MONTREAL PROTOCOL

ON SUBSTANCES THAT DEPLETE

THE OZONE LAYER

UNEP

REPORT OF THE

TECHNOLOGY AND ECONOMIC ASSESSMENT PANEL

MAY 2013

VOLUME 2

DECISION XXIV/7 TASK FORCE REPORT

ADDITIONAL INFORMATION TO ALTERNATIVES ON ODS

(DRAFT REPORT)

May 2013 TEAP XXIV/7 Task Force Report iii

UNEP

MAY 2013 REPORT OF THE

TECHNOLOGY AND ECONOMIC

ASSESSMENT PANEL

VOLUME 2

DECISION XXIV/7 TASK FORCE REPORT 

ADDITIONAL INFORMATION ON ALTERNATIVES TO ODS

(DRAFT REPORT)
iv May 2013 TEAP XXIV/7 Task Force Report

Montreal Protocol

On Substances that Deplete the Ozone Layer

Report of the

UNEP Technology and Economic Assessment Panel

Volume 2

May 2013

DECISION XXIV/7 TASK FORCE REPORT:

ADDITIONAL INFORMATION ON ALTERNATIVES TO ODS (DRAFT REPORT)

The text of this report is composed in Times New Roman.

Co-ordination: TEAP and its XXIV/7 Task Force

Composition: TEAP and its XXIV/7 Task Force

Layout: Lambert Kuijpers, Paul Ashford and UNEP’s Ozone Secretariat

Reproduction: UNON Nairobi

Date: May 2013

Under certain conditions, printed copies of this report are available from:

UNITED NATIONS ENVIRONMENT PROGRAMME

Ozone Secretariat, P.O. Box 30552, Nairobi, Kenya

This document is also available in portable document format from

http://ozone.unep.org/new_site/en/assessment_panels_main.php

No copyright involved. This publication may be freely copied, abstracted and cited, with 

acknowledgement of the source of the material.

Printed in Nairobi, Kenya, 2013.

ISBN: 978-9966-20-016-7
May 2013 TEAP XXIV/7 Task Force Report v

UNEP

MAY 2013 REPORT OF THE

TECHNOLOGY AND ECONOMIC

ASSESSMENT PANEL

VOLUME 2

DECISION XXIV/7 TASK FORCE DRAFT REPORT 

ADDITIONAL INFORMATION ON ALTERNATIVES TO ODS
vi May 2013 TEAP XXIV/7 Task Force Report

DISCLAIMER

The United Nations Environment Programme (UNEP), the Technology and Economic Assessment Panel 

(TEAP) co-chairs and members, the Technical and Economic Options Committee, chairs, co-chairs and 

members, the TEAP Task Forces co-chairs and members, and the companies and organisations that employ 

them do not endorse the performance, worker safety, or environmental acceptability of any of the technical 

options discussed. Every industrial operation requires consideration of worker safety and proper disposal of 

contaminants and waste products. Moreover, as work continues - including additional toxicity evaluation -

more information on health, environmental and safety effects of alternatives and replacements will become 

available for use in selecting among the options discussed in this document.

UNEP, the TEAP co-chairs and members, the Technical and Economic Options Committee, chairs, co-chairs 

and members, and the Technology and Economic Assessment Panel Task Forces co-chairs and members, in 

furnishing or distributing the information that follows, do not make any warranty or representation, either 

express or implied, with respect to the accuracy, completeness, or utility; nor do they assume any liability of 

any kind whatsoever resulting from the use or reliance upon any information, material, or procedure 

contained herein.

ACKNOWLEDGEMENT

The UNEP Technology and Economic Assessment Panel and the XXIV/7 Task Force co-chairs and members 

wish to express thanks to all who contributed from governments, both Article 5 and non-Article 5, 

furthermore in particular to the Ozone and the Multilateral Fund Secretariat, as well as to a large number of 

individuals involved in Protocol issues, without whose involvement this assessment would not have been 

possible.

The opinions expressed are those of the Panel and its Task Force and do not necessarily reflect the reviews of 

any sponsoring or supporting organisation.

The TEAP and its XXIV/7 Task Force thank the Academy for Fire Protection in Moscow, Russian 

Federation, for hosting the meeting, 9-12 April 2013 where final inputs from Parties were reviewed, the 

outline for this report was discussed and proposals were made for a next round of drafting in April 2013, after 

which last reviews took place by email circulation during the first week of May 2013.
May 2013 TEAP XXIV/7 Task Force Report vii

Foreword

The May 2013 TEAP Report

The May 2013 TEAP Report consists of three volumes:

Volume 1: May 2013 TEAP Progress Report

Volume 2: May 2013 TEAP XXIV/7 Task Force Draft Report

Volume 3: May 2013 TEAP XXIV/8 Task Force Report

Volume 1

Volume 1 contains the MTOC essential use report, progress reports, the MB CUN report etc. 

Volume 2

Volume 2 is the Draft Report of the TEAP XXIV/7 Task Force on additional information on 

alternatives to ozone-depleting substances.

Volume 3

The separate Volume 3 of the TEAP Progress Report contains the report of the Task Force 

responding to Decision XXIV/8.

The UNEP Technology and Economic Assessment Panel:

Lambert Kuijpers, co-chair NL Kei-ichi Ohnishi J

Bella Maranion, co-chair USA Roberto Peixoto BRA

Marta Pizano, co-chair COL Jose Pons-Pons VEN

Stephen O. Andersen USA Ian Porter AUS

Paul Ashford UK Miguel Quintero COL

Mohamed Besri MOR Ian Rae AUS

David Catchpole UK Helen Tope AUS

Biao Jiang PRC Dan Verdonik USA

Sergey Kopylov RF Ashley Woodcock UK

Michelle Marcotte CDN Masaaki Yamabe J

Shiqiu Zhang PRC

May 2013 TEAP XXIV/7 Task Force Report ix

UNEP

MAY 2013 REPORT OF THE

TECHNOLOGY AND ECONOMIC ASSESSMENT PANEL

VOLUME 2

DECISION XXIV/7 DRAFT TASK FORCE REPORT

ADDITIONAL INFORMATION ON ALTERNATIVES TO ODS

Table of Contents Page

FOREWORD ....................................................................................................................................................VII

1 INTRODUCTION........................................................................................................................................1

1.1 TERMS OF REFERENCE 1

1.2 SCOPE AND COVERAGE 1

1.3 COMPOSITION OF THE TASK FORCE 1

1.5 THE STRUCTURE OF THE XXIV/7 REPORT 2

2 METHODOLOGICAL CHALLENGES ...................................................................................................5

2.1 AGREEING ON THE INTERPRETATION OF DEFINITIONS 5

2.2 DEFINING THE BASELINE AND ASSESSING HISTORIC PERFORMANCE 6

2.3 INTEGRATING FUTURE ESTIMATES 7

3 REFRIGERATION AND AIR CONDITIONING ....................................................................................9

EXECUTIVE SUMMARY 9

3.1 ODS ALTERNATIVES 13

3.2 DOMESTIC REFRIGERATION 23

3.2.1 Introduction...................................................................................................................................23

3.2.2 HFC-134a .....................................................................................................................................24

3.2.3 HC-600a........................................................................................................................................24

3.2.4 HFC-1234yf...................................................................................................................................25

3.3 COMMERCIAL REFRIGERATION 26

3.3.1 Stand-alone equipment..................................................................................................................26

3.3.2 Condensing units...........................................................................................................................27

3.3.3 Centralised systems.......................................................................................................................27

3.4 TRANSPORT REFRIGERATION 28

3.5 LARGE SIZE (INDUSTRIAL REFRIGERATION) 30

3.6 AIR CONDITIONING AND HEAT PUMPS 31

3.6.1 Small self-contained (window, portable, through-the-wall, packaged terminal)..........................31

3.6.2 Mini-split (non-ducted)..................................................................................................................33

3.6.3 Multi-split......................................................................................................................................35

3.6.4 Split (ducted) .................................................................................................................................36

3.6.5 Ducted split commercial and non-split air conditioners...............................................................37

3.6.6 Hot water heating heat pumps.......................................................................................................38

3.6.7 Space heating heat pumps.............................................................................................................39

3.7 CHILLERS 40

3.7.1 Positive displacement chillers.......................................................................................................41

3.7.2 Centrifugal chillers........................................................................................................................43

3.8 MOBILE AIR CONDITIONING 44

3.8.1 Cars...............................................................................................................................................44

3.8.2 Public transport.............................................................................................................................46

3.9 REDUCTION OF NEGATIVE ENVIRONMENTAL IMPACT DUE TO AMOUNTS THAT COULD HAVE BEEN OR 

COULD BE AVOIDED 47
x May 2013 TEAP XXIV/7 Task Force Report

4 FOAMS .......................................................................................................................................................51

EXECUTIVE SUMMARY 51

4.1 ODS ALTERNATIVES 53

4.2 POLYURETHANE - APPLIANCES 55

4.2.1 Historical perspective (including non-Article 5 / Article 5 Party differences)..............................55

4.2.2 Commercially available alternatives to Ozone Depleting Substances ..........................................58

4.2.3 Emerging alternatives ...................................................................................................................60

4.2.4 Barriers and restrictions ...............................................................................................................61

4.3 POLYURETHANE - BOARDSTOCK 62

4.3.1 Historical perspective (including non-Article 5 / Article 5 Party differences)..............................62

4.3.2 Commercially available Alternatives to Ozone Depleting Substances..........................................64

4.3.3 Emerging alternatives ...................................................................................................................65

4.3.4 Barriers and restrictions ...............................................................................................................66

4.4 POLYURETHANE - PANELS 66

4.4.1 Historical perspective (including non-Article 5 / Article 5 Party differences)..............................66

4.4.2 Commercially available alternatives to Ozone Depleting Substances ..........................................69

4.4.3 Emerging alternatives ...................................................................................................................70

4.4.4 Barriers and restrictions ...............................................................................................................71

4.5 POLYURETHANE - SPRAY 71

4.5.1 Historical perspective (including non-Article 5 / Article 5 Party differences)..............................71

4.5.2 Commercially available alternatives to Ozone Depleting Substances ..........................................73

4.5.3 Emerging alternatives ...................................................................................................................74

4.5.4 Barriers and restrictions ...............................................................................................................74

4.6 POLYURETHANE – IN-SITU/BLOCK 75

4.6.1 Historical perspective (including non-Article 5 / Article 5 Party differences)..............................75

4.6.2 Commercially available alternatives to Ozone Depleting Substances..........................................77

4.6.3 Emerging alternatives ...................................................................................................................78

4.6.4 Barriers and restrictions ...............................................................................................................78

4.7 POLYURETHANE – INTEGRAL SKIN 79

4.7.1 Historical perspective (including non-Article 5 / Article 5 Party differences)..............................79

4.7.2 Commercially available alternatives to Ozone Depleting Substances ..........................................80

4.7.3 Emerging alternatives ...................................................................................................................80

4.7.4 Barriers and restrictions ...............................................................................................................81

4.8 EXTRUDED POLYSTYRENE - BOARD 82

4.8.1 Historical perspective (including non-Article 5 / Article 5 Party differences)..............................82

4.8.2 Commercially available alternatives to Ozone Depleting Substances ..........................................85

4.8.3 Emerging alternatives ...................................................................................................................85

4.8.4 Barriers and restrictions ...............................................................................................................86

4.9 PHENOLIC FOAMS 86

4.9.1 Historical perspective (including non-Article 5 / Article 5 Party differences)..............................87

4.9.2 Commercially available alternatives to Ozone Depleting Substances ..........................................89

4.9.3 Emerging alternatives ...................................................................................................................90

4.9.4 Barriers and restrictions ...............................................................................................................90

5 FIRE PROTECTION ALTERNATIVES TO OZONE DEPLETING SUBSTANCES .......................91

EXECUTIVE SUMMARY 91

5.1 INTRODUCTION 91

5.2 RESPONSE TO QUESTION 1 (A) 93

5.2.1 Commercially Available, Technically Proven Alternatives to ODS for Total Flooding Fire 

Protection Using Fixed Systems....................................................................................................93

5.2.1.1 Halocarbon Agents........................................................................................................................93

5.2.1.2 Inert Gas Agents............................................................................................................................94

5.2.1.3 Carbon Dioxide .............................................................................................................................94

5.2.1.4 Water Mist Technology..................................................................................................................95

5.2.1.5 Inert Gas Generators.....................................................................................................................95

5.2.1.6 Fine Solid Particles (Powders)......................................................................................................95

5.2.2 Commercially Available, Technically Proven Alternatives to ODS for Local Application Fire 

Protection Using Portable Systems...............................................................................................95
May 2013 TEAP XXIV/7 Task Force Report xi

5.2.2.1 Carbon Dioxide .............................................................................................................................96

5.2.2.2 Halogenated Agents ......................................................................................................................96

5.2.2.3 Dry Chemical ................................................................................................................................96

5.2.2.4 Water.............................................................................................................................................97

5.2.2.5 Fine Water Spray...........................................................................................................................97

5.2.2.6 Aqueous Salt Solutions..................................................................................................................97

5.2.2.7 Aqueous Film-forming Foam ........................................................................................................98

5.3 RESPONSE TO QUESTION 1 (B) 98

5.3.1 Alternative Total Flooding Agents Under Development For Use In Fixed Systems .....................98

5.3.2 Alternative Local Application Agents Under Development For Use In Portable Systems............98

5.4 RESPONSE TO QUESTION 1 (C) 98

5.5 RESPONSE TO QUESTION 1 (D) 99

5.6 RESPONSE TO QUESTION 1 (E) 100

6 SOLVENTS ..............................................................................................................................................101

EXECUTIVE SUMMARY 101

6.1 INTRODUCTION 101

6.2 RESPONSE TO QUESTION 1(A) 102

6.2.1 Commercially Available, Technically Proven Alternatives for Solvent Cleanings .....................102

6.3 RESPONSE TO QUESTION 1(B) 106

6.3.1 Alternatives Under Development ................................................................................................106

6.4 RESPONSE TO QUESTION 1(C) 106

6.4.1 Barrier and restrictions; the feasibility of options to HCFCs in solvents...................................106

6.5 RESPONSE TO QUESTION 1(D) 110

6.6 RESPONSE TO QUESTION 1(E) 110

7 MATERIAL SUBMITTED BY PARTIES ............................................................................................111

8 TECHNICAL, ECONOMIC AND ENVIRONMENTAL DEFINITIONS .........................................119

TECHNICAL AND ECONOMIC DEASIBILITY 119

COST EFFECTIVENESS 119

ENVIRONMENTALLY SOUND 119

LOW GWP 120

9 LIST OF ACRONYMS AND ABBREVIATIONS................................................................................121

10 REFERENCES.........................................................................................................................................123

May 2013 TEAP XXIV/7 Task Force Report 1

1 Introduction

1.1 Terms of Reference

Decision XXIV/7 of the Twenty-fourth Meeting of the Parties requested the Technology and 

Economic Assessment Panel (TEAP) to prepare this draft report for consideration by the Open-ended 

Working Group at its 33rd meeting and a final report for the Twenty-fifth Meeting in 2013.

1.2 Scope and coverage

The text of Decision XXIV/7 is as follows:

1. To request the Technology and Economic Assessment Panel in consultations with 

experts from outside the Panel with the relevant expertise if necessary, to update information on 

alternatives and technologies in various sectors and prepare a draft report for consideration by the 

Open-ended Working Group at its thirty-third meeting and a final report to be submitted to the 

Twenty-Fifth Meeting of the Parties that would by end use:

(a) Describe all available alternatives to ozone-depleting substances that are 

commercially available, technically proven, environmentally-sound, taking into account their 

efficacy, health, safety and environmental characteristics, cost-effectiveness, and their use including 

in high ambient temperatures and high urban density cities;

(b) Update information provided by previous Panel reports on alternatives under 

development; 

(c) Identify barriers and restrictions to the adoption and commercial use of certain 

environmentally-sound alternatives to ozone-depleting substances;

(d) Estimate, if possible, the approximate amount of alternatives with negative 

environmental impacts that could be or could have been avoided or eliminated by both non-Article 5 

and Article 5 parties in the process of phasing-out ozone-depleting substances;

(e) Identify the opportunities for the selection of environmentally-sound alternatives to 

HCFCs in the future; 

2. To invite the Panel to take into account any information relevant for the report to be 

prepared under paragraph 1 of the present decision provided by parties to the Secretariat;

1.3 Composition of the Task Force

The TEAP established a XXIII/9 Task Force (RTF) to prepare this report to respond to Decision 

XXIII/9. The composition of the Task Force is as follows:

 Lambert Kuijpers (The Netherlands, co-chair TEAP, co-chair RTOC);

 Roberto Peixoto (Brazil, co-chair RTOC);

 Paul Ashford (UK, co-chair FTOC);

 Samir Arora (India, member FTOC)

 Dave Catchpole (UK, co-chair HTOC)

 Denis Clodic (France, member RTOC) 

 Daniel Colbourne (UK, member RTOC)

 Mike Jeffs (UK, member FTOC)

 Ilhan Karaagac (Turkey, FTOC member)

 Osami Kataoka (Japan, outside expert)

 Michael Kauffeld(Germany, member RTOC)

 Tingxun Li (China, RTOC member)

 Keiichi Ohnishi (Japan, co-chair CTOC);

 Rajan Rajendran (USA, RTOC member)
2 May 2013 TEAP XXIV/7 Task Force Report

 Enshan Sheng (China, member FTOC);

 Helen Walter Terrioni (USA, member FTOC)

 Samuel Yana-Motta (Peru, outside expert)

 Fred Wang (China, FTOC member)

The XXIV/7 Task Force is co-chaired by Paul Ashford, Lambert Kuijpers and Roberto Peixoto. 

A preliminary outline of this draft report was discussed by the TEAP during its meeting in Moscow, 

Russian Federation, 9-12 April 2013 and key challenges in responding to the Decision were 

highlighted, especially as they related to Clause 1(d). Co-chairs were also able to review the latest 

submissions from Parties, including those received immediately prior to the Moscow meeting, before 

assembling the draft materials already received from the Task Force members and continuing with 

the drafting activities. Subsequent chapter drafts were then circulated to relevant sub-groups of the 

Task Force before the final draft was circulated by email to the XXIV/7 Task Force as a whole and 

the TEAP for endorsement in early May. Although the timescale for wider TEAP review was short, it 

was recognised that this is a working document (draft report) for the consideration of the Parties at 

the Open Ended Working Group in June and that further opportunity for comment by TEAP would 

exist once additional direction had been received from Parties and duly considered by the Task Force. 

It should also be noted that the Task Force will also be reporting on a number of additional topics in 

its final report for the Meeting of the Parties in November 2013, including aerosols, sterilants and 

metered dose inhalers. The Task Force will also be interested to learn from Parties at the Open Ended 

Working Group meeting whether there are other sectors which should be considered (e.g. methyl 

bromide).

1.5 The Structure of the XXIV/7 report

The structure of the TEAP XXIV/7 Task Force Report is as follows:

There is no stand-alone Executive Summary in this draft report since the methodologies adopted 

within individual chapters are viewed as sufficiently different to make it difficult to consolidate the 

findings in a helpful way. Executive Summaries have therefore been provided at the Chapter level for 

each of the sectors reviewed. Once discussion has taken place with Parties at the Open Ended 

Working Group about the most appropriate approaches of addressing the Decision, consideration can 

be given to a consolidated Executive Summary.

Chapter 1, “Introduction”, presents the Terms of Reference, establishment of the Task Force and the 

consultative processes used to prepare this report.

Chapter 2, “Methodological Challenges” describes how the Task Force gave consideration to the 

request of the Parties, especially with respect to the quantification of negative environmental impact, 

and explains the decision to allow sectors covered within the report to address the requirements of 

Clause 1(d) from perspectives seen as most pertinent to their situations. 

Chapter 3, “Refrigeration and air-conditioning”, describes the commercially available and technically 

proven environmentally sound ODS alternatives in R and AC. It also describes the barriers against 

uptake of alternatives. The sub-sectors considered are domestic, commercial, transport, large size 

refrigeration, unitary and mobile air conditioning. In response to Clause 1(d), the chapter also seeks 

to describe consequences of certain HCFC-22 conversions on the “amounts to be avoided”, including 

the lower impact from the different amounts that will be needed in servicing as a result of conversion.

Chapter 4, “Foams”, describes the technical and economic experience gained with commercially 

available and emerging ODS alternatives. It also updates the timelines for the commercialisation of 
May 2013 TEAP XXIV/7 Task Force Report 3

the emerging alternatives. In response to Clause 1(d), it seeks to derive some assessment of the 

impact of ‘missed opportunities’ and potential incremental mitigation from future actions.

Chapter 5, “Fire protection”, describes the use of ODS alternatives in fire protection.

Chapter 6, “Solvents”, describes the ODS alternatives for solvents.

May 2013 TEAP XXIV/7 Task Force Report 5

2 Methodological Challenges

2.1 Agreeing on the interpretation of definitions

Chapter 8 of this draft report provides an indication of the approach taken by the Task Force to 

address the language used in Decision XXIV/7. Some of that language is not new (e.g. low-GWP, 

cost effectiveness etc.) but some terms (e.g. environmentally sound) had not been used in recent 

decisions and it was important to consider their relative positioning against similar phrases (e.g. 

environmentally benign) which had been used in those decisions. The Task Force has sought to make 

an initial interpretation in these areas but would certainly welcome further input and discussion at the 

Open Ended Working Group meeting to ensure that the intent of the Parties is addressed fully in the 

final report. One particular term, ‘negative environmental impacts’, was of particular concern 

because it is associated with a request for quantification. The following paragraphs give some focus 

to the aspects considered. 

Negative Environmental Impacts

Much of the discussion surrounding the environmental impact of ODS alternatives has focused 

understandably on climate-related factors. However, there are numerous other environmental 

parameters that should be legitimately considered. These would at least include ozone depletion, 

VOC emission and eutrophication. A further factor to be considered would be the extension of the 

evaluation of impacts to potential breakdown products.

The word ‘negative’ is inevitably subjective and needs to be measured against some benchmark, since 

all options will have some environmental footprint. This benchmark would typically be the 

environmentally sound alternative identified as that with the minimum ‘negative environmental 

impact’. The key question is how ozone depletion, climate change, eutrophication, bio-accumulation 

etc. should be compared and ranked. The Task Force is not aware of a definitive ranking option at the 

time of writing. 

The Decision asks the Task Force to estimate (quantify) the amount of alternatives with negative 

environmental impacts. It does not require the quantification of those impacts, although this might 

have been the intent. In a situation where one alternative might have a more negative impact than the 

benchmark in climate terms, but a less negative impact in VOC terms, the question would arise about 

whether the amount of the alternative should be included in the assessment or not. Taking this to its 

logical conclusion, the quantification of substances with negative environmental impacts would result 

in different derived values depending on the environmental parameter selected. This is reflected in 

the various chapter treatments. 

For the purposes of this report, the existence of global regulatory drivers has been taken as the basis 

on which and ranking should be enacted. Therefore the hierarchy of negativity becomes: 

 Ozone depletion (excluding those short-lived compounds with de minimis ODPs)

 Climate forcing 

 VOC emissions 

 Other environmental impacts

Although ozone depletion is rightly deemed as the highest priority for the Montreal Protocol, the fact 

that the future scenario being considered is the final phase-out of ozone depleting substances means 

that climate forcing becomes the predominant negative environmental parameter in most cases. 

Nevertheless, the impact of previous technology selection decisions on ozone layer recovery is taken 

into account by several of the sectors responding to the Decision.
6 May 2013 TEAP XXIV/7 Task Force Report

2.2 Defining the baseline and assessing historic performance

The approach adopted by the Task Force has been to assess the ‘negative environmental impacts’ 

from 1990 onwards, since this was viewed as the first date by which the Montreal Protocol could be 

seen as having its own effects. The baseline in 1990 for most sectors would either be the use of CFCs 

or Halons. However, in the case of refrigeration and air conditioning, HCFC-22 has had a long 

history of use and, in many cases, was never a substitute for CFCs. HCFC-22 is therefore a legitimate 

part of the baseline in a large number of applications as of 1990. 

One of the consequences of this reality is that delays in subsequent transition would be less impacting 

on ozone depletion than similar delays would have been in other sectors. Additionally, where 

alternatives to HCFC-22 were likely to involve similar or higher climate impact, a delay in transition 

might even be beneficial to the climate. However, this necessitates a value judgement between 

residual ozone depletion and climate mitigation, if taken together. A further diluting factor to 

consider in the case of those sectors involving significant consumption for maintenance purposes is 

that technology transition for new equipment would not impact the overall environmental footprint 

for the sector as abruptly as for those sectors without such a maintenance component (e.g. foams). 

One approach adopted in this draft report to avoid the need for value judgements between differing 

environmental impacts is to look at the ‘most favourable option’ from an ozone perspective and to 

compare what was actually achieved against the ‘potential’ related to that ‘most favourable option’. 

Similarly for climate, the potential of the ‘most favourable option’ for climate would be compared 

with what actually happened. This ratio can be represented formulaically for each environmental 

impact as follows: 

(‘Baseline’ minus ‘Most Favourable Option’) compared with (‘Baseline’ minus ‘Actual Impact’) 

(‘potential’) (‘actual achieved’)

If this relationship is provided as a percentage (i.e. ‘actual achieved’ as a percentage of ‘potential’) 

then it is a measure of how well the sector responded to the opportunity. However, it gives no 

indication about how significant in real terms that shortfall in achievement might have been to the 

ozone layer or the climate. This only emerges when the size of the sector is considered and the 

difference between the ‘actual achieved’ and the ‘potential’ are quantified for each environmental 

impact.

In addition, one of the consequences of this approach is that there is no single, absolute ‘most 

favourable option’, although in many cases the ‘most favourable option’ for ozone and climate is the 

same.

To determine the ‘most favourable option’ several factors need to be considered: 

 Technical feasibility of candidate in the applications being considered 

 Economic viability of the candidate in the applications being considered

 Other barriers and restrictions to the adoption of the candidate

 Environmental impact of the systems in which the candidate is being considered 

As discussed in the previous section, negative environmental impact is a relative assessment and the 

candidate with the minimum negative environmental impact becomes the benchmark against which 

other technological options are compared. However, this assumes that the technical feasibility and 

economic viability are comparable for all options. In practice, it may be that there are performance 

trade-offs for the option with the lowest environmental impact or, perhaps, a cost premium. In 

addition, there may be health and safety or other regulatory/standard factors to be considered in 

making the final selection of the ‘most favourable option’.
May 2013 TEAP XXIV/7 Task Force Report 7

The other option would have been to identify an alternative reality of ‘what could have been 

avoided’. However, to do that the Task Force would need to understand the complete scenarios 

(technical feasibility, economic viability, health & safety and regulatory/standards issues) as they 

pertained at the time the decision on technology selection was taken. To do this in any other way 

would otherwise assess previous decisions without consideration of the full facts pertaining at the 

time. Such an assessment would likely be perceived as inappropriate by stakeholders, since it could 

lead to unjustified criticism. By adopting the ‘most favourable option’ approach, without speculating 

about ‘what might have been’ or ‘what should have been’, the analysis stays within bounds that are 

objective and largely indisputable. 

In some instances, the timing of the availability of the ‘most favourable option’ might not be easily 

identified retrospectively and almost certainly the option would not have been equally available in all 

regions of the world at the same time. Where this form of analysis has been undertaken (e.g. in 

foams), it is assumed that the ‘most favourable option’ has been available throughout the period from 

1990 to the present day and throughout all regions of the world.

2.3 Integrating future estimates 

A similar methodology is applied to estimating projected future performance against the ‘potential’ 

created by the ‘most favourable option’. However, in this instance, the identity of the ‘most 

favourable option’ also has to be projected – as does the likely growth rates of markets and forecast 

uptake of alternative technologies in the business-as-usual scenario. There is clearly a greater level of 

uncertainty in this analysis - especially with respect to emerging technologies, where costs may not 

be fully known and market penetration may not yet be assured. The approach of evaluating the 

maximum contribution of the ‘most favourable option’ quantifies the ‘potential’ without making a 

judgement about availability and future selection. The alternative with the lowest environmental 

footprint becomes the benchmark against which others, including the projected business-as-usual are 

assessed. 

Since the Task Force understands that the purpose of Clause 1(d) is to limit consideration only to 

options that are technically feasible and economically viable, it makes sense to eliminate from the 

assessment those options that, for a given application, are already known not to be technically 

feasible or economically viable for any significant quantities of replacement. The same might apply 

to other technology options where the barriers and restrictions are known to be insurmountable within 

the time-scale available for transition. These are therefore excluded as candidates for the ‘most 

favourable option’. 

The Task Force felt uncomfortable to project these parameters beyond 2020 at this point and elected 

to limit its analysis to 2020 bearing in mind that assessment at ‘consumption’ (potential emissions) 

level means that future impacts from products and equipment installed before 2020 are already 

factored into the analysis. These choices can be revisited during discussion at the Open Ended 

Working Group meeting if alternative approaches need to be considered within the final report.

As noted in Section 1.5, the Task Force anticipates further discussion at the Open Ended Working 

Group to define the most appropriate approach in response to Clause 1(d) of the decision. The Task 

Force is conscious that the lack of a homogeneous approach makes it difficult currently to make 

comparisons between end-use sectors. However, it is also aware that the circumstances are different 

for each sector and that a single approach to the objectives might also result in misleading 

conclusions.

May 2013 TEAP XXIV/7 Task Force Report 9

3 Refrigeration and air conditioning 

Executive Summary 

Initially, the chapter provides generic information relating to selected alternative substances. This 

includes a description of five classes of alternatives:

- Ammonia (R-717)

- Carbon dioxide (R-744)

- Hydrocarbons (HC-290 and others)

- HFCs (medium and high GWP), and 

- HFCs (low GWP)

For each alternative, general efficiency aspects, cost effectiveness and barriers and restrictions are 

given. Subsequently, additional information, including current trends, is presented in the sub-sector 

specific sections that follow, wherever applicable. 

For this report it was considered under the current circumstances to discuss a small number of 

currently unassigned refrigerant blends where it is anticipated that they are close to 

commercialisation and receiving R-number designations.

In domestic refrigeration, the main refrigerants used are hydrocarbon HC-600a (isobutane) and 

HFC-134a. More than 50% of current new production (globally) employs HC-600a, the remainder 

uses HFC-134a.

HC-600a continues to be the main alternative to HFC-134a. Concerns in connection with the high 

flammability no longer exist for the low charges applied. No new alternative has matured to become 

energy-efficient and cost-competitive. Considering the product costs, HC-600a is less expensive than 

HFC-134a, but additional investment cost for HC-600a products are due to the larger size of 

compressors. Production cost for refrigerators can be higher due to the requirements for safety 

systems.

Initial developments to assess HFC-134a replacement with HFC-1234yf have begun, but is not being 

pursued as a high priority. Still HFC-1234yf has demonstrated the potential for comparable efficiency 

to HFC-134a. The lower flammability makes its application easier in countries with strong 

reservations about HC-600a. R-744 (CO2) is also being evaluated, but its application implies 

additional costs.

In commercial refrigeration stand-alone equipment HFC-134a and R-404A are still the dominant 

refrigerants. HC-600a and HC-290 are used for small commercial equipment with refrigerant charges 

varying from 15 g to 1.5 kg. R-744 is mainly used in vending machines; the technology is operating 

well but it is a technical challenge and only one supplier is able to provide an efficient system. The 

small additional cost associated with safety in HC equipment is integrated in the price, and is not 

much different compared with HFC equipment. Where it concerns low GWP HFCs, HFC-1234yf can 

replace HFC-134a in any application. Due to its comparable energy-efficiency with HFC-134a, 

vending machines with HFC-1234yf have been introduced in countries such as Japan (two 

manufacturers). One of the lead compressor manufacturers of small reciprocating compressors is 

already producing them. Currently a main barrier is still (the wide) availability of the chemical. 

Regarding condensing units, some new R-744 based units are sold in northern Europe, but the 

penetration in the market is slow. Several indirect condensing units with HC-290 or HC-1270 are 

operating in Europe with typical refrigerant charges varying from 1 to 20 kg, with good energy 

efficiency. Costs for these HC based systems are typically 5 to 15% higher compared with HFC 

systems.
10 May 2013 TEAP XXIV/7 Task Force Report

HFC-134a, R-404A, and, at a small level, R-410A are HFCs of choice for condensing units. As in all 

other commercial applications, high GWP HFCs are seen as short-term options.

In supermarket refrigeration, the current options for large European commercial companies area 

HFC-134a system at the medium-temperature level connected to an indirect system or to a R-744 

direct system for the low temperature level since this is a global option for all climates. Ammonia is 

used in indirect centralised systems for large capacities; usually R-744 is used at the low-temperature 

level. Due to safety issues the number of installations so far is limited. For applying lower GWP 

options, HFC-134a can be replaced by HFC-1234yf or HFC-1234ze where the lower flammability of 

these refrigerants can be addressed during the design stage. For non-flammable options, small 

temperature-glide blends --such as N-13 and XP-10-- can also be used in existing facilities. Twostage R-744 systems for the medium-temperature level and the low-temperature level have taken a 

certain market share in Europe and are now installed in more than 1000 stores. R-744 trans-critical 

cycle developments are on-going to make the technology more energy-competitive under higher 

ambient conditions. The additional cost is again limited to 10 to 15%. For the non-low GWP 

refrigerants, R-404A is currently the dominant refrigerant, even if it is now replaced in new 

installations by HFC-134a at the medium-temperature level. R-407F is proposed as an intermediate 

option. There are also non-flammable options with lower GWP such as the HFC blends N-40 and 

DR-33. Two-stage R-744 systems for the medium-temperature level and the low-temperature level 

have taken a certain market share in Europe and are now installed in more than 1000 stores. R-744 

trans-critical cycle developments are on-going to make the technology more energy-competitive 

under higher ambient conditions. The additional cost is again limited to 10 to 15%. 

The refrigerant of choice for transport refrigeration systems in non-Article 5 countries is HFCs. R404A has become a preferred choice for practically all trailers and large trucks. HFC-134a is used in 

small trucks and vans. Testing of low-GWP HFC and non-HFC alternatives are in progress 

elsewhere, but not one option seems viable in the short term. The main issue is that the performance 

of R-404A is difficult to meet. Current and previous tests with trucks using R-744 suggest that 

introduction of R-744 will be possible when more efficient compressors with more than one 

compression stage, which are under development, will be commercially available. The use of 

hydrocarbons (mainly HC-290) in truck refrigeration units has been tested; they would be the 

preferred choice because they can provide lower energy consumption in the order of 20% or more. 

HFC-1234yf can be an interesting alternative to HFC-134a due to its lower discharge temperature.

On vessels, hydrocarbons are technically feasible, but the strict safety concerns currently do not 

favour application of flammable refrigerants aboard. Natural refrigerants have been commercialised 

to a small extent aboard marine vessels worldwide. For European fishing vessels highly efficient 

ammonia-CO2-cascade systems are the systems of choice. 

Over 90% of the large industrial refrigeration installations use R-717 whereas the market share of 

R-717 is only 5% (India and China) to 25% (Europe and Russia) for smaller industrial refrigeration 

systems. Energy efficiency is in general 15% higher than HFCs systems. Hydrocarbons are not 

widely used, other than in situations where safety measures are already required, e.g. in a 

petrochemical plant.

In Small Self-Contained (SSC) air conditioners R-744 is not widely considered for use. The main 

barriers for SSC air conditioners are related to efficiency and cost implications. Due to efficiency 

implications, the use of cooling only R-744 systems is not really feasible. However, there are 

developments on units for specific purposes, where both cooling and heating is needed. HC-290 has 

been used in portable ACs for many years and several companies are producing them. Window units 

are also under development. HC-290 seems to be preferred over HC-1270 for smaller capacity 

systems. 
May 2013 TEAP XXIV/7 Task Force Report 11

R-410A is used in most SSC ACs, where HCFC-22 is not used. It is feasible to use HFC-32 in SSC 

ACs, for example, where R-410A is already used. HFC-32 energy efficiency deterioration due to high 

ambient is a few per cent worse than HCFC-22, but not as severe as R-410A. 

HC-290 has been used in split ACs for many years on a limited scale but now some companies are 

developing and producing them on a larger scale. Although HC-290 seems to be the preferred HC 

option, HC-1270 is under evaluation by some companies. HC-290 units are available from several 

companies. Currently, no split air conditioners are available using R-744, although some studies have 

been carried out.

In hot water heat pumps and space heating heat pumps, R-717 is used fairly widely in capacities 

from 250 kW to very large/industrial-scale (>1 MW). Such systems are located outside or in special 

machinery rooms in order to handle the higher toxicity characteristics. As with R-717 systems in 

general, the main barriers are related to the minimal capacity required for cost-effectiveness and 

certain national regulation controlling installation. A large number of manufacturers globally are 

producing domestic and small commercial sized hot water heating heat pumps using R-744. 

Generally, the efficiency that can be achieved by R-744 in hot water heaters is much higher than that 

of other refrigerants. It is feasible to use HFC-32 in hot water heat pumps, for example, where R410A is already used. HCs, particularly HC-290, had been used widely in Europe for small 

(domestic) heat pumps, and there are also large commercial-sized heat pumps being marketed, which 

use HC-290 or HC-1270. It is feasible to use HFC-32 and the L-20 blend in space heating heat 

pumps.

Considering the use of low-GWP refrigerants in reciprocating and screw chillers the following 

describes the current situation. R-717 is used fairly widely for process refrigeration, food storage 

facilities and air conditioning. The efficiency of R-717 is high for chillers in both medium and high 

temperature applications. The barriers for chillers are consistent with R-717 systems in general. R744 is now used in reciprocating chillers by many manufacturers. As with other types of systems, the 

efficiency is compromised with increasing ambient temperatures. The main barrier for R-744 chillers 

is the poorer efficiency in climates with consistently higher ambient temperatures. Both HC-290 and 

HC-1270 are produced by a number of manufacturers in Europe and some countries in other regions. 

There are certain barriers in the case of HC applications, depending upon chiller configurations.

HFC-1234ze(E) is a refrigerant that can be used in existing HFC-134a technologies with minor 

modifications (compressor sizing), and it has been trialled in systems in Europe. When used in 

reciprocating, scroll or screw type of compressors, it produces efficiency levels comparable to HFC134a. In centrifugal compressors, this refrigerant produces efficiency levels slightly better than HFC134a. HCFC-1233zd(E) can replace HCFC-123 (a low-GWP HCFC) in low pressure centrifugal 

chillers with slightly better efficiency levels. In chiller applications, both HFC-1234ze(E) and HCFC1233zd(E) should perform very well in warm climates, due to their high critical temperatures.

Both R-407C and R-410A are widely used in positive displacement chillers as is HFC-134a. HFC134a is used widely in various capacities of centrifugal chillers.. 

HCs are used to a limited extent in centrifugal chillers typically within the petro-chemical industries 

where hazardous area protection is already in common use.

In mobile air conditioning systems (dependent on the country), the preferred option is to shift to 

HFC-1234yf, but the delayed market availability of this refrigerant seems to slow down the shift. 

Other future options are still being reconsidered by certain car manufacturers; in fact, this would be 

R-744, while staying with HFC-134a until R-744 would have been commercialised. R-744 has been 

demonstrated to be as efficient as the best in class HFC-134a system. However, the main barrier for 
12 May 2013 TEAP XXIV/7 Task Force Report

R-744 systems has been the cost, as well as issues related to safety, compressor durability and leak 

detection.

A current barrier for HFC-1234yf is related to patent issues between the chemical manufacturers; 

where mass-production of low GWP HFC systems has been delayed. Even when e.g. the German car 

industry favours to stay with HFC-134a until R-744 would have been commercialised, the change 

from HFC-134a to HFC-1234yf seems to be the likely solution because the car industry favours 

global options for AC systems. This has been supported by LCCP analysis, which showed superiority 

of HFC-1234yf for most ambient temperatures.

Reduction of negative environmental impacts due to amounts that could have been or could be 

avoided

In the case of domestic refrigeration, the following can be stated. For the period 2010-2015, the use 

of HFC-134a (compared to CFC-12) would yield a lower negative environmental impact of 230 Mt 

CO2-eq. per year; the use of HC-600a (isobutane) would add another 33 Mt CO2-eq. annually. In 

practice, the entire global domestic refrigeration has been converted, with about 50% to HC-600a. So 

the conversion of all now (2013) remaining HFC-134a to HC-600a would yield a saving of about 17 

Mt CO2-eq. annually. 

Whereas relatively simple considerations give insight in the case of domestic refrigeration and similar 

other uses that do not have to deal with servicing etc., the question in the case of RAC sectors that 

needs a lot of servicing, is whether in making selections early a consideration of a pure R-410A 

environment or a pure hydrocarbon environment has any value for common practice. A change of 

100% as of a given year to a certain refrigerant with a negligible GWP means that one would avoid 

200,000 tonnes of HCFCs in a given year, and servicing amounts of HCFC-22 for the equipment that 

has not been manufactured in such a year during many future years, i.e., for a 15 years lifetime of the 

equipment it would be something like 2,400,000 tonnes over a period of 15 years, due to a conversion 

of 200,000 tonnes in a start-up year.

