Alternatives to HFCs in the Refrigeration and Air Conditioning Sector: Practical Guidelines and Case Studies for Equipment Retrofit and Replacement

8/2/2019 Alternatives to HFCs in the Refrigeration and Air Conditioning Sector: Practical Guidelines and Case Studies for Equi

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Alternativestohcfcs

intherefrigerationandairconditioningsector

Practical Guidelines and Case

Studies or Equipment Retrotand Replacement

Unite

d

nations

environment

Progr

amme


2/822

Copyright United Nations Environment Programme 2010

This publication may be reproduced in whole or in part and in any orm or educational

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acknowledgement o the source is made. UNEP would appreciate receiving a copy o

any publication that uses this publication as a source.

No use o this publication may be made or resale or or any other commercial prupose

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Disclaimer

The designations employed and the presentation o the material in this publication do

not imply the epression o any opinion whatsoever on the part o the United Nations

Environment Programme concerning the legal status o any country, territory, city or area

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4/824 UNITED NATIONS ENVIRONMENTAL PROGRAM

Acknowledgements

This pubication as poduced b the UNEP Diisiono Technoo, Indust and Economics (DTIE)OonAction Banch ith nancia suppot o the SedishEnionmenta Potection Aenc. It as poducedin the ameok o the HCFC Hep Desk poject toencouae deeopin counties to achiee compianceith thei HCFC phaseout obiations and adopt

enionmenta iend atenaties to HCFCs.The poject as manaed b the ooin team in theOonAction Banch, UNEP DTIE, Fance:

mr. Rajra shHead

mr. Ja s. curInteim Netok and Poic Manae

m. Barbara HubrPoamme Assistant

mr. Rupr d JuPoamme Assistant

m. muur kb UruDocumentation Assistant

THIS PUBlICATION wAS wrITTEN By:

mr. ka BrOne, Beo reieationTechnoo ltd, Seden

THE rEvIEwErS:

dr. Huau AhaaSenio AdiseSedish Enionmenta Potection Aenc

dr. Jau kaAssociate Poesso, Head o Oone lae

and Cimate Potection Unit, ICrI, Poand

dr. era carPoamme Oce, OonAction Banch,UNEP DTIE, Fance

DESIgN:

A dAmstedam

PHOTO CrEDITS:Photos used in ues Kas BeoPhoto o r22 cinde on pae 17 Enionmenta Inestiation Aenc

JOB NUMBEr: DTI/1282/PA


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section01Ara HcFc in the reieation and Ai Conditionin Secto

5

Practical Guidelines and Case StudiesFor Equipment Retrot and Replacement

Atenaties to HCFCs

in the Rerigeration andAir conditioning Sector

United nAtions enviRonment PRogRAmme

Division o Technology, Industry & Economics

OzonAction Programme

15, rue de Milan

75441 Paris CEDEX 09

France

swedisH enviRonmentAl PRotection Agency

106 48 Stockholm, Sweden

Visiting address:

Valhallavgen 195, Stockholm

Telephone: +46-8-698 10 00.

Fax: +46-8-20 29 25

Internet: www.naturvardsverket.se


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section01 Ara HcFc in the reieation and Ai Conditionin Secto

6

Introduction

Alternatives to HCFCs

in the rerigerationand air conditioningsectorPraa gu a ca su reup cr, Rr a Rpa

HydRocHloRoFlUoRocARBons (HcFcs) are ozone

depleting substances (ODS) controlled by the Montreal

Protocol on Substances that Deplete the Ozone Layer that

are widely used in rerigeration and air conditioning, oam

blowing and solvent applications.

In September 2007, the Parties to the Protocol accelerated

the phase-out schedule or these chemicals through

Decision XIX/6. Developing countries operating under Article

5 o the Protocol (Article 5 countries) now have to reeze by2013 their HCFC production and consumption to the average

o their 2009-2010 levels, ollowed by a 10 percent reduction

by 2015, by 35 percent by 2020, by 67.5 percent by 2025, and a

100 percent phase-out by 2030 (with 2.5 percent allowed, i

necessary, or servicing existing equipment until 2040). The

same decision requires developed countries to accelerate

their phase-out schedule by 10 years to completely eliminate

HCFCs by 2020) with 0.5 percent allowed, i necessary, or

servicing existing equipment until 2030).

Action on HCFCs is important in that these chemicals have

an impact on both ozone depletion and climate change. Interms o direct impact, the most commonly-used HCFCs

have ozone depleting potentials (ODPs) ranging rom 0.02

(HCFC-123) to 0.11 (HCFC-141b) and global warming potentials

(GWPs) ranging rom 76 (HCFC-123) to 2270 (HCFC-142b).

Equipment using HCFCs consumes energy, which

contributes to indirect global warming impacts.

The rerigeration and air conditioning (RAC) sector was the

biggest consumer o CFCs and in preparation or the total

CFC phase-out on January 1, 2010, it gradually shited to the

alternative rerigerants, including HCFCs. Today the sector

has become one o the primary consumers o HCFCs and will

need appropriate assistance to enable it to comply with the

accelerated phase out.

UNEP DTIE in cooperation with the Swedish Environmental

Protection Agency (SEPA) has produced this publication to

provide decision makers in Article 5 countries, the end-users

and the service technicians a comprehensive source o

inormation on alternative technologies that can be adopted

to phase out HCFCs in the RAC.

The report contains a section on alternative technologies

including technical aspects and inormation on current

market situation in developed countries (Article 2

countries) and Article 5 countries. Another section covers acollection o industry case studies that exemplies state-o-

the-art solutions using dierent technologies or dierent

market segments.


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sUmmARy

tecHnicAl inFoRmAtion


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8

Executive

Summary

tHe PHAse-oUt o chlorouorocarbons (CFCs), one o the

most aggressive Ozone Depleting Substances (ODS), is now

almost completed in accordance with the Montreal Protocol.

The ocus is now gradually shiting towards the phase-out

hydrochlorouorocarbons (HCFCs) whose phase-outschedule has been accelerated by the Parties to the Protocol

in Spetember 2007 through Decision XIX/6. Developing

countries operating under Article 5 o the Protocol (Article 5

countries) now have to reeze by 2013 their HCFC production

and consumption to the average o their 2009-2010 levels

ollowed by a 10 percent reduction by 2015; 35 percent by

2020; 67.5 percent by 2025 and a 100 percent phase-out by

2030 (with 2.5 percent allowed, i necessary, or servicing

existing equipment until 2040). The same decision requires

developed countries to accelerate their phase-out schedule

by 10 years to completely eliminate HCFCs by 2020) with

0.5 percent allowed, i necessary, or servicing existingequipment until 2030).

