in the vapor phase will minimize the loss of oil from the system.

- Most refrigerant and recycling machines require a regular oil and filter change.

- Removal of the refrigerant charge from a system can be accomplished more quickly by cooling the recovery tank by packing it in ice.

- Recovery during low ambient temperatures will slow the recovery process because the vapor pressure of the refrigerant and the refrigerant's density are lowered as the temperature is lowered. Some technicians incorrectly believe the cooler temperatures will shorten recovery time because the recovery tank is cooler, but this is not true. It is correct that a cooler recovery tank speeds recovery compared to a warm recovery tank but if both the system and the recovery tank are cooler then the disadvantage of the lower pressure on the suction side of the recovery compressor far outweigh the benefit of the lower pressure in the recovery tank. For fastest recovery, we want a hot system and a cold recovery tank.

- In a system that utilizes a thermal expansion valve, the liquid receiver directly follows the condenser.

- The accumulator directly follows the evaporator of a refrigeration system.

- The gauge port can be closed by backseating a suction shutoff valve.

- Before using a recovery unit to remove a charge, always check service valve positions, evacuate the recovery unit/receiver, and check the recovery unit oil level.

- The state of refrigerant leaving the receiver of a refrigeration system is high pressure liquid.

- The evaporator, suction line and accumulator are all parts of the low side of a refrigeration system.

- Recycling or recovery equipment using a hermetic compressor has the potential to overheat when drawing deep vacuums because the compressor motor relies on the flow of refrigerant through the compressor for cooling.

- When recovering R-134a, as well other refrigerants, special precautions must be taken to avoid contamination of the R-134a with oil from the other refrigerants. We recommend that a set of hoses, gauges, vacuum pump, recovery cylinders, recovery machine, and oil containers be dedicated for R-134a only.

- After reaching the required recovery vacuum on an appliance, turn off the recovery device (isolate the system) and wait for a few minutes to see if the system pressure rises, indicating that there is either refrigerant in liquid form, refrigerant trapped in the oil, or a leak in the system.

- Appliances containing refrigerant can be evacuated to atmospheric pressure, instead of sub-atmospheric pressures, when leaks in the appliance make evacuation to the EPA-prescribed level unattainable because air would be drawn into the recovery device from its surroundings.

- When evacuating a vapor compression system, the vacuum pump should be capable of pulling a vacuum of 500 microns. One mm of mercury = 0.039 inch of mercury = 1,000 micron.

- Non-condensables in a refrigeration system result in a higher discharge pressure.

- Using a heater on a recovery vessel increases the head pressure and increases the speed of charging refrigerant from the recovery vessel back into the system during system charging.

- Cooling the recovery vessel reduces the recovery vessel head pressure and increases the speed of refrigerant recovery from a system and into the recovery vessel.

- If you have to leak check a unit that has lost a complete charge, the leak check gas that would cause the least damage to the environment would be dry nitrogen.

- Whenever dry nitrogen is used from a portable cylinder, always make sure that a relief valve is available downstream from the pressure regulator.

- Factors that affect the speed of evacuation include the size of the equipment being evacuated, the ambient temperature and the amount of moisture in the system.

- The capacity of the vacuum pump and its suction line size will determine the dehydration time.

- When using a vacuum pump, every effort should be made to reduce the pressure drop between the vacuum pump and the system. Therefore the piping connection should be as short as possible (using the largest diameter pipe that is practical).

- An alcohol spray can be used to remove ice from sight glasses or viewing glasses.

- All refrigerants must be recovered with equipment regulated by the EPA.

- When using vapor recovery, the fill level of the recovery cylinder can be controlled by mechanical float devices, electronic shut-off devices or weight of the cylinder.

- A refrigerant label should be placed on a refrigerant cylinder to be returned for reclaiming.

- Ammonia, water and hydrogen may be present as components of refrigerants used in small appliances in campers or other recreational vehicles and should NOT be recovered with current EPA-approved recovery devices.

- When a household refrigerator compressor does not run, it is recommended that low and high side access valves be installed to recover the refrigerant from the system. This will increase recovery speed and is necessary to achieve the required recovery efficiency.

- Solderless-type piercing valves should not remain installed on refrigeration systems after completion of repairs because they tend to leak over time.

- When using a system-dependent (passive) recovery process on operating compressors, technicians should run the appliance's compressor and recover the refrigerant from the high side.

- An unopened recovery tank inlet valve or excessive air in the recovery tank can cause excessive pressure on the high side of a recovery device.