However, financial constraints will flatten the profile of the introduction of new technologies in new 

manufacture, and a conversion of 5-10% of the total per year would be a reasonable amount to 

assume as the maximum achievable. 

The table below gives the approximate consumption in HCFC-22 (or HFC blends such as R-404A or 

R-410A) for non-Article 5 and Article 5 countries in the year 2013. It concerns commercial 

refrigeration and stationary air conditioning.

It assumes 40% of the consumption being used for new manufacture in developed countries, 20% of 

the consumption used for new manufacture in the developing countries. It assumes 10% of the new 

manufacture being converted to alternatives in a given year and gives the numbers for the reduction 

in negative environmental impact in that year, as well as the influence on the negative environmental 

impact (i.e., in many cases a reduction) over a period of 15 years after the conversion in manufacture, 

which is due to the reduction of the impact in the servicing amounts (assumed over a period of 15 

years).

A change of 10% in the manufacture for commercial refrigeration in developing countries to HFC 

blends such as R-404A gives an increase in negative environmental impact of about 4 Mt CO2-eq., 

and an increase over 15 years in servicing of 32-64 Mt CO2-eq. (dependent on whether the servicing 

per year would be 50-10% of the original charge. Going from HCFC-22 to low GWP options (having 

an average GWP of 300) yields a decrease in negative environmental impact of 3 Mt CO2-eq and 

another 23-46 Mt CO2-eq reduction over the period of 15 years thereafter.
May 2013 TEAP XXIV/7 Task Force Report 13

In particular for refrigeration and air conditioning, it will be clear that a conversion to alternatives 

with a low negative environmental impact is one of the first priorities. This holds in particular, 

because a change in manufacturing now will have consequences for many years to come, via 

servicing amounts. A calculation of the consequence in tonnes in the negative environmental impact 

should give an adequate first impression.

Countries Approx. 

Cons. (t)

Assumed in 

manufacture 

10% of 

manufacture

Avoidance

(Mt CO2-eq.) 

per year

Avoidance via 

servicing in 15 

years (Mt 

CO2-eq.)

Commercial refrigeration (2013)

Non-Article 5 countries

From HCFC22 to HFCs**40,000 16,000 1,600 -3.2 -10/ -20

From HFCs** 

to low GWP

40,000 16,000 1,600 5.4 16-32

Article 5

From HCFC22 to HFCs**100,000 20,000 2,000 -4.2 32-64

From HCFC22 to low 

GWP

100,000 20,000 2,000 3 23-46

Stationary Air Conditioning (2013)

Non-Article 5

From HCFC22 to 

blends/410A

140,000 56,000 5,600 -2.2 17-34

From HFCs to 

low GWP

140,000 56,000 5,600 10.5 32-64

Article 5

From HCFC22 to 

blends/410A

400,000 80,000 8,000 -3.2 24-48

From HCFC22 to low 

GWP

400,000 80,000 8,000 11.8 88-176

** HFCs in commercial refrigeration are given a GWP of 3800 (which would be the GWP of R-404A)

***Low GWP chemicals, which could be different types of blends etc., natural refrigerants, have been given an 

average GWP of 300 

3.1 ODS alternatives

Initially, generic information relating to selected alternatives substances is provided in the first 

section. This includes a description of each alternative, general efficiency aspects, cost effectiveness 

and barriers. Subsequently, additional information, including trends is included in the sub-sector 

specific section, where applicable. Whilst the convention within TEAP reports has been to only 

discuss refrigerants with ISO/ASHRAE R-number designation only, it was considered under the 

current circumstances to also discuss a small number of currently unassigned blends where it is 

anticipated that they are close to commercialisation and receiving R-number designations. This is 

against a background of an excess of 50 different unassigned blends currently being cited by different 

refrigerant produces and elsewhere in the literature.
14 May 2013 TEAP XXIV/7 Task Force Report

R-717

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

R-717 (ammonia, NH3) is a single component substance. It has a 

safety classification of B2 (higher toxicity, lower flammability). It has 

a zero ODP and zero GWP. 

Extent of commercialisation R-717 has been used for more than 100 years in a variety of different 

types of refrigerating machines and is widely used today.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

In principle, R-717 has thermo-physical properties which lead to 

excellent efficiency. The vapour pressure and refrigerating capacity is 

similar to HCFC-22. However, it has a very high discharge 

temperature so for lower temperature applications two stage 

compression is normally needed. 

Costs, cost effectiveness 

(compared to a standard)

The cost of the substance is very low, typically less that $1/kg. 

Generally systems require the use of steel piping and components and 

as a result smaller capacity systems can cost much more than HCFC22 or HFC systems, although as the capacity approaches and exceeds 

around 400-600 kW, they can become cost-competitive (UNEP 2011, 

UNEP 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

There are several general barriers. From a practical level these include 

the lack of suitable components for small capacity systems (although 

some companies are working on these aspects). In addition, the use of 

R-717 required well-trained and competent technicians (in handling R717), which can sometimes be difficult. Another is the restriction of 

use (in direct systems) in occupied spaces due to its higher toxicity. 

Similarly, certain countries have specific national regulations 

controlling its use. A comprehensive assessment of the barriers to the 

use of R-717 and other low-GWP refrigerants is provided in a study 

for UNEP (Colbourne, 2010).

Hydrocarbons (HCs)

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

Hydrocarbons (HCs) include three main pure refrigerants, HC-290 

(propane), HC-1270 (propene) and HC-600a (iso-butane) and a 

number of mixtures; R-433A, R-433B, R-433C, R-441A and R-443A, 

some of which also comprise HC-170 (ethane). All pure substances 

and the mixtures have safety classification A3 (lower toxicity, higher 

flammability). They have zero ODP and GWP (direct GWP plus 

indirect GWP) ranges from 1.8 to 5.5 (WMO, 2010). 

Extent of commercialisation The pure substances have been used commercially for decades, whilst 

mixtures such as R-436A and R-436B have been used since the phaseout of CFC-12. Most of the other mixtures are not known to be used 

commercially.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

Generally, the efficiency is shown to be good under most conditions. 

In principle, they have thermo-physical properties which lead to very 

good efficiency and low discharge temperatures. Performance 

comparisons for high ambient conditions are sparse, although one 

study showed performance to be comparable to HCFC-22 (Chen, 

2012). 

Costs, cost effectiveness 

(compared to a standard)

The cost of the substances is low, typically less that $1 - $10/kg. Due 

to the safety classification, there are often additional costs necessary 

for handling flammability characteristics in the design of the 

equipment, although thermo-physical properties mean that other costs 

associated with system construction can be reduced. However, the 

overall cost implication can vary widely depending upon the type of 

equipment. Values for cost-effectiveness are included in previous 

TEAP reports (UNEP, 2011; UNEP, 2012).
May 2013 TEAP XXIV/7 Task Force Report 15

Barriers and restrictions (safety, 

energy efficiency etc.)

The main barriers associated with the use of HCs arise from its 

flammability. In practical terms this means that systems located 

indoors with moderate to large charge sizes are often restricted. 

Similarly, concerns by component manufactures means that there are 

gaps in availability of certain types of components including 

compressors. In addition, technicians must be well-trained and 

competent in handling HCs if the flammability is to be dealt with 

safely. Some building safety codes may ban use flammable refrigerants 

in certain types of buildings. A comprehensive assessment of the 

barriers to the use of HCs and other low-GWP refrigerants is provided 

in a report for UNEP (Colbourne et al, 2010). 

R-744

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

R-744 (carbon dioxide, CO2) is a single component substance. It has a 

safety classification of A1 (lower toxicity, non-flammable). It has a 

zero ODP and a GWP of 1. 

Extent of commercialisation R-744 has been used from 1900 to 1930 in refrigerating machines and

then supplanted by CFCs. Since 1990 CO2 its use was revisited and is 

used in a variety of different types of systems. 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

R-744 has thermo-physical properties which lead to good efficiency

for proper levels of temperatures. The vapour pressure is several times 

greater than usual refrigerants and the volumetric refrigerating 

capacity is correspondingly higher. However, with a low critical 

temperature, the cycle efficiency declines as the temperature before the 

expansion device increases and other features are needed to achieve 

similar (to R22) efficiency values at high ambient conditions. 

Compared to the baseline, 10 – 20% energy efficiency improvement 

can be achieved by applying an ejector instead of an ordinary 

expansion device (Hafner, 2012). Other features to help improve 

efficiency in high ambients include economiser (parallel compression), 

expander, liquid-suction heat exchange and mechanical subcooling.

Costs, cost effectiveness 

(compared to a standard)

The cost of the working fluid is very low, typically around €1/kg. 

However, because of the high pressure, certain types of systems 

require more robust designs for pressure safety which adds cost, while 

specific tube dimensions are much smaller compared to current 

technology which gives the advantage of compact tubing and 

insulation material. However, as the capacity approaches a certain 

value (depending upon the type of application, between 50 – 500 kW), 

they can become cost-competitive. Similarly the features that are 

needed to improve efficiency under higher ambient temperature also 

result in increased cost. Values for cost-effectiveness are included in 

previous TEAP reports (UNEP, 2011; UNEP, 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

There are two main technical barriers, being components and system 

design for high operating pressure and performance degradation at 

high ambient temperatures, leading to a resultant incremental cost 

increase. (Although such additional costs at the present time are 

largely influenced by economies of scale.) Also, due to its relatively 

unusual characteristics, technicians require dedicated training and 

tooling. A comprehensive assessment of the barriers to the use of R744 and other low-GWP refrigerants is provided in a study for UNEP 

(Colbourne, 2010).
16 May 2013 TEAP XXIV/7 Task Force Report

HFCs (GWP ≤ 300)

HFC-1234yf

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

HFC-1234yf is a single component refrigerant with a GWP of about 4. 

It can replace HFC-134a in same systems since the pressuretemperature characteristics are almost identical. It is classed is under 

FDIS ISO 817 as an A2L refrigerant (low toxicity, lower 

flammability). 

Extent of commercialisation This chemical is currently produced at a fairly small scale but 

commercial scale production is anticipated when there is a sufficient 

market demand.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

In general this refrigerant produces efficiency levels comparable to 

HFC-134a although the theoretical COP is several percent below that 

of HFC-134a.

Costs, cost effectiveness 

(compared to a standard)

As a new molecule that requires a complex production process, this 

refrigerant has significantly higher cost than HFC-134a. 

Barriers and restrictions (safety, 

energy efficiency etc.)

The main barriers are related to the safe use lower flammability 

refrigerants (A2L under FDIS ISO 817). Standards such as ISO-5149 

and IEC-60335-2-40 are being updated to accommodate this new 

class. In practical terms this means that systems located indoors with 

moderate to large charge sizes are often restricted. Similarly, due to 

uncertainties over future adoption component manufactures means that 

there are gaps in availability of certain types of components including 

compressors. In addition, technicians must be well-trained and 

competent in handling flammable refrigerants if the flammability is to 

be dealt with safely. Some building safety codes may ban use 

flammable refrigerants in certain types of buildings.

HFC-1234ze(E)

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

HFC-1234ze(E) is a single component refrigerant with a GWP of 6. It 

can replace HFC-134a in new equipment where its lower volumetric 

capacity can be addressed in the design of the equipment. This 

refrigerant is under FDIS ISO 817 as A2L (low toxicity, lower 

flammability). 

Extent of commercialisation This chemical is already produced at a commercial scale. It is 

anticipated that this refrigerant will be available as and when there is a 

market demand.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

When used in with reciprocating or scroll type of compressors, this 

refrigerant produces efficiency levels comparable to HFC-134a. When 

used in scroll and reciprocating compressors, the same POE lubricant 

oil can be used.

Costs, cost effectiveness 

(compared to a standard)

As a new molecule, this refrigerant has higher cost than HFC-134a. 

This is mainly due to its different manufacturing process.

Barriers and restrictions (safety, 

energy efficiency etc.)

The main barriers are related to the safe use lower flammability 

refrigerants (A2L under FDIS ISO 817). Standards such as ISO-5149 

and IEC-60335-2-40 are being updated to accommodate this new 

class. In practical terms this means that systems located indoors with 

moderate to large charge sizes are often restricted. Similarly, due to 

uncertainties over future adoption component manufactures means that 

there are gaps in availability of certain types of components including 

compressors. In addition, technicians must be well-trained and 

competent in handling flammable refrigerants if the flammability is to 

be dealt with safely. Some building safety codes may ban use 

flammable refrigerants in certain types of buildings.
May 2013 TEAP XXIV/7 Task Force Report 17

HCFC-1233zd(E)

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

HCFC-1233zd(E) is a single component refrigerant with a GWP of 6, 

which reduces substantially the direct environmental impact. This 

refrigerant is likely to be A1 (low toxicity, non-flammable) under ISO 

817. 

Extent of commercialisation This chemical is already produced at a commercial scale for solvents 

and blowing agent applications. It is anticipated that this refrigerant 

will be available as and when there is a market demand.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

When used with centrifugal compressors, this refrigerant produces 

efficiency levels slightly better than HCFC-123, allowing the design of 

systems with very high energy efficiency.

Costs, cost effectiveness 

(compared to a standard)

As a new molecule, this refrigerant has higher cost that HCFC-123. 

Still this cost would be moderate and will have a reasonable payback 

period due to its high energy efficiency which lowers the expenses for 

end users.

Barriers and restrictions (safety, 

energy efficiency etc.)

Being non-flammable and having a moderate cost, this refrigerant is 

on a fast track for adoption. R-number designation application is 

expected for 2013.

“L-40” [HFC-32/HFC152a/HFC-1234yf/HFC1234ze(E); 40/10/20/30%]

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

L-40 is a mixture of HFCs (HFC-32 and HFC-152a) with the new 

unsaturated HFCs (HFC-1234yf and HFC-1234ze(E)). With a GWP of 

290 it reduces substantially the direct environmental impact. It is 

intended to replace R-404A in medium and low temperature 

refrigeration equipment without any major modifications as its 

pressures are similar. All components of the mixture are under FDIS 

ISO 817 as A2L (low toxicity, lower flammability). 

Extent of commercialisation All components are already produced at a commercial scale. It is 

anticipated that this refrigerant will be available during the next 1-2 

years.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

When used in the current R-404A system, L-40 is apparently exceeds 

the capacity of R-404A with an efficiency improvement of around 

10%. 

Costs, cost effectiveness 

(compared to a standard)

The direct cost of this refrigerant is likely to be higher than R-404A. It 

probably works with existing POE lubricants. 

Barriers and restrictions (safety, 

energy efficiency etc.)

The main barriers are related to the safe use of the mildly flammable 

refrigerants (class 2L under FDIS ISO 817). Current standards such as 

ISO-5149 are being updated to accommodate this new class. In 

practical terms this means that systems located indoors with moderate 

to large charge sizes are often restricted. Similarly, due to uncertainties 

over future adoption component manufactures means that there are 

gaps in availability of certain types of components including 

compressors. In addition, technicians must be well-trained and 

competent in handling flammable refrigerants if the flammability is to 

be dealt with safely. Some building safety codes may ban use 

flammable refrigerants in certain types of buildings.

HFCs (GWP > 300)

R-407C

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

R-407C is a mixture refrigerant comprising HFC-134a, HFC-125 and 

HFC-32 with a GWP of 1700. It has been used widely in air 

conditioning, chiller and heat pump systems, especially to help the 

transition from HCFC-22. It is classed as an A1 refrigerant (lower 

toxicity, non-flammable).

Extent of commercialisation It is well commercialised globally. 
18 May 2013 TEAP XXIV/7 Task Force Report

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

The efficiency is acceptable, although heat exchangers need to be 

designed suitably to take account of the temperature glide. 

Costs, cost effectiveness 

(compared to a standard)

The cost of the refrigerant is approximately two to three times greater 

than HCFC-22. Values for cost-effectiveness are included in previous 

TEAP reports (UNEP, 2011; UNEP, 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

There are no significant barriers to its use. 

R-407A

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

R-407A is a mixture of the same components of R-407C but in slightly 

different proportions. Its GWP is 2100. It is typically used recently for 

centralised commercial refrigeration systems. It is classed as an A1 

refrigerant (lower toxicity, non-flammable).

Extent of commercialisation It is well commercialised globally. 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

The efficiency is acceptable and better than of the R-404A it is 

normally used to replace. However, heat exchangers need to be 

designed suitably to take account of the temperature glide. 

Costs, cost effectiveness 

(compared to a standard)

The cost of the refrigerant is approximately two to three times greater 

than HCFC-22. Values for cost-effectiveness are expected to be 

similar to those of R-407C and R-404A as detailed in the TEAP 

reports (UNEP, 2011; UNEP, 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

There are no significant barriers to its use. 

R-407F

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

R-407F is a mixture of the same components of R-407C but in slightly 

different proportions. Its GWP is 1820. It is typically used recently for 

centralised commercial refrigeration systems. It is classed as an A1 

refrigerant (lower toxicity, non-flammable).

Extent of commercialisation It is well commercialised globally. 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

The efficiency is acceptable and better than of the R-404A it is 

normally used to replace. However, heat exchangers need to be 

designed suitably to take account of the temperature glide. 

Costs, cost effectiveness 

(compared to a standard)

The cost of the refrigerant is approximately two to three times greater 

than HCFC-22. Values for cost-effectiveness are expected to be 

similar to those of R-407C and R-404A as detailed in the TEAP 

reports (UNEP, 2011; UNEP, 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

There are no significant barriers to its use. 

R-404A

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

R-404A is a mixture refrigerant comprising HFC-134a, HFC-125 and 

HFC-143a with a GWP of 3700. It has been used widely in 

commercial refrigeration systems. It is classed as an A1 refrigerant 

(lower toxicity, non-flammable).

Extent of commercialisation It is well commercialised globally. 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

The efficiency is acceptable. 

Costs, cost effectiveness 

(compared to a standard)

The cost of the refrigerant is approximately two to four times greater 

than HCFC-22. Values for cost-effectiveness are included in previous 

TEAP reports (UNEP, 2011; UNEP, 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

There are no significant barriers to its use, although it is now 

becoming considered less desirable within several regions due to its 

comparatively high GWP.
May 2013 TEAP XXIV/7 Task Force Report 19

R-410A

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

R-410A is a mixture refrigerant comprising HFC-HFC-125 and HFC32 with a GWP of 2100. It is used widely in air conditioning, chiller 

and heat pump systems. The safety is classed as an A1 refrigerant 

(lower toxicity, non-flammable).

Extent of commercialisation It is well commercialised globally.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

Generally the efficiency is good, although it deteriorates at higher 

ambient temperatures. 

Costs, cost effectiveness 

(compared to a standard)

The cost of the refrigerant is approximately two to three times greater 

than HCFC-22. Values for cost-effectiveness are included in previous 

TEAP reports (UNEP, 2011; UNEP, 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

A slight barrier to its use it the operating pressures being higher than 

that of HCFC-22, although this is more perceived than practical. For 

countries which experience high ambient temperatures capacity and 

efficiency can degrade more rapidly than with HCFC-22. 

HFC-134a

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

HFC-134a is a pure substance with a GWP of 1370. It is used in a 

variety of equipment including heat pumps and chillers. It is classed as 

an A1 refrigerant (lower toxicity, non-flammable).

Extent of commercialisation It is well commercialised globally.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

Energy efficiency is good, provided that pipes and heat exchangers are 

suitably sized. 

Costs, cost effectiveness 

(compared to a standard)

The cost of the substance is greater than HCFC-22 but less than HFC 

blends. Values for cost-effectiveness are included in previous TEAP 

reports (UNEP, 2011; UNEP, 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

There are no significant barriers to its use. 

HFC-32

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

HFC-32 is a single component refrigerant that was originally used as a 

component of R-410A which is 50% HFC-32 and 50% HFC-125. 

HFC-125 was used to reduce the flammability of HFC-32 and high 

discharge temperature. With a GWP of 716, it produces a moderate 

reduction compared to R-410A or HCFC-22. Pressure and capacity are 

around 1.5 times higher than HCFC-22 and equivalent to R-410A. It is 

classed as A2L (low toxicity, lower flammability) under FDIS ISO 

817.

Extent of commercialisation HFC-32 is one of components of R-410A and R-407C, so fairly large 

production capacity is already available, though commercial 

availability of cylinders is not yet common. 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

The efficiency of HFC-32 systems is similar to R-410A and the 

theoretical COP is a few per cent better than R-410A at typical air 

conditioning conditions. The capacity is approximately slightly higher 

(~ 5%) but it can be easily accommodated with slight adjustment of 

the compressor displacement in new systems. Its system charge is 

somewhat lower than for R-410A. It has better heat transfer properties 

and transport properties than R-410A due to lower molar mass. 

Discharge temperatures are significantly higher than R-410A, making 

necessary the use of new lubricant oils (PVE, POE) and some 

mitigation devices. This is especially required at high ambient 

temperatures.
20 May 2013 TEAP XXIV/7 Task Force Report

Costs, cost effectiveness 

(compared to a standard)

The direct cost of this refrigerant is similar to R-410A. The new 

lubricant oils and mitigation devices for high discharge temperature 

may add some cost. Values for cost-effectiveness are included in 

previous TEAP reports (UNEP, 2011; UNEP, 2012).

Barriers and restrictions (safety, 

energy efficiency etc.)

The main barriers are related to the safe use of the lower flammable 

refrigerants. Current standards such as ISO-5149 and IEC-60335-2-40 

are being updated to accommodate this new class. In practical terms 

this means that systems located indoors with moderate to large charge 

sizes are often restricted. Similarly, due to uncertainties over future 

adoption component manufactures means that there are gaps in 

availability of certain types of components including compressors. In 

addition, technicians must be well-trained and competent in handling 

flammable refrigerants if the flammability is to be dealt with safely. 

Some building safety codes may ban use flammable refrigerants in 

certain types of buildings. 

“L-41” [HFC-32/HFC1234ze(E); 73/27%]

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

L-41 is a mixture of HFCs; HFC-32 and new unsaturated HFC-1234ze. 

It replaces R-410A in AC equipment. All components of the mixture 

are classified in FDIS ISO 817 as A2L (lower toxicity, lower 

flammability). It has a GWP of around 490. 

Extent of commercialisation All components are already produced at a commercial scale. It is 

anticipated that this refrigerant will be available during the next 1-2 

years in Asia (China, Japan, Korea), followed by other regions 

(Middle East, Europe). North America may take longer due to building 

codes restrictions and lack of regulatory drivers.

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

The efficiency of L-41 systems is at the same level of R-410A. The 

capacity is approximately 6% to 10% lower than R-410A still this 

capacity is easily recovered in new systems. Discharge temperatures 

are slightly higher than R-410A, still below the limit of existing 

compressors technologies. Due to its relative higher critical point 

compared to other refrigerants, L-41 performs well at high ambient 

temperatures (warm climates).

Costs, cost effectiveness 

(compared to a standard)

The direct cost of this refrigerant is similar to R-410A. It works well 

with existing POE lubricants. Power consumption increases its 

effectiveness at high ambient temperatures relative to R-410A.

Barriers and restrictions (safety, 

energy efficiency etc.)

The main barriers are related to the safe use of the class 2L flammable 

refrigerants . Current standards such as ISO-5149 and IEC-60335-2-40 

are being updated to accommodate this new class. In practical terms 

this means that systems located indoors with moderate to large charge 

sizes are often restricted. Similarly, due to uncertainties over future 

adoption component manufactures means that there are gaps in 

availability of certain types of components including compressors. In 

addition, technicians must be well-trained and competent in handling 

flammable refrigerants if the flammability is to be dealt with safely. 

Some building safety codes may ban use flammable refrigerants in 

certain types of buildings.
May 2013 TEAP XXIV/7 Task Force Report 21

“L-20” [HFC-32/HFC152a/HFC-1234ze(E); 

45/20/35%]

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

L-20 is a mixture of HFCs (HFC-32 and HFC-152a) with the new 

unsaturated HFC-1234ze. With a GWP of 330 it reduces substantially 

the direct environmental impact. It replaces HCFC-22 in AC 

equipment without any major modifications as its pressures are similar. 

All components of the mixture are under FDIS ISO 817 as A2L (low 

toxicity, lower flammability). 

Extent of commercialisation All components are already produced at a commercial scale. It is 

anticipated that this refrigerant will be available during the next 1-2 

years in Asia (China, Japan, Korea), followed by other regions 

(Middle East, Europe). 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

When use in the current HCFC-22 technologies, L-20 matches the 

capacity of HCFC-22 with an efficiency ranging from 95% to 97%. 

Further improvements can produce better efficiencies, especially for 

cooling only operation in warm climates. The above mentioned good 

performance in warm climates is mainly due to its relative high critical 

point (~93°C) compared with other options such as R410A and HFC32.

Costs, cost effectiveness 

(compared to a standard)

The direct cost of this refrigerant is similar to current HFCs such as R407C. It works well with existing POE lubricants. Due to its good 

efficiency at high ambient temperatures, power consumption would be 

lower relative to other options.

Barriers and restrictions (safety,

energy efficiency etc.)

The main barriers are related to the safe use of the mildly flammable 

refrigerants (class 2L under FDIS ISO 817). Current standards such as 

ISO-5149 and IEC-60335-2-40 are being updated to accommodate this 

new class. In practical terms this means that systems located indoors 

with moderate to large charge sizes are often restricted. Similarly, due 

to uncertainties over future adoption component manufactures means 

that there are gaps in availability of certain types of components 

including compressors. In addition, technicians must be well-trained 

and competent in handling flammable refrigerants if the flammability 

is to be dealt with safely. Some building safety codes may ban use 

flammable refrigerants in certain types of buildings.

“DR-5” [HFC-32/HFC1234yf; 72.5/27.5%]

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

DR-5 is a mixture of HFCs (HFC-32) with the new unsaturated HFC1234yf and has a GWP of 490. It replaces R-410A in AC equipment. 

All components of the mixture are classified by FDIS ISO 817 as A2L 

(low toxicity, lower flammability). 

Extent of commercialisation All components are already produced at a commercial scale. It is 

anticipated that this refrigerant will be available during the next 1-2 

years in Asia (China, Japan, Korea), followed by other regions 

(Middle East, Europe). 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

The efficiency of L-41 systems is at the same level of R-410A. The 

capacity is approximately 6% to 10% lower than R-410A still this 

capacity is easily recovered in new systems. Discharge temperatures 

are slightly higher than R-410A, still below the limit of existing 

compressors technologies. Due to its relative higher critical point 

compared to other refrigerants, DR-5 performs well at high ambient 

temperatures (warm climates).
22 May 2013 TEAP XXIV/7 Task Force Report

Costs, cost effectiveness 

(compared to a standard)

The direct cost of this refrigerant would be slightly high as it contains 

HFC-1234yf which has an expensive manufacturing cost. It works 

well with existing POE lubricants. Due to its good efficiency at high 

ambient temperatures, power consumption would be lower relative to 

R410A.

Barriers and restrictions (safety, 

energy efficiency etc.)

The main barriers are related to the safe use of the lower flammable 

refrigerants. Current standards such as ISO-5149 and IEC-60335-2-40 

are being updated to accommodate this new class. In practical terms 

this means that systems located indoors with moderate to large charge 

sizes are often restricted. Similarly, due to uncertainties over future 

adoption component manufactures means that there are gaps in 

availability of certain types of components including compressors. In 

addition, technicians must be well-trained and competent in handling 

flammable refrigerants if the flammability is to be dealt with safely. 

Some building safety codes may ban use flammable refrigerants in 

certain types of buildings.

“N-13” [HFC-134a/HFC1234ze(E); 42/58%]

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

N-13 is a binary mixture of HFC-134a and HFC-1234ze(E) which as 

formulated is non-flammable. It has a GWP of 600 therefore reduces 

substantially the direct environmental impact. It replaces HFC-134a in 

new equipment where its lower volumetric capacity can be addressed 

in the design of the equipment. This refrigerant would be classified by 

FDIS ISO 817 A1 (low toxicity, non-flammability). 

Extent of commercialisation These chemicals are already produced at a commercial scale. It is 

anticipated that this refrigerant will be available during the next 1-2 

years in Asia (China, Japan, Korea), followed by other regions 

(Middle East, Europe). 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

When used in with reciprocating or scroll compressors, this refrigerant 

produces efficiency levels comparable to HFC-134a. When used in 

scroll and reciprocating compressors, the same POE lubricant oil can 

be used. 

Costs, cost effectiveness 

(compared to a standard)

Being a blend of new molecules HFC-1234ze(E) and existing ones 

(HFC-134a), its cost is moderate and not significant different from 

existing bends available in the market.

Barriers and restrictions (safety, 

energy efficiency etc.)

Being non-flammable and having a moderate cost, this refrigerant is 

on a fast track for adoption. R-number designation is expected for 

2013. 

“XP-10” [HFC-134a/HFC1234yf; 44/56%]

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

XP-10 is a binary mixture of HFC-134a and HFC-1234yf which as 

formulated is non-flammable. It has a GWP of 630 therefore reduces 

substantially the direct environmental impact. It replaces HFC-134a in 

new equipment, producing similar capacity end efficiency. As 

formulated, this refrigerant would be classified by ISO FDIS 817 A1 

(low toxicity, non-flammable). 

Extent of commercialisation These chemicals are already produced at a commercial scale. It is 

anticipated that this refrigerant will be available during the next 1-2 

years in Asia (China, Japan, Korea), followed by other regions 

(Middle East, Europe). 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

When used in with reciprocating or scroll compressors, this refrigerant 

produces efficiency levels comparable to HFC-134a. When used in 

scroll and reciprocating compressors, the same POE lubricant oil can 

be used. Due to its high critical temperature, it will perform very well 

in warm climates.
May 2013 TEAP XXIV/7 Task Force Report 23

Costs, cost effectiveness 

(compared to a standard)

Being a blend of a high manufacturing cost molecule (HFC-1234yf) 

and HFC-134a, its cost is expected to be high.

Barriers and restrictions (safety, 

energy efficiency etc.)

Its high cost would be the main barrier for widespread adoption by the 

market.

“N-40” [HFC-32/HFC125/HFC-134a/HFC-1234yf; 

25/25/20/30%]

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

“N-40” is a mixture of saturated HFCs (HFC-32, HFC-125 and HFC134a) and unsaturated HFC-1234yf which as formulated is nonflammable. It has a GWP of 1330 and is therefore similar to pure 

HFC-134a. It replaces R-404A in new refrigeration equipment. This 

refrigerant would be classified by FDIS ISO 817 A1 (low toxicity, 

non-flammable). 

Extent of commercialisation The component chemicals are already produced at a commercial scale. 

It is anticipated that this refrigerant will be available during the next 1-

2 years. 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

This refrigerant has a capacity marginally higher than R-404A and a 

slightly greater efficiency. The same POE lubricant oil can be used as 

with R-404A. 

Costs, cost effectiveness 

(compared to a standard)

Being a blend which includes HFC-1234yf, its cost is likely to be 

higher than conventional HFC mixtures. 

Barriers and restrictions (safety, 

energy efficiency etc.)

No significant barriers are anticipated with this refrigerant.

“DR-33” [HFC-32/HFC125/HFC-134a/HFC-1234yf; 

24/25/26/25%]

Description and discussion of 

each technology/chemical 

(including health and safety etc.)

“DR-33” is a mixture of saturated HFCs (HFC-32, HFC-125 and HFC134a) and unsaturated HFC-1234yf which as formulated is nonflammable. It has a GWP of 1410 and is therefore similar to pure 

HFC-134a. It replaces R-404A in new refrigeration equipment. This 

refrigerant would be classified by FDIS ISO 817 A1 (low toxicity, 

non-flammable). 

Extent of commercialisation The component chemicals are already produced at a commercial scale. 

Energy efficiency, efficacy 

(taking into account ambient 

conditions)

This refrigerant has a capacity marginally higher than R-404A and a 

slightly greater efficiency. The same POE lubricant oil can be used as 

with R-404A. 

Costs, cost effectiveness 

(compared to a standard)

Being a blend which includes HFC-1234yf, its cost is likely to be 

higher than conventional HFC mixtures. 

Barriers and restrictions (safety, 

energy efficiency etc.)

No significant barriers are anticipated with this refrigerant.

Note: Most of the various HFC mixtures without an assigned R-number have a composition that is not yet 

finalised. Extensive testing by manufacturers is ongoing so minor changes to the composition are still possible. 

Final compositions for most of the mixtures are expected to be submitted within 2013.

3.2 Domestic refrigeration

3.2.1 Introduction 

Domestic refrigeration sub-sector comprises appliances that are broadly used domestically, such as 

refrigerators, freezers and combined refrigerator/freezer products. Beverage dispensing machines, 

commonly included in domestic refrigeration, represent a small fraction of total units.

Approximately 100 million domestic refrigerators and freezers are produced annually, and it is 

estimated that this quantity is equally divided between non-Article 5 and Article 5 countries. A 

typical product contains a factory-assembled, hermetically sealed, vapour-compression refrigeration 

system employing a 50 to 250 watt induction motor, and now also linear motors, containing 50 to 250 
24 May 2013 TEAP XXIV/7 Task Force Report

grams of refrigerant. Alternative technology to vapour-compression refrigeration is employed in 

specific products, such as absorption cycles for small fridges in hotels and so. The age distribution of 

the global installed products is extremely broad with median age estimates ranging from 9 to 19 years 

at retirement. Long product life and high volume annual production combine for an estimated 1500 to 

1800 million unit global installed inventory.

Old refrigerant CFC-12 was replaced by non-ODS refrigerants in almost all new products. Presently, 

the main refrigerants used are HC-600a and HFC-134a. More than 50% of current new production 

(globally) employs HC-600a, whilst the remainder uses HFC-134a (approximately 1% employs either 

HFC-152a or HCFC-22 or blends comprising these). This equates to about 3.8 ktonnes consumption 

of HFC-134a in non-Article 5 countries and 7.7 ktonnes in Article 5 countries. The reason for such 

dissimilarity in HFC-134a consumption is related to substantial regional differences; the vast 

majority of European refrigerators and freezers are produced with HC-600a whereas some other 

regions use HC-600a to lesser extent. There is fairly widespread production of HC-600a appliances in 

Asia and to some extent in South and Central America and Southern Africa; it is virtually nonexistent in North America although production in Australasia is now increasing. 

Improvement in energy efficiency is the main effort in new product development, through the use of 

advanced components such as variable speed compressors (virtually all new high level products in 

Europe have frequency variation device) and vacuum insulation panel insulation. Energy benefits are 

also obtained with the use of electronic controls.

Progress slowly continues on product redesign to facilitate transition from HFC-134a to HC-600a in 

certain countries.

3.2.2 HFC-134a

HFC-134a has been the predominant refrigerant for domestic refrigeration since the phase-out of 

CFC-12. It is a class A1 refrigerant (lower toxicity, non-flammable) and as such there are no

significant safety implications concerning its use. 

Energy efficiency is similar to that of CFC-12, although with continual optimisation the current HFC134a refrigeration units are considerably more efficient that those that used CFC-12. Generally 

systems are marginally more costly than HCFC-22 because they are less compact. 

Since HFC-134a is well established, it is evident that there are no significant barriers to its use. It is 

likely that HFC-134a will continue to be a dominant option on domestic refrigeration appliances for a 

number of years. 

3.2.3 HC-600a

HC-600a is the main alternative to HFC-134a. Concerns in connection with the high flammability at 

the introduction of the refrigerant in 1994 in Europe no longer exist, particularly as the charges 

required for domestic refrigeration are below 150 g. No new alternative has matured to become 

energy-efficient and cost-competitive.

When the statutory requirements for safety are met (e.g. IEC 60335-2-89), HC-600a is the ideal 

refrigerant for such units, giving about higher efficiency than HFC-134a while at the same time 

reducing noise level of the unit. Considering the product costs, HC-600a is less expensive than HFC134a, but additional investment cost for HC-600a products are due to larger size of compressors, and 

also production cost for refrigerators can be higher due to the requirements for safety systems.

In general there are no significant barriers to the use of HC-600a, exemplified by the existence of 

over 500 m domestic fridges in the market to date. However, in some regions the use of HC-600a is 
May 2013 TEAP XXIV/7 Task Force Report 25

almost non-existent (e.g. USA) and this can be considered to be due to a number of factors. These 

include general concerns regarding public safety (or the perception of), misconceptions about 

flammability safety and accidents and are similarly reflected in the restrictive national standards and 

the reluctance to be one of the early movers in the region. Whilst legal concerns have so far limited 

the use of HC-600a in USA, in 2011 their Environmental Protection Agency (EPA) approved HC600a and an HC blend (R-441A) under their Significant New Alternatives Policy Program (SNAP) 

for household and small commercial refrigerators and freezers. As such some North American 

manufacturers have started production of high-end products with HC-refrigerants. 

HC-600a is the standard refrigerant for European domestic refrigerators and freezers. Worldwide 

over 50 million appliances each year are produced with HC-600a. Increased energy efficiency and 

HC-600a refrigerant have drastically reduced the climate impact of household refrigerators, due to 

mitigation of direct (refrigerant) and indirect (CO2 associated with electricity consumption) GHG 

emissions.

3.2.4 HFC-1234yf

It is feasible to use HFC-1234yf in domestic refrigerators and freezers and its application can be 

considered as some way between the use of HFC-134a and HC-600a, since the pressure and capacity 

are slightly lower than HFC-134a and it has lower flammability characteristics than HC-600a. The 

lower flammability makes application easier in countries that have still strong reservations related to 

the application of HC-600a.

Initial developments to assess the HFC-134a replacement by HFC-1234yf have begun. Its use in 

domestic refrigeration has begun but is not being pursued with high priority, which is more 

demanding than automotive applications. A preliminary assessment is that HFC-1234yf has the 

potential for comparable efficiency to HFC-134a, although often slightly worse in practice. As such, 

investment costs for equipment are estimated to be 1% higher than for HFC-134a technology due to 

the larger surfaces of heat exchangers applied (to account for poorer energy performance) and given 

the price, an additional 1% higher investment cost results from the cost of the refrigerant for the first 

charge. As implied above, two main barriers are the cost implications and the flammability, although 

in most cases the latter is not of major concern given the acceptability of HC-600a.

3.2.5 R-744

Currently R-744 (considering the transcritical use of R-744, CO2) seems to be the only alternative 

option with good prospects, in addition to conventional vapour-compression technology for mass 

produced domestic refrigeration equipment. Experience is available from a large number of vending 

machines which have been in use since many years, and are similar, low-charged applications.

R-744 application will imply in additional cost, which can be attributed to the greater mass of 

materials necessary to achieve the minimum level of efficiency, particularly for freezers in all 

climates and for both refrigerators and freezers in warmer climates. However, since the majority of 

these appliances are used indoors, the impact of outside temperature will have a lesser impact on the 

ambient temperature and thus the efficiency degradation. Higher cost is also predicted in the 

evaporator construction when applying high pressure R-744.

The main barrier associated with the use of R-744 in these systems is that a higher cost requirement 

associated with the system materials, thus making commodity products uncompetitive. In addition 

there are some more peripheral hurdles such as a general perceived fear of high pressures, effects of 

national and international standards which requirements result in greater cost, lack of training 

materials and higher costs for servicing equipment.
26 May 2013 TEAP XXIV/7 Task Force Report

No major domestic refrigerator manufacturers are actively developing R-744 systems for 

commercialisation, so it is unlikely that its use will become widespread in this sector. 

Due to the cost-efficiency implications and the fact that other low-GWP alternatives (such as HC600a) are widely accepted, it is unlikely that R-744 will become commercialised to any major extent. 

3.3 Commercial refrigeration

Commercial refrigeration is characterised by storing and displaying food and beverages at different 

levels of temperature for chilled and frozen food. The refrigerating capacities of equipment vary from 

some hundreds of Watts to 1.5 MW. Commercial refrigeration is composed of three main categories 

of equipment: stand-alone equipment, condensing units, and supermarket systems. Refrigerant 

choices depend on the refrigerant charge, the level of temperature, energy efficiency, and regulations.

3.3.1 Stand-alone equipment

Stand-alone equipment consists of systems where all refrigeration components are integrated and, for 

the smallest types, the refrigeration circuit is entirely brazed or welded.

R-717 has not so far been used in these systems due to limitations on its use in occupied spaces 

related to safety and toxicity concerns. 

Carbon dioxide is mainly used in vending machines and bottle coolers; the technology is operating 

well, but it is a technical challenge. The energy efficiency of the vending machine and bottle cooler 

cassettes is similar to HFC-134a machines with an energy penalty at high ambient conditions. The 

cost is slightly higher, but the global company ordering that equipment has made a political and 

environmental choice. The high technological level of expertise required forms a barrier for the 

application. R-744 has been chosen instead of hydrocarbons since the safety risk in public areas is 

lower.