HCFCs are widely used as a rerigerant in rerigeration and air

conditioning systems and equipment as well as a blowing

agent in the exible and rigid oam sector.

The rst target in the rerigeration and air conditioning

sector should be to minimize the installation o new HCFC

systems. Considering that the pre-charged air conditioning

systems constitute the biggest sub-sector, minimising

their production will create a specic challenge in non-

producing Article 5 countries. th au HcFc

a h h pr b

u h aua h pr urHcFc up ba r h ar 20092010.

Hr a h r , a r HcFc

r h ra a, paruar

ar h r 2013 a hruhu h phau

pr. On the other hand, countries that export pre-

charged systems will start with a high HCFC consumption

baseline but they will be able to comply easily with the

phase-out schedule by simply converting their production

processes to use nonODS technologies.

There are well established alternative substances to R-22

applications in the rerigeration and air conditioning sector.The prominent group o alternative substances are HFCs

which are synthetic rerigerants with similar characteristics

to HCFCs but no ozone depleting potential (ODP).

As HFCs have a high global warming potential (GWP)

there is a strong interest to minimize the introduction

and emissions o HFCs. Other alternatives with lower or

near zero ODP are available but are all associated with

challenges that have to be overcome in order or them

to play a major role on the market. Alternatives with


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9

negligible or zero GWP are ammonia, carbon dioxide and

hydrocarbons. These are oten called natural rerigerants.

Only hydrocarbons have similar technical characteristics

to HFCs that could allow them to be used without major

technology changes. Hydrocarbons are ammable andsaety precautions need to be considered during design,

manuacturing, installation, service and decommissioning.

For larger systems ammonia is well established on many

markets but several Article 5 countries lack qualied

technicians. Most countries need to increase the ocus on

training or all technologies and good practice to acilitate

the use o the best alternatives or dierent applications.

There is no one-size-ts-all solution.

All the HCFC alternative technologies require Article 5

countries to upgrade the capacity o the servicing sector.

In spite o the activities conducted during the phase outo CFCs, most o the Article 5 countries have a workorce

that, to a large extent, still do not work according to

internationally accepted good rerigeration and air

conditioning paractises. The shortcomings in training,

tools and enorcement o good practises cost industry

and consumers large amounts o money in increased

ailure rates and unnecessary high energy consumption.

The strong ocus on initial cost oten results in poorly

optimised systems and little interest to train sta.

The industrialised countries have in most cases introduced

certication schemes and restrictions on who can do certain

activities related to ODS as well as HFCs. The alternatives all

require special competencies to be used in an environmentally

acceptable and sae way. A signicant upgrade o thecompetence level has taken place during the last 10 years in

many non-Article 5 countries, where the use o virgin HCFCs

have mostly been eliminated or totally phased out. Due

to the challenges in upgrading the industry which mainly

consists o small and medium enterprises (SMEs) most Article

5 countries are only beginning this process. In order to phase

out HCFCs and improve reliability as well as energy efciency,

it is important or the industry to upgrade its competence in

all alternative technologies as there is no single technology

to date that can provide the ideal solution or all applications.

To justiy investment in tools and training in alternative

technologies, it is important to create an environmentwhere it is good business to do good practise. Providing clear

regulatory rameworks and inormation to equipment owners

is important to make necessary investments attractive or the

industry. I purchasing environmentally hazardous rerigerants

and working in the industry with little training and tools persist,

the change will be very slow as there are many equipment

owners with limited awareness and competence. Moreover,

the high energy consumption and unnecessary short liespan

o equipment are actors that are oten unknown to many.


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11

ContentsIntroduction 6

Guide to the Reader 7

Executive summary 8

Contents 11

1 Alternatives to HCFCs in rerigeration and air conditioning 12

1.1 Background 13

1.2 HCFCs used in the rerigeration and air conditioning sector 15

1.2.1 Air conditioning and industrial rerigeration traditional R-22 sub-sectors. 16

1.2.2 Split and unitary air conditioning sector (including air-to-air heat pumps) 16

1.2.3 VRV/VRF/multi-split systems (including heat pumps) 19

1.2.4 Chillers in air conditioning and cooling applications (including heat pumps with indirect systems) 19

1.2.5 HCFCs in commercial rerigeration 20

1.2.6 Other HCFC-using sub-sectors in the RAC sector 20

1.3 Energy efciency o air conditioning equipment 20

1.4 Alternatives to HCFCs in air conditioning and rerigeration 21

1.4.1 Ammonia 25

1.4.2 Hydrocarbons 25

1.4.3 Carbon dioxide (CO2) 27

1.4.4 HFC alternatives used in new and retrotted systems with new oil 29

1.4.5 HFC service blends used in existing systems 32

1.5 Oils in rerigeration and air conditioning sytems 34

1.6 Retrot procedures 36

1.6.1 Documentation o status and perormance 38

1.6.2 How to replace the oil? 39

1.6.3 Retrot with the oil change method 41

1.6.4 Retrot through ushing with the old rerigerant 411.6.5 Retrot through ushing with a solvent 41

1.6.6 Number o oil changes required 43

1.6.7 Methods o oil analysis and moisture content in oil 44

1.6.8 Laboratory tests 44

1.6.9 Reractometer test 44

1.6.10 Test kit 44

2 Case studies Alternative technologies in dierent applications 46

2.1 The transition in the unitary and split air conditioning market 48

2.1.1 Retrot o split air conditioning rom R-22 to R-407C with oil-change through ushing 48

2.2 Chillers with HFCs 52

2.2.1 Large low pressure chillers 52

2.2.2 Medium-sized and small chillers 522.3 Fruit Storage with hydrocarbon chillers at Nickle arm in UK 53

2.4 Cold store with low charge ammonia chiller 55

2.5 Retrot o R-22 chiller to R-422D (oil change not required) 58

2.5.1 Description o conversion procedures. 59

2.6 Carbon dioxide heat pumps or domestic heating and tap water 60

2.7 Carbon dioxide in supermarkets 62

2.7.1 Evaluation o carbon dioxide supermarket in Sweden 63

2.7.2 Evaluation o three carbon dioxide stores in Norway 66

2.7.3 Market situation or CO2 as a rerigerant in supermarkets 67

2.8 Retrot o R-22 supermarket in Romania to R-404A 67

2.8.1 Results obtained or the rerigeration circuit operating at medium temperature 69

2.8.2 Results obtained or the reezing circuit (LT) 71Appendix I - List o rerigerants 72

Appendix II - Reerences 77

Appendix II - Abbreviations and denitions 79


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13

UndeR tHe montReAl PRotocol on Substances

that Deplete the Ozone Layer, developing countries (i.e.

countries that operate under Article 5 o that agreement)

have developed strategies and successully implemented

measures which have phased out chlorouorocarbons

(CFCs) - ODS with high ODP by 1 January 2010. In

the coming years, the ocus will be to move away rom

the HCFCs, substances with lower ODP values which

have been used as transitional replacements while CFCs

were being phased out. In Article 5 countries, HCFCs arescheduled to be completely phased out by 2030 (with a

small servicing tail o only 2.5% allowed rom 2030-2040).