- The motor winding of a hermetic refrigeration compressor can be damaged if it is energized when under a deep vacuum because there will be no refrigerant flow to cool the motor.

- When refrigerant has been recovered from an air-conditioning system and held in a refillable cylinder in order to make a repair, the refrigerant can be legally charged back into the system.

- A reciprocating compressor should never be energized when the discharge service valve is closed since an excessive pressure will develop, potentially damaging the compressor.

- High head pressure indicates that there is either a lack of condenser cooling or non-condensables (such as air or nitrogen) in the system.

- Refrigeration and air-conditioning crankcase compressor heaters reduce the amount of refrigerant trapped in the lubricating oil.

- A filter drier removes acid and moisture from the refrigerant.

- Always use gloves and safety goggles when working with liquid refrigerant, avoid spilling liquid refrigerant on skin, and never siphon refrigerant by mouth.

- According to the EPA regulations, flushing with liquid refrigerant to clean field tubing is not an approved technique for system cleanup after a burnout.

- During refrigerant recovery, when the system's compressor does not run, it is good practice to access both the low and high sides of the system to assure that refrigerant is not trapped in the system. For passive systems this becomes even more critical because the pressure differential in passive recovery is typically much smaller. For small systems with an operating compressor a single access valve on the high side can be used.

- According to ASHRAE Guideline 3-1996, if the pressure in a system rises from 1 mm Hg to a level above 2.5 mm during a standing vacuum test, the system should be checked for leaks.

- While R-410A is a high pressure refrigerant, it can still be stored in the back of your service van as long as the temperature inside the vehicle does not exceed 125F. This is the same guidance given for R-22 and other common refrigerants.

- People who service or repair MVAC-like appliances (e.g. farm equipment and other non-roads vehicles) can choose to be certified by either the Section 609 program or under Section 608 Type II. Due to the similarities between MVAC and MVAC-like appliances, EPA recommends that technicians servicing MVAC-like appliances consider certification under Section 609. Note that buses using CFC-12 are MVACs, however buses using HCFC-22 are not MVACs or MVAC-like appliances, but rather high-pressure equipment covered under Type II of the Section 608 test. Therefore if you service busses with both HCFC-22 and CFC-12 refrigerant a Type II certification covers both.

 

SECTION VI: PROPOSED EPA RULE CHANGES

Visit www.epatest.com for the latest updates and changes

Technician Certification and Sales Restriction

While HFCs and PFCs are not ozone-depleting substances, they have been identified as potent greenhouse gases with long atmospheric lifetimes and are part of the six gases included in the Kyoto Protocol. The Kyoto Protocol calls for the aggregate emissions of the six gases to be reduced to an average of 5% below 1990 levels in developed countries in the 2008-2012 timeframe. However, actual implementation of Technician Certification and Sales Restrictions on HFC and PFC are pending further cost and emissions reductions analysis. It is currently assumed that because of the significant cost savings associated with recovery of large quantities of refrigerant safe handling practices of HFCs and PFCs will be performed voluntarily. However, sales restrictions and certifications specific to HFCs and PFCs are still a future possibility if the United States fails to reach the emissions goals set by the Kyoto Protocol in the near future. Please remain informed by frequently checking www.epa.gov and the Frequently Asked Questions section of www.epatest.com.

 

Conversion Factors

To Convert From PSIG To PSIA Add 14.7 to the PSIG reading.
To Convert From PSIA To PSIG Subtract 14.7 to the PSIA reading.
To Convert From Inches of Mercury To Millimeters of Mercury Absolute Multiply the Inches of Mercury by 25.4 and Subtract the result from 760.
To Convert From Millimeters of Mercury Absolute To Inches of Mercury Subtract the vacuum in mm Hg Absolute from 760 and Divide by result by 25.4

Examples of the Conversion of Vacuum Units

PSIA Reading

Reading in Inches
of Mercury
[in. Hg]

Reading in Millimeters of Mercury Absolute
[mm Hg Absolute]

14.7 PSIA 0" Hg 760 mm Hg Absolute

12.2 PSIA

5 "Hg

633 mm Hg Absolute

9.8 PSIA

10 "Hg

506 mm Hg Absolute

7.3 PSIA

15 "Hg

379 mm Hg Absolute

4.8 PSIA

20 "Hg

252 mm Hg Absolute

2.4 PSIA

25 "Hg

125 mm Hg Absolute

0.5 PSIA

28.9 "Hg

25 mm Hg Absolute

0.0 PSIA

29.9 "Hg

0 mm Hg Absolute