Where it concerns low GWP HFCs, HFC-1234yf can replace HFC-134a in any application but 

availability of HFC-1234yf is limited and so there is no large amount of available equipment. The 

energy efficiency of HFC-1234yf will be in the same range, based on published tests. There are 

reciprocating compressors already approved for use with HFC-1234yf. Vending machines that use 

this refrigerant have been already introduced in Japan. As mentioned, a barrier for current application 

is the refrigerant availability question, but also the cost of the substance, to some extent.

HC-600a and HC-290 are the two hydrocarbons used for small commercial equipment. R-600a is 

chosen for smaller refrigeration capacity. For bottle coolers both refrigerants will be used. Ice 

machines, small display cases use HC-290. The energy efficiency of a hydrocarbon based system is 

always as good or even slightly better compared to HCFCs or HFCs commonly used in those 

applications. The small additional cost associated to safety is integrated in the price, not much 

different compared to HFC equipment.

The EN 378 standard in Europe allows the use of HCs up to 1.5 kg in public areas if the volume of 

the room is sufficiently large. Large global companies have committed to not use HFCs in their new 

systems. The uptake of HCs is significant for small commercial equipment with refrigerant charges 

varying from 15 g to 1.5 kg.

HFC-134a and R-404A are still the dominant refrigerants for stand-alone equipment; in Europe R404A is seen as a short-term option. Where it concerns barriers and restrictions, the GWP is the issue 

for both refrigerants and (future) regulations will require the phase-down of HFC-134a and the phaseout of R-404A at least in Europe. At this stage, there are two possible replacements for R-404A:

1) Non-flammable options such as N-40 and DR-33 

2) 2L flammable refrigerants such as L-40, which provides further reduction of the GWP
May 2013 TEAP XXIV/7 Task Force Report 27

As for HFC-134a, there are also two types of replacements:

1) Non-flammable options such as N-13 and XP-10 

2) 2L flammable refrigerants such as HFC-1234yf and HFC-1234ze(E)

The pure HFCs are still the current standard options but are not seen as viable longer than 10 years.

3.3.2 Condensing units

Condensing units exhibit refrigerating capacities ranging typically from 1 kW to 20 kW. They are 

composed of one (or two) compressor(s), one condenser, and one receiver assembled into a so-called 

“condensing unit”, which is normally located external to the sales area. Condensing units are 

typically installed in specialty shops such as bakeries, butcher shops, and convenience stores. In most 

Article 5 countries there is extensive use of condensing units. 

R-717 is never used in these systems for cost and safety issues. Some new carbon dioxide based 

condensing units are sold in Northern Europe, but the penetration on the market is slow. R-744 

systems require double-stage design if high outdoor temperatures occur frequently. Single-stage 

systems are designed for cold climates. The additional cost for a double-stage system is significant; 

cost is the main barrier for these R-744 systems. Further development is possible when there are 

general decisions to not choose HCs; the future market share will be limited.

Several indirect condensing units with HC-290 or HC-1270 are operating in Europe with typical 

refrigerant charges varying from 1 to 20 kg. The energy efficiency is good. The indirect system

energy penalty is limited if the secondary loop is well designed, with larger heat-exchanger areas. 

Costs for these HC based systems are typically 5 to 15% higher compared to HFC systems.

Choosing hydrocarbons usually requires a “policy” decision of the commercial chain management. 

The development of hydrocarbons for condensing units depends on the outcome of the competition 

with future low GWP HFCs. Hydrocarbons are seen as a long-term solution and require a better 

refrigerant management due to safety precautions for the maintenance.

A number of possible low GWP blends are proposed in presentations at technical conferences but so 

far there are no viable options in the field. 

HFC-134a, R-404A, and, at a small level, R-410A are HFCs of choice for condensing units. HFC134a is chosen for small capacities and evaporation temperatures > -15°C. R-404A or 

R-410A are chosen for larger capacities for all temperature levels. HFCs form the energy efficiency 

references for benchmarking other refrigerants. 

As in all other commercial applications, high GWP HFCs are seen as short-term options, even if they 

are still dominating the market. 

3.3.3 Centralised systems

Centralised systems are the preferred option in supermarkets. They operate with racks of compressors

installed in a machinery room. Two main design options are used: direct and indirect systems. 

Direct systems are the most widespread. The refrigerant circulates from the machinery room to the 

sales area, where it evaporates in display-case heat exchangers, and then returns in vapour phase to 

the suction headers of the compressor racks. The supermarket cold rooms are cooled similarly. 

Ammonia is used in indirect systems for large capacities; usually carbon dioxide is used at lowtemperature level. Due to safety issues the number of installations so far is limited. Ammonia is an 

efficient refrigerant for refrigeration applications.
28 May 2013 TEAP XXIV/7 Task Force Report

The additional cost is in the range of 10 to 15% compared to indirect systems using HFCs and R-744, 

because of the use of steel instead of copper, although at capacities over several hundred kW the 

economics become more competitive. Ammonia competes with HFCs, hydrocarbons and even with 

carbon dioxide in cold climates, however, ammonia will remain dependent to user preferences. Even 

though being an efficient solution, it is unclear what its future market potential in this sub-sector will 

be.

Two-stage R-744 systems for the medium-temperature level (-10 to -15°C) and the low-temperature 

level (-35 to -38°C) have taken a certain market share in Europe and are now installed in more than 

1000 stores.

The preferred option for large European commercial companies is HFC-134a at the mediumtemperature level connected to an indirect system and a R-744 direct system for the low temperature 

since it is a global option for all climates. R-744 is efficient when the condensing temperature is 

below 25°C. For higher outdoor temperatures, the trans-critical cycle implies a significant energy 

penalty, although developments are on-going to make the technology more energy-competitive under 

higher ambient temperature conditions. The additional cost is again limited to 10 to 15%.

The lower energy efficiency for hot climates forms one barrier. The high pressure under which R-744 

is operated requires higher brazing quality than the usual HFC design. R-744 is seen as a long-term 

solution for low temperatures in cascade with a medium-temperature refrigerant. Taking into account 

the ambient climate conditions, R-744 is seen as the main option for northern and central Europe. In 

summary, R-744 is clearly a significant option for future centralised systems in commercial 

refrigeration.

Hydrocarbons are used in less than 100 centralised systems in Europe either with HC-290 or HC1270. HC-290 or HC-1270 is efficient in both medium and low temperatures of commercial 

refrigeration. The additional costs are related to containment and safety. The refrigerant charge limits 

associated to regulations and standards form a barrier. The competition with R-744 as a low GWP

option has limited the expansion of HCs in centralised systems. In summary, HCs in large centralised 

systems will have a limited market share due to safety standards. 

For low GWP HFCs, the situation is identical as previously mentioned; there is no available single 

low GWP HFC currently proposed for centralised systems. Non-flammable options such as N-40 and 

DR-33, which can be used for retrofit of existing systems, may improve energy-efficiency (~7%). 

Lower flammability refrigerants such as L-40 can be used in indirect systems such as with brine or 

pumped CO2 where flammability can be addressed. For HFC-134a, there are additional 

replacements: non-flammable options such as N-13 and XP-10 which can be used for retrofit of 

existing systems and lower flammability refrigerants such as HFC-1234yf and HFC-1234ze(E), 

which could be applied in cascade systems

For the non-low GWP refrigerants, R-404A is currently the dominant refrigerant, even if it is now 

replaced in new installations by HFC-134a at the medium-temperature level. Some trials have been 

done using R-410A in new installations without a significant success. R-407A and R-407F are 

proposed as intermediate options. The price levels of R-404A are currently decreasing. The GWP of 

R-404A will limit its use in Europe in the next few years in particular due to the updated F-Gas 

regulation that will enter into force. As a conclusion, high GWP HFCs have a limited future in all 

developed countries, dependent on when regulations enter into force.

3.4 Transport refrigeration

Technical requirements for transport refrigeration systems are extremely complex. The equipment 

has to operate over a wide range of ambient temperatures and weather conditions (wind, solar 

radiation, rain, sea water spray, etc.). The equipment has to be able to carry any one of a wide range 
May 2013 TEAP XXIV/7 Task Force Report 29

of cargos with different temperature needs and even different temperatures simultaneously in 

different compartments.

The refrigerant of choice for transport refrigeration systems within non-Article 5 countries is HFCs, 

with refrigerant charges from less than 1 kg (refrigerated vans) to more than several kg (trucks, 

trailers and reefer containers) to 3,000 kg on board large fishing vessels (Schwarz, 2011). Leakage 

rates are estimated at 20% for trucks/trailers, 30% for vans and up to 40% for fishing vessels 

(Schwarz 2011). All intermodal containers use hermetic 

or semi-hermetic systems, which have an estimated leakage rate below 5%. 

Trucks, trailers and intermodal containers.

R-404A has become a preferred choice for practically all trailers and large trucks. One German 

manufacturer uses R-410A. HFC-134a is used in small trucks and vans, because they can utilise 

automotive components. Not that HFC-134a is excellent – it is convenient. Some small trucks and 

vans use R-404A when a higher capacity is needed. ODS have not been used in new equipment for 

many years.

A phase-out of refrigerants with a non-low-GWP solution would put all road transport equipment on 

the spot. Testing of low-GWP alternatives is in progress elsewhere, but no option seems viable in the 

short term. The main issue is that the performance of R-404A is difficult to meet. Although R-410A 

outperforms R-404A, it has higher pressures (requires technology change for most manufacturers) 

and it still has a relatively high GWP.

HFC-134a and its low-GWP alternatives may look attractive, but validations for frozen cargo (in 

addition to chilled cargo where it could be acceptable) have to be done. 

Current and previous tests with trucks using R-744 suggest that introduction of R-744 will be 

possible when more efficient compressors with more than one compression stage, which are under 

development, will be commercially available. In 2012, two large global manufacturers of transport 

refrigeration equipment exhibited concepts of trailer refrigeration units with R-744 at a trade show 

(ThermoKing, 2012, Carrier, 2011), although at least one other manufacturer has developed such 

products. Among other features reducing the carbon footprint, the units utilise multi-stage 

compressors. 

The use of hydrocarbons (mainly HC-290) in truck refrigeration units has been tested with a small 

number of vehicles in the UK, Australia and Germany. They would be the preferred choice because 

they can provide lower energy consumption in the order of 20% or more. Recently, a refrigerated 

truck with propene (HC-1270) was developed by a German company and is now in field tests for a 

supermarket chain in Germany. The system was reported to be superior to R-404A and comparable to 

R-410A (Burke, 2011). For a broader market introduction, manufacturers and customers require 

specific legal rules and standards for hydrocarbons to ensure safety in mobile applications.

In contrast to trailers, intermodal containers use HFC-134a in most cases and R-404A in some. The 

reasons for choosing HFC-134a could have been the global availability of HFC-134a, and lower cost 

per kg, otherwise R-404A (or today R-410A) would be more suitable. Because HFC-134a systems 

operate at lower pressures, they can have lower leak rates than R-404A but also a higher risk of air 

intake to circuits with frozen cargo. 

Initial field tests with small fleets of containers using R-744 have started. In 2011, a large global 

manufacturer of transport refrigeration equipment exhibited a container refrigeration system with R744 at a trade show. By using two-stage compression, cylinder unloading and variable speed drive, 
30 May 2013 TEAP XXIV/7 Task Force Report

the R-744 design was reported to deliver efficiencies equal to their best-in-class HFC container unit 

(Carrier, 2011).

Hydrocarbons are technically feasible, but the strict safety concerns currently do not favour 

application of flammable refrigerants aboard vessels (with exceptions, discussed below).

Ammonia is deemed unacceptable in all truck, trailer and intermodal container applications because 

of toxicity and material compatibility.

Cryogenic or open loop systems, which evaporate the liquid CO2 or N2 charged to an insulated 

container aboard the truck, are alternatives to the vapour compression cycle for recurring distribution 

routes. The systems have advantages of being quiet and reliable. They offer a constant capacity that is 

independent of the engine (vehicle) speed. On the other hand, systems that discharge CO2 or N2 to 

the cargo box (not all do) bear a risk of asphyxiation if not equipped by gas sensors. They require 

energy for the liquefaction of the cryogenic liquid, which can make the systems more or less 

expensive to operate, depending on the energy source. The systems need periodic refilling; 

consequently, the user needs to provide storage and refilling infrastructure for the liquefied gases. 

Nevertheless, they are fundamentally the most inefficient and least environmentally friendly of all 

options. This is because their liquid working fluid must be drawn from the environment or recovered 

from certain processes which invariably demand compression from almost atmospheric pressure thus 

using many times the energy needed for a closed compression circuit. Consequently when 

considering lifetime energy use they are unfavourable.

Vessels

The variety of types is great. The majority of them uses HCFC-22, which can be replaced by R-417A 

or R-422D. Other HFC alternatives, namely R-410A, R-407C and R-427A, require modifications. 

The GWP of these fluids ranges between 1700 and 2700. Modern cruise ships use R-410A and HFC134a for air conditioning. Where refrigeration is needed for provision rooms or process cooling, R404A is used. Low-GWP alternatives are considered, but except R-717 and R-744 in limited 

numbers, these options have not been commercialised.

An important issue aboard ships is safety – ships are difficult to evacuate. Specific requirements 

inherent to vessels mean that not all stationary systems can be applied at sea, and if so, they require 

modifications. 

Natural refrigerants have been commercialised to a small extent aboard marine vessels worldwide 

(ammonia, CO2) (RTOC, 2010). For European fishing vessels highly efficient ammonia-CO2-

cascade systems are the systems of choice, using approximately 6% less energy (Schwarz, 2011). 

3.5 Large size (industrial refrigeration)

Industrial refrigeration systems are characterized by heat extraction rates in the range 10 kW to 10 

MW, typically at evaporating temperatures from –50 °C to +20 °C. About 75% of all industrial 

refrigeration capacity is installed in the food industry, the rest in industrial processes and leisure 

applications (Schwarz, 2011). Over 90% of the large industrial refrigeration installations use R-717 

whereas the market share of R-717 is only 5% (India and China) to 25% (Europe and Russia) for 

smaller industrial refrigeration systems (RTOC, 2010). Industrial ammonia systems are in general 

15% more energy efficient than their HFC-counterparts and 40% of the European industrial 

refrigeration systems use R-717 (Schwarz 2011). While industrial refrigeration systems using R717 

are very tight due to the pungent smell of R717, HFC systems in the EU show leakage rates of 8-10% 

at present (Schwarz, 2011).

Alternatives to HCFCs include R-717, which is already widely used, hydrocarbons, R-744 for low 

temperature (freezing), HFCs and air for very low temperatures.
May 2013 TEAP XXIV/7 Task Force Report 31

A replacement of a 3.2 MW HCFC-22 refrigeration system by one using R-717 resulted in 40% 

reduction of energy consumption (McNeill, 2011). As the new plant utilises heat recovery and water 

heating by means of an additional heat pump, the total annual cost savings are more than £1.4 

million, resulting in a payback time of 2.7 years (McNeill, 2011). Applying improvement levers such 

as reduced condensing temperature, increased evaporation temperature, variable speed compressors 

and multistage systems, the energy consumption of the ammonia plants can be drastically reduced 

(Gerwen, 2011).

Hydrocarbons are not widely used, other than in situations where safety measures are already 

required, e.g. in a petrochemical plant. They offer excellent efficiency, and compatibility with most 

materials and lubricants. However the precautions required to prevent ignition are significantly more 

expensive than those required for ammonia systems (RTOC, 2010).

R-744 is used with excellent efficiency in systems as the low temperature stage to a cascaded upper 

ammonia system especially in the food industry where the refrigerant has to evaporate in freezing 

equipment in the factory. According to Van Gerwen (2011) “the use of R-744 as a refrigerant in the 

low pressure stage of a cascade refrigeration system, with ammonia in the high stage, could be an 

opportunity for further improvement”. In colder climates R-744 is energy efficient as the sole 

refrigerant.

Air can be used with good energy efficiency in low temperature applications, namely below -60 °C. 

At least one manufacturer is offering such systems (Machida,2011). According to Unilever: “The 

refrigerant choice for industrial refrigeration is ammonia, using an optimised standard core design 

concept and an appropriate safety management system” (Gerwen, 2011). 

Nestlé committed to the use of natural refrigerants in 2001, and has since also supported the use of R717/R-744 systems: “As already publicly stated in 2001, Nestle reiterates its commitment to the use 

of natural refrigerants that are environmentally friendly. Especially and whenever feasible, carbon 

dioxide (CO2) in combination with ammonia (NH3) must be used for all low temperature 

applications. Beyond many technical and economic advantages, carbon dioxide is safer for the 

environment, people and goods” (Nestle, 2008).

Industrial refrigeration sometimes uses compression chillers; these are discussed in more detail in 

section 3.7.

3.6 Air conditioning and heat pumps

3.6.1 Small self-contained (window, portable, through-the-wall, packaged terminal)

Small Self-Contained (SSC) air conditioners are small capacity air conditioners in which all of the 

refrigeration system components are contained within a single package. These products have cooling 

capacities typically ranging from 1.0 kW to 10 kW. This category of products includes window 

mounted, through-the wall, portable and packaged terminal air conditioners. Small self-contained air 

conditioners are designed to heat or cool single spaces, such as bedrooms, small shops, restaurants 

and offices.

R-717 has so far not been used in these systems due to limitations on its use in occupied spaces 

related to safety and toxicity concerns. In addition, the construction requirements for smaller 

capacities would take up too much space as well.

R-744 is not widely considered for use in SSC air conditioners. However, there are developments on 

units for specific purposes, where both cooling and heating is needed, such as so-called 

environmental control units (ECUs). Whilst the performance at lower ambient temperatures may be 
32 May 2013 TEAP XXIV/7 Task Force Report

favourable, as the temperature exceeds the critical temperature of R-744 (31°C), efficiency can 

degrade at a greater rate than refrigerants with much higher critical temperatures. Thus, at standard 

rating conditions, which typically require a 35°C outside air temperature (e.g., EN 14511) the 

efficiency of non-enhanced R-744 systems is lower than for other refrigerants. Nevertheless, recent 

work on this type of system using advances features such as variable speed compressors and ejectors 

have shown to improve efficiency considerably even at high ambient temperatures (e.g., Liu et al, 

2012; Lee et al, 2011). However, when systems are designed also to provide heating, the overall 

efficiency can even for countries which experience hot climates be favourable (e.g., Hafner et al, 

2007). Literature relating to the costs associated with the use of R-744 in SSC air conditioners is 

sparse, but depending on component selection and material requirements, R-744 units may have 

greater or lower theoretical cost than those for HCFC-22. 

In conclusion it can be said that there are fairly widespread developments ongoing globally for R-744 

systems, but no production of systems except for niche applications. The main barriers for SSC air 

conditioners are those described previously in regards to efficiency and cost implications. In addition, 

there may also be poor availability of components in certain regions. Due to efficiency implications, 

the use of cooling only R-744 systems is not really feasible. Where models are developed to also 

provide heating, this technology is considered to be more interesting. It is possible that some 

commercially available products will become available in the future but only for regions where both 

cooling and heating is required.

HC-290 has been used is portable ACs for many years and several companies are producing them. 

Window units are also under development. HC-290 seems to be preferred over HC-1270 for smaller 

capacity systems, whilst he other HC blends are not known to be in use. 

HC-290 has the same or higher COP than HCFC-22. For example, Teng et al (2012) reports HC-290 

has the same or greater cooling capacity and a higher COP than HCFC-22, provided the charge is 

properly optimised and Devotta et al (2005) found a 2-8% drop in capacity and 8-14% increase in 

COP for HC-290. At higher ambient temperatures the differences between HCFC-22 and HC-290 

show little difference from normal ambient conditions. For SSC systems, there is negligible 

additional cost, if at all, considering the additional cost for safe electrics and negative costs for heat 

exchangers. Zheng (2012) reports that the overall cost for HC-290 is less than an R-410A model, 

whilst gaining 10% reduction in efficiency. 

For SSC ACs the safety issues pose less safety-related hurdles than for systems that have to be siteinstalled because refrigerant handling is not necessary. However, certain safety standards impose 

obstructive limits on refrigerant charge sizes for certain categories of equipment. Nevertheless, 

several manufacturers are now newly developing HC-290 SSC ACs. 

In conclusion, HC-290 is an attractive refrigerant for SSC ACs, offering good efficiency and cost 

implications. 

R-407C has been used in a large proportion of SSC ACs, more so earlier on in the transition from 

HCFC-22 in non-Article 5 countries since the vapour pressure is a close match for HCFC-22. 

Because it is a class A1 refrigerant (lower toxicity, non-flammable) there are no significant safety 

implications concerning its use. Energy efficiency is typically poorer than HCFC-22, although similar 

COPs can be achieved if the system is carefully designed. Generally systems are marginally more 

costly than HCFC-22. Since R-407C is well established, it is evident that there are no significant 

barriers to its use. Where R-407C has been used widely, it use is declining in favour of R-410A 

whilst in other countries who transitioned from HCFC-22 later, it is unlikely that it will be used to 

any significant extent. 
May 2013 TEAP XXIV/7 Task Force Report 33

R-410A is used in most SSC ACs, where HCFC-22 is not used. The design of the system components 

is different because of the higher operating pressure. Because it is a class A1 refrigerant (lower 

toxicity, non-flammable) there are no significant safety implications concerning its use. Energy 

efficiency is about the same as HCFC-22, although higher COPs can be achieved if the system is 

carefully designed. As ambient temperatures increase the efficiency (and cooling capacity) degrades 

at a greater rate than HCFC-22 does. Generally systems are marginally more costly than HCFC-22. 

Since R-410A is well established, it is evident that there are no significant barriers to its use, except 

for the issues relating to high ambient temperatures and concerns within the service sector over the 

higher operating pressures. Currently, R-410A is developing as the standard refrigerant for air 

conditioning systems. 

It is feasible to use HFC-32 in SSC ACs, for example, where R-410A is already used. Although HFC32 is flammable, the required charge of such units is unlikely to reach concentration that can be 

ignited (LFL). HFC-32 has the optimum heat transfer at higher flow rate in heat exchanger compared 

to HCFC-22 and R-410A, so a relatively better COP can be achieved in compact products. Energy 

efficiency deterioration due to high ambient is a few per cent worse than HCFC-22, but not as severe 

as R-410A. Under high ambient temperatures the compressor discharge temperature can be very high, 

compromising reliability of systems or demanding most costly injection technology. The costs of 

units are equivalent to R-410A and HCFC-22 in small units. Electric components of these units are 

unlikely to ignite HFC-32, but initial confirmation of it requires certain cost. One major Chinese 

manufacturer has made an application to commercialise compact SSC units with HFC-32 in 

Australia.

It is also proposed to use the L-41 blend in SSC ACs, for example, where R-410A is already used. 

Since L-41 has low flammability, the required charge of such units is unlikely to reach concentration 

that can be ignited (LFL). In principle the main barrier is the flammability; however, guidelines in the 

form of international standards do not restrict their use in this type of equipment under most 

situations. Currently there are no reported developments of L-41 SSC underway. 

3.6.2 Mini-split (non-ducted)

Residential and light commercial air-conditioning is often done with non-ducted split air 

conditioners. Non-ducted split air conditioners are widely applied in commercial buildings, schools, 

apartments and free-standing residences. They comprise a compressor/heat exchanger unit 

(condensing unit) installed outside the space to be cooled or heated. The outdoor unit is connected via 

refrigerant piping to a fan-coil unit located inside the conditioned space, generally on the wall but 

also can be ceiling or floor mounted designs. Reversible air conditioners (heat pumps) are gaining 

market acceptance in cool and cold climates where they are used primarily for heating but also 

provide cooling during summer operation.

R-717 is never used in these systems due to limitations on its use in occupied spaces and the small 

capacity and installation requirements would also mean that they are not competitive. 

Currently no split air conditioners are available using R-744, although some studies have been carried 

out to investigate the performance and viability of R-744 in these systems. As detailed for SSC air 

conditioners, the cooling COP at rated conditions makes R-744 seem uncompetitive. However, when 

considering seasonal efficiency and when including for heating mode, a reversible R-744 air 

conditioner can achieve the same seasonal efficiency as a state-of-the-art R-410A unit (Hafner, 2009). 

The cost implications for split air conditioners are the same as with SSC air conditioners using R744, although a greater cost increment is likely due to site-installed pipework. The barriers for split 

AC are the same as with SSC air conditioners, although there are additional hindrances associated 

with installation of the piping and the necessity for technicians to be competent in handling R-744. 

As with SSC ACs, there are ongoing research and development activities. Due to efficiency 

implications, the use of cooling only R-744 systems is not really feasible but where models are 
34 May 2013 TEAP XXIV/7 Task Force Report

developed to also provide heating, this technology is considered to be more interesting. It is possible 

that some commercially available products will become available in the future but only for regions 

where both cooling and heating is required.

HC-290 has been used is split ACs for many years on a limited scale but now with some companies 

developing and producing them on a larger scale. Although HC-290 seems to be the preferred HC 

option, HC-1270 is under evaluation by some companies. The other HC blends are not known to be in 

use in new systems. In most cases, HC-290 has the same or higher COP than HCFC-22, with 

numerous studies reporting improvements in COP of up to 15% (without capacity reduction) 

(Colbourne and van Gerwen, 2012). At higher ambient temperatures even up to 52°C, there is 

virtually no difference between both capacity and COP of HCFC-22 and HC-290 than from normal 

ambient conditions (Chen, 2012). There is negligible additional cost; considering the additional cost 

for safe electrics and negative costs for heat exchangers there can be improvements in cost 

effectiveness. Additional expenditure is necessary for more in-depth technician training and certain 

tooling. Two main barriers exist; one is that technicians require additional training in order to handle 

flammability issues and another is that certain safety standards impose obstructive limits on 

refrigerant charge sizes for certain categories and characteristics of equipment. 

HC-290 units are available from several companies and other manufacturers report that models will 

become available one production lines are completed. In particular, China has committed to 

converting some 18 production lines from HCFC-22 to HC-290 by 2015. Commensurate to this, 

extensive research and development are continuing on safety matters and on charge size reduction. 

HC-290 is an attractive refrigerant for split air conditions within the smaller capacity range, offering 

good efficiency and cost implications. 

R-407C is used in a proportion of split ACs, more so earlier on in the transition from HCFC-22 in 

non-Article 5 countries since the vapour pressure is a close match for HCFC-22. Because it is a class 

A1 refrigerant (lower toxicity, non-flammable) there are no significant safety implications concerning 

its use. All other aspects are as for SSC ACs. 

R-410A is used in most split air conditioners, where HCFC-22 is not used. The design of the system 

components is slightly different because of the higher operating pressure. Because it is a class A1 

refrigerant (lower toxicity, non-flammable) there are no significant safety implications concerning its 

use. All other aspects are as for SSC ACs. 

Again, the L-41 blend is feasible for use in split ACs, for example, where R-410A is already used. 

Since L-41 has low flammability, the required charge of such units is unlikely to reach concentration 

that can be ignited (LFL). The efficiency is comparable to that of R-410A, although data has not 

found for high ambient conditions. The cost implications should be comparable to that of R-410A 

although marginally greater due to the refrigerant cost. In principle the main barrier is the 

flammability, however, guidelines in the form of international standards do not restrict their use in 

this type of equipment under most situations. Currently there is extensive testing and trialling 

ongoing and manufacturers in Japan, Korea, China and New Zealand are developing prototypes and 

at least one company has recently showed prototypes in exhibitions. 

It is feasible to use HFC-32 in split ACs, for example, where R-410A is already used. Since HFC-32 

has low flammability, the required charge of such units is unlikely to reach concentration that can be 

ignited (LFL) in the event of a leak. HFC-32 has comparable efficiency to that of R-410A and HCFC22 in many mini-split air conditioners. Drop in tests in high efficiency R-410A units have equivalent 

performance sometimes, because the flow rate in heat exchanger is optimised for R-410A and is too 

low for HFC-32. As theoretical COP, heat transfer properties and transport properties are better than 

R-410A, optimisation to HFC-32 is likely to result in better COP than R-410A and HCFC-22. Under 

high ambient temperatures the compressor discharge temperature can be very high, compromising 
May 2013 TEAP XXIV/7 Task Force Report 35

reliability of systems or demanding most costly injection technology. Costs of units are equivalent to 

R-410A and HCFC-22 in small units whilst costs of larger units are equivalent to ones with R-410A, 

but slightly higher than HCFC-22 due to higher operating pressure. Electric components of these 

units are unlikely to ignite HFC-32, but initial confirmation of it is required. 

One Japanese company commercialised mini-split products with HFC-32 in 2012 in Japan and in 

2013 in India. A few companies have recently showed prototypes in exhibitions. In conclusion HFC32 has a high potential to penetrate this market due to its balanced property in cost, energy efficiency, 

and safety.

Use of the L-20 blend is feasible in split ACs, for example, where HCFC-22 or R-407C are already 

used. Since L-20 has low flammability, the required charge of such units is unlikely to reach 

concentration that can be ignited (LFL) in the event of a leak. The efficiency is comparable to that of 

HCFC-22, although data has not been found for high ambient conditions. The cost implications 

should be comparable to that of HCFC-22 and R-407C although probably greater due to the 

refrigerant cost. In principle the main barrier is the flammability; however, guidelines in the form of 

international standards do not restrict their use in this type of equipment under most situations. 

Currently there is extensive testing and trialling ongoing and manufacturers in Japan, Korea and 

China are developing prototypes. 

It is also feasible to use the DR-5 blend in split ACs, for example, where R-410A is already used. 

Although DR-5 has low flammability, the required charge of such units is unlikely to reach 

concentration that can be ignited (LFL) in the event of a leak. The efficiency is comparable to that of 

R-410A, although data has not been found for high ambient conditions. The cost implications should 

be comparable to that of R-410A although somewhat greater due to the refrigerant cost. Again, the 

principle barrier is the flammability, however, guidelines in the form of international standards do not 

restrict their use in this type of equipment under most situations. Currently there is extensive testing 

and trialling ongoing and manufacturers in Japan and USA are developing prototypes.

3.6.3 Multi-split

A second type of non-ducted products are multi-split; essentially the same as a single split (as 

described in 3.6.2) but a single condensing unit may feed two or more indoor units (sometimes, up to 

50). Whilst dual indoor unit models may be used for residential applications, this category of split 

systems is more often used in commercial buildings. As with single splits, multi-splits also offer 

reversible (heating) options. Variable Refrigerant Flow (VRF) systems are a sub-category of the 

multi-split non-ducted air conditioning systems and are distinguished from regular multi-split systems 

by their ability to modulate the refrigerant flow in response to the system demand. VRF systems have 

capacities ranging from 10 kW to over 130 kW.

R-717 is never used in these systems due to limitations on its use in occupied spaces.

There are at least two manufacturers producing multi-split air conditioners using R-744. However, as 

with other system types described before, it is preferable where at least half of the demand is for 

heating. The same energy efficiency considerations as for other types of air conditioners also apply 

for multi-splits. As with single splits, the cost implication for multi-splits is greater than for selfcontained systems since site-installed pipework is required, more so than for single splits. The same 

barriers exist for R-744 multi-splits as with the other types of air conditioners above, however, for 

larger systems, an additional barrier can be that the use can be restricted due to the possibility of 

relatively large quantities of refrigerant being leaked into small occupied spaces resulting in acute 

toxicity effects to occupants. Introducing advanced safety features could help overcome this. It is 

expected that if not already, other manufacturers will be issuing R-744 multi-split systems for heating 

and cooling, although these will be aimed at temperature climates and will not be in wide scale use. 
36 May 2013 TEAP XXIV/7 Task Force Report

At least one manufacturer has developed a dual cooling/heating multi-split system but such systems 

are unsuitable for situations where the primary demand is for cooling. 

Although feasible in a minute proportion of situations, HCs are not used in these systems due to 

charge size limitations in occupied spaces. 

For R-407C and R-410A, all aspects are as with single split ACs. 

In principle, it is feasible to use L-41 in multi-split systems, for example, where R-410A is already 

used. It is likely that the efficiency is comparable to that of R-410A, although again there is no data 

found for high ambient conditions. The cost implications should be comparable to that of R-410A 

although slightly greater due to the refrigerant cost and additional features for handling flammability. 

In principle the main barrier is the flammability where guidelines in the form of international 

standards can currently introduce some restrictions to their use in this type of equipment. However, 

work is underway to enable the use more accessible. Currently there are no developments of L-41 

multi-splits reported. 

It is feasible to use HFC-32 in most types of multi-split ACs. The pressure loss of HFC-32 is lower 

than HCFC-22 and R-410A due to its smaller molar mass, higher pressure, and lower required 

circulating mass of refrigerant so it has a greater potential to be used in such systems from an energy 

efficiency viewpoint. The cost should be equivalent to R-410A and slightly higher than HCFC-22 due 

to high operating pressure. The concerns over implications over high discharge temperatures in high 

ambient temperatures are of a lesser concern in multi-split systems and compressor injection 

technology is less likely to have an observable cost impact. Especially components for large multisplits are close to the boundary to ignite, detailed tests are necessary. Since multi-split systems has 

the potential to release the entire charge to one of the many occupied spaces that the system serves it 

may generate a significant flammable cloud. However, it is proposed that the probability of rapid 

refrigerant release indoors is not so high so safety measures have to be established to minimise such 

concentrations. A risk assessment study for multi-split with A2L refrigerants is on-going in Japan. In 

conclusion the commercialisation of HFC-32 in this category seems to take a few years. 

In principle, it is feasible to use L-20 in multi-split systems, for example, where HCFC-22 or R-407C 

is already used. The efficiency is comparable to that of HCFC-22 and R-407C, although data is not 

found for high ambient conditions. The cost implications should be comparable to that of R-407C 

systems although slightly greater due to the refrigerant cost and additional features for handling 

flammability. In principle the main barrier is the flammability where guidelines in the form of 

international standards can currently introduce some restrictions to their use in this type of 

equipment. However, work is underway to enable the use more accessible. Currently there is no 

development work reported for multi-splits. 

In principle, it is feasible to use DR-5 in multi-split systems. Due to the characteristics being very 

close to those of HFC-32, the same observations can be made. Currently there is no development 

work reported for this type f equipment.

3.6.4 Split (ducted)

Ducted, split residential air conditioners are typically used where central forced-air heating systems 

necessitate the installation of a duct system that supplies air to each room of a residence or small 

zones within commercial or institutional buildings. A condensing unit (compressor/heat exchanger), 

placed outside the conditioned space, supplies refrigerant to one or more indoor coils (heat 

exchangers) installed within the duct system or air handler. Air in the conditioned space is cooled or 

heated by passing over the coil and is distributed to the conditioned spaces by the duct system. 

Systems can in principle be designed as reversible types, although for this category of ducted air 

conditioners it is done less frequently. Capacities range from 5 kW to 17.5 kW.
May 2013 TEAP XXIV/7 Task Force Report 37

R-717 is never used in these systems due to limitations on its use in occupied spaces and the small 

capacity and installation requirements would also mean that they are not competitive.

With R-744 the issues in ducted split systems are similar to those of single and multi-split systems. 

Although feasible in a small proportion of situations, HCs are not currently used in these systems due 

to charge size limitations in occupied spaces.

For R-407C and R-410A, all aspects are as with split ACs. 

As regards HFC-32, the L-20, the L-41 and the DR-5 blend , their application in ducted splits is 

feasible and comparable to that of multi-splits. 

In particular typical installation of ducted split includes small closet, attic, and such, so the rapid 

release can generate flammable concentration in a small space. Therefore special design features 

must be considered and are currently under development. Risk assessment studies have been carried 

out in the USA. The commercialisation of HFC-32 and the L-41 blend in this category is likely to 

take a few years.

Currently there is testing and trialling ongoing and manufacturers in Japan, Korea and China are 

developing prototypes for all of these substances. 

3.6.5 Ducted split commercial and non-split air conditioners

Ducted commercial air conditioners and heat pumps are manufactured in two forms: split system 

units which are matched with an indoor air handler/heat exchanger assembly and single packaged 

units which contain an integral fan and heat exchanger assembly which is connected by means of 

ducting to the air distribution system of the commercial structure. The majority of ducted commercial 

packaged air conditioners and heat pumps are mounted on the roof or outside on the ground of 

offices, shops, restaurants or institutional facilities. Multiple units containing one or more 

compressors are often used to condition the enclosed space of low-rise shopping centres, shops, 

schools or other moderate size commercial structures. Commercial ducted systems are offered in a 

wide range of capacities from around 10 kW to over 100 kW.

R-717 is never used in these systems due to limitations on its use in occupied spaces and the small 

capacity and installation requirements would also mean that they are not competitive

There are several companies within Europe that produce R-744 split ducted and rooftop systems, with 

a wide capacity range. As with other R-744 air conditioners, the efficiency at higher ambient 

temperatures of non-enhanced R-744 systems tends to be slightly reduced, although when systems are 

operated at lower ambient temperatures the efficiency is competitive with HCFC-22 and similar 

refrigerants. The cost effectiveness is similar for other types of R-744 air conditioners. 

Although feasible in a small proportion of situations, HCs are not widely used in direct systems due 

to charge size limitations in occupied spaces, although at least two companies are trialling systems.

For R-407C and R-410A, all aspects are as with split ACs. The application of HFC-32, the L-20, L41 or DR-5 blend in commercial ducted and rooftop systems is feasible and the issues are essentially 

the same as for ducted splits. 
38 May 2013 TEAP XXIV/7 Task Force Report

3.6.6 Hot water heating heat pumps

These are a category of heat pumps designed to heat domestic and other service hot water to 

temperatures between 55 and 90 °C. These operating temperatures must be considered when selecting 

the refrigerant. A HPWH consists of a water storage tank and a heat pump water heating unit and in 

some designs an additional heat exchanger. In the heat pump unit, water supplied from the storage 

tank or directly from the mains water supply is heated by the condenser (or, for transcritical cycles 

the gas cooler) and then returned to the storage tank. Stored hot water is supplied to each tapping 

point, in response to the demand. In order to obtain high water temperatures at low outdoor ambient 

temperatures, air to water heat pump systems can utilise a cascade refrigerating system with two 

different refrigerants.

R-717 is used fairly widely in capacities from 250 kW to very large/industrial-scale (>1 MW) heat 

pumps. Such systems are located outside or in special machinery rooms in order to handle the higher 

toxicity characteristics but also due to sound reduction. Yearly service and maintenance requirement 

demands the room to be accessible for qualified technicians and engineers. Systems are often used for 

district heating and cooling systems but also for process heating and cooling. The efficiency of R-717 

heat pumps is known to be very good (Stene, 2008), particularly since the critical point is very high 

compared to most other refrigerants. The cost effectiveness becomes favourable as the heating 

capacity approaches 250 kW, relative to HCFC-22.

As with R-717 systems in general, the main barriers are related to the minimal capacity required for 

cost-effectiveness and certain national regulation controlling installation. Also the perceived danger, 

true or not, is a barrier. Within Europe and North America, there is an increasing tendency to use R717 heat pumps, especially in industrial plants that are already familiar with R-717, although this is 

also commensurate with the increase in the use of heat pump technology anyway. For large 

commercial and industrial applications, R-717 is generally an attractive option and (neglecting 

national regulations) can normally be applied in most situations. The use of heat pumps is more 

restricted by subsidies to the energy sector than by the technology. In many countries the electricity is 

too expensive compared to cheap subsidised fossil fuels. 

Due to the high discharge superheat of R-744 and heat rejection at gliding temperatures, it provides a 

particular advantage when being used for hot water heating. As such a large number of manufacturers 

globally are producing domestic and small commercial sized hot water heating heat pumps using R744. Annual production of domestic sized systems is in the order of several million. The energy 

efficiency is high. It is also noted that higher ambient temperatures only provide energy advantages in 

such systems, enhancement technologies like ejectors are commonly used to further improve energy 

efficiency of these heat pump systems. If the cold side is applied for AC during hot water production 

a very high total COP’s are achieved. Generally, the efficiency that can be achieved by R-744 in hot 

water heaters is much higher than that of other refrigerants and therefore it is difficult to make a costeffectiveness comparison. The main barrier is the cost relative to that of conventional fossil fuel 

boilers. Hourly electricity rate supports R-744 heat pumps implemented in Smart–grids, so that heat 

is produced when electricity is cheap. Continued growth for R-744 hot water heaters, particularly in 

Asia is expected and to some extent in Europe. It is evident that R-744 is one of the most suitable 

alternatives for these types of heat pumps. 

Although HCs are viable alternatives for use in hot water heat pumps, they are not in common use.

For R-407C and R-410A, all aspects are as with split ACs. R-410A is commonly used in such 

systems in both Article 5 and non-Article 5 countries. HFC-134a is also used in such systems, 

although due to its lower pressure the systems are less compact and as such incur higher costs. 