This might seem to be a long time, but many countries are

increasing their consumption o HCFCs rapidly and risk

building an HCFC-based inrastructure that can be costly

and complicated to convert to nonODS rerigerants

in the uture. The reeze in 2013 (baseline is the average

HCFC consumption between 2009 and 2010) will become

a challenge i measures are not initiated immediately.

It is important to ensure that all HCFC consumption

(production and import - export) is correctly reported

prior to baseline o 2009-2010 and reeze year o 2013,and that early actions are taken to reduce new HCFC

consumption to a minimum.

The rst priority should be to stop all new installations using

HCFCs as soon as possible. There is a special challenge or

countries importing HCFC-22 (R-22) equipment as they

are shipped pre-charged with the rerigerant and does not

count in the calculation o the countrys HCFC consumption

baseline. As these equipment become old and servicing

needs increase, only a limited quantity o HCFCs will be

available on the market. Many Article 5 countries have

no HCFC equipment production, but imports o R-22 air

conditioning units are quickly increasing. Equipment thatuse alternative rerigerants are readily available or a slightly

higher price, but it should also be kept in mind that R-22

equipment on the market are o an older design, whereas

newer models have been redesigned to meet much higher

energy efciency standards. Thereore the installation o such

equipment, while slightly higher in cost, will lead to additional

energy savings in the long run. Many o the substances

used to replace HCFCs have a signicant GWP which should

be taken into account when alternative technologies are

evaluated. The selection o alternative substances and

technologies will signicantly aect the uture impact on

the climate rom this sector. Both the direct impact rom thechosen substances and the energy consumed will depend on

the technologies selected.

1.1 Background

01 Alternatives to

HCFCs in rerigerationand air conditioning


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14

the installation o HCFCs has been in place since 2004 and a

total ban on the use o virgin HCFCs began in 2010.

The ollowing HCFCs are the most commonly used in the

dierent sectors:

HCFCs have traditionally been the global solution in sectors

that are now rapidly growing in many developing countries,such as stationary air conditioning and large commercial

and industrial rerigeration. In the later applications, HCFCs

have been competing with ammonia, another well-proven

mature technology. Other applications are new, since

HCFC has been used as a replacement to acilitate the phase-

out o CFC. Traditionally the retail ood sector mostly uses

R-12 (CFC) and R-502 (containing CFC) but moved to R-22 as

a transitional product beore non-ODS alternatives such as

R-134a and R-404A/R-507 were accepted.

HCFCs are used as a component in a large number o

rerigerant blends, oten designed to match the behaviourand perormance o R-12 and R-502. These are oten called

service or drop-in blends as they are intended to acilitate

an easy replacement o CFCs in existing plants with minimal

changes to the system.

Technologies to move away rom HCFCs are well-known

and proven in the industrialised countries and many o the

alternatives are already partly introduced in developing

countries due to inuences rom neighbouring markets and

international companies. The strongest incentive or the

continuous growth o markets or HCFCs is the lower initial

price o both the substance and the equipment intended oruse with HCFC (although this is oten only in a short time

perspective as long-term energy and uture retrot cost

will be high). R-22 is also a product that the entire industry is

amiliar with. Alternatives with less environmental impact are

oten associated with slightly higher initial cost and a need

or technical know-how to be dispersed to a large number

o technicians. This creates an uncertainty in the market

that can be taken advantage o by competing companies

by preserving old technologies at minimal cost. For some

o the environmentally-preerred solutions, there are also

saety barriers to be addressed to make these alternatives

viable solutions. A more extensive list o alternatives toHCFCs are listed in Appendix I - List o rerigerants. In

Article 2 (i.e. developed country) markets, the transition has

been happening over the last 15 years, so the commercial

alternatives are well-proven. For example, in Europe a ban on

sectoR tyPe oF HcFc

Rrra auaur a r

Domestic eieation limited use o seice dopin bends (nee used in equipment poduction)

(HCFC141b in appiance insuation oam)

Commecia reieation HCFC bends in seice, (HCFC141b in oam)

Industia eieation HCFC22, r502 (a bend o CFC/HCFC), HCFC bends, (HCFC141b in oam)

Tanspot eieation HCFC22, r502, HCFC bends, (HCFC141b oam)

saar Ar c

residentia and commecia AC HCFC22

Chies HCFC22, HCFC123

mb ar None o minima (poo compatibiit ith hoses)

Fa HCFC141b, HCFC142b, HCFC22

ma Ar None

nma Ar HCFC22, HCFC141b, HCFC142b

Fr Pr HCFC123, HCFC124, HCFC22 (bends)

s HCFC141b, HCFC225ca, HCFC225cb

Dieent sectos hee HCFCs ae most common used.


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1.2 HCFCs used in the rerigeration andair conditioning sector

sUmmARy HcFc Use in tHe RAc sectoRHCFCs ae ide used oe the entie industia and commecia eieation secto incudin o ood pocessin,distibution, stoae and etai (shops and supemakets). In ai conditionin, HCFCs hae paed a dominant oe

in unita, spit and chie tpe sstems o ai conditionin in piate homes, hotes, oce buidins, estauants

and othe pubic buidins.

r22 is b a the most commonused HCFC in this secto. Othe HCFCs such as r124 and r123 hae been used in

smae quantities o specia appications. Sti othe HCFCs such as HCFC141b and HCFC142b hae been used as

boin aents in eieation equipment insuation ate the phase out o CFCs, sometimes in mitues ith r22.

reieation and ai conditionin equipment is oba one o the sectos ith the hihest eectica poe consumption.

The apid oth in this secto in man counties i esut in a need to epand poe poduction and distibution sstems.

The ene consumption o counties in this secto aso contibutes sinicant to oba amin. with the epectedequiements in the oba aeements on eduction o een house ases the emissions o eieants such as HCFCs and

HFCs as e as ene consumption in this secto i pa a sinicant oe in hethe these aeements achiee its taets.

Aside FRom Being one o the major ODS-consuming

sectors the rerigeration and air conditioning sector (RAC)

including heat pumps and dehumidiers, also uses 15% to

20% (IIR, 2002) o global electrical energy. The economic

growth in many Article 5 countries in hot climates results in

a corresponding growth o the RAC sector. The applications

where HCFCs are used are important to reduce the losses

in the ood production and distribution chain. There arealso many applications that are essential or industrial

production and human comort where HCFCs play an

important role today. The growth will result in increasing

energy consumption i measures to improve efciency

including the introduction o more energy-efcient

technologies - are not implemented eectively/appropriately.

thr ar pr h aaab rpa

HcFc h p uba a a

pr r a rrra a ar

appa.Alternatives such as HFCs can

be used with minimal changes to the existing technology, but

have a high GWP. Rerigerants with a low or zero GWP should

be the preerred solution when they can be used in a saeand cost-eective manner without resulting in higher energy

consumption. High GWP rerigerants should only be used when

technical, economic or saety reasons require them, and in such

cases they should be used in systems with minimized leakage

and emissions during service and at the end o equipment lie.

HCFC is also used as eedstock or the production o plastics

and other chemicals.

When replacing HCFCs it is important to evaluate the envi-

ronmental impact o the alternatives since the most com-

mon replacements are hydrouorocarbons (HFCs) which

have a signicant Global Warming Potential. The impact

o alternative rerigerants and the energy consumption o

selected system solutions should also be evaluated

to minimize their total impact on the environment.

Adopting measures to reduce the rerigeration and

air conditioning loads through good building design

and processes are obviously the most efcient way

o reducing the environmental impact o these

technologies.


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The emissions should be minimized through implementation

o good servicing practices and eective re-use schemes.

The main HCFC commonly used in air conditioning and

rerigeration applications beore 1985 was R-22. The main

sectors where R-22 was the preerred rerigerant were in the

air conditioning and industrial systems sectors where it was

also competing with ammonia. When CFCs were identied

as powerul ODS and a global phase-out was agreed under

the Montreal Protocol in 1987, HCFCs were identied as less

harmul substances and introduced in several sub-sectors

tHe PHysicAl PRoPeRties o R-22 result in good

perormance in a wide range o applications but with a

limiting actor caused by the high temperatures occurringduring compression. In rerigeration applications where the

temperature dierence between the desired temperature

and the surroundings is high, the risk o unacceptable

conditions and ailures increases. In hot climates, the

challenge in commercial rerigeration applications increases

signicantly more than in air conditioning systems. In

industrial applications R-22 was an alternative to ammonia

where it provided better cooling capacities than R-12 andwas more readily available and cost less than R-502. In large

installations the high temperatures could be handled with

dierent technical solutions, but it was not as cost-eective

in smaller commercial systems where R-12 and R-502 were

more common.

1.2.2 sPlit And UnitARy AiR conditioning sectoR (inclUding AiR-to-AiR HeAtPUmPs)

that were not traditional HCFC applications. As a result,

R-22 and HCFC-containing drop-in blends are now ound

in commercial rerigeration and to some extent in transport

rerigeration. The result is that replacement o HCFCs

will have an impact on many sectors and to some extent

the alternatives used will sometimes be the alternatives

designed to replace CFCs rather than those designed or

R-22 applications. The main ocus in this report will be on

segments where R-22 has a signicant market share but in

order to give a more complete update, other sectors will

also be covered, although with less attention.

1.2.1 AiR conditioning And indUstRiAl ReFRigeRAtion tRAditionAl R-22sUB-sectoRs.

sUmmARysPlit And UnitARy systemsr22 is used main in spit and unita ai conditionin equipment (see Fiue 1.2). The quantit used in this

appication is sometimes undeated because in the manuactuin/epotin count the initia chae is

consideed consumption heeas it is not consideed as such in the impotin count hee the equipment i

be instaed and seiced.

In ne sstems atenaties ae eadi aaiabe. Most oten r22 is epaced ith r410A o r407C. lae oumes

o r22 sstems ae sti bein instaed in some makets due to oe inestment outa and essinomed

customes. As these units ae, the can be epected to pa a sinicant oe in the consumption o HCFCs, once the

eee in HCFC consumption (this is usua equiaent to impots in most Atice 5 counties) in 2013 takes eect.

One o the pioities shoud be to stop the intoduction o ne r22 equipment. The soone eisation to ban the

impot, maketin and instaation o ne r22 sstems is estabished, the easie the tansition i be. The cost o

tansition i be oe as the added initia cost is much oe than the cost to etot the sstem.

F. 1.1 (opposite pae) HCFCsae used in a eieation and aiconditionin equipment that in tunis used eehee in societ.


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tHis mARket is dominAted by large volume

production, mostly rom Asia, but in some markets,

small local manuacturers are also present (see 2.1 The

transition in the unitary and split air conditioning market).

The price competition is extremely tough and quality/

perormance is not always a actor that the customer can

evaluate. These systems are installed in ofces, hotels,

restaurants, bars,shops and private homes. The numbers

o suppliers/installers/service providers involved are high

and the level o competency is oten low. Global players

have local representation in many countries either through

their own subsidiaries or through local distributors, but

signicant volumes are traded by less skilled and specialised

companies competing in segments with low pricing, which

makes this sector challenging and diversied.

A signicant part o the market will be ocused solely on low

initial price at the expense o equipment efciency. As this

market rapidly grows in many countries, so does the numbero units installed each year increase. Thereore this sector

can play a signicant role as the limit on imports o HCFCs

or servicing comes into eect. These units are supplied with

a ull rerigerant charge and the HCFCs contained therein

are not counted as part o the imported HCFC quantities,

but their leakage rates can be expected to increase gradually

through the year as the units grow old.

The leakage rates are urther increased due to the oten low

skills o the installers, particularly or split units, as they are

installed on site with one component located outside and

the other inside the building. For more than ten years, ODS-

ree but high GWP HFC-based alternatives such as R-410A

and R-407C have been available in this sector. However, due

to the cost o retrot and relatively low value o old units,

retrots to HFCs have not been the preerred solution on

most markets since these systems will oten already be old

beore the phase out o R-22 becomes urgent. On the other

hand, in Article 5 countries, the price o labour is relatively

low and retrots can be a more interesting option than

replacements. This will be described urther in the sectionpresenting the case studies on retrot methods, options

and available solutions or existing equipment.