It is feasible to use HFC-32 in hot water heat pumps, for example, where R-410A is already used. The 

flammability and cost implications associated with the use of HFC-32 in this application are similar 
May 2013 TEAP XXIV/7 Task Force Report 39

to that of single split systems. The theoretical cycle efficiency is better than R-410A, but slightly less 

than HCFC-22, whilst the pressure is 1.5 times higher than HCFC-22 and equivalent to R-410A. 

Discharge temperature is higher at high pressure ratio operation, so application in this category 

requires more rapid and accurate control of temperatures. It is not known whether any manufacturers 

are developing HFC-32 based hot water heat pumps commercially. 

It is feasible to use the L-20 blend in hot water heat pumps, for example, where HCFC-22 is already 

used. The flammability implications are the same as with HFC-32. 

HFC-1234ze(E) can also be used in HWHPs that can be used in existing HFC-134a technologies with 

minor modifications (compressor sizing). Due to its lower flammability classification, the safety 

implications are comparable to those of HFC-32 and L-20 blend applications. Otherwise the 

application characteristics are close to HFC-134a except that greater incremental costs would be 

incurred as a result of less compact systems (due to lower pressure) and higher refrigerant price. No 

information about real performance or whether any manufacturers are developing systems using this 

option was found.

N-13 is a refrigerant blend that can be used in existing HFC-134a technologies with minor 

modifications (compressor sizing). The various implications with using this blend would be the same 

as those with HFC-1234ze(E) except that the flammability issues would not apply. No information 

about real performance or whether any manufacturers are developing systems using this option was 

found.

3.6.7 Space heating heat pumps

Comfort heating heats the room by heating water for distribution to an air handling unit, radiator or 

under floor panel. The required water temperature depend on the types of emitter, low temperature 

application ranging from 25 to 35 °C for under floor heating, for moderate temperature application 

such as air handling units around 45 °C, for high temperature application such as radiant heating 55 

to 60 °C, and for very high temperature application, as high as 65 to 80 °C, such as for the fossil fuel 

boiler replacement market. The required warm water temperature affects the selection of refrigerant. 

Heat pump systems are more efficient at lower sink temperatures, but each product must fulfil the 

required operating temperature.

R-717 is used fairly widely in systems from 250 kW up to very large/industrial-scale (>1 MW) heat 

pumps. Such systems are located outside or in special machinery rooms in order to handle the higher 

toxicity characteristics and giving the necessary space around the system and giving some sound 

reduction. Systems are normally designed with hot water heating function. The efficiency of R-717 

heat pumps is known to be very good (Stene, 2008). The cost effectiveness becomes favourable as the 

heating capacity approaches 250 kW, relative to HCFC-22. The return on investment of less than 2 

years has been reported. As with R-717 systems in general, the main barriers are related to the 

minimal capacity required for cost-effectiveness and certain national regulation controlling 

installation. Within Europe and North America, there is an increasing tendency to use R-717 heat 

pumps, although this is also commensurate with the increase in the use of heat pump technology 

anyway. For large commercial and industrial applications, R-717 is generally an attractive option and 

(neglecting national regulations) can normally be applied in most situations. 

R-744 is used in space heating heat pumps, but not as widespread as it is for hot water heating. This 

is mainly due to the efficiency advantages declining as the output water temperature lowers. 

However, numerous manufacturers (with thermodynamic knowledge) are producing such systems, 

although mainly in combination with hot water heating systems where dual temperature levels are 

needed. The relative efficiency of R-744 space heating heat pumps is sensitive to many design 

considerations, but in general, where the supply air temperature is above 40°C, R-744 provides 

efficiency benefits (Richter et al, 2001). This is particularly of interest in systems that, for example, 
40 May 2013 TEAP XXIV/7 Task Force Report

utilise radiators (Khoury, 2012). It is also noted that higher ambient temperatures only provide energy 

advantages in such systems. However, R-744 heat pumps can operate at very low ambient 

temperatures with acceptable COP’s. Water-to-water or air-to-water systems, which are factory 

sealed arrangements can be comparatively compact and therefore incur reduced material costs. 

However, the addition of certain components needed to improve efficiency can result in additional 

cost compared to conventional HCFC-22 systems. Whilst the market penetration is low, the main 

barrier is cost. However, it is anticipated that as more products enter the market such heat pumps 

(Smart Grid applicable) will become more competitive. Within Asia and Europe more manufacturers 

are producing space water and dual temperature level heat pumps using R-744 and it is expected that 

this trend will continue. The use of R-744 in space heating heat pumps is less straight forwards than 

for hot water heating, but as the technology develops efficiencies are becoming more competitive and 

more products are entering the market. 

The share of heat demanded for hot water and space heating also plays a decisive role in determining 

competitive options. According to simulation results of R-744-heat pumps in low energy houses in 

Norway (in the context of the IEA Heat Pump Centre project on the “economical heating and cooling 

systems for low energy houses”), R-744 heat pumps for combined space heating and domestic hot 

water outperforms a conventional (HFC) heat pump if the share of domestic hot water is at least 60%. 

Using improved R-744 compressor and ejector technology the break-even point is shifted to a 

domestic hot water share of 50% (Annex32). Moreover, with the trend towards “near Zero Energy” 

buildings that have minimal needs for space heating, hot water heating is expected to account for 

most of the heat demand in future new buildings.

Historically, HCs, particularly HC-290, had been used widely in Europe for small (domestic) heat 

pumps, although the introduction of the EU Pressure Equipment Directive resulted in a decline in its 

use due to compressor availability. However, in principle their continued use is not otherwise limited 

and now a number of manufacturers have products on the market. Such systems are located outside or 

in special ventilated enclosures. In addition, there are also large commercial-sized heat pumps using 

HC-290 and HC-1270 being sold within Europe. The other HC blends are not known to be currently 

in use. The efficiency of HC-290 and HC-1270 in heat pumps is known to be very good (Palm, 2005). 

The cost effectiveness in general is favourable, although sensitive to the design of safety features. As 

with the use of HCs in general, the main barriers are related to the safety guidelines. For systems with 

parts which are located in occupied spaces, the charge size can be prohibitively limited, whereas for 

systems locate outside or in ventilated enclosures there are no major restrictions. Again, it is 

necessary to ensure that technicians are appropriately trained to handle flammability. Within Europe 

there is steady use of HCs in heat pumps, with an increase for commercial sized systems. Similarly, 

research and development is also continuing. In conclusion for small and commercial sized 

applications, HCs are viable alternatives for space heating heat pumps. 

Both R-407C and R-410A are widely used in these heat pumps. All aspects apply as with split ACs. 

It is feasible to use HFC-32 and the L-20 blend in space heating heat pumps, as with hot water heat 

pumps. Their efficiency implications are comparable and the cost implications similar to those of hot 

water heat pumps. If refrigerant water heat exchanger is located in outside occupancy, the safety issue 

is easier to solve. It is not known whether any manufacturers are developing HFC-32 or L-20 hot 

water heat pumps commercially. 

3.7 Chillers

Comfort air conditioning in large commercial buildings and building complexes (including hotels, 

offices, hospitals, universities, and other central systems) is commonly provided by chillers. They 

cool water or other heat transfer fluid (such as a water-antifreeze mixture) that is pumped through 

heat exchangers in air handlers or fan-coil units for cooling and dehumidifying the air. Chillers also 

are used for process cooling in commercial and industrial facilities such as data processing and 
May 2013 TEAP XXIV/7 Task Force Report 41

communication centres, electronics fabrication, precision machining, and moulding. District cooling 

is another application that provides air conditioning to multiple buildings through a large chilled 

water distribution system, as opposed to air conditioning each building with separate systems. Chiller 

operation is driven by cooling requirements but provision for heat recovery may be included. The 

principal components of a vapour-compression chiller are one or more compressors driven by electric 

motors (or less commonly, engines or turbines using open drive compressors), a liquid cooler 

(evaporator), a condenser, a refrigerant, a lubrication system, a refrigerant expansion and flow control 

device, a power handling device (commonly a starter or variable speed electronic drive), and a 

control and protection unit. The complete chiller usually is factory assembled and tested; no 

connection between refrigerant-containing parts is required on site by the installer except for very 

large chillers which may be shipped as multiple assemblies. Installation is accomplished by 

connection to water, power, and control systems. Vapour-compression chillers are identified by the 

type of compressor they employ; centrifugal or positive displacement compressors. Chillers can be 

further divided according to their condenser heat exchanger type, the most common being watercooled or air-cooled and less common are evaporatively-cooled condensers and dry coolers.

3.7.1 Positive displacement chillers

Positive displacement chillers include those with reciprocating piston, screw, and scroll compressors. 

Smaller capacity models tends to be air cooled, which accounts for the majority of chillers, but as the 

capacity increases above around 350 kW water-cooled models become more frequent. Capacities can 

exceed several MWs. 

R-717 is used fairly widely in reciprocating and screw chillers for process refrigeration, food storage 

facilities and air conditioning. Chillers must be located outside or in special machinery rooms in 

order to handle the higher toxicity and flammability characteristics. The sound levels from this kind 

of high capacity systems also require a sound limiting room. This type of chillers has been widely 

used in airports and similar high capacity areas. The efficiency of R-717 is high for chillers in both 

medium and high temperature applications (RTOC, 2010). The cost effectiveness becomes 

favourable as the cooling capacity approaches 200 kW and up to about 6 MW, relative to HCFC-22. 

The barriers for chillers are consistent with R-717 systems in general. However R-717 is more 

accepted in industrial and large capacity systems. The regulations have been successfully in place for 

many years. However, there are concerns of possible changes to certain standards. Within Europe and 

North America, there is an increasing tendency to use R-717 chillers, although the total number is 

still small compared to HCFC-22 and HFC machines.

For large commercial and industrial applications, R-717 is generally an attractive option and 

(neglecting national regulations) can normally be applied in most situations. 

R-744 is now used in reciprocating chillers by many different manufacturers. The capacities range to 

up to several hundred kW and cover both air conditioning and refrigeration applications. As with 

other types of systems, the efficiency is compromised with increasing ambient temperatures. As such 

water-cooled chillers are of more interest in countries with hotter climates. However, where chillers 

are also used for heating purposes, seasonal efficiency benefits can be achieved. With knowledge in 

thermodynamics and system understanding, new concepts are under development, which are more 

energy efficient (SPF) compared to current HCFC and HFC systems. The cost of small capacity R744 chillers is higher than that of HCFC-22 systems due to the piping and component design 

necessary to handle higher pressures, however, at capacities of around one hundred kW the relative 

cost approaches parity. Consistent with other applications, the main barrier for R-744 chillers is the 

poorer efficiency in climates with consistently higher ambient temperatures. At least within Europe, 

there is an increase in the output of R-744 positive displacement chillers. R-744 chillers are widely 

available and are increasingly being used for both air conditioning and refrigeration applications. 

However, due to efficiency constraints their use if preferred for cooler climates. 
42 May 2013 TEAP XXIV/7 Task Force Report

Both HC-290 and HC-1270 are produced by a number of manufacturers in Europe and some 

countries in other regions. Historically they have been used widely in petro-chemical industry but are 

now being applied for air conditioning, food storage and process refrigeration. The majority of 

chillers are reciprocating and screw type. The use of the various HC blends appears not to be 

currently used in chillers. The efficiency of HC-290 and HC-1270 is the same or greater than HCFC22 in both medium and high temperature applications. Most manufacturers report that their HC 

models have higher COP than their equivalent HCFC/HFC models. Generally the cost implications of 

applying HCs in chillers are negligible, although the incremental cost depends on how safety 

measures are handled. 

There are certain barriers with HCs, depending upon the chiller configuration. For air-cooled or 

water-cooled chillers that are positioned in the open air (within certain separation distances), there 

are no significant hindrances. For systems installed in machinery rooms, electrical equipment must be 

suitable for hazardous areas and gas detection with emergency ventilation is required (although in 

fact this should be applied to any refrigerant). The main barrier is that unless properly designed with 

additional safety measures, HC chillers cannot be used below ground level (such as in cellars). In 

addition, technicians must be suitably trained. At least within Europe and some other regions, there is 

an increasing tendency to use HCs in chillers, although the total number is still small compared to 

HCFC-22 and HFC machines. For commercial and industrial applications, HCs are generally a viable, 

efficient cost effective alternative except for situations that require installation below ground level.

HFC-1234ze(E) is suitable for chillers and has been trialled in systems in Europe. When used in with 

reciprocating, scroll or screw type of compressors, this refrigerant produces efficiency levels 

comparable to HFC-134a. When used in scroll and reciprocating compressors, the same POE 

lubricant oil can be used. For screw compressors, the same type of oil (POE) can be used but the 

viscosity grade should be verified with the equipment manufacturer. Although HFC-1234ze(E) is a 

low flammability refrigerant, there are guidelines and standards available which provide guidance on 

safe installation, at least for outdoor locations. HFC-1234ze(E) is a refrigerant that can be used in 

existing HFC-134a technologies with minor modifications (compressor sizing). Due to its high 

critical temperature, it will perform very well in warm climates. 

Both R-407C and R-410A are widely used in positive displacement chillers and all aspects are as 

with split and other types of ACs and heat pumps.

HFC-134a is used widely in various capacity reciprocating, scroll and screw chillers. The design of 

the system components is slightly different from HCFC-22 (and R-407C and R-410A) because of the 

lower operating pressure. Because it is a class A1 refrigerant (lower toxicity, non-flammable) there 

are no significant safety implications concerning its use. The energy efficiency is similar to that of 

HCFC-22, although higher COPs can be achieved if the system is carefully designed. Generally 

systems are marginally more costly than HCFC-22 because they are less compact. Since HFC-134a is 

well established, it is evident that there are no significant barriers to its use. Currently, HFC-134a use 

in chillers is neither declining nor increasing significantly. 

The L-20 blend is a replacement for HCFC-22 or R-407C in positive displacement chillers that 

employ reciprocating or scroll compressor technologies. No major modifications are needed as its 

pressures are similar to HCFC-22 and R-407C. Although L-20 is a low flammability refrigerant, there 

are guidelines and standards available which provide guidance on safe installation. These are the 

same as those for the flammability aspects of R-717 for both chiller design and machinery room 

requirements. It is not known what the real performance implications are relative to HCFC-22 and 

similarly it is not known whether any manufacturers are developing equipment with this refrigerant.

The N-13 blend is feasible for use in positive displacement chillers and can be used in existing HFC134a technologies with minor modifications (compressor sizing). When used with reciprocating, 
May 2013 TEAP XXIV/7 Task Force Report 43

scroll or screw type of compressors, this refrigerant produces efficiency levels comparable to HFC134a. When used in scroll and reciprocating compressors, the same POE lubricant oil can be used. 

For screw compressors, the same type of oil (POE) can be used but the viscosity grade should be 

verified with the equipment manufacturer. Due to its high critical temperature, it will perform very 

well in warm climates. Testing and trials are being carried out in reciprocating and screw chillers and 

prototypes are under development by manufacturers in Europe and the USA.

The XP-10 blend is feasible for use in positive displacement chillers as is the N-13 blend in systems 

based on HFC-134a architecture with only minor modifications (primarily compressor sizing). When 

used in with reciprocating or scroll compressors, this refrigerant produces efficiency levels 

comparable to HFC-134a. When used in scroll and reciprocating compressors, the same POE 

lubricant oil can be used. It is not known what the real performance implications are relative to HFC134a chiller and similarly it is not known whether any manufacturers are developing equipment with 

this refrigerant. 

It is feasible to use HFC-32 in positive displacement chillers, for example, where R-410A is already 

used, provided that the flammability characteristics are handled appropriately. The energy efficiency 

is equivalent or slightly better than HCFC-22 and R-410A due to its better heat transfer properties. 

Larger capacity per compressor swept volume is beneficial for chiller with large scroll compressors. 

On the contrary, it is disadvantage for ones with small screw compressors. Better heat transfer 

properties are beneficial for chillers as they are limiting factor in water heat exchangers. Lower 

pressure drop in air cooled heat exchanger is a merit of HFC-32 for large air cooled chillers. 

Flammability requirements for machinery rooms are comparable to those for R-717. Electric 

switching components for large chillers have potential to ignite HFC-32, but ventilation in machinery 

room is mandatory to prevent flammable concentration. So, requirements for such switching 

components are not established for A2L specifically. A risk assessment study for chillers with A2L 

refrigerants is on-going in Japan. HFC-32 may be employed for small chillers, but large ones will 

probably employ the HFC-1234 series substance mainly. 

3.7.2 Centrifugal chillers 

These are chillers which employ centrifugal compressors with one, two, and three compression 

stages. Centrifugal compressors most commonly are used in water cooled systems, especially those 

with capacities exceeding 1 MW. Air cooled centrifugal chillers are less common. They are generally 

used for air conditioning applications in very large buildings and for district cooling.

R-717 is seldom used in centrifugal chillers, although products are available and installed for certain 

applications. R-744 is not currently used in centrifugal chillers. 

HCs are used to a limited extent in centrifugal chillers typically within the petro-chemical industries 

where hazardous area protection is already in common use. However, they are not generally 

considered as alternatives for replacement of HCFC centrifugal chillers. 

Where it concerns HFC-1234ze(E) use in centrifugal compressors, this refrigerant produces 

efficiency levels slightly better than HFC-134a. Since most of these chillers are located outside, the 

safety concerns are minor, but nevertheless, the same as for positive displacement chillers. Due to its 

high critical temperature, it will perform very well in warm climates. There are already several 

chillers using this refrigerant currently in use. 

HFC-1233zd(E) can replace HCFC-123 (a low-GWP HCFC) in low pressure centrifugal chillers. 

When used in centrifugal compressors, this refrigerant produces efficiency levels slightly better than 

HCFC-123, allowing the design of systems with high energy efficiency. As a new molecule, this 

refrigerant has a higher cost than HCFC-123. Still this cost would be moderate and will have a 

reasonable payback period due to the high energy efficiency of the refrigerant which lowers the 
44 May 2013 TEAP XXIV/7 Task Force Report

expenses for end users. This refrigerant is currently under evaluation by manufacturers. Most of the 

information available has been presented in public forums for refrigerants, solvents and blowing 

agents applications.

HFC-134a is used widely in various capacities of centrifugal chillers. The design of the system 

components is slightly different from HCFC-123 because of the higher operating pressure. Because it 

is a class A1 refrigerant (lower toxicity, non-flammable) there are no significant safety implications 

concerning its use. The energy efficiency is marginally lower than that of HCFC-123. Generally, 

systems are comparable to HCFC-123. Since HFC-134a is well established, it is evident that there are 

no significant barriers to its use. Currently, the HFC-134a use in chillers is neither declining nor 

increasing significantly. 

It is feasible to use HFC-32 in centrifugal chillers, provided that the flammability aspects are handled 

appropriately. The thermal conductivity is basically better than R-410A, but due to high internal leak 

flow and high pressure difference with smaller molar mass, the compressor efficiency is not as high 

as one with HFC-134a or other low pressure refrigerants such as HFC-1234ze. In addition, boiling 

volume is not as high as HFC-134a and HFC-1234ze, so use of HFC-32 will result in a larger 

evaporator. Consequently, the use of HFC-32 is very limited and negligible in general centrifugal 

chillers.

3.8 Mobile air conditioning 

Cars and truck cabins used the same refrigerants CFC-12 from the 50’s to 1992; then it was replaced 

by HFC-134a, which is still in use everywhere, even if the European ban should have begun in 2012. 

Depending on the country, the preferred option is to keep going with HFC-134a or to shift to HFC1234yf, but the delayed wide market availability of this refrigerant seems to slow down the shift and 

other options are to be reconsidered for the future, mainly CO2.

For city or long haul buses and also trains cabins, choices have always been more open: CFC-12 and 

HCFC-22, and then followed by HFC-134a and R-407C. In Germany some buses are operated on R744 and the alternative air cycle (Brayton-Joule) technology has been installed on more than 100 ICE 

trains.

3.8.1 Cars 

The car industry has organized its global production (more than 60 million vehicles in 2012) with a 

high level of specialization. Air-conditioning systems are supplied by tier 1 suppliers that 

manufacture the complete AC system: heating, cooling and ventilation, and the control system. The 

car companies organize a strong competition among their suppliers and the consequence is that the 

best refrigerant is a single, unique, and global one. The refrigerant has to be a commodity. The 

history shows that HFC-134a has been the only refrigerant chosen by all car companies to replace 

CFC-12, and now the expectation is still to have a single refrigerant worldwide.

As previously said, R-744 has seen a number of developments from 2000 to 2010 and several 

manufacturers reportedly reached “implementation readiness”. Tier 1 suppliers as well as car makers 

have developed several technical options with R-744: internal heat exchangers, external control 

compressors, micro-channel gas coolers, and evaporators dedicated to R-744. New hoses with ultralow permeation have been developed. In 2013 there has been a renewed interest in R-744 MAC, with 

several German OEMs announcing their intention to develop such systems (see e.g. www.R744.com, 

2013) and prefer to stay with HFC-134a until R-744 will have been commercialised.

A number of tests have been performed in hot and cold climates. R-744 has been demonstrated to be 

as efficient as best in class HFC-134a system, except when the vehicle is idling and under very hot 

conditions.
May 2013 TEAP XXIV/7 Task Force Report 45

The main barrier for R-744 systems has been their cost . Even for series of at least 150,000 R-744 AC 

systems per year, costs were at least doubled compared to the baseline. Another barrier has been that 

the solution was not a global one, requiring two AC systems (R-744 and HFC-134a) to be mounted 

on the same assembly line. Two other barrier issues were related to reliability and servicing:

 the shaft of the open-type compressor was a highly potential leak-prone component with no 

lessons learned at large scale 

 R-744 servicing requires special training and also specific equipment requiring to develop a 

new world-wide servicing for global car companies

For electric cars or hybrid cars with high voltage available, hermetic compressors can be used.

Consequently, the shaft seal issue disappears, which makes the R-744 MAC system reliable.

Nevertheless the cost issue remains. In summary, R-744 is technically difficult and creates a barrier 

in terms of technical offer; only the best in class Tier 1 companies have been able to develop efficient 

R-744 compressors.

Hydrocarbons are efficient refrigerants and as other refrigerants have to be chosen according to their 

condensing and evaporating pressures. When safety is not taken into account, additional costs are 

limited. Safety is a clear and strong barrier against the use of HCs in cars. During the competition 

between R-744 and HFC-152a, HFC-152a received a very strong opposition from the German car 

makers that are vehemently against any use of flammable refrigerants in cars. 

The sales of HC blends for car AC systems will continue in some countries but do not constitute a 

global trend and will not receive the support of any car company. In conclusion, HCs are not a global 

option for car AC systems and will remain marginal.

Because of the flammability issue, new low-GWP non-flammable blends such as Blend H and DP-1 

have been proposed by chemical manufacturers as of 2003; Blend-H failed for decomposition issues 

and DP-1 for toxicity of one of its component.

A major step forward was the proposal and introduction of HFC-1234yf. Even though slightly 

flammable, its thermodynamic properties are very close to those of HFC-134a and so the adaptation 

is easy without significant constraints due to its very moderate flammability. 

Many tests have been performed and some adaptations on the suction line diameter and on the heatexchanger tuning have been done in order to match HFC-134a energy performances. Developments 

have been made and no significant differences are measured compared to the best in class HFC-134a 

systems.

The cost is announced to be 5 to 7 times more than that of HFC-134a systems, but it is known that, in 

the chemical industries, prices could vary from 1 to 10 depending on the sales volume.

A current barrier is related to patent issues between the chemical manufacturers; the patent has been 

invalidated in both US and EU patent courts and is under appeal by the manufacturer Honeywell. As 

a result, the mass-production of low GWP HFC systems is being delayed. HFC-1234yf with its low 

GWP of 4 is seen as the solution for the car industry, even if the current low availability creates 

uncertainties, especially in Europe where the regulation requires refrigerants with a GWP < 150 for 

new cars since 2011. The change from HFC-134a to HFC-1234yf seems to be one of the likely 

options because the car industry favours global options for AC systems. The preference of companies 

outside Germany would be to change to HFC-1234yf, because there are too many barriers perceived 

to the introduction of R-744, in particular related to safety, compressor durability and leak testing. It 

is also supported by LCCP analysis, which shows that HFC-1234yf would be superior to R-744 for 

most ambient temperatures. It can be mentioned that HFC-1234yf is currently available to some 

extent and the first cars using this refrigerant are therefore in production now.
46 May 2013 TEAP XXIV/7 Task Force Report

HFC-134a is currently the only refrigerant in use except the refilling of existing AC systems with HC 

blends. Due to the absence of mass-produced HFC-1234yf, even in Europe HFC-134a is currently 

charged in new AC systems. HFC-134a AC systems are the bench mark technology for all 

alternatives. The cost is also the reference for mass produced AC systems with a strong competition 

among Tier 1 suppliers. Obviously the only barrier is its GWP. It is likely that HFC-134a will be 

replaced under different schedules in the various world regions.

3.8.2 Public transport

AC systems of trains and buses are similar and are produced in small series of some hundreds per 

year. The cooling capacities vary from 10 to 35 kW depending on the size of the bus or the train car.

Due to the small market of this application, technologies in use are coming from stationary airconditioning industry for heat exchangers. For buses, compressors are open-type compressors driven 

by the engine as for the car AC system. For trains, compressors are electrically-driven hermetic 

compressors. So the refrigerant choice could be different for those applications.

Carbon dioxide has been developed in Germany since 1996 by one company and the total fleet is 

about 50 city buses. In moderate climates, R-744 performs well and lessons learned from several 

years of experiences do not show significant troubleshooting. Another German manufacturer 

proposes and sells R-744 based AC systems for trains. The energy efficiency seems to be in the range 

for the German climate conditions. For hot climates, the energy efficiency is lower at equal design 

efforts. The main barrier is related to cost, design habits and also sophisticated designs for hot 

climates. R-744 systems, developed for refrigerated transport by companies manufacturing also AC 

systems for buses and trains, may trigger the development of R-744 systems for buses and trains.

In conclusion, AC systems for buses and trains are a niche application. New developments with R744 will be a consequence of developments in larger market application and regulatory constraints.

HCs are not applicable in trains and buses based on safety issues for common transportation.

The HFC-1234yf development for car AC systems will have direct consequences for buses and trains 

cars AC systems operating currently with HFC-134a. The shift can be done based on first lessons 

learned in the car industry. For train AC systems operating with R-407C, new blends including HFC1234yf or HFC-1234ze could be proposed in the near future.

As mentioned for car AC systems, the energy efficiency can be as good as the reference line with 

HFC-134a, based on simple adaptations taking into account thermodynamic properties of HFC1234yf. The refrigerant cost, although greater than the usual price, is not a strong barrier, because its 

cost represents less than 1% of the total cost of those AC systems. The current barrier is related to the 

fact that no current regulation constraints exist. The change from HFC-134a to HFC-1234yf is a 

relatively easy option, as well as the possible shift from R-407C to new low GWP blends.

Air systems based on the reverse Brayton-Joule cycle with air compressors and turbines are the 

standard system for airplane AC systems. The difference between airplanes and trains is the outdoor 

temperatures (-50°C for airplanes). The efficiency of air systems is relatively poor and intrinsically 

lower compared to vapour compression systems. For hot outdoor temperatures, the cooling capacity 

is decreasing rapidly. During the summer of 2010, several ICE trains equipped with AC air systems 

were not able to provide sufficient cooling in Germany, showing the limit of a design based on fair 

weather. For moderate climates, air systems are possible. The advantage is the absence of refrigerant; 

the drawback is the limited cooling capacity for high outdoor temperatures.

The two dominant refrigerants are currently HFC-134a and R-407C in developed countries and HFC134a and HCFC-22 in developing countries. R-407C is often chosen for train cars due to the 

necessary compactness of the AC system to be integrated in the roof of the train car. Barriers are 
May 2013 TEAP XXIV/7 Task Force Report 47

based on the GWP of those refrigerants even if those applications could be exempted of using lowGWP refrigerants for some years in Europe. In the next 10 years R-407C is expected to be replaced 

by all the different alternatives previously mentioned. 

The current HFCs could be used longer in those niche applications, the shift from high-GWP 

refrigerants to alternatives will be related to the overall evolutions in AC systems.

3.9 Reduction of negative environmental impact due to amounts that could have been 

or could be avoided

As mentioned in section 2.4, the most transparent approach for investigating “amounts avoided” 

would be to investigate the environmental impact of certain refrigerants or chemical choices, 

compared to a certain baseline. As can be seen in chapter 4 under foams and its subsectors this is 

feasible. Consumption is then seen as potential emissions. Domestic refrigeration can be compared to 

PUR appliance foam. In the case of domestic refrigeration a consumption could be assumed as 

baseline or as consumption profile over the period 1990-2020 using the original chemical (CFC-12), 

since consumption is rather straightforward and the domestic refrigeration sector is not significantly 

impacted by servicing, maintenance and safety concerns, as with some the other sectors of 

refrigeration and air conditioning. Particularly considering a baseline for CFC-12 up to the year 2020 

in domestic refrigerator applications makes the negative environmental impact decrease (or the 

smallest negative environmental impact) by the selection of the two available options very clear. It is 

obvious in this case that a large step is made by the conversion from CFC-12 to HFC-134a, both in 

ODP and in GWP (climate) terms. Use of the hydrocarbon option HC-600a reduces the negative 

environmental impact even further, but compared to the first step from CFCs to HFCs (when 85% of 

the reduction in tonnes CO2 equivalent can be made), a further reduction (to hydrocarbons) can at 

maximum be another 15% of the baseline, as implied by the respective GWPs of the refrigerants.

Assuming a global consumption of 25,000 tonnes annually for the period 2010-2015, the use of HFC134a (compared to CFC-12) would yield a lower negative environmental impact of 230 Mt CO2-eq. 

per year; the use of HC-600a would add another 33 Mt CO2-eq. annually. In practice, the entire 

global domestic refrigeration has been converted, with about 50% to HFC-134a, the rest to HC600a. So the conversion of all now (2013) remaining HFC-134a to HC-600a would yield a saving of 

about 17 Mt CO2-eq. annually. 

It would be desirable if one could make a similar exercise for other sectors in refrigeration and air 

conditioning. This could be possible, in principle, by assuming a baseline of HCFCs starting in the 

20th century (1990) and going to 2020-2030 following a BAU trend. Other cases would be the 

consideration of only R-404A or R-410A starting in the 20th century (i.e., hypothetically in 1990) 

and simply proceeding into the future following the BAU scenario, or mixtures of HFC-32 with low 

GWP HFCs, other blends or simply hydrocarbons (HC-290 or HC-1270).

Whereas this kind of consideration gives insight in the case of domestic refrigeration and similar 

other uses that do not have to deal with servicing etc., the question in the case of many other RAC 

sectors where refrigerant handling and large charge sizes of refrigerant are involved , is whether a 

consideration of a sole replacement with, e.g., R-410A or a sole replacement with, e.g., hydrocarbon 

in making selections early has any value for common practice. This in particular since the 

considerations of low GWP cases as of 1990 (or even before) would yield a picture of a very low 

environmental impact in manufacture and in service throughout the decades, which is far from the 

current reality.

Two issues are important here:

 the fact that one would assume low GWP options (or others) to start at a very early phase, 

would also imply that regulatory decisions and costs considerations how to deal with 
48 May 2013 TEAP XXIV/7 Task Force Report

flammability issues, would have been resolved in all sub-sectors of RAC, which could have led 

to a completely different reality in a given year, far from the usual discussion on conversions 

and retrofits to reduce the need for common refrigerants (such as HCFCs, and also HFCs at 

present).

 the fact that a change from a refrigerant such as HCFC-22 to a certain other refrigerant or 

blends of refrigerants would occur in a given year, does not mean that the negative 

environmental impact would have much to do with the impact of the new refrigerant to which 

one has converted (to a certain degree) in new manufacture. For 10-15 years, the servicing 

needs for the “old” refrigerant (which are in the order of 60-80% in the total in an equilibrium 

scenario) will play a substantive role in the total negative environmental impact, before that the 

change to new refrigerants will be clearly visible. This of course will depend on the economic 

growth (the growth in the numbers of equipment), the percentage of (the new) refrigerant that 

will take over in manufacture, and the lifetime of the average equipment.

As an example, assuming that a certain group of countries is completely dependent on a certain 

chemical (i.e., HCFC-22), with 80% of the total consumption of say, 1,000,000 tonnes per year, used 

for servicing, it means that 200,000 tonnes per year would be used in new manufacture. A change of 

100% in a given year to a certain refrigerant or blend with a negligible GWP means that one would 

avoid 200,000 tonnes of HCFCs in that year, and servicing amounts of HCFC-22 for the equipment 

that has not been manufactured in that year during future years, i.e., for a 15 years lifetime of the 

equipment it would be something like 2,400,000 tonnes over a period of 15 years, due to a conversion 

of 200,000 tonnes in one first year.

However, financial constraints will flatten the profile of the introduction of new technologies in new 

manufacture, and a conversion of 5-10% of the total per year would be a reasonable amount to 

assume as the maximum achievable (depending upon the size of the sector and distribution of main 

manufacturers). This implies that, after a given year when a decision would have been made to 

convert 10% of the original HCFC based equipment to an alternative with a low environmental 

impact (with the original HCFC consumption at 1,000,000 tonnes), the HCFC consumption with a 

new (low GWP) alternative would be 180,000 tonnes for new manufacture. The amount that can be 

avoided in servicing would be 16,000 tonnes (being 80% of the amount of 20,000 tonnes that had 

been converted). The total amount avoided in the year after conversion would then be 36,000 tonnes 

(of which 20,000 tonnes due to the conversion in manufacture).

Two years of each 10% conversion would lead to a reduction of slightly more than 10% in total 

(HCFC) consumption, or in the case of a low GWP alternative, to the same reduction of the negative 

environmental impact in climate terms. In this case one would have avoided 100,000 tonnes in a 

given year, and dependent on the penetration rate of the alternative, once could calculate all kinds of 

consequences over the period 2015-2030. It is believed that forecasting for the future 15 years is 

rather uncertain. The above therefore just serves as a first example.

In order to demonstrate how difficult the reality is and how consequences of decisions in 2013-2015 

can be deducted, an example from commercial refrigeration is given here. One could assume a certain 

HCFC baseline in a given year in the past. At a certain stage HFCs as well as the blend R-404A (with 

a GWP more than twice that of HCFC-22) gradually take over. This implies that in the period 2000-

2012 one has different types of profiles for the consumption of the different refrigerants (with each 

having certain servicing percentages in their total consumption). The negative environmental impact 

has considerably increased due to the introduction of, in particular, R-404A. As of a given stage after 

the year 2010, new alternatives enter the market in large quantities or expand their share 

considerably, from having “HCFC-22 level” GWPs, to lower GWPs (several blends), to negligible 

ones (in the case of ammonia, carbon dioxide etc.). 
May 2013 TEAP XXIV/7 Task Force Report 49

If the HCFC-22 BAU curve for consumption is declining, whilst the R-404A curve is increasing over 

the years, with each of them having considerable impacts on the total via the servicing amounts, the 

following question comes up. The question is what the introduction of 5-10% in a given year of 

blends or low GWP refrigerants in new manufacture would mean. It would definitely imply a 

substantial amount if one would look at the consumption of HCFC-22 it would replace, but it would 

not mean anything, rather, it would not be visible if the R-404A consumption would increase due to 

an increasing equipment base and further increasing servicing amounts. The question then is in how 

far a consideration or study of separate HCFC-22, R-404A and low GWP blend consumption curves 

make sense. If one would look at the consequences for the negative environmental impact, the 

decision to convert 5-10% of the equipment may not be visible in the environmental impact, even 

when it would be there, due to much larger effects of the existing capacities and servicing 

(particularly in the case of high GWP refrigerants). In summary, the answer to the question ”what 

could be avoided”, the calculation of the “avoidance potential” (the forward looking question), would 

actually be a quite complicated one and would ask for an extensive analysis. 

Nevertheless, in order to give an impression of the order of magnitude of the reduction in negative 

environmental impact, and then essentially in reduction of potential GWP emissions in Mt CO2-eq.) 

Table 3.1 below gives some numbers.

The table gives the approximate consumption in HCFC-22 (or HFC blends such as R-404A or R410A0 for non-Article 5 and Article 5 countries in the year 2013. It concerns commercial 

refrigeration and stationary air conditioning.

It assumes 40% of the consumption being used for new manufacture in non-Article 5 countries, and 

20% of the consumption used for new manufacture in Article 5 countries. It the assumes 10% of the 

new manufacture being converted to alternatives in a given year and gives the numbers for the 

reduction in negative environmental impact in that year, as well as the influence on the negative 

environmental impact (i.e., in many cases a reduction) over a period of 15 years after the conversion 

in manufacture, which is due to the reduction of the impact in the servicing amounts (assumed over a 

period of 15 years).

A change of 10% in the manufacture for commercial refrigeration in developing countries to HFC 

blends such as R-404A gives an increase in negative impact of about 4 Mt CO2-eq., and an increase 

over 15 years in servicing of 32-64 Mt CO2-eq. (dependent on whether the servicing per year would 

be 50-10% of the original charge. Going from HCFC-22 to low GWP options (assuming an average 

GWP of 300; this is an assumption for the average of a number of alternatives that could be applied) 

yields a decrease in negative environmental impact of 3 Mt CO2-eq and another 23-46 Mt CO2-eq 

reduction over the period of 15 years thereafter, compared to the use of HCFC-22.

In particular for refrigeration and air conditioning, it will be clear that a conversion to alternatives 

with a low negative environmental impact is one of the first priorities. In particular because a change 

in manufacturing now will have consequences for many years to come via the amounts consumed in 

servicing. A calculation of the consequence in tonnes in the negative environmental impact should 

give an adequate first impression.
50 May 2013 TEAP XXIV/7 Task Force Report

Table 3.1: Amounts (tonnes, Mt CO2-eq.) reduced in negative environmental impact when 

converting from HCFC-22 (or HFCs) in commercial refrigeration and stationary air conditioning

Countries Approx. 

Cons. (t)

Assumed in 

manufacture 

10% of 

manufacture

Avoidance

(Mt CO2-eq.) 

per year

Avoidance via 

servicing in 15 

years (Mt 

CO2-eq.)

Commercial refrigeration (2013)

Non-Article 5 countries

From HCFC-22 

to HFCs**

40,000 16,000 1,600 -3.2 -10/ -20

From HFCs** to 

low GWP

40,000 16,000 1,600 5.4 16-32

Article 5

From HCFC-22 

to HFCs**

100,000 20,000 2,000 -4.2 32-64

From HCFC-22 

to low GWP

100,000 20,000 2,000 3 23-46

Stationary Air Conditioning (2013)

Non-Article 5

From HCFC-22 

to blends/410A

140,000 56,000 5,600 -2.2 17-34

From HFCs to 

low GWP

140,000 56,000 5,600 10.5 32-64

Article 5

From HCFC-22 

to blends/410A

400,000 80,000 8,000 -3.2 24-48

From HCFC-22 

to low GWP

400,000 80,000 8,000 11.8 88-176

** HFCs in commercial refrigeration have a GWP of 3800 (which would be the GWP of R-404A or similar)

***Low GWP chemicals, which could be different types of blends etc., natural refrigerants, have been given an 

average GWP of 300 

Similar calculations can be done for stationary air conditioning, with a current large consumption of 

HCFC-22. Conversion of 10% of the manufacture in developing countries to low GWP blends (with 

an average GWP of 300) would result in a lower negative environmental impact of about 12 Mt CO2-

eq. in a given year, and a further reduction (due to servicing) of 88-176 Mt CO2-eq. over the 15 years 

thereafter, quite a considerable amount.

The whole of this can be analysed in more detail, but this should be the subject of a separate study.

Thinking this over, in particular for refrigeration and air conditioning, it will be clear that a 

conversion to alternatives with a low negative environmental impact is one of the first priorities. In 

particular because a change in manufacturing now will have consequences for many years to come. A 

calculation of the consequence in tonnes in the negative environmental impact should give first 

impressions.

However, it should be stated that an investigation 

 whether and how regulations can be adjusted for a quicker introduction of certain flammable 

refrigerants in certain products, or 

 how approaches can be put in place to have more expensive equipment with more expensive 

low GWP refrigerants or blends entering the market faster would be very important and would 

have considerable impact on the calculation of the reduction in negative environmental impact. 
May 2013 TEAP XXIV/7 Task Force Report 51

4 Foams 

Executive Summary

The foams sector has made transitions from its CFC baseline, through HCFCs in some cases, to either 

high-GWP or low-GWP non-ozone depleting solutions. As of 2013, the residual reliance on HCFC 

use in Article 5 regions rests to some extent in polyurethane appliance foams (often within 

commercial appliances), but mostly in PU Spray and XPS Board. 