Fan

Fan

Air evaporator

Air condenser

Air condenser

Air evaporator

Connections to joinindoor and oudoor unit

Fan

Fan

Outdoorun

it

Indoorunit

F. 1.2 Unita sstems (et) ae mounted thouh the a ithout the need to connect the eieation sstem on site.Spit sstems (iht) ae assembed on site.

sp fhar:

UnitARy systemsp fhar:

sPlit system


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19

cHilleRs ARe systems tHAt indiRectlycool a

building or a process. Typically they are used in larger

systems and the cooling distributed with water or amixture o water and anti-reeze when it is necessary to

work at low temperatures. Chillers are mainly actory-built

units that are intended to cool a liquid such as water or, i

a lower temperature is desired, uids with lower reezing

points. Chillers can be air-cooled, i.e. where the condenser

is directly cooled by air, or water-cooled, where the

condenser is cooled by circulating water (possibly with

reeze depression i the climate is such that the water would

risk reezing in the winter). Their main applications are

or air conditioning in larger buildings, i.e. hotels, ofces,

hospitals, military complexes, etc. or or process cooling in

various industries. This solution is oten associated with ahigher investment cost than solutions with split systems or

air conditioning or smaller units or each object in need o

cooling in the industry. In many cases, small non-chiller RAC

units can be installed gradually and oten by tenants, thus

eliminating the need or the owner to invest and charge

costs to the tenants. Central systems with chillers are oten

preerred in larger systems where the possibilities o more

stable operation by balancing cooling loads over time (as

the loads are not occurring simultaneously over the whole

building), reducing maintenance cost are preerred as it also

avoids noise and/or esthetical drawbacks o having large

numbers o split/unitary systems. This option is oten usedin larger buildings operated by owners with the capability

to invest in more long term solutions. Chillers are globally

used in central air conditioning systems where R-22 is one

o the most commonly used rerigerants, apart rom CFCs

1.2.4 cHilleRs in AiR conditioning And cooling APPlicAtions (inclUding HeAtPUmPs witH indiRect systems).

1.2.3 vRv/vRF/mUlti-sPlit systems (inclUding HeAt PUmPs)

which are still present in large quantities in the old chiller

equipment in both developed and developing countries.

Apart rom their use in the air conditioning sector, HCFCchillers using R-22 are also common in the ood processing

industry as well as in other industries where processes need

to be cooled. At one point a large chiller segment using R-11

was to some extent converted to R-123 which is an HCFC,

but has low ODP and low GWP. At the time this report was

Pump

secondary fluid i.e.

water/glychol/brine/CO 2

Refrigerant inside: NH3, HC or HFC

Air or liquidcondenser

F. 1.3 Chies use seconda fuid to indiect coo the oomo object.

tHese ARe systems that have been developed rom the

split systems (Daikin Industries developed and launched

Variable Rerigerant Volume and protected the use o

the acronym VRV so other manuacturers use VRF

or Variable Rerigerant Flow). These system designs

are characterised by one unit cooling (and sometimes

heating) several rooms and adapting its capacity to

the variations in the demand. These units have a lot

in common with split systems, but are dependent on

complex electronic controls and have an intricate design,

which will make them more difcult to retrot. This is

because oil transport and control behaviour could be

aected and difcult to predict unless there is access to

design ino and proper test acilities or support rom the

manuacturer. For obvious reasons, the manuacturers are

rarely interested in investing the resources required to

extend the lie o existing equipment.

sp fhar:

cHilleR


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20

smAlleR volUmes o HCFCs are used in almost all other

RAC sectors. Both R-22 and HCFC-containing service blendsare used to replace R-12 and R-502. In transport rerigeration

some manuacturers have converted to R-22 while the

majority went directly to R-134a and R-404A. In some niche

markets such as the high temperature air conditioning in theindustry, there are applications where CFC rerigerant R-114

was replaced with R-124, which is an HCFC.

1.2.6 otHeR HcFc-Using sUB-sectoRs in tHe RAc sectoR

1.2.5 HcFcs in commeRciAl ReFRigeRAtion

in mAny ARticle 5 coUntRies, commercial rerigeration

has traditionally been dominated by smaller plug-in systems

and display cases cooled by individual condensing units. The

introduction o larger central systems was limited to newerand larger supermarkets.

These systems in stores and shops were oten cooled with

R-12 and to some extent R-502 in the low temperature

applications. With increasing pressure to phase out

CFCs, transition to R-22 had occurred in many countries

beore R-404A or R-507 were accepted as the rerigerants

or this sector. In the process o phasing out R-22 rom

commercial systems, R-404A and R-507 are being used

as alternatives more requently than in air conditioning.The use o R-22 in commercial rerigeration is signicantly

more challenging than the rerigerants it replaced and the

non-ODS alternatives developed or this sector. This is due

to the properties o R-22 which cause higher compressor

temperatures requiring signicant changes to the systems

design or quick xes such as installing water sprays or the

condensers as shown in Fig. 1.4.

F. 1.4 A commeciaeieation instaation usinr22 in a hot cimate. Thismode equies a ate spaon the condense to aoid hihpesssue and oeheatin othe compessos. Hoee thiscauses coosion and astesate that is oten in shot supp.In this case inceased eecticahaads ae obious and good

Pactice has not been popeconsideed.

written, there were no known alternatives to R-123 suitable

or existing systems.

R-245a is an HFC alternative that can be used in low pressure

chiller applications but has a higher pressure making it

unsuitable or most existing systems. With the current

inormation it can be expected that in this sector existing

systems using R-123 will be maintained with minimum leakages

until the end o their lie. In most developing countries the

introduction o R-123 has been limited although in some

markets low pressure R-123 chillers could be a segment that

will require special attention due to the challenges to replace

it. As there are only a ew suppliers that produce R-123 chillers,

six according to James M. Calm (James M. Calm, 2002), it

would be possible to identiy exactly how many units o this

system are in operation and where they were installed by

contacting the manuacturers/importers.

As the use o indirect systems make it possible to more

reely locate rerigeration units with toxic or ammable

rerigerant, chillers using ammonia and hydrocarbon

rerigerants are becoming more common.

the-art, non-ODS equipment then has to compete with the

low cost R-22 equipment. The price dierence is not mainlydue to the change o rerigerant but rather to the larger heat

exchangers and oten to design improvements that reduce

energy consumption and noise to meet international market

demands. A report o the International Energy Agency (IEA)

one ReAson wHy R-22 still prevails in the new installa-

tion market in many Article 5 countries is the lack o energyefciency requirements and the low awareness o customers

about the cost o running the systems. In this situation, the

equipment purchase price becomes the only criterion or

equipment selection. The more energy efcient state-o-

1.3 Energy efciency o air conditioningequipment


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21

[IEA, SATORU KOIZUMI, 2007] evaluated the impact on

energy consumption o increased efciency requirements

in Article 5 countries. The report gave the example o Ghana,

an Article 5 country which imports its AC equipment and

needs stronger national energy efciency requirements. It

demonstrated why the efciency o installed equipment in

the country is lower than that o the equipment available on

the market.

sUmmARyAlteRnAtives to HcFcThee is not and i most ike nee be one eieant that can be used to epace a HCFC appications, since

the use is so idespead and the equiement o bette ene ecienc i esut in an inceased demand to

adapt the technooies to the actua opeatin conditions.

Each sstem, o at east each tpe o sstem, needs to be eauated om seea pespecties to nd

the enionmenta and technica best option that can be used sae at an acceptabe inestmentand opeatin cost.

when eauatin the impact o rAC equipment on the cimate, the diect gwP o the eieant used as e

1.4 Alternatives to HCFCs in air conditioningand rerigeration

F. 1.6 Deeopment o ene ecienc o AC equipment in Japan.

6.0

5.0

4.0

3.0

2.0

1.0

0.0

eeR

1997 1998 1999 2000 2001 2002 2003 2004 2005

F. 1.5 Deeopment o ene ecienc o AC equipment inghana. The count has no domestic equipment poduction.

3.0

2.5

2.0

1.5

1.0

0.5

0.02000 2001 2003 2004 2005

eeR

In comparison, Japan, which has clear and strict energy

efciency requirements, showed a rapid improvement o

energy efciency despite the act that rom the beginning

the country already had a signicantly better perormance

rate than Ghana. The Japanese air conditioners used 50%

less electricity than those installed in Ghana. The expected

rapid increase in use o air conditioning systems in many

Article 5 countries will result in drastically higher electricity

consumption. The use o low efciency equipment will be

costly in terms o energy consumption. Furthermore, the

oten weak inrastructure used in producing and distributing

electricity will be requently overloaded by excessive

energy demands coming rom high air conditioning loads.An introduction o efciency requirements and labelling

schemes to improve efciency is vital or Article 5 countries.

For Ghana, an enorcement o minimum energy standards in

installed air conditioning units was estimated to reduce the

countrys total need or generated electrical power by 8%.

The report contains an evaluation o barriers and possible

counter-measures to introduce higher efciency equipment.


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22

dUe to tHe HUge nUmBeR o applications or

rerigeration and air conditioning systems with dierent

operating conditions and requirements, it is practically

impossible to nd a single ideal rerigerant. The ideal

rerigerant would need to have the ollowing properties and

characteristics, among others:

Zero Ozone Depleting Potential (ODP)

Energy efcient = have high Coefcient o Perormance

(COP), i.e. low indirect Global Warming Impact

Zero or low Global Warming Potential (GWP), i.e. low Direct

Global Warming Impact

Chemically stable at all temperatures and environments

including contaminated systems

Compatible with all materials

metals

elastomers (plastic/rubber materials)

oil, including suitable miscibility/solubility with oil

Non-toxic

Non-ammable

Low cost

Commercially available

The above list does not reect an order o priority as this

cannot be dened on a general level. Obviously, rerigerants

with high ammability and toxicity can be easily handled in

some applications and may be more or less impossible to

be applied in others, at least without a signicant increase

in energy consumption and/or cost. Zero ODP is a legal

requirement in many countries already. The total warming

impact o a rerigeration air conditioning system will consist

o a direct eect rom released rerigerants and an indirect

eect rom carbon dioxide emissions during the production

o energy used to operate the system. The combined eect

o Direct and Indirect warming eect is oten calculated

as the ta eua war ipa r tewi (see

Abbreviations and denitions)

TEWI takes into consideration leakage rates, emissions

rom the site where systems are scrapped and energy

consumption. As these actors are dierent or each system

and difcult to estimate, TEWI is oten calculated based on

statistical values and experience. The result will be aected by

how the dierent actors are estimated. Factors like leakage

and recovery rate are dependent on the quality o installation

and service. This will change over time as service is improved

through training in combination with regulations that require

end-users and contractors to keep records, discourage

emissions and enorcement actions. To assume leakage

rates o 30% common on many markets or 5% achieved inothers will drastically change the balance between direct

emissions rom leakage and indirect emissions rom energy

consumption. Few Article 5 countries have so ar been

successul in implementing unctional rerigerant re-use

as the sstems tota ene ecienc shoud be measued. A sstem usin a eieant ith a hihe gwP can

be moe ene ecient and hae a oe tota impact on the cimate.

U a r gwP rrra a a a r a a a apab a prrab u

u hh gwP ara uh a HFc. HFc u b a hu b u

h u a a hr a r a rr h ar pa. HFc ar a

h r uba ur h k Pr a a b p b har h ra

ruar r h uur.

Thee is aas a numbe o atenatie technooies that can be used. The easiest oute oud seem to be

to choose the atenaties that equie no o minima sstem chanes but it is impotant to eaise that ne

technooies ae continua bein intoduced and that the indust i eentua hae to keep its knoede

abeast ith these ne technooies. An eauation o enionmenta impact incudin ene ecienc, cost,

technica as e as saet isks is equied. The outcome i be dieent o dieent opeatin conditions and

i depend on hee the equipment is instaed and ho it is used. geneaisations oten esut in poo decisions

and that is h it is impotant to estabish indust standads to hae acceptabe seice aaiabiit and to make

the equied tainin o the seice secto manaeabe.


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23

schemes that reprocess signicant volumes. As the average

recovery rate in Article 5 countries is currently low the relative

impact o direct emissions is high. With a strong ocus on

the introduction o good practice, the relative impact o

GWP is expected to decrease although energy consumption

also decreases with improved service practice. I a low-GWP

rerigerant can be used saely at the same or lower energy

consumption level with an acceptable investment, this will

obviously be the solution with the lowest TEWI.

Energy efciency is becoming more and more the ocus

when selecting rerigerants but it is important to realise that

efciency is only, to a small part, a result o the rerigerant

selection. Typically the dierent rerigerants theoretical

impact on the total perormance varies within a ew

percent, whereas the dierence between various technical

solutions o equipment design with a given rerigerant can

be 20-30% or more. The solution that is 20% better in one

application can also be signicantly worse at other operatingconditions. Simplied generalisations o perormance that is

not specically reerring to a specic application should be

viewed with scepticism. i u b ru,

prbab .

In the technical sections and case studies below, a number

o technical and commercial aspects to be considered will

be covered. In many countries there is a need to establish or

increase local capacity to evaluate the suitability o dierent

alternatives and to implement them in dierent systems.

It is important to evaluate not only the lowest investment

options but also the energy efciency and cost eectivenesso the dierent options.

Thereore, it is easy to conclude that the ideal one-size-

ts-all rerigerant does not exist and that some rerigerants

will be more suitable in some applications than others. All

rerigerants have their advocates on the market and there

are interest groups promoting the dierent technologies.

It is important that the rerigeration and air conditioning

sector and equipment owners do a proper evaluation

o the total environmental impact o using dierent

alternatives. Any attempt to come up with one solution or

all applications will with almost certainly not be the mostenvironmental nor the most cost-eective option.

The opportunity to make improvements to the system in

terms o efciency when they are replaced or retrotted

tHeRe ARe FoUR mAin RoUtes to RePlAcing HcFcs in tHe RAc sectoR

1 Ammonia NH3 (r717)

2 Hdocabons Isobutane (r600a), popane (r290), popene (r1270),

bends, etc.