It is important to note that, of the 5.6 million ODP baseline footprint of the foam sector between 1990 

and 2012, over 80% of the footprint was avoided. Similarly, for a cumulative baseline climate 

footprint of 26.3 billion tonnes CO2-eq over 66% has been avoided. This assessment has taken the 

rather stringent approach of not correcting for the 10 year grace period given to Article 5 Parties, so 

the avoided baseline percentages against regulatory requirements are considerably higher. A similarly 

stringent approach has been taken with respect to the availability of non-ozone depleting alternatives 

and low-GWP solutions. It has effectively been assumed that these were available throughout the 

period of analysis and thereby over-estimates the ‘missed opportunities’ in order to place a worst case 

perspective to the data generated and avoid subjective scenarios. The following graphs illustrate the 

missed opportunities analysed in this way for both ozone and climate: 

The reasons for these ‘missed opportunities’, especially for the XPS board sector, are fully explained 

in the foams chapter and it remains difficult to identify significant areas where the transition process 

could have been accelerated substantially given the constraints faced. It should also be noted that the 

effect of changes in thermal performance have not been factored into the climate assessment in view 

of the complex and non-determinable usage patterns to which most building insulation foams are 

subject. 
52 May 2013 TEAP XXIV/7 Task Force Report

Moving forward to assess the potential for further savings, the period of assessment has been limited 

to 2013-2020 in view of the uncertainties surrounding market growth in the foam sector beyond that 

date. However, it should be noted that the potential savings will be under-estimated by taking this 

relatively cautious approach. The following four charts show the potential savings available assuming 

an immediate transition in 2013. While recognizing that this is not possible in most cases, it does 

compensate to some extent for the relatively short assessment period: 

Again, it should be noted that, although these savings are assumed to remove all of the remaining 

ozone and climate impacts for the period 2013-2020, the ozone-related savings represent only 2.3% 

of the footprint that would have existed without the Montreal Protocol. Similarly, the removal of the 

remaining climate impacts only represents 13.3% of the climate footprint that would have existed 

without the Montreal Protocol. 

With HCFC Phase-out Management Plans now well into their first phase, it is clear that most of the 

significant sectors identified in Article 5 Parties are already being addressed. However, this is not 

necessarily the case in non-Article 5 Parties where the drivers for further transition need to come 

from the climate agenda, bearing in mind that the phase-out of ozone-depleting substances is already 

complete. Apart from regulatory intervention, one of the key drivers may ultimately be the 

improvement in thermal efficiency offered by low-GWP substitutes such as unsaturated HFCs, 

unsaturated HCFCs or blends containing them. 

It is clear that the timing of further transitions is less critical to the environment than was the case for 

CFC phase-out, where delay had substantial consequences. There are still some difficult transitions to 

address (e.g. in the XPS sector) and it may be that waiting for the maturing of emerging technologies 

will offer better long-term solutions than forcing the transition too soon. Where this is unavoidable 

because of ODS phase-out commitments, it may still be better to consider a low-cost interim solution 

in order allow for a subsequent transition.
May 2013 TEAP XXIV/7 Task Force Report 53

4.1 ODS alternatives

The foam sector has made significant strides in addressing the phase-out of ozone depleting 

substances since the signing of the Montreal Protocol in 1987. The availability of hydrocarbons at an 

early stage of the transition period has made it that a genuine low-GWP and cost-effective alternative 

has been available for large parts of the foam sector throughout that period, even at the time of the 

phase-out of CFCs in non-Article 5 Parties. Therefore, the account of the transition history since 

1987 in the polyurethane and phenolic product sectors is dominated by whether a specific foam subsector could adopt hydrocarbon technologies or not. There have been a number of reasons cited over 

the period to explain why hydrocarbon solutions were not appropriate. These have included:

 The flammability risks associated with the production/deposition process 

 The flammability risks associated with product installation and use

 The higher gaseous thermal conductivity leading to poorer thermal efficiency of the foam

 The cost of flame-proofing measures for production processes in relation to the size of the 

manufacturing plant (lack of economies of scale) 

 Local health & safety regulations

 Local regulations on volatile organic compounds (VOCs) 

 Waste management issues

Some of these have largely been discounted in more recent times, but others continue to be of 

importance and some are even growing in significance (e.g. waste management issues) as 

hydrocarbon blown foams reach end-of-life. Nevertheless, the market penetration of hydrocarbon 

technologies has had a substantial impact as shown by the graph below: 

The dominance of the hydrocarbon technologies is even greater than it appears from the graph, since 

the blowing efficiency of hydrocarbon blowing agents is considerably better than the CFCs and 

HCFCs that were replaced. This means that the amount of foam blown by the 170,000 tonnes of 

hydrocarbons predicted to be used in the foam industry in 2014 will be 30-40% greater than would be 

achieved by the same quantity of CFCs. The optimisation of hydrocarbon technologies over the years 

has also resulted in improvements in thermal performance through improved cell structure, thereby 

negating some of the earlier concerns about poorer thermal efficiency. 
54 May 2013 TEAP XXIV/7 Task Force Report

It can be seen that the other major groups of blowing agents being used for the polyurethane and 

phenolic foam sectors at this point are HCFCs (in Article 5 Parties) and HFCs (in non-Article 5 

Parties. The reasons for this will be explained in the sections that follow within this chapter.

In the Extruded Polystyrene sector, the main low-GWP and cost-effective alternative has been CO2

itself. Again, the main challenge throughout has been to understand why this solution could not be 

universal in its application. Reasons have included: 

 Processing difficulties with CO2 and even CO2/HCO blends

 The higher gaseous thermal conductivity leading to poorer thermal efficiency of the foam

 Costs of conversion - including licencing constraints resulting from patents

 Loss of processing flexibility ruling out some board geometries completely

For these reasons considerable proportions of the extruded polystyrene (XPS) industry have remained 

using HCFCs and HFCs rather than CO2. This will be explained further in section 4.8 of this chapter.

In the intervening years, the search for low-GWP, high performance blowing agents without the 

limitations of hydrocarbons and CO2 has been continuing. For the first time, the emergence of 

unsaturated HCFCs and HFCs seems to be offering a level of performance which not only allows the 

replacement of blowing agents with high-GWPs such as HCFCs and saturated HFCs, but also 

threatens to replace some elements of the hydrocarbon and CO2-blown sectors, based primarily on 

improved thermal properties. However, the continuing unknowns with these technologies are the 

overall system cost and the global availability. Until, these issues are fully addressed, it will be 

difficult to elevate their status beyond ‘emerging’. Most manufacturers are indicating levels of 

commercialisation between late 2013 and 2015. However, in the first instance, this availability is 

likely to be targeted in markets within non-Article 5 Parties where the requirement for improved 

thermal efficiency is best identified. Even in these markets, it is expected that blowing agent blends 

will become predominant, especially where unsaturated HCFCs and HFCs can be blended with 

hydrocarbons to obtain better thermal performance with minimum system cost increase.

Other blowing agents are also emerging as potential replacements for HCFCs and HFCs. These 

include a group of oxygenated hydrocarbons (HCOs) which include methyl formate and methylal. 

These are generally seen as less flammable than the hydrocarbons themselves, although the 

significance of those differences can often depend on local product codes and the regulatory 

frameworks governing foam manufacture. Again, there is a growing tendency to see these used as 

components of tailored blends where they can contribute to overall performance criteria.

For the XPS sector, the emergence of gaseous unsaturated HFCs such as HFO-1234ze also presents a 

significant opportunity to replace any remaining HCFCs, saturated HFCs and even CO2 in some 

instances. However, cost remains a key issue and blending with oxygenated hydrocarbons (e.g. 

dimethyl ether) may well be required to deliver a commercially viable alternative technology. 

In summary, the following table provides an overview of the blowing agent classes which have either 

previously offered, or are currently offering, alternatives to ozone depleting substances in the sectors 

being specifically considered in this chapter. 
May 2013 TEAP XXIV/7 Task Force Report 55

Sector CFCs HCFCs HFCs HCs HCOs HFOs CO2-based

ODS being replaced

PU Appliances CFC-11 HCFC-141b

HCFC-22

HFC-245fa

HFC-365mfc/227ea

cyclo-pentane

cyclo/iso-pentane

MethylΔ

Formate

HFO-1233zd(E)

HFO-1336mzzm(Z)

AFA-1 (undisclosed)

CO2 (water)*Δ

PU Board CFC-11 HCFC-141b HFC-365mfc/227ea n-pentane

cyclo/iso pentane

HFO-1233zd(E)

HFO-1336mzzm(Z)

AFA-1 (undisclosed)

PU Panel CFC-11 HCFC-141b HFC-245fa

HFC-365mfc/227ea

n-pentane

cyclo/iso pentane

HFO-1233zd(E)

HFO-1336mzzm(Z)

AFA-1 (undisclosed)

CO2 (water)*

PU Spray CFC-11 HCFC-141b HFC-245fa

HFC-365mfc/227ea

HFO-1233zd(E)

HFO-1336mzzm(Z)

AFA-1 (undisclosed)

CO2 (water)*

Super-critical 

CO2

PU In-situ/Block CFC-11 HCFC-141b HFC-245fa

HFC-365mfc/227ea

n-pentane

cyclo/iso pentane

HFO-1233zd(E)

HFO-1336mzzm(Z)

AFA-1 (undisclosed)

CO2 (water)*

PU Integral Skin CFC-11 HCFC-141b

HCFC-22

HFC-245fa

HFC-134a

Methyl 

Formate/

Methylal

CO2 (water)*

XPS Board CFC-12 HCFC-142b

HCFC-22

HFC-134a

HFC-152a Iso-butane DME HFO-1234ze(E) CO2CO2/ethanol

Phenolic CFC-11 HCFC-141b HFC-245fa

HFC-365mfc/227ea

n-pentane

cyclo/iso pentane

HFO-1233zd(E)

HFO-1336mzzm(Z)

AFA-1 (undisclosed)

*CO2(water) blown foams rely on the generation of CO2 from reaction of isocyanate with water in the PU system itself

Δ Primarily in the commercial refrigeration sector (e.g. vending machines) 

4.2 Polyurethane - appliances

In the strictest sense, this sector covers both domestic and commercial appliances, although the major 

trends characterised in this section of the chapter will be related to the larger, and more 

homogeneous, domestic sector. However, the statistical information presented graphically will cover 

both groups of appliances.

4.2.1 Historical perspective (including non-Article 5 / Article 5 Party differences)

The adoption of polyurethane foams within the appliance sector took place substantially in the late 

1960s and 1970s as concerns began to rise about energy use in the wake of oil crises of the period. 

An additional advantage was identified, in that polyurethane foams also contributed to the physical 

strength of refrigeration cabinets and allowed for a reduction in the steel structures used and, as a 

consequence, the weight of the cabinets themselves. This has ultimately been beneficial for both the 

economics and the environmental footprint of the industry. 

Although there have been regional differences in the design of refrigerators and freezers over the last 

40 years, the ability to transport units over long distances has resulted in a gradual levelling of the 

global refrigerator market over time. Nevertheless, there continues to be a substantial range of units 

on offer, from the large ‘American style’ cabinets to the smaller compact European, Japanese and 

Chinese models.

Polyurethane foam is now the insulation of choice for over 99% of the global market. There is 

increasing interest in the use of vacuum panels in some quarters, but the market penetration is 

expected to be limited to highly energy-sensitive areas of a cabinet, since cost remains an issue.

At the time of the transition out of CFCs in the early-to-mid 1990s, the design differences were truly 

on a regional basis. Indeed, the ‘American style’ refrigerator used throughout North America created 

transitional challenges that were not seen in either Europe or Japan. These challenges were largely 

down to the manufacturing processes and product designs in operation at that time. Effectively, the 

adoption of hydrocarbons as a direct alternative for CFCs was not seen as an option for two major 

reasons:
56 May 2013 TEAP XXIV/7 Task Force Report

 The inappropriateness of the existing manufacturing facilities to accommodate the use of 

hydrocarbons for such large cabinets

 The poorer thermal performance of hydrocarbon blown foam when compared with CFCcontaining foam and HCFC-containing foam, which was seen as the other obvious 

replacement at that time 

 Risk of violating existing local regulation on volatile organic compound (VOC) limits

Despite some initial issues with the interaction between HCFC-141b and the refrigerator liners, 

HCFCs became the accepted alternative for CFC-11 in North America in contrast to the rest of the 

developed world, where the adoption of hydrocarbon was widespread. It is estimated that this 

approach led to additional ozone-related consumption of approximately 13,500 ODP tonnes in the 

period from 1995-2002 (~72% of the developed country total for appliances in that period). However, 

it should be noted that this total was equivalent to around 9 months of non-Article 5 Party 

consumption in 1990. This observation brings into sharp relief the situation at the time, which was 

that delays in implementation would be more costly to the ozone layer than the precise choice of 

ODS alternative. This was a time when HCFCs were seen by most as ‘part of the solution rather than 

part of the problem’. The combined impact of the delay in converting out of CFCs in the post-1990 

period and the choice of HCFCs in North America is seen in the graph below – amounting to 

approximately 125,000 ODP tonnes in all: 

Since 2003, the use of HCFCs in domestic appliances has largely been eliminated in non-Article 5 

countries, meaning that the subsequent periods have broadly maximised their potential for avoiding 

further ozone depletion. 

For Article 5 Parties, the CFC phase-out date was set 10 years later than for non-Article 5 Parties. 

However, in those Article 5 Parties, the use of domestic refrigerators and freezers was less 

widespread in the period between 1990 and 2000. Accordingly, the impact of deferred phase-out date 

was less severe than it would have been had it been applied in non-Article 5 Parties. Nevertheless, the 

overall implication in the 1990-2000 period was 188,000 ODP tonnes but reducing in the subsequent 

decade to 27,500 ODP tonnes indicating the efforts applied in Article 5 Parties, with the support of 

the Multilateral Fund to ensure that CFC transitions in the appliance sector were achieved well ahead 

of the final 2010 phase-out deadline. The following graph illustrates the extent to which the appliance 

sector in Article 5 Parties has limited its impact on the ozone layer, not only through its preference 

for early transition, but also through the avoidance of HCFCs in a number of key markets. 
May 2013 TEAP XXIV/7 Task Force Report 57

It should be noted that Article 5 Party strategies for CFC phase-out have not been uniform from 

region to region. China, and other parts of Asia, have focused primarily on transitioning from CFCs 

directly to hydrocarbons, whereas much of the domestic appliance sector in Latin America took a 

different route, with a focus on HCFC-141b as an alternative for its CFC phase-out. This was driven 

in part by the growing importance of the North American market for its exports.

With respect to climate impacts, the initial choice taken in North America has continued to impact 

subsequent choices when phasing out HCFC-141b use, with saturated HFCs being preferred to 

hydrocarbons. Again, the main reason cited was the superior thermal efficiency of the fluorinated 

substitutes. The following graph illustrates the significance of these subsequent choices on the overall 

climate impacts for the period from 2000-2010 and those projected for the following decade. 

The overall impact of not choosing low-GWP alternatives in the period from 2000-2020 is currently 

estimated to be around 400,000 ktCO2-eq. However, if low-GWP alternatives could be adopted 

immediately, this would be reduced by approximately 175,000 ktCO2-eq. in the period to 2020. Of 

course, this simple analysis fails to account specifically for the potential energy benefits from using 

fluorinated substitutes such as saturated HFCs and this matter will be picked up again in Section 

4.2.3. 
58 May 2013 TEAP XXIV/7 Task Force Report

For Article 5 Parties, the retained use of CFCs in the period to around 2005 dominates the assessment 

of climate impact because of the high global warming potential associated with CFC-11. However, 

the large-scale switch directly to hydrocarbons showed considerable benefits for the on-going climate 

impact of the appliance sector. Nonetheless, the residual impact of the use of higher GWP solutions 

(e.g. HCFCs) through until 2020 is estimated to be in the order of 190,000 ktCO2-eq, as is shown in 

the graph below: 

4.2.2 Commercially available alternatives to Ozone Depleting Substances 

The Task Force Report in response to Decision XXIII/9 provided a full list of HCFC replacement 

options and offered a summary of the pros and cons of each option, as well as some additional 

commentary on critical aspects for decision-making in the appliance sector. Decision XXIV/7 has 

requested that the commercially available options and the alternatives under development (emerging 

options) be treated separately. Therefore, the Decision XIII/9 Report tables have been reconstituted 

and updated accordingly.
May 2013 TEAP XXIV/7 Task Force Report 59

HCFC REPLACEMENT OPTIONS FOR APPLIANCES (DOMESTIC & COMMERCIAL), 

TRUCKS & REEFERS

SECTOR/OPTION PROS CONS COMMENTS

Domestic refrigerators/freezers

Cyclopentane & cyclo/iso blends

Low GWP Highly flammable

High incremental capital costs but 

most enterprises in sub-sector are 

large

Low operating costs Global industry standard 

Good foam properties

Saturated HFCs (HFC-245fa)

Non-flammable High GWP Low incremental capital costs

High operating costs Improved insulation (cf. HC)

Good foam properties Well proven technology

Commercial refrigerators/freezers plus vending equipment

Cyclopentane & cyclo/iso blends

Low GWP Highly flammable High incremental capital cost, 

may be uneconomic for SMEs

Low operating costs Well proven technology

Good foam properties

HFC-245fa, HFC-365mfc/227ea

Non-flammable High GWP Low incremental capital cost

Good foam properties High operating costs Improved insulation (cf. HC)

CO2 (water)

Low GWP

Moderate foam 

properties – high 

thermal conductivity & 

high foam density

Low incremental capital cost

Non-flammable High operating costs 

Improved formulations (second 

generation) claim no need for 

density increase vs HFC co-blown

Methyl Formate

Low GWP

Moderate foam 

properties -high thermal 

conductivity & high foam 

densityModerate incremental capital cost 

(corrosion protection 

recommended)

Flammable although 

blends with polyols may 

not be flammable

High operating costs 

Refrigerated trucks & reefers

Cyclopentane & cyclo/iso blends

Low GWP Highly flammable High incremental capital cost, may 

be uneconomic for SMEs

Low operating costs

Good foam properties

HFC-245fa, HFC-365mfc /227ea

Non-flammable High GWP Low incremental capital cost

Good foam properties High operating costs Improved insulation (cf. HC)

CO2 (water) Low GWP

Moderate foam 

properties -high thermal 

conductivity & high foam 

densityLow incremental capital cost

Non-flammable High operating costs Not used in reefers

The assessment of these alternatives against the criteria of commercial availability, technical proof of 

performance, environmental soundness (encompassing efficacy, health, safety and environmental 

characteristics), cost effectiveness (capital and operating) and processing versatility in challenging 

ambient conditions is, in itself a challenging objective. Typically, performance against such criteria 

can only be judged fully on a case-by-case basis and assessments made at a higher level will only be 

indicative. With this in mind, the following table seeks to give such an indicative assessment based 

on a nominal ranking of seven categories from ‘+++’ (the best) to ‘---‘ (the worst): 
60 May 2013 TEAP XXIV/7 Task Force Report

c-pentane i-pentane HFC-245fa HFC365mfc/227ea CO2(water) Methyl 

Formate

Proof of performance +++ +++ +++ ++ + +

Flammability --- --- ++ +(+) +++ --

Other Health & Safety 0 0 + + - 0

Global Warming +++ +++ -- --- ++ ++

Other Environmental - - 0 0 ++ -

Cost Effectiveness (C) --- --- ++ ++ ++ 0

Cost Effectiveness (O) +++ +++ -- -- + +

Process Versatility ++ ++ ++ + 0 0

As has been noted in previous reports, the mix of performance properties (technical, economic and 

environmental) does not lead unambiguously to one single selection. Indeed, the proliferation of 

blends across the whole of the foam sector and nowhere more so than the appliance sector is an 

indication of the reality that there is no single best solution. Often a key factor is the size of the 

manufacturing plant, since the economies of scale have a considerable bearing on the relative 

importance of capital and operational costs. Cost also is a major factor in the consideration of the 

major emerging technologies.

4.2.3 Emerging alternatives

As noted in the 2012 Task Force Report in response to Decision XXIII/9, the major emerging 

technologies in the appliance sector are based mostly around liquid unsaturated HCFCs/HFCs. These 

are all fairly similar in their properties and all seem to suggest a stepwise improvement in thermal 

performance over other low-GWP alternatives. The following table provides an overview of the 

‘pros’ and ‘cons’ of these technologies.

HCFC REPLACEMENT OPTIONS FOR APPLIANCES (DOMESTIC & COMMERCIAL), 

TRUCKS & REEFERS

SECTOR/OPTION PROS CONS COMMENTS

Domestic refrigerators/freezers

Unsaturated HFC/HCFCs 

(HFOs) 

Low GWP High operating costs

Successful commercial trials; first 

expected commercialization in 

2013

Non-flammable

Promising energy efficiency 

performance: equal or better than 

saturated HFCs

Low incremental capital cost

Commercial refrigerators/freezers plus vending equipment

Liquid Unsaturated HFC/HCFCs 

(HFOs) 

Low GWP High operating costs First expected commercialization in 

2013

Non-flammable

Promising energy efficiency 

performance: equal or better than 

saturated HFCs

Low incremental capital cost

Refrigerated trucks & reefers

Liquid Unsaturated HFC/HCFCs 

(HFOs) 

Low GWP High operating costs First expected commercialization in 

2013

Non-flammable

Promising energy efficiency 

performance: equal or better than 

saturated HFCs

Low incremental capital cost

The range of unsaturated HCFCs/HFCs remains unchanged from the Decision XXIII/9 Report, with 

the disclosure of the molecule behind Arkema’s code name AFA-L1 still awaited. However, the 
May 2013 TEAP XXIV/7 Task Force Report 61

following table provides an analysis of these new molecules against the criteria considered for the 

commercially available alternatives based on limited experience in appliance sector trials. 

HFO-1234ze(E) HFO-1336mzzm(Z) HFO-1233zd(E) AFA-L1

gaseous liquid liquid Liquid

Proof of performance + ++ ++ +

Flammability ++ +++ +++ +++

Other Health & Safety + + + +

Global Warming +++ +++ +++ +++

Other Environmental + + + +

Cost Effectiveness (C) ++ ++ ++ ++

Cost Effectiveness (O) -- -- -- --

Process Versatility + + + +

The appliance sector is clearly one of the most sensitive to the thermal performance of the insulation 

contained within the cabinet, since this dictates both external dimensions and internal storage space. 

Evidence from trials in the sector continue to reinforce the fact that unsaturated HCFCs/HFCs will 

deliver 8-12% better thermal performance than cyclo-pentane and 2% better performance than HFC245fa. The key question is whether these differences will be sufficient to drive the adoption of these 

alternatives, in place of existing hydrocarbon technologies, in both non-Article 5 and Article 5 Parties. 

For HFC-245fa replacement in non-Article 5 parties, the driver will be more about environmental 

pressure to transition from high-GWP solutions. Finally, where HCFCs are still in use within Article 

5 Parties, the question is whether these new blowing agents will be commercially available in time to 

pose a genuine alternative to hydrocarbon options.

4.2.4 Barriers and restrictions

As noted above, the commercialisation time-line and global availability of the various unsaturated 

HCFCs/HFCs will have a considerable bearing on their widespread adoption under the HCFC Phaseout Management Plans currently being enacted. Two of the three potential manufacturers are 

committing to timelines of 2015 or better, but the supply/demand curves for these alternatives are still 

not fully understood. 

One factor in the adoption of these new technologies is the potential use of blends of unsaturated 

HFCs/HCFCs with hydrocarbons to achieve intermediate thermal performance benefits at affordable 

cost. If the compromises made are too great, then the benefits will be too marginal to justify transition 

from existing hydrocarbon solutions where they are already in place, and to prefer unsaturated 

HCFC/HFC solutions over hydrocarbon where they are not. However, with the cost of these new 

compounds not completely established at this point, it is not clear whether solutions maximising the 

thermal performance benefits will be affordable. 

For those still using HCFC-141b, one strategy being considered in the case of some manufacturers is 

to make an intermediate transition to a high-GWP (lower investment) technology option such as 

saturated HFCs on the written understanding that a further transition to a low-GWP option will 

follow within a specified period. The choice would be left open until such time as optimum 

technology approaches have been established.

For transitions directly from HCFC-141b to hydrocarbons, there are potential strategies to reduce the 

investment costs for smaller enterprises. These include the potential for using pre-blended mixes 

containing cyclo-pentane. However, this approach is not expected to impact the domestic appliance 

sector too greatly, since economies of scale would generally support a more comprehensive 

conversion strategy. However, in the case of some manufacturers of commercial appliances (e.g. 

vending machines), there may be more relevance. Further information is covered under Section 4.4.4.
62 May 2013 TEAP XXIV/7 Task Force Report

4.3 Polyurethane - boardstock

This is one of the largest markets for rigid polyurethane foams in non-Article 5 Parties, but has only 

recently started to grow significantly in Article 5 Parties as requirements for building energy 

efficiency have increased. The historical analysis therefore focuses primarily on the non-Article 5 

experiences.

4.3.1 Historical perspective (including non-Article 5 / Article 5 Party differences)

The adoption of polyurethane boardstock (also known as flexibly-faced continuous laminate) has 

varied substantially across the range of non-Article 5 Parties because of substantial differences in 

building practices. In North America, the widespread use of timber-frame construction techniques has 

led to the use of boardstock as a siding material. Similar trends have occurred in Japan where metalframed construction systems are also quite prevalent. In Europe, however, where brick and block 

cavity construction has been more typical for residential buildings, the bulk of the early uptake of 

polyurethane boardstock was in the non-domestic sector, particularly in offices, warehouses and 

industrial buildings. These non-domestic applications have also been evident in Japan and North 

America as well, but have been less conspicuous in view of the residential demand. In more recent 

times, the European residential buildings have also embraced polyurethane boardstock, since 

increasing insulation requirements have meant that wall cavities have not been able to accommodate 

the thicknesses required of less efficient insulation types.

CFC-11 was the predominant blowing agent throughout the early development of the polyurethane 

boardstock market. In the early stages of the search for a replacement blowing agent, HCFC-123 had 

emerged as an option, but was subsequently ruled out on the basis of unfavourable toxicity. This led 

to a broad consideration of HCFC-141b, especially in North America. However, after substantial 

consideration of the flammability implications and reformulation to include flame retardants in some 

products, it was decided that, to a large extent, it would be possible to leapfrog HCFCs and move 

directly to hydrocarbons – typically pentanes. In order to limit the loss of thermal performance 

resulting from this transition, cyclo-pentane was often favoured in the blends chosen – so much so 

that there was concern for a while about the availability of sufficient supplies. As foam formulations 

have been optimised, some of the blends have been able to switch towards n-pentane. However, 

choices continue to vary.

The graph above illustrates the consequence of the delay while boardstock manufacturers made their 

decisions in exiting CFC consumption. However, in the decade from 2001-2010 the lack of 
May 2013 TEAP XXIV/7 Task Force Report 63

significant HCFC use resulted in the achievement of a virtually complete phase-out of ozone 

depleting substances. 

From a climate perspective, the continuing use of CFC-11 in the period from 1990-2000 had a 

detrimental effect in excess of 900 million tonnes CO2-eq in view of its high global warming 

potential compared with the alternatives. However, it could be argued that this impact was somewhat 

offset in the next decade by the avoidance of widespread HCFC-141b use. Once again, the balance 

between the speed of transition and the relative efficacy of the alternatives is an obvious discussion 

point.

The first comment to make with respect to the manufacture and use of PU boardstock in Article 5 

Parties is this that it is relatively minor when compared to non-Article 5 activity. Back in the 1990s 

the total consumption of blowing agent was less than 1% of that in developed regions. Those few 

manufacturers in Article 5 Parties understandably waited for a technology lead from the larger 

producers and this resulted in a relatively measured transition between 2001 and 2010. Again, with 

the major alternative being hydrocarbons, the impact on consumption of ODS after 2010 has been 

minimal, as shown in the following graph.
64 May 2013 TEAP XXIV/7 Task Force Report

The impact on climate from the slow transition out of CFCs was no more than 6.3 million tonnes 

CO2-eq. The growth of the sector since 2005, especially in places like China, has been achieved 

through the adoption of hydrocarbon technologies from the outset and therefore there has been little 

overall ‘missed opportunity’ since then. This trend is expected to continue in the period to 2020 as is 

shown in the graph below.

4.3.2 Commercially available Alternatives to Ozone Depleting Substances 

Again, drawing from the evaluations conducted for Decision XXIII/9 with relevant updates where 

necessary, the following table illustrates the commercially available options for the polyurethane 

boardstock sector. 

HCFC REPLACEMENT OPTIONS FOR PU FOAM FOR BUILDING/ CONSTRUCTION 

APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Boardstock – continuously produced

Cyclopentane & n-Pentane

Low GWP Highly flammable

High incremental capital costs but 

most enterprises in sub-sector are 

large 

Low operating costs Industry standard

Good foam properties

HFC-245fa, HFC-365mfc/277ea

Non-flammable High GWP Low incremental capital cost

Good foam properties High operating costs

Improved insulation (cf. HC)

In general, saturated HFCs have shown little uptake in most PU boardstock markets because the 

hydrocarbon-based products have been shown to be fit-for-purpose at a more competitive cost. Since 

new capacity in the industry can accommodate hydrocarbon process safety issues at the design stage, 

the high incremental capital costs associated with later transitions can be mitigated to some extent. 

As building energy standards increase, there could be increasing pressure for better thermal 

efficiency, especially where space is limited and product thickness is constrained. There has therefore 

been some interest in possible blends of hydrocarbons with saturated HFCs. Indeed, it is suspected 

that some manufacturers may have adopted this strategy commercially, although it is difficult to track 

because no further plant modifications would normally be necessary. Such trends may also be shortlived, since there is increasing market pressure (e.g. through LEED and other environmental building 

schemes) to avoid the use of saturated HFCs.
May 2013 TEAP XXIV/7 Task Force Report 65

According to the chosen criteria, the relative performance of alternative technology solutions in this 

sector can be summarised as follows: 

c-pentane n-pentane i-pentane HFC-245fa HFC365mfc/227ea

Proof of performance +++ +++ +++ ++ ++

Flammability --- --- --- ++ +(+)

Other Health & Safety 0 0 0 + +

Global Warming +++ +++ +++ -- ---

Other Environmental - - - 0 0

Cost Effectiveness (C) -- -- -- ++ ++

Cost Effectiveness (O) ++ +++ +++ -- --

Process Versatility ++ ++ ++ ++ +

The slight environmental concerns reflected for hydrocarbon options relate to some emerging 

concerns about local VOC regulations. In some regions there are exemptions for thermal insulation 

manufacturing plants, but this approach is not universal.

4.3.3 Emerging alternatives

The market pressure on saturated HFCs outlined in the previous section opens up the possibility for 

hydrocarbon blends with unsaturated fluorocarbons (both HCFCs and HFCs). The uncertainty of cost 

makes this option even less clear cut for PU boardstock than it is for domestic appliances. 

Nonetheless, there continues to be sufficient interest in the option to justify its inclusion in this 

section as an emerging technology – albeit as a blend with hydrocarbons.

HCFC REPLACEMENT OPTIONS FOR PU FOAM FOR BUILDING/ CONSTRUCTION 

APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Boardstock – continuously produced

Liquid Unsaturated HFC/HCFCs 

(HFOs) Low GWP High operating costs First expected commercialization in late 2013

Non-flammable Trials in progress, particularly with 

blends 

Low incremental capital cost

The overall assessment of the criteria for unsaturated HCFCs/HFCs is very similar to that shown for 

PU appliances.

HFO-1234ze(E) HFO-1336mzzm(Z) HFO-1233zd(E) AFA-L1

gaseous Liquid liquid liquid

Proof of performance + ++ ++ +

Flammability ++ +++ +++ +++

Other Health & Safety + + + +

Global Warming +++ +++ +++ +++

Other Environmental + + + +

Cost Effectiveness (C) ++ ++ ++ ++

Cost Effectiveness (O) -- -- -- --

Process Versatility + + + +

The only potential difference is that the use of a gaseous option being used in the PU Boardstock 

sector is less likely than for PU Appliances. Nevertheless, it has been retained for completeness.
66 May 2013 TEAP XXIV/7 Task Force Report

4.3.4 Barriers and restrictions

In practice, the quantity of PU boardstock foam still using HCFCs is very limited and this fact alone 

testifies to the lack of barriers to appropriate transition. As noted earlier, much of the new capacity in 

the sector has been installed since the ozone issue emerged and the necessary requirements for 

hydrocarbon have typically been designed in.

The only likely transition pressure now emerging relates to the on-going goal of improved thermal 

efficiency. The major barrier to the adoption of blends of saturated HFCs with hydrocarbons is 

market pressure, while the potential barrier to the wider use of unsaturated HFCFs/HFCs is one of 

cost and, in the short term, availability.

4.4 Polyurethane - panels

In the context of this analysis, the primary panels being referred to are steel-faced and either 

continuously or discontinuously produced. The market for such panels has developed very differently 

in various regions of the world, with the early adoption being mostly in Europe. However, the 

prefabricated approach to building that these panels allow is becoming increasingly widespread 

globally and manufacturing capacity has continued to grow to meet the need.

4.4.1 Historical perspective (including non-Article 5 / Article 5 Party differences)

Back in the 1990s, the panel market was split between emerging building cladding applications such 

as those described above and the commercial refrigeration market (both mobile and stationary) where 

polyurethane-cored panels have been used for both walk-in cold rooms and refrigerated transport 

applications. A substantial portion of the market was served by discontinuous manufacturing 

equipment at that time. However, continuous manufacture has grown to dominate the sector as the 

greater demand in the building sector created consistency of demand and economies of scale. 

As was the case with other insulation foams, CFC-11 was the blowing agent of choice in the period 

through to 1990. Since much of the manufacturing equipment at that stage was discontinuous there 

was a considerable reluctance to experiment with hydrocarbons and the natural replacement was 

HCFC-141b. Initial transitions took place alongside those in other foam sectors in the period between 

1994 and 1996. However, as capacity began to increase for continuously produced panel, it became 

possible to design plants to accommodate hydrocarbon while minimising the impact on investment 

cost. The thermal performance disadvantages of hydrocarbon at the time were of less importance in 

the panel sector than in the PU boardstock sector. This reflects the fact that the thickness of panels is 

generally driven by the requirements on them for structural integrity over long spans rather than by 

the thermal performance itself. 

The impact of these trends is shown in the graph below, where the initial transition decision-making 

process caused some lost time and arguably missed opportunities. However, despite the selection of a 

number of HCFC transitions, they became less significant in the 2001-2010 decade as the continuous 

panel industry grew based, as it is on hydrocarbon (typically pentanes).
May 2013 TEAP XXIV/7 Task Force Report 67

The climate consequences of these transitions are a little more clear-cut and the on-going use of 

HCFCs, and later HFCs, in the discontinuous panel sector looks likely to deliver the same pattern 

going forward, as shown below. 

The Task Force’s analysis suggests that the impact of the HCFC and HFC technology selections in 

the discontinuous panel sector may have resulted in an additional climate burden of over 700 million 

tonnes CO2-eq. and could provide a future avoidance of up to 170 million tonnes CO2-eq by 2020 if 

appropriate low GWP solutions can be introduced. The barriers to this are covered in Section 4.4.4.

In Article 5 Parties, except those supplying markets in adjacent non-Article 5 Parties, the economies 

of scale have historically been too low to support continuous panel production. This is changing as 

the larger economies amongst the Article 5 Parties grow strongly, but the account still holds true for 

the bulk of developing countries. With a substantial base of discontinuous plants, the tendency was to 

retain the use of CFCs for the bulk of the ten year available grace period in order to take advantage of 

the technology developments occurring in parallel small and medium enterprises in non-Article 5 

Parties. This impact of this decision to wait is clearly seen in the 1990-2000 period of the graph 

below.
68 May 2013 TEAP XXIV/7 Task Force Report

The on-going impact of the discontinuous panel sector and its limited choice of options is also 

evident from the bars in the chart covering later periods. These indicate that HCFC phase-out will not 

be complete in the panel sector before 2020. The impact of the use of high GWP substitutes for CFCs 

is also seen in the following chart:

However, the missed opportunity is slightly less severe at 322 million CO2-eq because of the smaller 

size of the market currently in developing regions. It seems likely that future growth in panels for 

buildings in the larger economies will be served by new investment and the transplant of hydrocarbon 

technologies from non-Article 5 Parties. This will serve to ‘dilute’ the overall impact of the panel 

sector, particularly if the improved energy savings are factored in.
May 2013 TEAP XXIV/7 Task Force Report 69

4.4.2 Commercially available alternatives to Ozone Depleting Substances 

The following table illustrates the main commercially available alternatives in the panel sector. 

HCFC REPLACEMENT OPTIONS FOR PU FOAM FOR BUILDING/ CONSTRUCTION APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Steel-faced panels – continuously produced

Cyclopentane & n-Pentane

Low GWP Highly flammable

High incremental capital costs 

but most enterprises in subsector are large 

Low operating costs Industry standard

Good foam properties

HFC-245fa, HFC-365mfc/277ea

Non-flammable High GWP Low incremental capital cost

Good foam properties High operating costs

Improved insulation (cf. HC)

Steel-faced panels – discontinuously produced

Cyclopentane & n-Pentane

Low GWP Highly flammable High incremental capital cost, 

may be uneconomic for SMEs 

Low operating costs

Good foam properties

HFC-245fa, HFC-365mfc/277ea, 

HFC-134a

Non-flammable High GWP Low incremental capital cost

Good foam properties High operating costs Improved insulation (cf. HC)

CO2 (water)

Low GWP

Moderate foam properties 

–high thermal 

conductivityLow incremental capital cost

Non-flammable

Methyl Formate

Low GWP

Moderate foam properties 

- high thermal 

conductivityModerate incremental capital 

cost (corrosion protection 

recommended)

Flammable although 

blends with polyols may 

not be flammable

As noted earlier, the pressure for improved thermal performance in the architectural (cladding) panel 

is less pronounced than it is for other building insulation types because of the structural requirements 

which are associated with that application. However, the same cannot be said for refrigerated 

transport where additional benefits in thermal performance can improve the load-carrying capacity of 

a vehicle. Therefore, there is on-going interest in saturated HFCs as legitimate alternatives, or at least 

components of blends for that application. 

In the discontinuous sector, there are other potential technologies based around CO2 (water) and 

HCOs such as methyl formate. These reduce the perceived risks associated with the use of 

hydrocarbons on discontinuous plants but do result in some compromises in foam properties 

including higher density and potentially poorer thermal performance. Nonetheless, they do offer lowGWP solutions in markets which may not be too sensitive to thermal performance issues. These are 

all important considerations in the Article 5 context where the need to phase-out HCFCs requires the 

widest range of alternatives, especially for small and mixed use discontinuous panel facilities. The 

strengths and weaknesses of these alternatives are once again shown in the following table – this time 

relating to the panel sector. 
70 May 2013 TEAP XXIV/7 Task Force Report

c-pentane

i-pentane 

n-pentane

HFC-245fa HFC365mfc/227ea CO2(water) Methyl 

Formate

Proof of performance + ++ ++ ++ ++ +

Flammability --- --- ++ +(+) +++ --

Other Health & Safety 0 0 + + - 0

Global Warming +++ +++ -- --- ++ ++

Other Environmental - - 0 0 ++ -

Cost Effectiveness (C) -- --- ++ ++ ++ 0

Cost Effectiveness (O) ++ +++ -- -- + +

Process Versatility ++ ++ + ++ + +

4.4.3 Emerging alternatives

Again, the major emerging alternatives are unsaturated HCFCs/HFCs. In view of the relative 

abundance of commercially available alternatives, these blowing agents are likely to be focused on 

niche markets in the panel sector. 

HCFC REPLACEMENT OPTIONS FOR PU FOAM FOR BUILDING/ CONSTRUCTION APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Steel-faced panels – continuously produced

Liquid Unsaturated HFC/HCFCs 

(HFOs Low GWP High operating costs First expected commercialization in 2013

Non-flammable Trials in progress

Low incremental capital cost

Steel-faced panels – discontinuously produced

Liquid Unsaturated HFC/HCFCs 

(HFOs Low GWP High operating costs First expected commercialization in 2013

Non-flammable Trials in progress

Low incremental capital cost

In principle, unsaturated HCFCs/HFCs offer opportunities for improving thermal performance while 

retaining a low-GWP blowing agent. For reasons stated in respect of other foam sectors, the cost of 

these blowing agents is still uncertain and could prevent reliance on them in isolation. That said, the 

added value of a panel is certainly greater than that of boardstock, so the ability to adsorb cost could 

be greater in this sector. Nevertheless, the most likely approach will be the adoption of blends with 

hydrocarbons provided that an incremental improvement in thermal performance can be achieved. 