3 Cabon dioide CO2 (r744)

4 Hdofuoocabons HFCs (i.e. r134a and bends such as r407C, r410A)

should not be neglected. The pay o time or such

improvements is oten short when done in connection with

other work on the plant. Ensuring a proper commissioning

and adjustment o controls can oten in itsel save a

signicant amount o energy.

Due to the phase-out o R-134a in the automotive air

conditioning sector, a new low-GWP HFC alternative

named HFO-1234y has been developed by DuPont and

Honeywell. At this stage it is not clear i the automotiveindustry will go this way or move to CO2. As o March 2010

several HFO (hydrouoroolene) components are also

being considered/studied or RAC applications. There

is no sufcient inormation available to date whether

HFO1234y, by itsel or in mixtures with other rerigerants, is

a good solution or the RAC sector or i and when it will be

commercially available. I the automotive industry takes this

route it will require large amount and production capacity:

It will take time to establish this to satisy MAC demand

increasing rom 2011 as the quantities required in this

sector are signicant. Introducing additional products in

the stationary sector will not be the highest priority in thatscenario. It can be expected that the development work in

the RAC sector, i it takes place, will require several years o

additional research and development. The interest on the

market will be dependent on how cost eectively these

substances are in design o highly efcient equipment.


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ANy ATTEMPT TOCOME UP wITH ONESOlUTION FOr AllAPPlICATIONS wIll

AlMOST CErTAINlyNOT BE THE MOSTENvIrONMENTAlly-FrIENDly NOrTHE MOST

COST-EFFECTIvEOPTION


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AmmoniA is A well-PRoven rerigerant in largercommercial and industrial applications. Ammonia has

technical properties that make it considered incompatible

with copper which is a preerred material or tubing and

motor winding or mass produced hermetic systems.

The toxicity and risk to human saety i released, limit the

applications where ammonia can be used saely and at an

acceptable cost. The extremely strong and irritating odour

emitted by ammonia when released may incite people

to panic as they try to evacuate the area. On the positive

side however, this odour also acts as a useul early warning

signal in case o system leakage. The use o ammonia in its

traditional sectors has increased on many markets due tothe desire to avoid the use o high GWP rerigerants such

as HFCs. Ammonia is still used mainly in the traditional

application o larger industrial rerigeration systems althoughit has also been introduced in certain new segments

such as large central air conditioning systems and smaller

commercial systems on some markets. One way o reducing

the risk when using ammonia is to minimize the charge by

building compact chillers that can be placed in machine

rooms specially designed or the purpose o eliminating the

risks. There are also systems designed to absorb any releases

o ammonia in water sprays beore it can reach the area with

public access.

The introduction o soluble oils or ammonia resulted in the

development o dry expansion systems with lower chargeand simplied oil return versus ooded systems with non-

miscible oil.

1.4.1 AmmoniA

1.4.2 HydRocARBons

sUmmARy AmmoniAAmmonia is a eestabished eieant equiin specia pesonne competencies and sstem desin. Thee ae

a numbe o epeienced companies and technicians ith these competencies. An inceased use o ammonia i

depend on moe technicians and eninees eceiin tainin in this secto.

Thee ae enionmenta benets om the use o ammonia because it has eo ODP and neiibe gwP.

Technica it is a ood eieant, but it has some saet dabacks and technica chaenes associated ith

mateia compatibiit and hih tempeatues occuin duin compession.

The inestment cost is tpica hihe than o conentiona sstems, at east in oe capacities. we desined

sstems can hae e ood ene ecienc and ne desins ae etendin the appication ane ith oe

chae and ne ois suitabe o nonfooded eapoatos. The fooded sstems tpica equie pocedues o oi

etun and ae tpica used in ocations hee thee ae quaied pesonne on site.

sUmmARy HydRocARBonsHdocabons ae ood eieants ith eo ODP and neiibe gwP. Thei fammabiit equies specic

competencies in desin, manuactuin and seice. To ensue sae use, thee ae estictions on hee and ho

the can be appied. Hdocabons as eieants ae adua bein coeed in Intenationa Standads detaiin

the necessa equiements o sae use (i.e. in EN 378 and ISO5149).

Isobutane (r600a) has become the standad eieant in ne domestic appiances in man makets. The sma

amounts used in a domestic appiance ae not consideed to be a sinicant isk ate edesin o the eieatos

F. 1.7 Ammonia instaationtpica o industia appications.


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26

hee a sitches (e.. themostats and amp sitches) hae been emoed om the eieated compatment.

A eak into the oom hee the unit is paced i dispese and not esut in daneous concentation.

Popane (r290) and Popene (r1270) hae moe appopiate popeties to epace r22. Seea hdocabon

mitues ee aso intoduced as epacements o CFCs and HCFCs. On seea makets hdocabons hae been

used in smae commecia eieation equipment and aicooed chies.

Sae use o hdocabons equies tainin o those inoed in the desin, instaation and seicin the equipment.

Standads and euations adapted o use in rAC sstems ae impotant so as to aoid the eposue o technicians

and uses to dane due to iesponsibe pactice.

Toda thee ae intenationa poduct standads that coe sma hemetic sstems (hain a chae o

appoimate ess than 150 ams) that ao them to be instaed in most paces poided that pope desin

pecautions hae been taken. Fo ae sstems the poduct standads ee to eeant nationa and intenationa

standads i.e. EN378 and ISO 5149 (gTzPokima, 2008).

I the chae o hdocabons can be kept o esus the ai oume in the oom (tpica 8 ams/m3) the isk o

ceatin fammabe mitues is eiminated.

The compatibiit o ois in connection ith hdocabons is sometimes an undeestimated question since hih

ees o miscibiit hae caused man sstem aiues hen hdocabons hae been intoduced ithout pope

edesin.