This will be particularly important for the thermally sensitive applications such as refrigerated 

transport. The proof of performance is at a lower level in this sector than elsewhere and this is 

reflected in the following table: 

HFO-1234ze(E) HFO-1336mzzm(Z) HFO-1233zd(E) AFA-L1

gaseous liquid liquid liquid

Proof of performance 0 + + 0

Flammability ++ +++ +++ +++

Other Health & Safety + + + +

Global Warming +++ +++ +++ +++

Other Environmental + + + +

Cost Effectiveness (C) ++ ++ ++ ++

Cost Effectiveness (O) -- -- -- --

Process Versatility + + + +
May 2013 TEAP XXIV/7 Task Force Report 71

4.4.4 Barriers and restrictions

The major barriers to the substitution of alternatives in the panel sector are not primarily related to 

the technologies available but to the wide range of enterprises involved (both in size and location) 

and the broad spectrum of applications served. Versatility is a key necessity for any technology in the 

discontinuous sector, but no single solution has emerged as being as versatile as the ozone depleting 

substances replaced. This may act as a deterrent to early phase-out of the remaining HCFC use in 

Article 5 enterprises where local requirements need to be matched.

4.5 Polyurethane - spray

Polyurethane spray foam has been used for many years as an efficient means of insulating structures 

which would be difficult to insulate in other ways, because of shape or location An example would be 

that of an insulated road tanker. Another would be the insulation of large flat roofs which may not be 

as flat as might be presumed! More recently, however, polyurethane spray foams have emerged as a 

vital component of renovation strategies for existing buildings. Again, the efficiency and versatility 

of application, as well as the relative durability and thermal efficiency are all characteristics which 

have contributed to the rapid growth of PU spray foam in both developed and developing regions.

4.5.1 Historical perspective (including non-Article 5 / Article 5 Party differences)

Polyurethane spray foam differs from a number of other products in that it is manufactured (applied) 

on site. In this respect, the system needs to be more robust and resilient than most factory controlled 

foam processes. For example, the process needs to cope with a wide variety of ambient temperatures.

Once again, CFC-11 was the original blowing agent of choice in the pre-1990 period. At the time of 

the first transition, the three major spray foam markets were North America, Spain and Japan. In the 

early stages of the transition there was considerable optimism in North America that hydrocarbons 

(particularly cyclo-pentane) could be used successfully as a replacement for CFCs. However, a series 

of incidents when spraying in confined areas confirmed that the management of the process was too 

sensitive to be deployed on a commercial basis, despite the best efforts of Exxon and others to 

provide appropriate guidance. The net outcome was that the industry defaulted to HCFC-141b and 

the impact is shown in the graph below. However, because spray is a fairly emissive process, the 

transition was prioritised by the industry and much of the benefit from early transition was gained.

The absence of a good low-GWP alternative has meant that the industry around the world has 

struggled with the global warming impact of substitutes. Once of the major HCFC substitutes was 
72 May 2013 TEAP XXIV/7 Task Force Report

saturated HFCs (HFC-245fa in North America and HFC 365mfc/227ea in parts of Europe). In Japan, 

there was some hope that super-critical CO2 would signal the way forward but this has remained 

rather a niche technology. CO2 (water) blown foams have also been adopted in some areas but the 

quality of foams has been variable, especially from a thermal perspective. Such foams have, however, 

found widespread use as low density, gap filling foams to counter air infiltration in residential 

buildings. These foams tend to be completely open celled and do not offer particular value in other 

applications. The lack of a good low-GWP solution is reflected in the graph below which shows that 

the actual/projected avoided impacts are considerably lower than would be associated with a true 

low-GWP solution. 

Although the size of the PU spray foam market in Article 5 Parties was relatively small in 1990, the 

graph below illustrates the substantial growth than has occurred in the sector since then. The graph 

also illustrates that the phase-out of HCFCs is still some way off since projections out to 2020 

continue to indicate that the fact that the complete avoidance of ODS consumption is not yet 

predicted.

This is also reflected in the assessment of climate impacts, which are also sub-optimal, as they are in 

other non-Article 5 regions.
May 2013 TEAP XXIV/7 Task Force Report 73

4.5.2 Commercially available alternatives to Ozone Depleting Substances 

The commercially available technologies have been largely referenced already in the narrative, but 

can be summarised as follows: 

HCFC REPLACEMENT OPTIONS FOR PU FOAM FOR BUILDING/ CONSTRUCTION APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Spray foam

HFC-245fa, HFC-365mfc/277ea

Non-flammable High GWP Industry standard

Good foam properties

High operating costs but 

improved by using mixed 

HFC/ CO2 (water)

CO2 (water) Low GWP

Moderate foam properties 

-high thermal conductivity 

& high densityExtra thickness leading to a cost 

penalty

Non-flammable

Methyl Formate Low GWP

Flammable although 

blends with polyols may 

not be flammable

Safety concerns when used for 

this application

It is important to note that the impacts of the saturated HFCs have been reduced by co-blowing with CO2 

(water) in order to deliver a lower overall global warming impact. However, one of the other major drivers 

has been to reduce cost. As will be seen in Section 4.5.3, this may be an important approach for the future. 

It should also be noted that although hydrocarbons with appropriate boiling points are available, they are 

not currently seen as ‘options’ for this sector because of process flammability risks.

By contrast, HCOs (most notably methyl formate) have been used for some PU spray work. The potential of 

supplying the system to site as blended polyol is believed to contribute to the management of risk, but it is 

still unclear whether the hazards seen with hydrocarbons in confined spaces have been avoided using the 

slightly less flammable methyl formate. Work continues in this area, although some systems are already 

being used commercially. The performance of these ODS alternatives against the criteria for this report can 

be summarised as follows: 
74 May 2013 TEAP XXIV/7 Task Force Report

HFC-245fa HFC365mfc/227ea Super-critical CO2 CO2(water) Methyl 

Formate

Proof of performance +++ +++ ++ ++ +

Flammability ++ +(+) ++ +++ --

Other Health & Safety + + + - 0

Global Warming -- --- ++ ++ ++

Other Environmental 0 0 + ++ -

Cost Effectiveness (C) ++ ++ 0 ++ 0

Cost Effectiveness (O) -- -- + ++ ++

Process Versatility ++ ++ + + +

4.5.3 Emerging alternatives

Alongside the appliance sector, the PU spray foam sector is attracting the most interest for potential 

adoption of the unsaturated HCFCs/HFCs. The rapid growth rate for the sector overall, the absence of 

serious low-GWP contenders and the fact that relatively high emission rates make the climate impact 

more immediate all align to encourage the manufacturers to focus on this application.

HCFC REPLACEMENT OPTIONS FOR PU FOAM FOR BUILDING/ CONSTRUCTION APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Spray foam

Liquid Unsaturated HFC/HCFCs 

(HFOs Low GWP

High operating costs but 

improved by using mixed 

HFC/ CO2 (water)

First expected commercialization 

from 2013

Non-flammable Trials in progress

Low incremental capital cost

The cost of the alternatives remains the key question but this consideration is slightly diffused by the 

fact that the CO2 (water) technology developed around HFC-245fa and HC-365mfc/227ea looks 

transferable to the unsaturated blowing agents as well. Manufacturers are in the process of field trials 

and the development of fairly sophisticated life cycle assessments to ensure that they have assessed 

the environmental impacts correctly. The co-blowing solution does not detract significantly from the 

overall thermal performance of the foam and the introduction of a low-GWP solution of this type 

would clear the way for widespread use of PU spray foam in a wide variety of refurbishment 

applications over the next 30-50 years as global attention focuses increasingly on building energy 

efficiency in existing stock. A summary of these blowing agents against the report criteria is as 

follows: 

HFO-1234ze(E) HFO-1336mzzm(Z) HFO-1233zd(E) AFA-L1

gaseous liquid liquid liquid

Proof of performance 0 ++ ++ 0

Flammability ++ +++ +++ +++

Other Health & Safety + + + +

Global Warming +++ +++ +++ +++

Other Environmental + + + +

Cost Effectiveness (C) ++ ++ ++ ++

Cost Effectiveness (O) -- -- -- --

Process Versatility + ++ ++ +

4.5.4 Barriers and restrictions

Since the future of the sector rests largely on the emerging technologies, the main barriers relate to 

the economics and availability of the unsaturated blowing agents. Much of the PU spray foam activity 

in China remains reliant on HCFC-141b and there is reluctance to make a transition to a sub-optimal 
May 2013 TEAP XXIV/7 Task Force Report 75

solution when an emerging technology could out-perform it within 5 years. Various strategies are 

being considered including a two-step option via saturated HFCs. However, there is a need to gain 

commitment to the second conversion at the outset. 

4.6 Polyurethane – in-situ/block

One of the enduring advantages of polyurethane chemistry in general, and polyurethane foams in 

particular, is their ability to meet a broad range of applications. Since these applications can be 

diverse, ranging from cavity filling (e.g. buoyancy on leisure boats) to the fabrication of complex 

shapes required for pipe and flange insulation, the in-situ and block processes provide a resource to 

meet these needs. Self-evidently, these applications are also difficult to track in any organised way 

since they vary so much. Nevertheless, it is possible to track the manufacturing facilities that provide 

these products and services.

4.6.1 Historical perspective (including non-Article 5 / Article 5 Party differences)

Once again, the traditional blowing agent for these applications was CFC-11. It offered the versatility 

and the tolerance to be able to deal with the wide range of applications described. Accordingly, the 

natural replacement for CFC-11 was HCFC-141b which was the closest to a drop-in solution 

available at that time. However, even in the 1990-2000 period, there were a few block applications 

which were able to switch directly to hydrocarbons. Another application which moved to 

hydrocarbons directly was pipe-in-pipe which is broadly an in-situ process used for district heating 

pipe manufacture. These pipes had been particularly widely used in the centralised economies of the 

former Soviet Union, but have been more recently growing as a result of the growth in microgeneration (small-scale CHP).

For non-Article 5 Parties the switch from ozone depleting substances was generally smooth and by 

2005 most technologies were based on ODS substitutes, as shown in the graph above. However, 

when the climate impact is considered in the second of the two graphs (below), it is clear that one of 

the significant transitions was to relatively high-GWP substitutes, resulting in some missed climate 

opportunities which persist to the present day. The estimate of these is approximately 200 million 

tonnes CO2-eq across the non-A5 regions. Moving forward, it is estimated that a further 25 million 

tonnes CO2-eq of climate impact could be avoided by prompt action to introduce low GWP options in 

this sector.
76 May 2013 TEAP XXIV/7 Task Force Report

For block and in-situ foams in Article 5 regions the application area are once again varied, but 

include applications not widely seen in non-Article 5 regions. These include such items as 

thermoware, which are designed for keep food insulated from the ambient conditions. The graph 

below illustrates that the phase-out of CFC-11 in these enterprises was relatively slow and that the 

use of HCFC-141b remains fairly widespread and is likely to do so until at least 2020. This reflects 

the reality that this sector is heavily populated with small and micro enterprises, making the 

economies of scale unattractive for conversion. These enterprises have often been captured as 

umbrella projects centre around the systems houses that serve them. Indeed, a similar approach is 

likely to be adopted in a number of HCFC Phase-out Management Plans (HPMPs) over the next 5-10 

years.

Unsurprisingly, the ability to avoid high-GWP solutions has also been lacking in a number of these 

operations. It is estimated that around 315 million tonnes CO2-eq has been missed as a result of the 

absence of a cost-effective low-GWP solution and a further 50 million tonnes CO2-eq will be missed 

in the period to 2020 without further action.
May 2013 TEAP XXIV/7 Task Force Report 77

As will be seen in the following sub-sections, the technical alternatives do exist, but the deployment 

of those technologies remains a challenge. 

4.6.2 Commercially available alternatives to Ozone Depleting Substances 

The commercially available alternatives to HCFCs in the in-situ and block sectors are summarised in 

the following table: 

HCFC REPLACEMENT OPTIONS FOR PU FOAM FOR BUILDING/ CONSTRUCTION APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Insulated pipes (pipe-in-pipe for district central heating systems)and other in-situ systems

Cyclopentane 

Low GWP Highly flammable High incremental capital cost

Low operating costs Industry standard

Good foam properties

HFC-245fa, HFC-365mfc/277ea

Non-flammable High GWP

Good foam properties High operating costs 

CO2 (water)

Low GWP

Moderate foam properties

-high thermal 

conductivityNon flammable

Block foams for various applications including panels, pipe insulation section, etc

Cyclopentane & n-Pentane 

Low GWP Highly flammable High conversion costs, may be 

uneconomic for SMEs

Low operating costs Well proven technology

Good foam properties

HFC-245fa, HFC-365mfc/277ea

Non-flammable High GWP Low conversion costs

Good foam properties

High operating costs but 

improved by using mixed 

HFC/ CO2 (water)

CO2 (water)

Low GWP

Moderate foam properties 

-high thermal conductivity 

& poor ageingExtra thickness leading to a cost 

penalty

Non flammable

As with other thermal insulation sectors, saturated HFCs are used in block foams with a CO2 (water) 

co-blowing agent to limit climate impact and also to optimise the cost/performance relationship. It 

has generally been found that levels of saturated HFC can be lowered in these formulations to around 

50-60% of the blowing agent mix without having a detrimental effect on thermal performance. The 
78 May 2013 TEAP XXIV/7 Task Force Report

blowing agent criteria for block and in-situ foams are shown below. In some instances, more than one 

rating is providing reflecting the fact that there is a disparate set of processes represented in this 

category.

c-pentane n-pentane HFC-245fa HFC365mfc/227ea CO2(water)

Proof of performance +/++ +/++ ++ ++ ++

Flammability --- --- ++ +(+) +++

Other Health & Safety 0 0 + + -

Global Warming +++ +++ -- --- ++

Other Environmental - - 0 0 ++

Cost Effectiveness (C) -- --- ++ ++ ++

Cost Effectiveness (O) ++ +++ -- -- +

Process Versatility ++ ++ ++ ++/+++ +/++

4.6.3 Emerging alternatives

In this instance, the Task Force has chosen to categorise methyl formate in the emerging alternative 

category. This reflects the fact that some of the applications across the sector have yet to be trialled 

using this HCO blowing agent. There are expected to be some limitations based on densities 

achievable and risks of corrosion with some equipment, but the availability of a relatively low cost, 

low-GWP solution with lower flammability than the pentanes may still prove of relevance for the 

sector going forward.

HCFC REPLACEMENT OPTIONS FOR PU FOAM FOR BUILDING/ CONSTRUCTION APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Block foams for various applications including panels, pipe insulation section, etc

HCO (Methyl Formate) Low GWP Higher density required Density increase necessary 

through role of MF as a solvent

Liquid Unsaturated HFC/HCFCs 

(HFOs

Low GWP High operating costs Trials in progress

Non-flammable 

The option of liquid unsaturated HCFCs/HFCs in this sector is legitimate, but there is some concern 

that price and geographic availability may be significant limiting factors. Again, co-blowing with 

CO2 (water) may prove helpful for cost reasons, but uptake is expected to be more limited than in 

other sectors of the foam industry. The following table shows an assessment against the report 

criteria: 

Methyl Formate HFO-1336mzzm(Z) HFO-1233zd(E) AFA-L1

liquid liquid liquid

Proof of performance 0/+ ++ ++ 0

Flammability -- +++ +++ +++

Other Health & Safety + + + +

Global Warming +++ +++ +++ +++

Other Environmental + + + +

Cost Effectiveness (C) ++ ++ ++ ++

Cost Effectiveness (O) -- -- -- --

Process Versatility + ++ ++ ++

4.6.4 Barriers and restrictions

One of the major barriers to transition in this sector is the size and location of the enterprises 

involved. The provision of sophisticated low-GWP alternatives does not extend easily to these more 

diffuse networks and the effectiveness of transitions relies massively on the competence and 
May 2013 TEAP XXIV/7 Task Force Report 79

commitment of the systems houses supplying the small and micro-enterprises. Efforts are needed to 

raise the profile of these operations with blowing agent technology providers and their supply 

networks.

4.7 Polyurethane – integral skin

Integral skin foams are the one group of foams using HCFCs and saturated HFCs which are not 

primarily used for thermal insulation purposes. They sub-divide into two types – ‘rigid integral skin’ 

(typically items such as steering wheels in automobiles) and ‘flexible integral skin’ (typically 

covering items such as shoe soles and some packaging foams). As the name suggests, the primary 

feature of integral skin products is their ability to encapsulate a relatively low density core (for 

weight saving purposes) with an integrated skin which is made from the same material and in the 

same process. As a polymer, polyurethane is particularly versatile in forming a resilient skin when 

moulded and this provides a level of utility which is rarely seen in other product types.

4.7.1 Historical perspective (including non-Article 5 / Article 5 Party differences)

As with many of the other foam sectors, PU Integral Skin foams relied on CFC-11 as their blowing 

agent in the pre-1990 period. With thermal performance not being a primary requirement, the 

blowing agent was chosen more for its ability to process well and to be used safely. Hence boiling 

points and flammability limits were key. When the CFC-phase-out was mooted in the sector, the 

natural transition was to HCFC-141b, even though there was some concern initially about its 

potential for limited flammability. One other characteristic to consider is the fact that most of the 

blowing agent is lost from these products within the first two years. Hence any environmental 

impacts are magnified by their rapid pathways to the surroundings. Other options used in the sector 

have been HCFC-22 and or HCFC-22/142b blends. 

The Foams Technical Options Committee has not routinely monitored consumption in this sector of 

use, since one of the initial purposes of tracking consumption was to estimate long-term banks in 

products. However, as the focus moved to quantifying emissions, there have been some one-off 

assessments for the purposes of reports like this. Nevertheless, there is no set of base data available at 

this time which allows the assessment of missed opportunities and future potential avoidance. The 

Task Force is considering an attempt to fill this data gap in time for the Final Report in November 

2013, although source data such as the AFEAS data collection reports have collected information at 

relatively high level – e.g. closed cell and open cell. It seems likely that rigid and flexible integral 

skin may have been categorised differently within this data set making it difficult to isolate the 

tonnages of blowing agent allocated to each type. This serves to illustrate that product definition 

remains a challenge in this sector.

Of the estimates that do exist, the energy-absorbing automotive market has been believed to consume 

around 50,000 tonnes of PU per year. However, formulations in the sector use typically less than 5% 

by weight of blowing agent making the annual consumption of blowing agent relatively modest at 

1,500-2,500 tonnes per annum. Although there are a large number of other Integral Skin Foam 

applications to consider, it is estimated that no more than 10,000 tonnes goes to this sector annually, 

making its significance relatively modest.

Concern over flammability has limited the use of hydrocarbons in this application, but it is known 

that some manufacturers have adopted the technology. Other options adopted following the phase-out 

of HCFCs have included HFC-134a and HFC-245fa. These might be considered as detrimental 

choices from a climate perspective but produce high quality products, especially in the shoe sole 

application. The other technology option that has been the focus of much attention has been CO2 

(water). However, early experiences with this technology were dominated by poor skin quality. The 

use of in-mould coatings was trialled but the economics of this approach were understandably less 

favourable. Several major systems houses have worked further on this technology since and 
80 May 2013 TEAP XXIV/7 Task Force Report

acceptable commercial systems are no available. The following section looks at the commercially 

available options currently.

4.7.2 Commercially available alternatives to Ozone Depleting Substances 

The following table lists the commercially available options as of today: 

HCFC REPLACEMENT OPTIONS FOR INTEGRAL SKIN PU FOAMS FOR TRANSPORT & 

FURNITURE APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Integral skin foams

CO2 (water) 

Low GWP Poor skin quality Suitable skin may require inmould-coating – added expense

Low conversion costs Well proven in application if skin 

acceptable

n-Pentane

Low GWP Highly flammable High conversion costs, may be 

uneconomic for SMEs

Low operating costs Low operating costs

Good skin quality Well proven in application

Shoe-soles

CO2 (water) 

Low GWP Well proven in application with 

polyester polyol technology

Low conversion costs

Skin quality suitable for 

sports shoe mid-soles

HFC-134a or HFC-245fa Used to give required 

skin in town shoes High GWP/Cost

The specific ranking of these blowing agent options is shown in the table below. 

n-pentane HFC-134a HFC-245fa CO2(water)

Proof of performance ++ ++ + ++

Flammability --- +++ ++ +++

Other Health & Safety 0 + + -

Global Warming +++ --- --- ++

Other Environmental - 0 0 ++

Cost Effectiveness (C) --- ++ ++ ++

Cost Effectiveness (O) +++ -- -- +

Process Versatility ++ ++ ++ 0

4.7.3 Emerging alternatives

The area of most interest with respect to emerging technologies is the potential use of oxygenated 

hydrocarbons (HCOs). Both methyl formate and methylal are being considered for these applications 

and the early indications are that they could be significant future alternatives in the sector. Although 

both a flammable, the level of flammability is less than that associated with pure hydrocarbons. There 

is also the potential that systems houses may be able to formulate blended systems in such a way as to 

avoid flammability issues in the workplace. One area of concern for methyl formate is the potential 

corrosion of moulds, but at the levels of addition, this may not be a problem in practice. The other 

issue relating to both HCOs the high solvency power of the blowing agents which could lead to some 

softening of the skins. The following table summarises the issues:
May 2013 TEAP XXIV/7 Task Force Report 81

HCFC REPLACEMENT OPTIONS FOR INTEGRAL SKIN PU FOAMS FOR TRANSPORT & 

FURNITURE APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Integral skin foams

Methyl formate

Low GWP

Flammable although 

blends with polyols may 

not be flammable

Moderate conversion costs 

Good skin quality Moderate operating 

costs

Newly proven in application 

Methylal

Low GWP

Flammable although 

blends with polyols may 

not be flammable

High conversion costs, may be 

uneconomic for SMEs

Good skin quality Moderate operating 

costs

No industrial experience 

Shoe-soles

Methyl formate

Low GWP

Flammable although 

blends with polyols may 

not be flammable

Moderate conversion costs 

Good skin quality Moderate operating 

costs

Newly proven in application 

Methylal

Low GWP

Flammable although 

blends with polyols may 

not be flammable

High conversion costs, may be 

uneconomic for SMEs

Good skin quality Moderate operating 

costs

No industrial experience 

Again, the specific performance ranking of the blowing agents is shown in the table below: 

Methylal Methyl Formate

Proof of performance + ++

Flammability -- --

Other Health & Safety 0 0

Global Warming ++ ++

Other Environmental - -

Cost Effectiveness (C) + 0

Cost Effectiveness (O) ++ ++

Process Versatility +(+) +(+)

It is noteworthy to mention that unsaturated HFCs/HCFCs are not seen as a realistic emerging 

technology in this sector because of the cost implications and the lack of any significant performance 

enhancement. 

4.7.4 Barriers and restrictions

There are no fundamental barriers to the introduction of the emerging technologies, although pilot 

projects on the pre-blending of HCOs in polyols will be necessary. There have been some concerns in 

the past about the implications of the limited supplier base and access to intellectual property, 

although these have been largely addressed. However, the biggest challenge to the replacement of any 

remaining use of ozone depleting substances will be the roll-out of these technologies on a 

sufficiently widespread basis. 

If the widespread introduction of HCOs can be successful, there is likely to be the gradual 

replacement of both saturated HFCs (HFC-134a and HFC-245fa) and CO2 (water) blown technologies. 

The replacement of saturated HFCs, will certain deliver some additional climate benefits.
82 May 2013 TEAP XXIV/7 Task Force Report

4.8 Extruded polystyrene - board

Extruded polystyrene board is unique amongst the foam sectors considered in this report in that it is 

blown exclusively with gaseous blowing agents. This is a consequence of the extrusion process. 

Extruded polystyrene (XPS) should not be confused with expanded polystyrene (EPS – also 

sometimes called ‘bead foam’) which uses pre-expanded beads of polystyrene containing pentane. 

EPS has never used ozone depleting substances and is seldom addressed in UNEP Reports for the 

Montreal Protocol. XPS is used primarily as a building insulation and often competes with PU 

Boardstock. Its particular competitive advantage is in relation to its moisture resistance which makes 

it especially useful for under-floor insulation applications. There is another form of XPS known as 

‘Sheet’ which is typically used for non-insulating applications such as leisure products (e.g. surf 

boards) and packaging materials. XPS sheet exited from CFC use early in the history of the Montreal 

Protocol and has used hydrocarbons almost exclusively ever since.

4.8.1 Historical perspective (including non-Article 5 / Article 5 Party differences)

The blowing agent of choice for XPS manufacturers in the pre-1990 period was CFC-12. Although 

this was allocated the same ozone depletion potential as CFC-11, the global warming potential was 

significantly higher, being well in excess of 10,000 when assessed over a 100 yr time horizon. 

Combined with the relatively significant losses of blowing agent during the processing of XPS, this 

made the product the focus of close attention from the introduction of the Montreal Protocol in 1987. 

It also put a priority on the early identification of alternatives.

Initial work in the global XPS industry focused on the switch to HCFCs and, in particular, 

combinations of HCFC-22 and HCFC-142b. HCFC-22 was already established as a readily-available, 

well-studied alternative based on its widespread use as a refrigerant. However, the drawback was that 

HCFC-22 was more soluble in polystyrene than CFC-12 and would defuse from foam cells more 

easily. The purpose of using HCFC-142b was therefore to ensure that sufficient blowing agent 

remained in the product over the lifecycle of the product to deliver reliable thermal performance. 

Since HCFC-142b was typically more expensive than HCFC-22, the ratio of the blends used tended 

to reflect the priority that was being placed on long-term thermal performance. 

The limited missed opportunity from an ozone perspective, as shown in the graph above, is testimony 

to the rapid transition from CFC-12 that was managed by the industry in the decade from 1990 to 

2000. However, the transition from HCFCs proved to be considerably more challenging. 
May 2013 TEAP XXIV/7 Task Force Report 83

The major point to emerge in the period of HCFC phase-out was just how varied the markets for XPS 

were in different regions of the world. The North American market was primarily in sheathing 

products for the timber-framed residential market. This is a highly cost-sensitive market with large 

surface areas of relatively thin board being applied. This contrasted significantly with the European 

market where products were primarily for the commercial building market, requiring thicker profiles 

with higher added value. In Japan, the market was something of a hybrid of these two extremes, but 

was also governed by fire codes that would permit the use of hydrocarbon blowing agents in products 

for some applications. This opened up an alternative which was not likely to be available for either 

Europe or North America.

The graph above illustrates the dominance of the global warming potential of CFC-12 in the 1990-

2000 period, even though it was in use for a relatively short time. However, with HCFC-22 and 

HCFC-142b themselves having global warming potentials above 1500, the climate impact was 

significant. The impact was also more long-lasting than it might have been because of the differences 

in regional approach being proposed and the difficulties that this created for the multi-national 

producers. For example, in Germany (by far the largest market for polystyrene insulation in Europe), 

there was substantial pressure on an early phase-out of HCFCs. This led to the development of CO2

blown technology (in several variants) for the more tolerant European product range. Even then, the 

technology could not make all grades of product, involved substantial capital cost and also was 

governed by a substantial base of patents. This was not unreasonable based on the research and 

development investments that had been made. 

The emergence of such technologies did not help solve the transition challenge in North America 

because the product portfolio was totally different and the costs the industry could absorb were also 

more limited. This left the North American industry looking primarily at variants of gaseous HFC 

solutions including HFC-134a and HFC-134a/152a blends. Within the blend approach, HFC-134a 

was seen to fulfil the former role of HCFC-142b, while HFC-152a would be more emissive, in similar 

fashion to HCFC-22. Although there would be more emission in the short term from HFC-152a, this 

was compensated for by the relatively low GWP of HFC-152a (~ 150). The emission rates did, 

however, raise other issues, such as the impact of local VOC regulations. The net result of these 

uncertainties was that transition out of HCFC-142b and HCFC-22 did not occur in North America 

until 2009/10, with the alternatives not having a substantially better climate profile than the HCFCs 

they replaced.

The overall lost opportunity arising from these transitional challenges is in the order of 2.4 billion 

tonnes making it far and away the most significant individual sector in its contribution to the ‘missed 
84 May 2013 TEAP XXIV/7 Task Force Report

opportunity’ discussion. However, the converse argument is that its prompt action over CFC-12 was 

one of the greatest contributors to early gains for the Montreal Protocol.

The development of XPS markets in Article 5 countries has been more difficult to track, but the 

graph below illustrates that close to exponential growth has occurred in the period from 1990 to date 

and this is expected to continue through until 2020. One of the main engines of this growth has been 

China, where the focus on building energy efficiency, coupled with the relatively low investment 

levels for small extruders has created a network of regional and sub-regional producers.

As much of this growth has taken place since 2005, the plants installed have tended to bypass CFCs 

and are largely based on HCFC-142b and HCFC-22. However, as a result of cost and availability, 

HCFC-22 has understandably been the dominant component of most blends. The challenge now 

facing the industry in Article 5 countries is which of the technology options being practiced in nonArticle 5 Parties should be followed. The use of HFC blends represents the least-cost transition from 

an investment perspective, but the adoption cost perspective. However, they do raise important issues 

in terms of product flammability. The graph below illustrates the on-going impact of these selection 

decisions on past and future climate impacts. 
May 2013 TEAP XXIV/7 Task Force Report 85

The implication of previous decisions may have led to a missed opportunity in this sector of 

approximately 1.18 billion tonnes of CO2-eq in Article 5 Parties, although it may be harsh to convey 

the situation in these terms bearing in mind the uncertainties about substitutes that continue to exist. 

The opportunity going forward offers the prospect of climate impact avoidance in the order of nearly 

900 million tonnes of CO2-eq. in the period to 2020, although achieving this will depend on the 

availability of meaningful alternatives in due time.

4.8.2 Commercially available alternatives to Ozone Depleting Substances 

The following table illustrates the commercially available alternatives in the extruded polystyrene 

sector: 

HCFC REPLACEMENT OPTIONS FOR XPS FOAM

SECTOR/OPTION PROS CONS COMMENTS

Extruded Polystyrene Foams 

Butane Low GWP Highly flammable

Low operating costs

HFC-134a/HFC-152a

Non-flammable High GWP

Good foam properties, 

especially thermal 

performance

Medium/high operating costs

CO2 /Ethanol/DME

Low GWP, low unit cost Small operation window Difficult to process especially for 

more than 50mm thickness board 

Non-flammable Flammable co-blowing 

agent

Need ethanol and DME as coblowing agent 

As described earlier in this section, these three alternatives describe the primary options available in 

each of the three main non-Article 5 regions of the world. It should be noted that blends of saturated 

HFCs (HFC-134a/HFC-152a) are substantially used in Europe and, to a lesser extent in Japan, 

primarily by smaller producers who do not have the access to CO2 technology or serve markets that 

cannot accept the flammability of hydrocarbon solutions. The assessment of these blowing agents via 

the criteria of this report is shown in the following table: 

butane HFC-134a/

HFC-152a

CO2 with ethanol 

or DME

Proof of performance ++ +++ ++

Flammability --- +++ ++

Other Health & Safety 0 + +

Global Warming +++ --- +++

Other Environmental - 0 0

Cost Effectiveness (C) -- ++ ---

Cost Effectiveness (O) +++ -- ++

Process Versatility ++ ++ +

4.8.3 Emerging alternatives

HCFC REPLACEMENT OPTIONS FOR XPS FOAM

SECTOR/OPTION PROS CONS COMMENTS

Extruded Polystyrene Foams 

Gaseous unsaturated HFCs 

(HFOs) Low GWP High unit cost Semi-commercial availability –under evaluation
86 May 2013 TEAP XXIV/7 Task Force Report

For all the reasons expressed in this section, there is considerable interest in the potential of 

unsaturated gaseous HCFCs/HFCs as either blowing agents or co-blowing agents with HCOs such as 

ethanol or dimethyl ether (DME). The technological solution has the potential of becoming a relative 

standard in the industry, but the key deciding factor in that respect will be the cost. This aspect is 

reflected in the criteria assessment below:

HFO-1234ze(E)

Gaseous

Proof of performance +

Flammability ++

Other Health & Safety +

Global Warming +++

Other Environmental +

Cost Effectiveness (C) ++

Cost Effectiveness (O) --

Process Versatility ++

4.8.4 Barriers and restrictions

For the HCFC consuming market in China and elsewhere, the challenge is to decide whether there is 

a transitional option that moves to a low-GWP alternative before the availability of unsaturated HFCs 

such as HFO-1234ze(E) is secured. It is clear that hydrocarbons would have been an obvious option 

and that would have been a high priority for a number of producers in China operating under the 

HCFC Phase-out Management Plan there. However, in recent years, there have been a series of fires 

(mostly in the construction phase of major building projects) which have caused a reaction against 

organic insulation materials in general and XPS in particular. One of the underlying problems has 

been the inconsistency in use of flame retardants within XPS formulations, with recycled feedstock 

not being properly characterised in some instance. The XPS industry is making a strong case that 

properly formulated XPS board can be used safely throughout its lifecycle, but these developments 

have created a further barrier to the introduction of hydrocarbons as blowing agents at this sensitive 

time. 

The introduction of unsaturated HFCs will certainly avoid such a controversy, but the availability of 

such technology in Article 5 Parties is uncertain – particularly when the technology is yet to be 

commercially adopted elsewhere. There is also the unanswered question concerning the impact on 

cost. A temporary switch to saturated HFC blends could ensure that the Montreal Protocol objectives 

are met, but this will do little to benefit the climate when over 1 billion tonnes of CO2-eq could be 

avoided by a more benign solution.

4.9 Phenolic foams

Phenolic foams are manufactured by a number of different processes, many of which shadow those 

already discussed for polyurethane foams. The largest markets for the product are as phenolic 

boardstock (manufactured by continuous lamination) and block foams, used primarily for fabricating 

pipe work insulation. Although the product made an entry into the North American market in the 

early 1980s, the particular technology was dogged with problems. As a result, there is little use of 

phenolic foam in that region today. However, successful phenolic boardstock technologies emerged 

in both Europe and Japan, with sales of the product continuing to grow, not only because of overall 

increases in the demand for thermal insulation, but also because of gains in market share. Phenolic 

foam’s main competitive advantage rests in its intrinsic fire and smoke properties. However, since it 

is made by an emulsion process, it also offers smaller cells which result in improved thermal 

performance. More recently, the product has begun to emerge on the Chinese market - in part as a 

response to concerns over recent fires.
May 2013 TEAP XXIV/7 Task Force Report 87

The use of phenolic foam as pipework insulation also stems from the intrinsic fire and smoke 

properties of the product and the growth of the product’s use has been particularly strong in regions 

where internal fire regulations are strict or where the high rise nature of construction requires 

additional fire precautions.

4.9.1 Historical perspective (including non-Article 5 / Article 5 Party differences)

Apart from the occasional phenolic block foam plant, the vast majority of installed phenolic foam 

capacity was in non-Article 5 regions in the pre-1990 period. As with other technologies, CFC-11 

was the predominant blowing agent as phenolic foam technologies became established during the 

mid/late 1980s. In line with other technologies, the phenolic foam industry was able to manage a CFC 

transition to HCFC-141b in the mid-1990s. However, there was more concern at that stage about 

moving directly to hydrocarbons (as the bulk of the PU boardstock industry had done) for fear of 

compromising the intrinsic fire properties. Nevertheless, when the subject was re-visited in the late 

1990s ahead of the pending HCFC phase-out, it was found that the fears were unsubstantiated and the 

fire properties held up, even with hydrocarbon blowing agents inside. However, hydrocarbon was not 

possible for discontinuous block foam plants because of process risks and saturated HFCs (typically 

HFC-365mfc/227ea) were adopted instead. 

In one specific phenolic boardstock technology, 2-chloropropane had been used as an alternative to 

CFC-11from the outset. Although the blowing agent is chlorinated, it has such a short atmospheric 

lifetime that it has never been a candidate for inclusion under the Montreal Protocol – along with a 

number of other short-lived compounds. Interestingly, 2-chloropropane could therefore have been 

used as an alternative to HCFC-141b in the earlier transitions, but this never widely trialled –

possibly because of patent constraints at the time.

The graph below illustrates the impact of relatively trouble-free and timely transitions across the 

industry. The delay in the implementation of non-ODS substitutes will have resulted in some 

contribution to the 7,500 ODP tonne ‘missed opportunity’, but the proportion will have been small. 

The equivalent graph (overleaf) for climate impacts in non-Article 5 countries shows a similar, and 

relatively non-controversial, transitional impact. However, the persisting shortfall against the ‘best 

available option’ is indicative of the continuing use of saturated HFCs in the phenolic block foam 

sector. Since most of this product is destined for pipe insulation, efforts have been made to find 

alternative manufacturing strategies to bypass the need for HCFCs. More recently, in markets where 

there is sufficient demand for pipe insulation of a specific dimension, it has been possible to transfer 
88 May 2013 TEAP XXIV/7 Task Force Report

substantial portions of the previous production to continuous pipe section laminators. This, in turn, 

has enabled a shift from saturated HFCs to hydrocarbon (typically pentane) blowing agents. 

The overall missed opportunity in climate terms for phenolic foam is estimated to be less than 50 

million tonnes CO2-eq in non-Article 5 countries. Moving forward the maximum additional saving 

achievable in the period through to 2020 is likely to be no more than 5 million tonnes CO2-eq.

For Article 5 regions, the first thing to note is the relatively low level of consumption involved. 

Indeed, the very few block foam manufacturers in the pre-2000 period elected to run their plants 

through to CFC phase-out and then close them down. This explains the lack of any actual 

consumption avoided in the decade from 1990-2000.

From 2000 onwards, new capacity began to emerge, but this was either already based on HCFCs (for 

discontinuous processes) or on hydrocarbons for continuous lamination processes. With phenolic 

boardstock demand being the continuing driver of growth, particularly in China, the significance of 

any remaining HCFC use has continued to diminish. This is also reflected in the climate assessment 

shown in the following graph. The dominance of hydrocarbon in more recent years means that there 
May 2013 TEAP XXIV/7 Task Force Report 89

is now little to gain from a climate perspective for further action in the phenolic foam sector, with 

maximum potential savings being less than 300,000 tonnes of CO2-eq.

Perhaps one point to retain in mind throughout these discussions is that the analysis has not tried to 

adjust for variations in energy efficiency between technology options. This would have been too 

complex in sectors where the use of insulation foams is not pre-determined. However, it is worth 

recalling that there could still be substantial interest in phenolic boardstock manufacturers 

considering solutions around unsaturated HFC/HCFC technologies if they were to deliver improved 

thermal performance, particularly in applications where space is constrained.

4.9.2 Commercially available alternatives to Ozone Depleting Substances 

The following table sets out the commercially available alternatives for the phenolic foam sector: 

HCFC REPLACEMENT OPTIONS FOR PF FOAM FOR BUILDING/ CONSTRUCTION APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Continuous processes (including flexibly-faced lamination and pipe section manufacture)

n- pentane/iso-pentane 

Low GWP Highly flammable High incremental capital cost

Low operating costs Industry standard

Good foam properties

HFC-365mfc/277ea

Non-flammable High GWP

Good foam properties High operating costs 

2-chloropropane

Low GWP Negligible ODP

Non flammable

Block foams for various applications including panels, pipe insulation section, etc

HFC-365mfc/277ea

Non-flammable High GWP Low conversion costs

Good foam properties

High operating costs but 

improved by using mixed 

HFC/ CO2 (water)
90 May 2013 TEAP XXIV/7 Task Force Report

The lack of low-GWP alternatives for discontinuous block foams signals the need for further work in 

this area. However, the ranking of these options against the report criteria can be summarised as 

follows:

n-pentane

i-pentane

2-chloropropane HFC-365/227ea

Proof of performance +++ +++ +

Flammability --- 0 ++

Other Health & Safety 0 0 +

Global Warming +++ +++ ---

Other Environmental - 0 0

Cost Effectiveness (C) --- - ++

Cost Effectiveness (O) +++ + --

Process Versatility ++ + ++

4.9.3 Emerging alternatives

As with other sectors, there is considerable focus on the potential of unsaturated HFCs/HCFCs.

HCFC REPLACEMENT OPTIONS FOR PF FOAM FOR BUILDING/ CONSTRUCTION APPLICATIONS

SECTOR/OPTION PROS CONS COMMENTS

Continuous processes (including flexibly-faced lamination and pipe section manufacture)

Unsaturated HFC/HCFC liquids

Non-flammable Low conversion costs Limited trials at this stage

Good foam properties High operating costs 

Block foams for various applications including panels, pipe insulation section, etc

Unsaturated HFC/HCFC liquids

Non-flammable Low conversion costs Limited trials at this stage

Good foam properties High operating costs

One drawback for the adoption of this technology in phenolic foam is that there is no CO2(water) coblowing to offset some of the cost. Another option might be to use unsaturated HFCs/HCFCs as 

components of blends with hydrocarbons or other blowing agents. However, care will need to be 

taken with discontinuous block foams to avoid process flammability issues. The following table 

summarises the current status of these emerging options with respect to phenolic foam.

HFO-1336mzzm(Z) HFO-1233zd(E) AFA-L1

liquid liquid liquid

Proof of performance 0 - --

Flammability +++ +++ +++

Other Health & Safety + + +

Global Warming +++ +++ +++

Other Environmental + + +

Cost Effectiveness (C) ++ ++ ++

Cost Effectiveness (O) -- -- --

Process Versatility +(+) +(+) +(+)

4.9.4 Barriers and restrictions

The main technical barriers to the transition to unsaturated HFCs/HCFCs have already been set out in 

the previous section and these need to be addressed in a first stage assessment. However, even if the 

technical hurdles are overcome, the investment case may not be compelling for the transition out of 

saturated HFCs in the discontinuous block foam sector in view of the small quantities consumed. It 

may require market pressure on the continued use of saturated HFCs or evidence of significant 

thermal performance improvements to provide additional support for the next transition step.
May 2013 TEAP XXIV/7 Task Force Report 91

5 Fire protection alternatives to Ozone Depleting Substances

Executive Summary

Ozone depleting substances (ODS) used as fire extinguishants possess unique efficacy and safety 

properties that serve as a basis of fire protection systems where the application of water (by hose 

stream or sprinkler heads), dry chemical agents, or aqueous salt solutions is problematic. This is 

especially true in high-value, commercial electronics environments and in military systems, to name 

only two of many applications where such systems had many serious technical disadvantages.

Commercially available, technically proven alternatives to ODS for Fire Protection have been 

developed and include: halocarbon agents, e.g., HFCs and a fluoroketone (FK); inert gases, e.g., 

nitrogen and argon and their blends; carbon dioxide; water mist technologies; inert gas generators; 

fine solid particles (powders); dry chemicals; and aqueous film-forming foam. Several 

environmentally sound alternatives to ODS fire extinguishing agents for both total flooding and local 

applications uses have been introduced to the market. If an environmentally sound alternative agent 

works in any specific application, there is no barrier to its adoption other than economic 

considerations. Additional environmentally sound alternatives are presently under development that 

may increase the number of applications where environmentally sound alternatives are technically 

viable.

The production of PFCs and HFCs for use in fire extinguishing systems and portable fire 

extinguishers as well as the production of alternatives (without negative environmental impacts) to 

these agents for uses in the same applications is performed by very few manufacturers, all of whom 

treat the information on their historical, present and projected production as proprietary. Without a 

clear understanding of these production levels for the alternatives without negative environmental 

impacts, and also for the PFCs and HFCs, there is no basis for making a sound judgment about the 

overall utility of any alternatives in replacing PFCs and HFCs in the fire protection sector.

Nevertheless, we can say that the fire protection community has acted responsibly in dealing with 

what have turned out to be unsuitable alternatives from an environmental impact perspective. The 

availability of several HFCs that collectively could perform as well as the PFCs in certain 

applications, and at the same time present a more favorable environmental impact, led to the collapse 

of the use of PFCs in those applications.

However, the need for chemical agents remains as inert gases, water mist and other agents are not 

suitable for many fire protection applications that had previously used halon. HFCs have filled that 

role and, since about 2005, a fluoroketone (FK) has increasingly become more accepted. There is no 

evidence to suggest that this FK is or is not living up to the expectations of the fire protection 

industry, which is still evaluating alternatives that have low environmental impacts.

The use of HCFCs in fire protection is declining, with the only total flood agent being provided for 

the maintenance of legacy systems that are themselves phasing out. Only HCFC-123 is used in any 

quantity in portable extinguishers and if the development of 2-Bromo-3,3,3-trifluoropropene proves 

to be commercially successful, it would be the natural replacement for it and halon 1211 –

particularly in the aviation industry.

5.1 Introduction 

This section addresses the requirements of “Decision XXIV/7: Additional information on alternatives 

to ozone-depleting substances” (given in chapter 1) as it pertains to fire protection. The Halons 

Technical Options Committee (HTOC) has provided these responses at the request of the Task Force 

addressing the Decision.
92 May 2013 TEAP XXIV/7 Task Force Report

The production and consumption of halons used in fire protection ceased in non-Article 5 Parties on 

January 1, 1994 and ceased elsewhere on January 1, 2010. The production and consumption of 

HCFCs for use in fire protection continues. Ozone depleting substances (ODS) used as fire 

extinguishants possess unique efficacy and safety properties that serve as a basis of fire protection 

systems where the application of water (by hose stream or sprinkler heads), dry chemical agents, or 

aqueous salt solutions is problematic, especially in high-value commercial electronics environments

and in military systems, to name only two of many applications where such systems had many serious 

technical disadvantages. 

Development of alternatives to ODS fire extinguishing agents, beginning in the early 1990’s, has 

progressed steadily and is now relatively mature. Interest remains, however, in development of new 

alternatives that offer further advancements in efficacy, safety, and environmental characteristics. 

This section summarizes the alternatives to ODS fire extinguishing agents that have achieved a 

significant presence in the marketplace, their key physical, safety, and environmental characteristics, 

and the status of prospective new alternatives that have yet to be commercialized. 

The following terms, used in the tables below, have the meanings indicted. 

Efficacy refers to suitability for fire extinguishing. Values of minimum design concentrations (MDC) 

are given for Class A and Class B hazards. [1]

Agent toxicity is benchmarked against the maximum agent concentration in air for which use in 

normally occupied spaces is allowed in many jurisdictions. The exposure limit for halogenated agents 

is related to inhalation toxicity and the risk of causing an adverse cardiac effect. The exposure limit is 

usually one of the following: [2]

(a) the NOAEL (No Observed Adverse Effect Level) value; or

(b) the LOAEL (Lowest Observed Adverse Effect Level) value; or

(c) a value based on PBPK (physiologically-based pharmaco-kinetic) modeling.

For the use of inert gas agents, other than carbon dioxide, in normally occupied spaces, the limiting 

agent concentration is related to the minimum allowed residual oxygen concentration achieved after 

discharge. On this basis the limiting inert gas agent concentration has been set at 52 vol% (See ISO 

14520-1).

Carbon dioxide is not suitable for use as a total flooding fire extinguishing agent in normally 

occupied spaces owing to its toxicity.

Safety characteristics are taken to mean with respect to aspects of an agent that relate to safe 

operational and handling activities.

Environmental characteristic refers to ozone depletion potential (ODP) and GWP (100-year Global 

Warming Potential) or other characteristics, if applicable.

The use of ODS in fire protection applications in high ambient temperatures and high urban density 

cities does not require special attention, i.e. they have no impact on the use. 

The use of ODS in fire protection applications at low ambient temperatures (below -20 C) is 

addressed. 

1

See ISO 14520 parts 5, 8, 9, 10, 12, 13, 14, and 15

2

See ISO 14520-1:2006, Annex G (informative), Safe personnel exposure guidelines.
May 2013 TEAP XXIV/7 Task Force Report 93

5.2 Response to Question 1 (a)

5.2.1 Commercially Available, Technically Proven Alternatives to ODS for Total Flooding 

Fire Protection Using Fixed Systems

In the tables below, cost effectiveness is represented by an index that is benchmarked against carbon 

dioxide total flooding systems, averaged over a wide range of application sizes, exclusive of the cost 

of pipe, fittings and installation and is based on 2003 data. Owing to commercial confidentiality, it 

has not been possible to use more current data, but nevertheless the indices are believed to be 

relatively accurate.

5.2.1.1 Halocarbon Agents

Agent FK-5-1-12 HFC-23 HFC-125 HFC-227ea

Efficacy For use in occupied 

spaces

MDC(A)3= 5.3 

vol%

MDC(B) = 5.9 

vol%

For use in occupied 

spaces

MDC(A) = 16.3 

vol%

MDC(B) = 16.4 

vol%

 Suitable for 

inerting some 

flammable 

atmospheres at 

concentrations 

below the LOAEL 

value. 

 Suitable for use at 

low temperatures 

(below -20 C).

For use in occupied 

spaces

MDC(A) = 11.2

vol%

MDC(B) = 12.1 

vol%

For use in occupied 

spaces

MDC(A) = 7.9

vol%

MDC(B) = 9.0 

vol%

Toxicity NOAEL = 10 vol% 

LOAEL > 10 vol%

NOAEL = 30 vol%

LOAEL > 30 vol%

NOAEL = 7.5 

vol%

LOAEL = 10 vol%

 Approved for use 

in occupied spaces 

at up to 11.5 vol% 

based on PBPK 

modelling.

NOAEL = 9 vol%

LOAEL = 10.5 

vol%

 Approved for use 

in occupied spaces 

at up to 10.5 vol% 

based on PBPK 

modelling.

Some acidic decomposition products are formed when a halogenated fire extinguishing 

agent extinguishes a fire.

Safety 

Characteristics

Liquid at 20 C

B.P. = 49.2 C

Liquefied 

compressed gas.

B.P. = -82 C

Liquefied 

compressed gas.

B.P. = -48.1 C

Liquefied 

compressed gas.

B.P. = -16.4C

Environmental 

Characteristics [4]

ODP = 0

GWP = 1[5]

ODP = 0

GWP = 12 000

ODP = 0

GWP = 3400

ODP = 0

GWP = 3500

Cost-Effectiveness, 

avg. for 500 to 

5000 m3 volume 

(2003 data)

~1.7 to 2.0 ~2.0 to 2.3 Not available ~1.5

3 MDC(A) and MDC(B) refer to the minimum design concentration for a Class A or Class B fire hazard.

4

100-year GWP, IPCC Third Assessment Report: Climate Change 2001

5 Reported by manufacturer 
94 May 2013 TEAP XXIV/7 Task Force Report

5.2.1.2 Inert Gas Agents

Agent IG-01 IG-100 IG-55 IG-541

Efficacy For use in occupied 

spaces

MDC(A) = 41.9 

vol%

MDC(B) = 51 

vol%

For use in occupied 

spaces

MDC(A) = 40.3 

vol%

MDC(B) = 43.7 

vol%

For use in occupied 

spaces

MDC(A) = 40.3

vol%

MDC(B) = 47.5 

vol%

For use in occupied 

spaces

MDC(A) = 39.9

vol%

MDC(B) = 41.2 

vol%

Toxicity 52 vol% limit for 5 min. egress

Safety 

Characteristics

High-pressure compressed gas up to 300 bar

Environmental 

Characteristics

No adverse characteristics

Cost-Effectiveness, 

avg. for 500 to 

5000 m3 volume 

(2003 data)

~1.8 ~1.8 ~1.8 ~1.8

5.2.1.3 Carbon Dioxide

Agent Carbon dioxide, CO2

Efficacy For use in unoccupied spaces

Basic design concentration = 34 vol% for a “material factor” of 1.

Design concentrations for specific combustible materials are determined by 

multiplying the basic design concentration by an applicable material factor. [6]

Toxicity Progressively more severe physiological effects as exposure concentration increases, 

especially above 10 vol%. Carbon dioxide concentrations that exceed 17 vol% 

present an immediate risk to life. [7]

Pre-discharge alarm and discharge time delay required.

Safety 

Characteristics

Liquefied compressed gas 

Storage pressure:

High-pressure cylinder: 55.8 bar at 20 C

Low-pressure tanks (refrigerated): 21 bar at -18 C

Sublimes at -78.5 C at atmospheric pressure; cold exposure hazard.

Vapours are denser than air and can accumulate in low-lying spaces. 

Environmental 

Characteristics GWP = 1

Cost-Effectiveness, 

avg. for 500 to 

5000 m3 volume 

(2003 data)

1

6

See ISO 6183:2009 

7

See U.S. Environmental Protection Agency, “Carbon Dioxide as a Fire Suppressant: Examining the Risks,” 

February 2000.
May 2013 TEAP XXIV/7 Task Force Report 95

5.2.1.4 Water Mist Technology

Agent Water mist

Efficacy For use in occupied spaces.

Uses ~1/10th water as a traditional sprinkler system to suppress fires, where tested.

Toxicity None

Safety 

Characteristics No adverse safety characteristics

Environmental 

Characteristics No adverse characteristics

Cost-Effectiveness, 

avg. for a 3000 m3

application space

~2 

5.2.1.5 Inert Gas Generators

Agent Inert gas by pyrotechnic generator

Efficacy For use in occupied spaces.

Toxicity None for generators that produce nitrogen or nitrogen-water vapour 

Safety 

Characteristics

Potentially hot-gas discharge; potential hot surfaces of generator body. Insulating 

consideration required by generator manufacturer.

Environmental 

Characteristics No adverse characteristics

Cost-Effectiveness Not available

5.2.1.6 Fine Solid Particles (Powders)

Agent Fine solid particles 

Efficacy For use in normally unoccupied spaces.

Toxicity Precautions require evacuation of spaces before discharge. 

Safety 

Characteristics

For establishments manufacturing the agent or filling, installing, or servicing 

containers or systems to be used in total flooding applications, United States EPA 

recommends the following:

- adequate ventilation should be in place to reduce airborne exposure to constituents 

of agent;

- an eye wash fountain and quick drench facility should be close to the production 

area;

- training for safe handling procedures should be provided to all employees that 

would be likely to handle containers of the agent or extinguishing units filled with 

the agent; 

- workers responsible for clean-up should allow for maximum settling of all 

particulates before re-entering area and wear appropriate protective equipment

Environmental 

Characteristics No adverse characteristics

Cost-Effectiveness Not available 

5.2.2 Commercially Available, Technically Proven Alternatives to ODS for Local 

Application Fire Protection Using Portable Systems

In the tables below, cost effectiveness is represented by an index benchmarked against the 

approximate cost of a portable carbon dioxide extinguisher unit that has a UL 10B rating. 
96 May 2013 TEAP XXIV/7 Task Force Report

5.2.2.1 Carbon Dioxide

Agent Carbon dioxide, CO2

Efficacy For use on Class B fires

Can be used on most electrically energized equipment fires.

Toxicity High exposure risk where carbon dioxide gas accumulates in confined spaces that 

may be entered by personnel. 

Safety 

Characteristics

Liquefied compressed gas 

Storage pressure: 55.8 bar at 20 C

Solid CO2 (“dry ice”) sublimes at -78.5 C at atmospheric pressure.

Presents a cold-exposure hazard.

Vapours usually flow to floor level so personnel exposure risk is normally low. 

Environmental 

Characteristics GWP = 1

Cost-Effectiveness 1

5.2.2.2 Halogenated Agents

Agent Halogenated agents 

Efficacy For use on Class A fires

For use on Class B fires

For use on fires involving electrified equipment

Toxicity Vapour exposure risk usually low. 

Vapour toxicity low to moderate.

Safety 

Characteristics

Pressurised hand-held container. 

Environmental 

Characteristics HFC agents: ODP = 0; GWP = 1430 to 9810 [8]

Cost-Effectiveness Varies from about 1 to about 2

5.2.2.3 Dry Chemical

Agent Dry chemical 

Efficacy For use on Class A fires

For use on Class B fires

For use on fires involving electrified equipment

Dry chemical applied to some electrical or sensitive equipment may cause damage 

otherwise not caused by a fire.

Toxicity Low

Safety 

Characteristics Pressurised containers 

Environmental 

Characteristics Low environmental risk

Cost-Effectiveness ~ 0.2 

8

IPCC 4th Assessment Report: Climate Change, 2007. 1.
May 2013 TEAP XXIV/7 Task Force Report 97

5.2.2.4 Water

Agent Water, straight stream , ~9 litre

Efficacy Where approved for use on Class A fires, water-stream extinguishers should not be 

used on fires involving electrified equipment or that involve materials that are 

reactive with water (e.g. metals).

Not suitable for Class B fires.

Water applied to some electrical or sensitive equipment may cause damage 

otherwise not caused by a fire.

Toxicity Non-toxic

Safety 

Characteristics The possibility of electrocution if used on electrically energized equipment.

Environmental 

Characteristics No significant risk

Cost-Effectiveness ~0.5

5.2.2.5 Fine Water Spray

Agent Water, fine spray 

Efficacy For use on Class A fires including use on electrified equipment up to 10 kV. Not 

suitable for use on materials that are reactive with water (e.g. metals). 

Not suitable for Class B fires. 

Water applied to some electrical or sensitive equipment may cause damage 

otherwise not caused by a localized fire.

Toxicity Non-toxic

Safety 

Characteristics No adverse characteristics

Environmental 

Characteristics No significant risk

Cost-Effectiveness ~0.6 (~9 litre extinguisher unit; cost index compared to a 10B-rated CO2 unit)

5.2.2.6 Aqueous Salt Solutions

Agent Aqueous salt solutions, fine spray 

Efficacy For use on Class A fires not involving electrified equipment or materials that are 

reactive with water (e.g. metals). 

Suitability for use on Class B fires depends on formulation and means of delivery. 

Used on cooking oil fires where nozzle design limits splatter of hot oil.

Salt solutions may cause damage to some electrical equipment not otherwise 

damaged by fire.

Toxicity Varies from low to moderate.

Safety 

Characteristics

pH usually basic varying from 8 to 13. Possible short-exposure skin irritation 

depending on duration of exposure if wetted with agent. 

Environmental 

Characteristics No significant risk

Cost-Effectiveness ~0.7 to 1 (~9 litre extinguisher unit; cost index compared to a 10B-rated CO2 unit)
98 May 2013 TEAP XXIV/7 Task Force Report

5.2.2.7 Aqueous Film-forming Foam

Agent Aqueous film-forming foam (AFFF) 

Efficacy For use on Class A fires not involving electrified equipment or materials that are 

reactive with water (e.g. metals). 

For use on Class B fires. 

Toxicity Moderate.

Safety 

Characteristics pH is approximately neutral, varying between about 6.5 and 8.

Environmental 

Characteristics

Uncontained run-off of agent poses risks of contamination of soil, streams, and 

rivers.

Cost-Effectiveness ~0.6 (~9 litre extinguisher unit; cost index compared to a 10B-rated CO2 unit)

5.3 Response to Question 1 (b)

5.3.1 Alternative Total Flooding Agents Under Development For Use In Fixed Systems

One chemical producer reports that significant progress has been made on a new, but as yet

undisclosed, chemical agent. Physical, toxicological, and fire extinguishing properties have not yet 

been published. The chemical producer has an undetermined amount of additional work to complete 

in order to establish efficacy and approval under national and international standards.

5.3.2 Alternative Local Application Agents Under Development For Use In Portable Systems

5.3.2.1 FK–6–1–14, C7 fluoro-ketone blend 

This substitute is a blend of two C7 isomers: 

3-Pentanone, 1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)- 813-44-5 (55 – 65%)

3-Hexanone, 1,1,1,2,4,4,5,5,6,6,6-undecafluoro-2-(trifluoromethyl)- 813-45-6 (35 – 45%)

Currently under review for use as a streaming agent in non-residential applications. Product approval 

program to be completed.

5.3.2.2 2-BTP, 2-Bromo-3,3,3-Trifluoropropene, CAS#: 1514-82-5

This substitute has been under study for more than ten years. 

Its environmental properties are: ODP ~ 0.0098, GWP ~ 0.007 to 0.03

It is reported by one manufacturer that research on the efficacy of 2-BTP in some applications has 

looked sufficiently promising to continue development to achieve final approval.

Final performance research and toxicity testing remain to be completed.

For information on 2-BTP research see references.

5.4 Response to Question 1 (c) 

Every fire hazard is unique and needs to be assessed by a fire protection engineer or other competent 

person skilled in modern fire protection technologies. Previously when using ODS for fire protection 

applications, the agent choice was usually very simple; halons were the agent-of-choice for fixed 

flooding applications, as well as for local application and portable applications. Today, the user is 

faced with a wide range of potential fire protection options, and they need to make a choice in a 

logical, hierarchical manner. 
May 2013 TEAP XXIV/7 Task Force Report 99

Working through a logical decision process will lead the user to selection of a suitable ODSalternative fire extinguishing agent and system. In some cases there will be a different “weighting” 

among the several requirements. In some regions of the world there are economic barriers to the 

adoption of environmentally-sound alternatives. There are, however, no other barriers to adoption of 

an environmentally sound alternative to an ODS fire extinguishing system.

Several environmentally sound alternatives to ODS fire extinguishing agents for both total flooding 

and local applications uses have been introduced to the market. If an environmentally sound 

alternative agent works in any specific application there is no barrier to its adoption other than 

economic considerations. New environmentally sound alternatives are presently under development 

that may increase the number of applications where environmentally sound alternatives are 

technically viable.

5.5 Response to Question 1 (d)

The HTOC is of the opinion that it is not possible to report or even estimate values in response to the 

question posed.

The production of PFCs and HFCs for use in fire extinguishing systems and portable fire 

extinguishers as well as the production of alternatives (without negative environmental impacts) to 

these agents for uses in the same applications is performed by very few manufacturers, all of whom 

treat the information on their historical, present and projected production as proprietary. The required 

factual data is thus not available. So, without a clear understanding of these production levels for the 

alternatives without negative environmental impacts and also for the PFCs and HFCs, there is no 

basis for making a judgment about the overall utility of any alternatives in replacing PFCs and HFCs 

in the fire protection sector, and doing so may result in data that is misleading.

Regarding the PFCs, we can also say that the fire protection community has acted responsibly in 

dealing with what have turned out to be unsuitable alternatives from an environmental impact 

perspective. The subject of the use of PFCs was debated at the International Maritime Organization 

(IMO) over a three years period and in the end PFCs were prohibited in fire extinguishing systems on 

all merchant ship new builds. The IMO decision was based entirely on the availability of several 

HFCs that collectively could perform as well if not better than the PFCs in shipboard applications and 

at the same time present a more favorable environmental impact. The prohibition of PFCs by IMO led 

to the collapse of any demand for the agent as other major industries, e.g., oil and gas production, 

followed suit, and led to the manufacturer abandoning the products.

However, the need for chemical agents remains as inert gases, water mist and other agents are not 

suitable for many fire protection applications that had previously used halon. HFCs have filled that 

role and, since about 2005 a fluoroketone (FK) has increasingly become more accepted – cost was 

initially a barrier but its physical properties also make it unsuitable in some applications, e.g., 

aviation and use in very cold climates.

With respect to HFCs, as stated above, although specific production data has not been provided, 

according to one HFC producer, estimates for volumes sold 2008-2012 (see the following table), are 

reasonably accurate and the percent over that time frame, worldwide, is fairly constant ±3-5%. Note 

this is not GWP weighted or emissions, just raw tonnage sold globally. 
100 May 2013 TEAP XXIV/7 Task Force Report

Sector Percentage

Refrigeration 68%

Foam Expansion 23%

Propellants 5%

Pharmaceutical 1.1%

Fire Protection 1.0%

Electronic Gases 0.3%

Cleaning 0.17%

Miscellaneous 1.43%

Unlike the other sectors, fire protection is highly regulated and there are design standards that have to 

be followed in consideration of life safety and property protection. As the agents are very valuable 

and are easily contained, recycling of HFCs in this sector is already mature.

With respect to the FK, there is no evidence to suggest that it is or is not living up to the expectations 

of the fire protection industry, which is still evaluating alternatives that have low environmental 

impacts.

5.6 Response to Question 1 (e)

The use of HCFCs in fire protection is declining, with the only total flood agent being provided for 

the maintenance of legacy systems that are themselves phasing out. Only HCFC-123 is used in any 

quantity in portable extinguishers and if the development of 2-Bromo-3,3,3-trifluoropropene proves 

to be commercially successful, it would be the natural replacement for it and halon 1211 –

particularly in the aviation industry.
May 2013 TEAP XXIV/7 Task Force Report 101

6 Solvents

Executive Summary

The HCFC solvents currently used are HCFC-141b and HCFC-225ca/cb with ODP of 0.11 and 

0.025/0.033 and GWP-100yr of 713 and 120/586, respectively. The elimination of HCFCs from

solvent applications still leaves many options available. Many alternative solvents and technologies 

developed so far since 1980s are the candidates for HCFC alternatives, which include, not- in kind 

technologies such as aqueous cleaning, semi-aqueous cleanings, hydrocarbon and alcoholic solvents, 

and in-kind solvents such as chlorinated solvents, a brominated solvent, and fluorinated solvents with 

various levels of acceptance. However, no single option seems well suited to replace HCFCs 

completely. 

Recently unsaturated fluorochemical HFOs (hydrofluoroolefins) with zero ODP and HCFOs 

(hydrochlorofluoroolefins) with negligibly small ODP are said to be under development. They have 

ultra low GWP (<10) and are expected to replace high GWP-HFC and low or moderate GWP HFE 

solvents. Among them, HCFOs are unique in their balanced solvency due to the presence of chlorine 

and fluorine atom in the molecule. If HCFOs with appropriate boiling points, low toxicity and enough

stability to the practical use be on market, they may replace HCFCs totally in the future.

6.1 Introduction

This section provides the updated information on alternatives that are used for solvent applications to 

addresses the requirements of “Decision XXIV/7”, which is given in chapter 1.

Solvents are widely used as process agents in a variety of industrial manufacturing processes 

although they are not contained in the final products to consumers. The main applications of solvents 

are metal cleaning, electronics cleaning, precision cleaning. Then career solvents and heat transfer 

media have minor shares.

Among ODSs controlled by Montreal Protocol, CFC-113 and 1,1,1-trichloroethane (TCA) use as 

solvents were banned in both of Article-5 and non-Article 5 countries except one essential use 

exemption. 

Several reports that describe the use of HCFCs in solvent applications have been published in the 

past. These include the IPCC TEAP Special Report, the TEAP Decision XXI/9 Task Force Report, 

XXIII/9 Task Force Report, and the Assessment Reports of CTOC and STOC.

Among ODSs controlled by Montreal Protocol, CFC-113 and 1,1,1-trichloroethane (TCA) use as 

solvents were banned in both of Article-5 and non-Article 5 countries except one essential use 

exemption. 

The only HCFC solvents currently used are HCFC-141b and HCFC-225ca/cb with ODP of 0.11 and 

0.025/0.033 and GWP-100yr of 713 and 120/586, respectively. Although HCFC-141b use as solvents 

in non-Article 5 countries was banned by 2010, its use in Article 5 countries may still be increasing.

HCFC-225ca/cb has been used as drop-in replacement for CFC-113 in many cases, as it resembles 

CFC-113 in its chemical and physical properties. It is higher in cost compared to CFC-113 and the 

market for it seems to remain only in Japan and USA with consumption of the order of thousand 

metric tons level.

The elimination of HCFCs from solvent applications still leaves many options available. Many 

alternative solvents and technologies developed so far since 1980s are the candidates for HCFC 

alternatives, which include, not- in kind technologies such as aqueous cleaning, semi-aqueous 

cleanings, hydrocarbon and alcoholic solvents, and in-kind solvents such as chlorinated solvents, a 
102 May 2013 TEAP XXIV/7 Task Force Report

brominated solvent, and fluorinated solvents with various levels of acceptance. However, no single 

option seems well suited to replace HCFCs completely. 

The following terms, used in the tables below, have meanings as given. 

Efficacy refers to suitability for solvent applications. It indicates merits of the agents in cleaning 

performances 

Toxicity refers to Threshold Limit Value (TLV) or Occupational Exposure Limit (OEL). As solvents 

are usually used as process agent in the cleaning process, their toxicity concerns are mainly focused 

on the allowable exposure limit to those who works in the process.

Safety characteristics refer to flammability of agents. The flash point and the combustible range are 

also noted in in-kind solvents.

Environmental characteristic refers to ozone depletion potential (ODP) and GWP (100-year Global 

Warming Potential) or other characteristics, if applicable

Cost effectiveness refers to investment cost and solvent cost. Due to the wide variety of alternatives 

available to replace HCFCs, a full discussion of the costs of these alternatives is not practical. So the 

capital investment is roughly compares as one time cost and solvent cost is roughly compared as 

operating cost. Solvent cost is classified as shown below.

Solvent Cost ($/kg): A=~5, B=5~10, C=11~20, D=21~50, E=51~80

6.2 Response to Question 1(a)

6.2.1 Commercially Available, Technically Proven Alternatives for Solvent Cleanings

6.2.1.1 Not in-kind alternatives

Aqueous Cleaning

Agent Water, surfactant, alkali/acidic agent , other additives

Efficacy Applicable to wide range of materials and parts to be cleaned by choosing additives

Toxicity Depend on additives

Safety Characteristics Non flammable

Corrosive when alkali or acidic agents are used

Environmental 

Characteristics

ODP: 0

GWP: 0

Waste water treatment is necessary

Cost Effectiveness*

Investment cost

Solvent cost

Very large

A-B

*May 2012 TEAP Task Force Report

Semi-aqueous Cleaning

Agent Glycol ethers/water, terpenes, Glycol ethers

Efficacy Applicable to wide range of materials and parts to be cleaned

Toxicity low to moderate (depend on organic solvents used)

Safety Characteristics Some organic solvents are flammable. Explosion proof equipments are necessary 

in the case.

Environmental 

Characteristics

ODP: 0

GWP: low

Waste water treatment is necessary

VOC

Cost Effectiveness*

Investment cost

Solvent cost

Very large

A~D

*May 2012 TEAP Task Force Report
May 2013 TEAP XXIV/7 Task Force Report 103

These aeqeous and semi-aequeous processes can be good substitutes for metal degreasing or even

electronics and precision cleaning when corrosion of the materials is not an issue. The availability of 

good quality water and water disposal issues need to be taken care of, right from the start of the 

process conception. Some aqueous cleaning processes have a low environmental impact (no VOC, 

low GWP, no ODP) and a low toxicity. However, others involving additives may emit VOCs and use 

toxic and corrosive chemicals. Investment costs can be high but operating costs are generally lower 

than those with solvents alternatives.

Hydrocarbon solvent cleaning

Agent n-Paraffin, iso-Paraffin, aromatic solvents

Efficacy High solvency to oil and grease

Toxicity Low to moderate (depend on solvents)

Safety Characteristics Flammable: to avoid explosion, the solvents with high flash points (>55°C)

are used. Explosion proof equipments are necessary

Environmental 

Characteristics

ODP: 0

GWP: low

VOC

Cost Effectiveness*

Investment cost

Solvent cost

Retrofitting

Large

A – C

Difficult

*May 2012 TEAP Task Force Report

This process has proven to be a good solution with paraffin hydrocarbon formulations; cleaning is 

efficient but the non-volatile or less-volatile residues can be incompatible with some downstream 

manufacturing or finishes. Their environmental impact is low (low GWP, no ODP) but they are 

generally classified as VOC and emissions are subject to regulation. Their toxicity is also low. Owing 

to their combustibility (flashpoint > 55°C), they have to be used in open tank equipment at a

temperature at least 15°C below their flashpoint.

Alcoholic solvents

Agent iso-propyl alcohol (IPA)

Efficacy High solvency to flux resin 

Toxicity (TLV or OEL) 200 ppm

Safety Characteristics Flammable

Explosion proof equipments are necessary

Environmental 

Characteristics

ODP: 0

GWP: low

VOC

Cost Effectiveness*

Investment cost

Solvent cost

Retrofitting

Large

A

Difficult

*May 2012 TEAP Task Force Report

These substances have been used for many years in cleaning applications. IPA is the most popular 

solvent. Their cost and environmental impact are low (low GWP and zero ODP), but they are 

classified as VOCs and may contribute to ground level ozone pollution. Also they require explosion 

proof equipment. 
104 May 2013 TEAP XXIV/7 Task Force Report

6.2.1.2 In-kind alternatives

Chlorinated solvents

Agent Trichloroethylene Tetrachloroethylene Dichloromethane

Boiling point 87 ̊C 121 ̊C 40 ̊C

Efficacy High solvency due to the presence of chlorine atom. Good to remove oil and 

grease. Incompatible with some materials

Toxicity*

TLV or OEL(USA) 10ppm 25ppm 50ppm

Safety Characteristics*

Flash point 

Combustible range

Non

8-10.5[vol%]

non

non

non

13-23[vol%]

Environmental 

Characteristics*

ODP:0.005

GWP:5

Lifetime: 13days

ODP:0.005

GWP:12

Lifetime: 0.3yrs

ODP:0.005

GWP:9

Lifetime: 0.38yrs

Cost Effectiveness*

Investment cost

Solvent cost

Retrofitting

Medium

A

Possible

*May 2012 TEAP Task Force Report

The primary in-kind substitute for TCA has been the chlorinated alternatives such as 

trichloroethylene, tetrachloroethylene and methylene chloride. These substitutes have very small 

(0.005-0.007) ozone depletion potentials and are generally classed as zero-ODP. They have similar 

cleaning properties to TCA. Therefore, material compatibility of cleaned parts must be checked if 

HCFCs are replaced by these chlorinated solvents. 

Brominated solvent

Agent n-Propyl bromide

Boiling point 72 ̊C

Efficacy* High solvency due to the presence of bromine atom. Good to remove 

oil and grease. Incompatible with some materials

Toxicity TLV or OEL(USA)* (0.1ppm)

Safety Characteristics*

Flash point 

Combustible range

Non

Non

Environmental Characteristics* ODP: 0.0049-0.01

GWP: very low

Lifetime: 20~25days

Cost Effectiveness*

Investment cost

Solvent cost

Retrofitting

Medium 

C

Possible

*May 2012 TEAP Task Force Report

A brominated solvent, n-propyl bromide has been another alternative for TCA and CFC-113 because 

of its similar cleaning properties. However, there has been significant concern about the toxicity of npropyl bromide. ACGIH proposed the reduction of the TLV for n-propyl bromide from 10 ppm to 0.1 

ppm in February 2012. No additional information has been announced yet.

HFC solvents
May 2013 TEAP XXIV/7 Task Force Report 105

Agent HFC-43-10mee HFC-365mfc HFC-c447ef

Boiling point 55 ̊C 40 ̊C 82 ̊C

Efficacy* Easy drying, good material compatibility due to their mild solvency

Toxicity*

TLV or OEL(USA) 200 ppm 1000 ppm** 120 ppm

Safety Characteristics*

Flash point 

Combustible range

non

non

≤27 ̊C**

3.6~13.3 [vol%]**

non

non

Environmental 

Characteristics*

ODP: 0

GWP: 1640

Lifetime: 15.9yrs

ODP: 0

GWP: 794

Lifetime: 7.0yrs

ODP: 0

GWP: 250

Lifetime: 3.4yrs

Cost Effectiveness*

Investment cost

Solvent cost

Retrofitting

Medium 

C – E

Possible

*May 2012 TEAP Task Force Report

**Data were supplied by the manufacturers

Although HFCs are available in all regions, their uses have been primarily in non-Article 5 countries, 

due to relatively high cost and important demands in high tech industries. On account of increasing 

concern about their high GWP, uses are focused in critical applications for which there are no other 

substitutes. Therefore, growth is expected to be minimal.

HFE solvents

Agent HFE-449s1 HFE-569sf1 HFE-64-13s1 HFE-347pc-f2

61 ̊C 72 ̊C 98 ̊C 56 ̊C

Efficacy* Easy drying, good material compatibility due to their mild solvency

Toxicity*

TLV or OEL(USA) 750ppm 200ppm 100ppm 50ppm

Safety Characteristics*

Flash point 

Combustible range

non

non

Non

2.1~10.7[vol%]

non

non

non

non

Environmental 

Characteristics

ODP: 0

GWP: 297

Lifetime: 3.8yrs

ODP: 0

GWP: 59

Lifetime: 0.77yrs

ODP: 0

GWP: 210

Lifetime: 3.8yrs

ODP: 0

GWP: 580

Lifetime: 7.1yrs

Cost Effectiveness*

Investment cost

Solvent cost

Retrofitting

Medium

D – E

Possible

*May 2012 TEAP Task Force Report

HFE (hydrofluoroether) is a new homologue of fluorinated solvents. All of these compounds are used 

as replacements for CFCs, HCFCs and are potential replacement for high GWP HFC solvents. The 

pure HFEs are limited in use in cleaning applications owing to their mild solvency. Therefore HFEs 

are usually used as azeotropic blends with other solvents such as alcohols and trans-1,2-

dichloroethylene and in co-solvent cleaning processes giving them broader cleaning efficacy. The 

relatively high cost of these materials limits their use compared to lower cost solvents such as 

chlorinated solvents and hydrocarbons. 
106 May 2013 TEAP XXIV/7 Task Force Report

6.3 Response to Question 1(b)

6.3.1 Alternatives Under Development

6.3.1.1 Unsaturated solvents (HFOs and HCFOs)

Agent HCFO-1233zd

Boiling point 190C

Efficacy Easy drying, good material compatibility, good solvency to 

common soils

Toxicity TLV or OEL(USA) 300ppm**

Safety Characteristics**

Flash point 

Combustible range

Non

Non

Environmental Characteristics*** ODP: 0.00024~0.00034

GWP: 4.7~7

Cost Effectiveness

Investment cost

Solvent cost

Retrofitting

Medium

(C- D)

Possible: chiller unit must be strengthened to minimize the 

emission.

*** Federal Register Volume 78, Number 32

Recently unsaturated fluorochemicals such as HFOs and HCFOs have been proposed. They are a new 

class of solvents specifically designed with a low atmospheric lifetime. The unsaturated molecules 

are known to be unstable in the atmosphere and therefore they show these low atmospheric lifetimes.

HFOs with zero ODP and ultra low GWP (<10) are being developed for the replacement of high 

GWP HFC and low or moderate GWP HFE solvents. They also could be candidates to replace 

HCFCs in certain solvent applications.

HCFO-1233zd (trans-1-chloro-3,3,3-trifluoropropene) is now announced for its commercial 

production. It has an atmospheric lifetime of less than one month and a (100 yr) GWP smaller than 5. 

The ODP is negligibly small due to its very short atmospheric lifetime. Due to the balanced solvency, 

HCFO solvents are potential replacements for HCFCs and potential high GWP HFC solvents.

6.4 Response to Question 1(c)

6.4.1 Barrier and restrictions; the feasibility of options to HCFCs in solvents

The next three tables summarize the feasibility of the alternative solvents in metals cleaning (Table

6.4.1), electronics cleaning (Table 6.4.2) and precision cleaning (Table 6.4.3).
May 2013 TEAP XXIV/7 Task Force Report 107

Table 6.4.1 Metals cleaning *1

*

GWP ODP Others

HCFC-225ca/HCFC-225cb Good Difficult C C ODS D

HCFC-141b Good Good C D ODS C

Trichloroethylene

Perchloroethylene

Dichloromethane

Good Good A B

VOC

Water&Soil

Pollutant A

trans-1,2-Dichloroethylene

Blending with other solvents Good Good A B

VOC

Water&Soil

Pollutant

A-B

Brominated solvents n-Propyl bromide Good Good B C

HFEs

 HFE-449s1

 HFE-569sf1

 HFE-347pcf2

(Blending with other solvents

Difficult Difficult B-C A D-E

HFCs

HFC-43-10mee

 HFC-365mfc

(Blending with other solvents

Difficult Difficult C- A C-E

Unsaturated Fluorocarbons(HFOs, HCFOs)

HCFO-1233zd

Difficult to

Good Difficult A A C-E

Hydorocarbons

n-Paraffine,

iso-Paraffin,

Aromatic solvents

Good Good - -

VOC

Water&Soil

Pollutant

A-C

Siloxane Methyl siloxanes Good Difficult - -

Semi-aqueous Glycol Ethers/Water

Terpenes, Glycol Ethers/ Water Good Difficult toGood - -

Alchoholic iso-Propyl alcohol Difficult Good - -

Aqueous Basic, Neutral, and Acidic systems Good Difficult to

Good - -

Others

Supercritical fluids,

Plasma cleaning,

UV / Ozone irradiation

Difficult Difficult - -

Environmental Effect*2

Alternatives

Market

 Price*3

Fluorinated solvents

Chlorinated solvents

ODS Hydrochlorofluorocarbon

*1 Cleaning applications are classifiedaccording to the definition of SNAP ( EPA /Significant New Alternatives

Policy

*2 Environmental Effect

GWP: A=~100 B=100~300, C=300~1000, D=1000~

ODP: A=~0.001, B=~0.01,C=~0.1, D=0.1~

*3 Market Price May 2012 TEAP XXIII/9 Task Force Report )

Cost($/kg): A=~5, B=5~10, C=11~20, D=21~50, E=51~

Metal cleaning is removing contaminants such as cutting oils, grease, or metal fillings from metal 

parts. High solvency is required to solvents to remove such contaminants. The cleaning is generally 

cost sensitive because most of the metals to be cleaned are not so expensive. So the chlorinated 

solvents, brominated solvent and hydrocarbon solvents are widely used in this application. 
108 May 2013 TEAP XXIV/7 Task Force Report

Table 6.4.2 Electronics Cleaning *1

GWP ODP Others

ODS Hydrochlorofluorocarbon

HCFC-225ca/HCFC-225cb

HCFC-141b

(Blending with other solvents

Good Good C C-D ODS C-D

Trichloroethylene

Perchloroethylene

Dichloromethane

Difficult to

Good Good A B

VOC

Water&Soil

Pollutant A

trans-1,2-Dichloroethylene

(Blending with other solvents

Difficult to

Good Good A B

VOC

Water&Soil

Pollutant

A-B

Brominated solvents n-Propyl bromide Difficult to

Good

Good B C

HFEs

 HFE-449s1

 HFE-569sf1

 HFE-347pcf2

Difficult Good

(Blending with other solvents Difficult to

Good Good

HFCs

HFC-43-10mee

HFC-365mfc

Difficult Good

(Blending with other solvents Difficult to

Good Good

Unsaturated Fluorocarbons(HFOs, HCFOs)

HCFO-1233zd

Difficult to

Good Good A A C - E

Hydorocarbons

n-Paraffine

iso-Paraffin

Aromatic solvents

Good Good - -

VOC

Water&Soil

Pollutant

A-C

Semi-aqueous Glycol Ethers/Water

Terpenes, Glycol Ethers/ Water Good Difficult toGood - - A-D

Alchoholic iso-Propyl alcohol Good Good - - A-B

Aqueous Basic, Neutral, and Acidic systems Good Difficult to

Good - - A-B

Others

Supercritical fluids

Plasma cleaning

UV / Ozone irradiation

Good Difficult to

Good - - - -

Market

Price* 3

B-C A D-E

Alternatives

A C-E

Chlorinated solvents

CFluorinated solvents

Environmental Effect* 2

*1 Cleaning applications are classified according to the definition of SNAP ( EPA /Significant New Alternatives Policy

*2 Environmental Effect

GWP : A=~ 100 B=100~300, C=300~1000, D=1000~

ODP: A=~0.001, B=~0.01, C=~0.1, D=0.1~

*3 Market Price May 2012 TEAP XXIII/9 Task Force Report )

Cost($/kg): A=~5, B=5~10, C=11~20, D=21~50, E=51~

Electronics cleaning is removing contaminants, primarily solder flux residues, from electronics or 

circuit boards. Milder solvency is required in this cleaning so that the parts to be cleaned may not be 

damaged during the process. In the case of HFCs and HFEs, blending with other solvents is 

commonly applied to enhance the solvency.
May 2013 TEAP XXIV/7 Task Force Report 109

Table 6.4.3 Precision cleaning *1

GWP ODP Others

ODS Hydrochlorofluorocarbon HCFC-225ca/HCFC-225cb

HCFC-141b Good Good C C-D ODS C-D

Chlorinated solvents

Trichloroethylene

Perchloroethylene

Dichloromethane

Difficult to

Good

Good A B

VOC

Water&Soil

Pollutant

A

trans-1,2-Dichloroethylene

(Blending with other solvents

Difficult to

Good Good A B

VOC

Water&Soil

Pollutant

A-B

Brominated solvents n-Propyl bromide

Difficult to

Good Good B C

HFEs

 HFE-449s1

 HFE-569sf1

 HFE-347pcf2

(Blending with other solvents

Good Good B-C A D-E

HFCs

HFC-43-10mee

 HFC-365mfc

(Blending with other solvents

Good Good C- A C-E

Unsaturated Fluorocarbons(HFOs, HCFOs)

HCFO-1233zd Good Good A A C-E

Hydorocarbons

n-Paraffine

iso-Paraffin

Aromatic solvents

Difficult Good - -

VOC

Water&Soil

Pollutant

A-C

Semi-aqueous Glycol Ethers/Water

Terpenes, Glycol Ethers/ Water

Good Good - - A-D

Alchoholic Iso-Propyl alcohol Good Good - - A-B

Aqueous Basic, Neutral, and Acidic systems Good Good - - A-B

Others

Supercritical fluids

Plasma cleaning

UV / Ozone irradiation

Good Difficult to

Good - - - -

Alternatives

Environmental Effect* 2 Market

 Price* 3

Fluorinated solvents

*1 Cleaning applications are classified according to the definition of SNAP ( EPA /Significant New Alternatives Policy

*2 Environmental Effect

GWP : A=~ 100 B=100~300, C=300~1000, D=1000~

ODP: A=~0.001, B=~0.01, C=~0.1, D=0.1~

*3 Market Price May 2012 TEAP XXIII/9 Task Force Report )

Cost($/kg): A=~5, B=5~10, C=11~20, D=21~50, E=51~

Precision cleaning is cleaning to a specific grade of cleanliness in order for products to maintain their 

value. Generally the solvent cost is not an issue because the cleaning performance is quite important 

rather than the cost performance in this cleaning. Depending on the required cleanliness level, 

materials used in the cleaned parts, the shape of cleaned parts, wide variety of solvents can be the 

alternative candidates to HCFCs.

Although the conversion of HCFCs to alternative solvents has been taken place steadily in each 

application, the following should be considered when replacing HCFCs.

In the case of not in-kind solvent cleanings, some conversion to aqueous cleaning is likely but there 

are limits to its use because some products/processes simply can’t tolerate water. There is also the 

additional requirement that an aqueous cleaning step be followed by a drying step which can be 

energy-intensive and need more floor space. 

Hydrocarbons and alcohols are effective solvents but are extremely flammable. Engineering controls, 

some of which are costly, can reduce the risk but flammability concerns may constrain growth. 

Additionally, most of the commonly used hydrocarbons are VOCs, which may further constrain 

growth in some countries.
110 May 2013 TEAP XXIV/7 Task Force Report

As for in-kind solvents, chlorinated solvents will be available as replacements for HCFCs in a variety 

of cleaning applications owing to their high solvency. However, large-scale conversions to 

chlorinated solvents would seem unlikely because of toxicity concerns. Those solvency powers are 

more aggressive than those of HCFCs. Therefore material compatibility should be evaluated carefully 

when HCFCs are replaced by chlorinated solvents.

n-PB is an effective and useful solvent but widespread growth in its use would seem unlikely because 

of toxicity concerns. ACGIH announced the reduction of the TLV for n-propyl bromide from 10ppm 

to 0.1ppm in February 2012. 

HFC and HFEs are also good candidates for the replacement for HCFCs. Due to their mild solvency, 

however, some modification may be necessary when HCFCs are replaced by HFCs and HFEs. All of 

HFCs and HFEs have zero ODP. Their GWP values vary depending on their structures. The relatively 

high cost of these materials limits their use.

Furthermore, unsaturated HFCs and HCFCs (HFOs and HCFOs) are also stated to be under 

development for the replacement of high GWP HFC and low or moderate GWP HFE solvents. Both 

HFOs and HCFOs have ultra low GWPs. HFOs also could be candidates to replace HCFCs in certain 

solvent applications. HCFO-trans-1233zd has a high solvency with common soils and may be used as 

a direct replacement for HCFCs. The relatively high cost of these materials would limit their use.

6.5 Response to Question 1(d)

The CTOC is of the opinion that it is not possible to report or even estimate values in response to the 

question posed. However, it should be noted that more than 90% of the ODS solvent use has been 

reduced already through conservation and substitution with not-in-kind technologies.

6.6 Response to Question 1(e)

Recently unsaturated fluorochemicals such as HFOs and HCFOs have been proposed. They are a new 

class of solvents specifically designed with a low atmospheric lifetime. The unsaturated molecules 

are known to be unstable in the atmosphere and therefore they show these low atmospheric lifetimes. 

Among them, HCFOs are unique in their balanced solvency due to the presence of chlorine and 

fluorine atom in the molecule. If HCFOs with appropriate boiling points, low toxicity and enough

stability to the practical use be on market, they may replace HCFCs totally.
May 2013 TEAP XXIV/7 Task Force Report 111

7 Material submitted by Parties

The U.S. government submitted the following list with reference material (4 February 2013):

SUMMARY of SUBMISSION

1. Recent (2011-2012) Relevant U.S. EPA Final SNAP Regulations and Listings

1.1.U.S. EPA, Significant New Alternatives Policy, 2011 Ruling on Hydrocarbon Refrigerants 

1.2.U.S. EPA, Significant New Alternatives Policy, 2011 Ruling on HFO-1234yf in Motor 

Vehicle AC 

1.3.U.S. EPA, Significant New Alternatives Policy, 2012 Ruling on CO2 in Motor Vehicle AC 

1.4.U.S. EPA, Significant New Alternatives Policy, 2012 Acceptability Determination 27

2. Fact Sheets on Alternatives 

2.1.Commercial Refrigeration HFC Fact Sheet 

2.2.Domestic Refrigeration HFC Fact Sheet 

2.3.Transport Refrigeration HFC Fact Sheet 

2.4.MVAC HFC Fact Sheet 

2.5.Unitary AC HFC Fact Sheet 

2.6.Construction Foams HFC Fact Sheet

2.7.Alternatives to HFCs Fact Sheet

3. HFCs Under the Montreal Protocol

3.1.Benefits of Addressing HFCs under the Montreal Protocol

3.2.Frequently Asked Questions on the North American Amendment Proposal to Phase Down 

HFCs under the Montreal Protocol

4. Available and Emerging Alternative Technologies

4.1.Advancing Ozone and Climate Protection Technologies: Next Steps

4.2.Montreal Technology Forum on Climate-friendly Alternatives in Commercial Refrigeration 

4.3.GreenChill Webinar Series on Alternative Technologies in the Commercial Refrigeration 

Sector HFC-Free Technologies Are Available in the Supermarket Retail Refrigeration 

Sector

4.4.HFC-Free Technologies Are Available in the Supermarket Retail Refrigeration Sector

4.5.Greenpeace - Cool Technologies: Working without HFCs Report

4.6.Purdue University 2012 Conference Presentations

4.7.AHRI Low-GWP Alternative Refrigerants Evaluation Program Reports

4.8.ASHRAE/NIST Refrigerants Conference 2012 Presentations and Conference Papers
112 May 2013 TEAP XXIV/7 Task Force Report

1. Recent (2011-2012) Relevant U.S. EPA Final Regulations and Listings 

1.1. U.S. EPA, Significant New Alternatives Policy, 2011 Ruling on Hydrocarbon Refrigerants

Title: Protection of Stratospheric Ozone: Listing of Substitutes for Ozone Depleting 

Substances - Hydrocarbon Refrigerants

Description: Adds isobutane (R–600a) and R–441A to the SNAP list of acceptable 

refrigerants, subject to use conditions, in household refrigerators, freezers, and 

combination refrigerators and freezers. Additionally adds propane (R –290), 

subject to use conditions, in retail food refrigerators and freezers (standalone 

units only).

Available at: http://www.gpo.gov/fdsys/pkg/FR-2011-12-20/pdf/2011-32175.pdf

Filename: SNAP Rule on Hydrocarbon Refrigerants for Household and Stand-alone 

Commercial Refrigerators and Freezers.pdf

1.2. U.S. EPA, Significant New Alternatives Policy, 2011 Ruling on HFO-1234yf in Motor 

Vehicle AC

Title: Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle Air 

Conditioning Sector Under the Significant New Alternatives Policy (SNAP) 

Program

Description: Finds hydrofluoroolefin (HFO)–1234yf as acceptable, subject to use conditions, 

as a substitute in motor vehicle air conditioning for new passenger cars and 

light-duty trucks.

Available at: http://www.gpo.gov/fdsys/pkg/FR-2011-03-29/pdf/2011-6268.pdf

Filename: SNAP Rule on HFO-1234yf in MVAC.pdf

1.3. U.S. EPA, Significant New Alternatives Policy, 2012 Ruling on CO2 in Motor Vehicle AC 

Title: Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle Air 

Conditioning Sector Under the Significant New Alternatives Policy (SNAP) 

Program

Description: Adds carbon dioxide (CO2) or R–744 to the SNAP list of acceptable 

refrigerants, subject to use conditions, in the motor vehicle air conditioning 

systems designed specifically for the use of CO2 refrigerant in passenger cars, 

light-duty and heavy-duty vehicles. 

Available at: http://www.gpo.gov/fdsys/pkg/FR-2012-06-06/pdf/2012-13189.pdf

Filename: SNAP Rule on CO2 in MVAC.pdf

1.4. U.S. EPA, Significant New Alternatives Policy, 2012 Acceptability Determination 27

Title: Protection of Stratospheric Ozone: Determination 27 for Significant New 

Alternatives Policy Program

Description: Adds low-GWP alternatives to the SNAP list of acceptable refrigerants, for 

commercial comfort air conditioning, heat transfer, vending machines, foam 

blowing, aerosols, and fire suppression.

Available at: http://www.gpo.gov/fdsys/pkg/FR-2012-08-10/pdf/2012-19688.pdf 

Filename: HFC-Free Technologies Are Available in the Supermarket Retail Refrigeration 

Sector.pdf
May 2013 TEAP XXIV/7 Task Force Report 113

2. Fact Sheets on Alternatives 

2.1. Commercial Refrigeration HFC Fact Sheet 

Title: Transitioning to Low-GWP Alternatives in Commercial Refrigeration

Description: This fact sheet provides information on low-GWP alternatives in newly 

manufactured commercial refrigeration equipment.

Available at: http://www.epa.gov/ozone/downloads/EPA_HFC_ComRef.pdf

Filename: Commercial Refrigeration HFC Fact Sheet.pdf

2.2. Domestic Refrigeration HFC Fact Sheet

Title: Transitioning to Low-GWP Alternatives in Domestic Refrigeration

Description: This fact sheet provides information on low-GWP alternatives in newly 

manufactured domestic refrigeration equipment.

Available at: http://www.epa.gov/ozone/downloads/EPA_HFC_DomRef.pdf

Filename: Domestic Refrigeration HFC Fact Sheet.pdf 

2.3. Transport Refrigeration HFC Fact Sheet 

Title: Transitioning to Low-GWP Alternatives in Transport Refrigeration

Description: This fact sheet provides information on low-GWP refrigerant and foam blowing 

agent alternatives used in transport refrigeration equipment.

Available at: http://www.epa.gov/ozone/downloads/EPA_HFC_Transport.pdf

Filename: Transport Refrigeration HFC Fact Sheet.pdf 

2.4. MVAC HFC Fact Sheet 

Title: Transitioning to Low-GWP Alternatives in MVACs

Description: This fact sheet provides information on low-GWP alternatives in newly 

manufactured MVACs.

Available at: http://www.epa.gov/ozone/downloads/EPA_HFC_MVAC.pdf

Filename: MVAC HFC Fact Sheet.pdf 

2.5. Unitary AC HFC Fact Sheet 

Title: Transitioning to Low-GWP Alternatives in Unitary Air Conditioning

Description: This fact sheet provides information on low-GWP alternatives in new 

equipment in unitary air conditioning.

Available at: http://www.epa.gov/ozone/downloads/EPA_HFC_UAC.pdf

Filename: Unitary AC HFC Fact Sheet.pdf 

2.6. Construction Foams HFC Fact Sheet

Title: Transitioning to Low-GWP Alternatives in Building/Construction Foams

Description: This fact sheet provides information on low-GWP foam blowing agent 

alternatives used in building and construction applications.

Available at: http://www.epa.gov/ozone/downloads/EPA_HFC_ConstFoam.pdf

Filename: Construction Foams HFC Fact Sheet.pdf 
114 May 2013 TEAP XXIV/7 Task Force Report

2.7. Alternatives to HFCs Fact Sheet

Title: CCAC Climate and Clean Air Coalition to Reduce Short-Lived Climate 

Pollutants: Fact Sheet - Alternatives to HFCs

Description: This fact sheet provides information on HFCs and the advancement of HFC 

reduction efforts; including projects to promote the international exchange of 

information on HFC use, emissions reductions strategies, alternative 

technologies, and standards.

Available at: http://www.unep.org/ccac/Portals/24183/PartnersArea/pdf/CCAC FACT 

SHEET-HFCs-EN-LR.pdf

Filename: CCAC Alternatives to HFCs Fact Sheet.pdf

3. HFCs Under the Montreal Protocol

3.1. Benefits of Addressing HFCs under the Montreal Protocol

Title: Benefits of Addressing HFCs under the Montreal Protocol, June 2012

Description: This paper presents an analysis of the potential benefits from globally reducing 

consumption of HFCs and reducing byproduct emissions of HFC-23 under the 

Montreal Protocol. This paper discusses the environmental downsides of 

continued HFC consumption and emissions; the proposal from Canada, Mexico 

and the United States to amend the Montreal Protocol to address HFCs, the 

availability of alternatives for meeting the reduction schedule; transitioning to 

low-GWP alternatives; case studies in the transition to low-GWP alternatives; 

and byproduct emissions of HFC-23. This paper was also presented at the 

ASHRAE/NIST conference in October, 2012, at the National Institute of 

Standards & Technology.

Available at: http://www.epa.gov/ozone/downloads/Benefits of Addressing HFCs Under the 

Montreal Protocol, June 2012.pdf

Filename: Benefits of Addressing HFCs under the Montreal Protocol.pdf

3.2. Frequently Asked Questions on the North American Amendment Proposal to Phase Down 

HFCs under the Montreal Protocol 

Title: Frequently Asked Questions on the North American Amendment Proposal to 

Phase Down the Use of Hydrofluorocarbons under the Montreal Protocol On 

Substances That Deplete The Ozone Layer

Description: Frequently asked questions and responses relating to the North American 

amendment proposal to phase down the use of hydrofluorocarbons under the 

Montreal Protocol on Substances that Deplete the Ozone Layer (Submitted by 

Canada, Mexico and the United States of America in November 2012)

Available at: http://conf.montreal-protocol.org/meeting/mop/mop-24/presession/Information 

Documents/MOP-24-INF-7.pdf

Filename: Frequently Asked Questions on the North American Amendment Proposal.pdf
May 2013 TEAP XXIV/7 Task Force Report 115

4. Available and Emerging Alternative Technologies

4.1. Advancing Ozone and Climate Protection Technologies: Next Steps

Title: Advancing Ozone & Climate Protection Technologies: Next Steps – Meeting 

Summary 

Description: This report summarizes the outcomes of the Bangkok Technology Conference 

and technology exhibition; including discussion of various alternatives and 

approaches to ensure that the phase out of CFCs and HCFCs is done in such as 

way as to limit the climate contribution of high‐GWP HFCs. Forum discussion 

included both policy and technical aspects of this transition in the refrigeration, 

air conditioning and foams sectors.

Available at: 

http://www.unep.org/ccac/Portals/24183/docs/Bangkok%20Technology%20Co

nference%20-%20Report%20and%20Cover%20-%20FINAL.pdf

Filename: Bangkok Technology Conference - Report and Cover - FINAL.pdf

Title: Hydrocarbons in Air-conditioners – The Godrej Experience

Description: This presentation from the Advancing Ozone & Climate Protection 

Technologies: Next Steps technology conference shares one company's 

experience with hydrocarbon refrigerants in air conditioning systems.

File Name: Session-V Air Conditioning (Dilip Rajadhyaksha - Godrej).pdf

4.2. Montreal Technology Forum on Climate-friendly Alternatives in Commercial 

Refrigeration 

Title: Montreal Technology Forum on Climate-friendly Alternatives in Commercial 

Refrigeration – Meeting Summary

Description: This summary report from the Montreal Commercial Refrigeration Technology 

Forum held in December, 2012, provides information on various topics 

discussed during the conference, including; the technical, financial and 

environmental aspects of some of the key low-GWP, energy-efficient alternative 

technologies that are available or emerging in the commercial refrigeration 

sector; potential applicability of these technologies in developing countries; and 

dialogue among government representatives, international organizations, 

industry, technology users and technology providers, on the opportunities and 

challenges involved in successfully adopting such technologies in developing 

countries.

Available at: http://www.unep.org/ccac/Techforum/tabid/105036/Default.aspx

Filename: The document is in the process of being finalized in early February. We will 

transmit the document when it becomes available.

4.3. GreenChill Webinar Series on Alternative Technologies in the Commercial Refrigeration 

Sector

Description: Information regarding new technologies being deployed in the commercial 

refrigeration sector can be accessed through archived webinars, presentations, 

and additional items; including the following webinars:

 Transcritical CO2 Refrigeration Systems 

 Cascade CO2 Refrigeration Systems 

 Ammonia Cascade Systems

Available at: http://www.epa.gov/greenchill/events.html

HFC-Free Technologies Are Available in the Supermarket Retail Refrigeration 

SectorTitle: HFC-Free Technologies Are Available in the US Market for 

the Supermarket - Retail Refrigeration Sector
116 May 2013 TEAP XXIV/7 Task Force Report

Description: This report discusses the availability of climate-friendly 

technologies for the refrigeration sector in U.S. supermarkets that will allow for 

the rapid phase-out of HFCs.

Available at: http://eia-global.org/PDF/USSUPERMARKETREPORT.pdf 

Filename: HFC-Free Technologies Are Available in the Supermarket 

Retail Refrigeration Sector.pdf

4.4. Greenpeace - Cool Technologies: Working without HFCs Report

Title: Greenpeace – Cool Technologies: Working without HFCs, Examples of HFCFree Cooling Technologies in Various Industrial Sectors, 2012 Edition

Description: This report documents the current availability of HFC-free cooling technologies 

in most sectors and more are rapidly coming on line. The report surveys an 

extensive list of companies and enterprises using HFC-free technologies, 

documenting the already wide array of safe and commercially proven HFC-free 

technologies for meeting nearly all needs formerly met by fluorocarbons.

Available at: http://www.greenpeace.org/international/Global/international/publications/

climate/2012/Fgases/Cool-Technologies-2012.pdf

Filename: Cool-Technologies-2012.pdf

4.5. Purdue University 2012 Conferences Presentations

Title: 21st International Compressor Engineering Conference at Purdue, 14th

International Refrigeration and Air Conditioning Conference at Purdue, 2nd

International High Performance Buildings Conference at Purdue – July 16-19, 

2012 at Purdue University

Description: Links to various sessions with presentations on alternative technologies 

including:

Session: Low GWP Refrigerants I

Title: Low Global Warming Potential (GWP) Alternative Refrigerants 

Evaluation Program (Low-GWP AREP)

Title: R32 And HFOs As Low-GWP Refrigerants For Air Conditioning

Title: Performance and Capacity Comparison of Two New LGWP Refrigerants 

Alternative to R410A in Residential Air Conditioning Applications

Title: Drop-in Performance of Low GWP Refrigerants in a Heat Pump System 

for Residential Applications

Title: Study of R161 Refrigerant for Residential Air-conditioning Applications

Available at: http://www.conftool.com/2012Purdue/index.php?page=browseSessions

&form_session=3

Session: R-31: Low GWP Refrigerants II

Title: A Reduced GWP Replacement for HFC-134a in Centrifugal Chillers: 

XP10 Measured Performance and Projected Climate Impact

Title: Latest Developments of Low Global Warming Refrigerants for Chillers

Title: Low Global Warming Refrigerants For Commercial Refrigeration 

Systems

Title: The Circulation Composition Characteristic of the Zeotropic Mixture 

R1234ze(E)/R32 in a Heat Pump Cycle

Title: Development of Refrigeration Oil for Use With R32

Title: Investigation Of Low GWP Refrigerant Interaction With Various 

Lubricant Candidates
May 2013 TEAP XXIV/7 Task Force Report 117

Available at: http://www.conftool.com/2012Purdue/index.php?page=browseSessions&

form_session=31

Session: Industrial/Commercial Refrigeration

Title: Drop-in Testing of Next-Generation R134a Alternates in a Commercial 

Bottle Cooler/Freezer

Title: Development of Low Global Warming Potential Refrigerant Solutions for 

Commercial Refrigeration 

Title: Modeling and Simulation of a Desiccant Assisted Brayton Refrigeration 

Cycle

Title: Taking a Sensible Choice of Sustainable Super Market Refrigeration 

Equipment

Title: Evaluation Of Defrost Options For Secondary Coolants In Multitemperature Indirect Transport Refrigeration: Mathematical Modeling & 

Sensitivity Analysis

Available at: http://www.conftool.com/2012Purdue/index.php?page=browseSessions&

form_session=14

4.6. AHRI Low-GWP Alternative Refrigerants Evaluation Program Reports

Title: Air-Conditioning, Heating, and Refrigeration Institute Low-GWP Alternative 

Refrigerants Evaluation Program final test reports.

Description: Final test reports evaluating low-GWP alternative refrigerants, including:

Title: System Drop-in Test of R-410A Alternative Fluids (ARM-32a, ARM-70a, 

DR-5, HPR1D, L-41a, L-41b, and R-32) in a 5-RT Air-Cooled Water Chiller 

(Cooling Mode)

File Name: AHRI Low-GWP AREP-Rpt-001.pdf

Title: System Drop-In Test of L-40, L-41a and N-40b in Ice Machines

File Name: AHRI Low-GWP AREP-Rpt-002.pdf

Title: System Drop-In Test of R-32/R-152a (95/5) in 5-ton Air Source Heat 

Pump

File Name: AHRI Low-GWP AREP-Rpt-003.pdf

Available at: http://www.ahrinet.org/ahri+low_gwp+alternative+refrigerants+evaluation+

program.aspx

4.7. ASHRAE/NIST Refrigerants Conference 2012 Presentations and Conference Papers

Title: 2012 ASHRAE/NIST Refrigerants Conference: Moving Towards Sustainability, 

October 29-30, 2012, Gaithersburg, Maryland

Description: Link to various presentations on alternative technologies

Available at: https://www.ashrae.org/membership--conferences/conferences/ashraeconferences/ASHRAE-NIST-Refrigerants-Conference
118 May 2013 TEAP XXIV/7 Task Force Report

On 15 March 2013, TEAP received the following correspondence from the European Commission:

Dear Ozone Secretariat:

Decision XXIV/7 invites parties to submit information relevant to the work of the TEAP as outlined 

in paragraph 1 of XXIV/7, so that this information may be taken into account for the production of 

the TEAP draft report for consideration by the 33rd OEWG. 

The European Union wishes to invite TEAP to take into account the following studies:

Schwarz et al. (2011): Preparatory study for a review of Regulation (EC) No 842/2006 on 

certain fluorinated greenhouse gases – Final Report. 

http://ec.europa.eu/clima/policies/f-gas/docs/2011_study_en.pdf

Annexes: 

http://ec.europa.eu/clima/policies/f-gas/docs/2011_study_annex_en.pdf 

SKM Enviros (2012): Phase Down of HFC Consumption in the EU – Assessment of Implications 

for the RAC Sector.

SKM Enviros (2012): Further Assessment for Policy Options for the Management and Destruction of 

Banks of ODS and F-gases in the EU.

http://ec.europa.eu/clima/policies/ozone/research/docs/ods_f-gas_destruction_report_2012_en.pdf

Umweltbundesamt (2011): Avoiding Fluorinated Greenhouse Gases – Prospects for Phasing 

out.

European Commission (2012): IMPACT ASSESSMENT - Review of Regulation (EC) No 842/2006 

on certain fluorinated greenhouse gases

http://ec.europa.eu/clima/policies/f-gas/legislation/docs/swd_2012_364_en.pdf

Yours sincerely,

Dr. ARNO KASCHL

Policy Officer

European Commission

Directorate-General for Climate Action

Transport & Ozone

BU-24 -1/33

B-1049 Brussels/Belgium

+32 229-93083

arno.kaschl@ec.europa.eu

On 8 April 2013, the Commission submitted four reports, on renewable cooling and sustainable 

cooling for datacenters and on fishery to the TEAP Task Force. 
May 2013 TEAP XXIV/7 Task Force Report 119

8 Technical, economic and environmental definitions

Technical and economic deasibility

Technical feasibility addresses whether a particular alternative depicted by equipment/systems using 

an ODS substitute can be made to work, and where/how they can be applied.

Economic feasibility should discuss how those costs for certain alternatives may change in the future 

(e.g., lower costs as production volumes increase, higher or lower electricity costs, potential influence 

of factors such as policy measures). Analysis of the factors that influence costs and how the costs 

may go up or down over the next 3-7 years would be valuable, but it is doubtful whether this can be 

applied to all alternatives considered.

Cost Effectiveness

There are two basic components of cost which are well understood by the Montreal Protocol – capital 

cost and operating cost. In simple terms, cost effectiveness would need to be defined in the context of 

whole life costing based on a certain required internal rate of return. The main problem is that this 

requirement will vary by geographic region, company size and the competing investment 

environment. 

Equally, there is also a need to decide whether this is going to be assessed at alternative level (only 

applicable to drop-ins) or system level. In addition we have to consider where the cost will be borne. 

At the level at which cost effectiveness is being determined, there is no real option but to make 

comparisons with the economics of previous conversions and decide whether there is a benchmark 

that can be drawn from the existing literature, outside of the rather narrow determinations made by 

the Multilateral Fund. 

Environmentally sound

The ‘Business Dictionary’ defines an ‘environmentally sound’ product or process as: 

Product or manufacturing process that, from beginning to end, is in essential harmony with its 

environment and the associated ecological factors.

Taken at face value, this is a high bar since it requires something that is in ‘essential harmony’ with 

its surroundings. In this context it is at least comparable with ‘environmentally benign’ and possibly 

higher according to this definition. The term ‘environmentally benign’ had been used previously in 

Decision XXIII/9, although authors of that Report had been unable to find a clear definition for the 

term. In normal English usage, ‘environmentally benign’ would be seen as a higher bar than 

‘environmentally sound’ since the word ‘sound’ would convey ‘fitness for purpose’ or ‘reliability’, 

whereas ‘benign’ would be seen as ‘creating no negative impacts’.

It can be argued that no solution is ‘environmentally sound’ against the Business Dictionary 

definition. However, the definition set out under the Agenda 21 Framework (and also adopted by the 

Global Development Research Centre) offers a more comparative approach. It states that: 

Environmentally Sound Technologies (ESTs) encompass technologies that have the potential for 

significantly improved environmental performance relative to other technologies. Broadly speaking, 

these technologies:-

Protect the environment

Are less polluting
120 May 2013 TEAP XXIV/7 Task Force Report

 Use resources in a sustainable manner

Recycle more of their wastes and products

Handle all residual wastes in a more environmentally acceptable way than the technologies 

for which they are substitutes 

It can be seen that this approach is one which provides a measure ‘relative to other technologies’, 

which, in turn, is more meaningful to the language of Decision XXIV/7, bearing in mind that all 

alternatives have some form of environmental footprint.

Where all other technical and economic factors are comparable, the Task Force has adopted the 

approach of taking ‘environmentally sound’ as meaning the alternative which delivers the least 

‘negative environmental impact’. This, in turn, has been expressed in this draft report as the ‘most 

favourable option’, although, as noted in Chapter 2, this identity of the ‘most favourable option’ may 

vary depending on the environmental impact being considered. This then links it to the next 

definition.

Low GWP

There have been numerous discussions about the nomenclature that should characterise the level of 

global warming potential displayed by ODS alternatives. In some sectors, the available alternatives 

have all been seen to be below a GWP of 25, and these have been classed as ‘low-GWP’. In other 

sectors, the benchmark is a GWP of 1,500 or above and alternatives with GWPs at 1,000 or 300 can 

also be considered as ‘low’. The challenge is that the terms are used in a ‘relative’ rather than an 

‘absolute’ way. 

The Task Force has considered whether there should be a formal nomenclature applied across all 

sectors involving terms such as ‘moderate’ (<1,000), ‘low’ (<300) and ultra-low (<25), but this type 

of approach was seen as controversial when proposed in the response to Decision XXIII/9.

The definition of environmentally sound technologies adopted under Agenda 21 makes an important 

further point in its expanded version. It notes that ‘...environmentally sound technologies are not just 

“individual technologies” but total systems which include know-how, procedures, goods and 

services, equipment as well as organisational and managerial procedures’ The implication is that a

systems approach is essential to truly identify what is environmentally sound. 

The evaluation of ODS alternatives has embraced this concept through a number of methodologies 

such as TEWI, LCCP and wider Life Cycle Assessment (LCA). However, such analyses are 

inevitably specific to the applications against which they are applied and are difficult to extrapolate 

for wider policy purposes. 

With these factors in mind, the Task Force has concluded that it is better to refer to holistic 

approaches such as TEWI, LCCP and LCA only in the context of individual applications and 

scenarios. It also believes that adopting a formal nomenclature for classes of global warming 

potential is misleading, since it implies a hierarchy which is not always borne out when other factors 

are taking into consideration (e.g. energy efficiency). Therefore, references to climate impacts are 

mostly related to the overall impact of technologies where such information is available. In addition, 

where reference is made to ‘low-GWP’ solutions, the terminology should be treated as a generic label 

of improved climate performance rather than a prescribed band of GWP values.
May 2013 TEAP XXIV/7 Task Force Report 121

9 List of acronyms and abbreviations

ABC Dry Chemical Powder

AIHA American Industrial Hygiene Association

ASTM American Society for Testing and Materials

BTP Bromotrifluoropropene

CEFIC European Chemical Industry Council

CEN European Committee for Standardisation

CFC Chlorofluorocarbon

CO2 Carbon Dioxide

COP Coefficient of Performance

CTOC Chemicals Technical Options Committee

EC European Commission

EPA US Environmental Protection Agency

EU European Union

FIC Fluoroiodocarbon

FK Fluoroketone

FTOC Foams Technical Options Committee

GWP Global Warming Potential

HARC Halon Alternatives Research Corporation

HCFC Hydrochlorofluorocarbon

HCFO Hydrochlorofluoroolefin

HCO Oxygenated hydrocarbon

HFC Hydrofluorocarbon

HFE Hydrofluoroether

HFO Hydrofluoroolefin

HTOC Halons Technical Options Committee

IIR International Institute for Refrigeration

IMO International Maritime Organisation

IPCC Intergovernmental Panel on Climate Change

ISO International Organisation for Standardisation

LCA Life Cycle Analysis

LCCP Life Cycle Climate Performance 

VCLCG Liquefied Compressed Gas

MT Metric Tonnes

NFPA National Fire Protection Association

NOAEL No Observed Adverse Effect Level

n-PB n-Propyl Bromide

ODP Ozone Depletion Potential

ODS Ozone Depleting Substance

OEL Occupational Exposure Limit 

PFC Perfluorocarbon

RTOC Refrigeration AC and Heat Pumps Technical Options Committee

SNAP Significant New Alternatives Policy

STOC Solvents, Coatings and Adhesives Technical Options Committee

TEAP Technology and Economic Assessment Panel

TEWI Total Equivalent Warming Impact

TLV Threshold Limit Value 

UL Underwriters Laboratories Inc.

UNDP United Nations Development Programme

UNEP United Nations Environment Programme

VOC Volatile Organic Compound

May 2013 TEAP XXIV/7 Task Force Report 123

10 References

(Atmosphere, 2010) How to bring natural refrigerants faster to market. Atmosphere 2010 

International Workshop on Natural Refrigerants Brussels, Belgium 27 - 28 

September 2010

(Brown, 2002) Brown, J. S., Kim, Y-C., Domanski, P. A. 2002. Evaluation of carbon dioxide 

as R-22 substitute for residential air conditioning. ASHRAE Trans. Vol. 208, 

Part 2, paper HI-02-13-3.

(Burke, 2011) Burke, M.; Grosskopf, P.: Development of environmentally friendly transport 

refrigeration machines. IIR Int. Congr. Refr. August 21 – 26, 2011, Prague, 

Czech Republic

(Carrier, 2011) Carrier: NaturaLine is the one. Container Line, December 2011

(Chen, 2012) Chen, Z. H. 2012. Research on Rotary Compressors Based on R-290 

Technology. Proc. UNEP conference on technologies for high ambient 

conditions, Dubai, 2012.

(Colbourne, 2012) Colbourne, D., van Gerwen, R. 2012. Hydrocarbon refrigerants for room air 

conditioners and commercial refrigeration. Proc. ASHRAE/NIST Refrigerants 

Conference. Gaithersburg, USA.

(Devotta, 2005) Devotta, S., Padalkar, A.S., Sane, N. K. 2005. Performance assessment of HC290 as a drop-in substitute to HCFC-22 in a window air conditioner. Int. J. 

Refrig., 28, 594-604.

(EIA, 2012) Availability of low GWP alternatives to HFCs: Feasibility of an early phaseout of HFCs by 2020. Environmental Investigation Agency (EIA), May 2012.

(Gerwen2011) Gerwen, R.J.M. v.: End-user strategies for sustainable industrial refrigeration. 

ICR 2011, August 21-26, Prague, Czech Republic

(Hafner, 2007) Hafner A., Garski, D. J., Manzione, J. 2007. Air reversing R744 air 

conditioning system. Proc. ???

(Hafner, 2009) Hafner, A. Nekså, P. Stene J. 2009 Reversible Residential Air-Conditioners 

and Heat Pumps Using Carbon Dioxide (CO2, R744) as Working Fluid. Proc. 

XIII European Congress: the Latest Technologies in Refrigeration and Air 

Conditioning, Milan, Italy. 

(Khoury, 2012) Khoury, G. 2012. Development of a high temperature CO2 Heat Pump for 

space heating. Proc. Atmosphere conf. Shecco. Brussels, Belgium. 

(Lee, 2011) Lee, J. S., Kim, M. S., Kim, M. S. 2011. Experimental study on the 

improvement of CO2 air conditioning system performance using an ejector.

Int. J. Refrig., Vol. 34, Issue 7, pp. 1614–1625

(Liu, 2012) Liu, F., Li, Y., Groll, E. A. 2012. Performance enhancement of CO2 air 

conditioner with a controllable ejector. Int. J. Refrig. Vol. 35, Issue 6, pp. 

1604–1616

(Machida, 2011) Machida, A., Boone, J.: Development of air refrigeration system “Pascal Air”. 

IIR International Congress of Refrigeration 2011, August 21 - 26 - Prague, 

Czech Republic

(McNeill, 2011) McNeill: Energy efficient combined cooling and heating at Nestlé UK. 

Eurammon "Future-proof solutions for Today", Schaffhausen, Switzerland, 7 

October 2011

(Nestle, 2008) Lopez, J.: Reminder on Nestlé Policy on the Use of Natural Refrigerants. 24 

April 2008

(Palm, 2008) Palm, B. 2008. Hydrocarbons as refrigerants in small heat pump and 

refrigeration systems - A review. Int. J. Refrig. 31.

(Richter, 2001) Richter, M. R., Bullard, C. W., Hrnjak, P. S. 2001. Comparison of R744 and R410A for Residential Heating and Cooling Applications. ACRC CR-39. Air 

Conditioning and Refrigeration Centre, USA. 
124 May 2013 TEAP XXIV/7 Task Force Report

(RTOC, 2010) 2010 Report of the Refrigeration, Air Conditioning and Heat Pumps Technical 

Options Committee. UNEP 2011

(Schwarz, 2011) Schwarz, W.; Gschrey, B.; Leisewitz, A.; Herold, A.; Gores, S.; Papst, I.; 

Usinger, J.; Oppelt, D.; Croiset, I.; Pedersen, P.H.; Colbourne, D.; Kauffeld, 

M.; Kaar, K.; Lindborg, A.: Preparatory study for a review of Regulation (EC) 

No 842/2006 on certain fluorinated greenhouse gases. Final report, Sept. 2011

(Teng, 2012) Teng, T-P., Mo, H-E., Lin, H., Tseng, Y-H., Liu, R-H., Long, Y-F. 2012. 

Retrofit assessment of window air conditioner. Applied Thermal Engineering. 

Volume 32, pp. 100–107

(UNEP, 2011) TEAP Replenishment Task Force Report for the Replenishment of the 

Multilateral Fund for the Triennium 2012-2014, UNEP, 2011

(UNEP, 2012) TEAP Task Force Report on Decision XXIII/9, UNEP, 2012 

(Zheng, 2012) Zheng, S. 2012. Application of HC Refrigerant in Package Portable Room Air 

Conditioners and Dehumidifiers. Proc. CACC Conf., Bangkok, Thailand.

From Chapter 5 on Fire Protection

ISO 6183:2009, Fire protection equipment — Carbon dioxide extinguishing systems for use on 

premises — Design and installation

U.S. Environmental Protection Agency, Office of Air and Radiation, Stratospheric Protection 

Division “Carbon Dioxide as a Fire Suppressant: Examining the Risks,” February 2000

Halon Replacement for Airplane Portable Fire Extinguishers – Progress Report, Sixth Triennial 

International Fire & Cabin Safety Research Conference, Atlantic City, NJ, October 26-28, 2010. 

http://www.fire.tc.faa.gov/2010Conference/files/Halon_Replacement_I/Boeing2BTPHandheld/Carlo

BTPupdatePres.pdf (7.9 MB) 

Colton, Bradford, “BTP (2Bromo-3,3,3-trifluoropropene) Status Update,” presentation to Federal 

Aviation Administration, IASFPWG and International Civil Aviation Organization, November 14-16, 

2012. 

http://www.fire.tc.faa.gov/ppt/systems/Nov12Meeting/Colton-1112-HandheldBTPUpdate.pptx (24 

MB) 

Robert Morrison, 747 Hidden Fire, 2-BTP Testing, “747 Hidden Fire, 2-BTP Testing,” Systems 

Working Group Meeting, Long Beach, CA, November 14 - 15, 2012. 

IPCC Fourth Assessment Report: Climate Change 2007

http://www.ipcc.ch/publications_and_data/aR-4/wg1/en/ch2s2-10-2.html

From Chapter 6 on Solvents

Guidelines for Cleaning of Printed Boards and Assemblies, IPC-CH-65B. Published by IPC. Revised 

July 2011.

Handbook for Critical Cleaning, Kanegsberg and Kanegsberg, Editors. Published by CRC Press. 

Published April 2011.