This epot i not discuss the etot o eistin HCFC sstems to hdocabons as the eauation o an od unit

desined and ocated ithout consideation to the eieant fammabiit is in most cases compe and i need

to be done in accodance ith intenationa as e as nationa eisation. It can be said that thee is obious much

ess isk inoed in sstems ith a chae beo that hich can ceate an eposie enionment in the oom o i

the hoe eieation sstem is paced outside i.e. ai cooed chies. The inomation on desin o hdocabon

sstems pesented hee i be eeant in considein hen hdocabons ae used, but additiona equiements

i oten app. Saet eated to opeation as e as seice must aas be caeu eauated beoe a fammabeeieant is appied. Thee ae seea makets hee etots ae caied out and the inomation is oten aaiabe

on the intenet. See .Hdocabons21.com.

inteRnAtionAl stAndARds have to some extent

been adapted to accommodate saety requirements

or hydrocarbons but uncertainty on regulations still

remain in some applications. There is a signicant interest

in hydrocarbons on the market since they are good

rerigerants, and as a result the number o components

and systems is gradually increasing. However due to saety

considerations and the small market outside domesticappliances, many components are not approved by the

manuacturers. There are concerns over liability and unclear

regulations even i the components unction. Due to the

potential damage a ailure can cause the requirements

are higher, in many cases, or components or ammable

rerigerants than or those that are non ammable. I there is

a lack o approvals the challenges or the technicians involved

increase as they cannot ully rely on manuacturers validation

which species that the particular component ulls all

relevant pressure and saety standards. For most applications

the relevant components are available rom some source, but

they can be more difcult to nd and the cost is sometimeshigher. For systems with rerigerant charges above 150 grams

and/or a charge over approximately 8 grams/m3 air in the

room (charge limitations can vary depending on country and

application) the saety requirements increase and it oten


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27

becomes necessary to make a risk assessment to ensure

that risks are acceptable. On most markets hydrocarbons

are rarely introduced in existing equipment as electrical

systems and controls are oten not suitable and need to be

redesigned. There are systems that ater careul evaluation

can be modied to be sae but the challenges are much

bigger than in new systems designed or a ammable

rerigerant. Extensive presentation o hydrocarbons as an

option in RAC systems can be ound in (GTZ-Proklima, 2008).

The hydrocarbons most commonly used in traditional HCFC

applications are:

Propane (R-290) having characteristics similar to those o

R-22 has been introduced in a wide range o commercial

and air conditioning applications. The cooling capacity is

typically signicantly lower than R-22 and perormance

(COP) in the range o -2 to +6% relative to R-22 [Bitzer,

2008]. Propane has been introduced in a wide range

o applications and when proper consideration o high

solubility in oils has been taken good operating experiences

are reported.

Propylene (R-1270) has higher cooling capacity and lower

boiling temperature than propane and is the preerred

option by some manuacturers. The higher pressures

and discharge temperatures need to be taken into

consideration especially or use in hot climates.

Hydrocarbons are oten claimed to be compatible with all

commonly used oil (mineral, alkyl benzene and ester oils).

This statement is very questionable as not all oils will give a

reliable unction with hydrocarbons. Use o hydrocarbons

with traditional oils without changing oil viscosity and/

or making system design modications has in many

cases resulted in high ailure rates caused by the extreme

miscibility between oils and hydrocarbons resulting

in increased wear in compressor. Besides redesign or

relocation o electrical systems and controls, it is oten

advisable to also increase the viscosity o the oil and

ensure sufcient superheat through a suction gas heatexchanger [Bitzer, 2008].

tecHnicAl inFoRmAtionFr a ua ara h a rrra

har ra a faab :

mma= 0.25 lFl A 2.2 [T. JABBOUr, D. ClODIC]

whee lFl is the loe Fammabiit limit in k/m3

and A is oom aea in m2

.

Fo popane (r290) lFl = 0.038 k/m3

Fo Isobutane (r600a) lFl = 0.043 k/m3

The saet imit o 0.25 is used to compensate o

the dieences in densit esutin in an inceased

concentation nea the foo.

Fo eampe, in a oom that is 34 metes the

maimum aoed chae o r290 is 250.8 ams, not

takin into account the inceased saet measues

accodin to standad IEC 60335240 [IEC, 2005].

1.4.3 cARBon dioxide (co2)

sUmmARy cARBon dioxideCabon dioide technoo is cuent the most innoatie aea in eieation. CO 2 is not a ne technoo, but

it has been ide used in the rAC secto o a on time because thee hae been easie and oe cost competin

technooies. Hoee, ith an inceased moement to educe the use o HFCs and the seach o nonfammabe,

nontoic eieants, CO2 has become an inteestin atenatie ith eo ODP and insinicant gwP. The to

main chaenes inoed ae the hih sstem pessue at noma opeatin tempeatues and the o eneecienc (COP) o a standad eieation cce.

It is possibe to desin ne equipment to make it suitabe o hihe pessues and moe and moe manuactues


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ae oein components and sstems o CO2 makin it possibe to desin a ide ane o appications.

CO2 is intoduced in dieent appications both as sine stae supecitica eieant, pat o a cascade ith a

second eieant and as seconda fuid in indiect sstems ith a dieent eieant in the compession cce.

The chaene and hat is oin to dene the utue maket shae o CO2 is deteminin at hat cost it i be

possibe to achiee competitie ene ecienc in ed conditions.

The specia chaacteistics o CO2 and the need to desin the sstems ith consideation to the oca conditions

to achiee competitie COP i (een moe than o conentiona technooies) make it necessa to eauate

soutions appication b appication. Discussion is onoin i supecitica CO2 sstem i be ene ecient in

am cimates.

Specia tainin is equied to desin, buid and seice sstems o CO 2 and hih pessues. This incudes not on

deain ith the hih pessues but aso the technica kno ho to make the sstem ene ecient.

cARBon dioxide has a negligible GWP but will operate

under signicant higher pressure than the traditionalrerigerants and cannot be used in existing equipment. As

CO2 has a low critical point the behaviour will be dierent

to traditional rerigeration systems. Above 31C the system

will work in supercritical (sometimes called trans-critical)

conditions, i.e. traditional condensing will not take place.

There are several applications where CO2 can be consideredas a commercially-available alternative although the price

level is oten higher than that o conventional technologies.

The ongoing discussion is in which applications the energy

efciency will be comparable with the one achieved in other

alternative technologies. In the commercial rerigeration

sector, much o the development is ocused on this

rerigerant due to the negligible direct GWP. The applications

with the longest experience are where CO2 is used as

secondary uid in indirect systems and at low temperature

industrial/commercial rerigeration in cascade system with

ammonia (or HFC) in the high stage. A signicant number

o supercritical CO2 systems have been installed and severalreports on the coefcient o perormance (COP) o these

systems have been published. The statements on efciency

vary depending on the source, and urther development

and more documentation rom commercial installations is

needed beore actual COP, cost and reliability in dierent

systems and conditions are established. It should be noted

that the relative energy efciency versus other technologies

will depend on the climate where the system operates

(warm climate will have a more negative eect on COP in

supercritical CO2 than in conventional HFC systems).

In Japan, CO2 heat pumps with supercritical operationor domestic hot water have ound a large market (their

development and introduction have been promoted

with the help o subsidies rom government and utility

companies). This technology has also been introduced in

Refrigerant inside: CO2

Gas condenser

F. 1.8 Supecitica CO2 sstem ith as cooe opeatin atpessues 2 to 3 times that o conentiona sstems.


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rerigerant charges and leak risk signicantly and is preerred

in several applications on some markets. Indirect systems

also give more exibility in the selection o rerigerants as

the risks and costs o using ammable (HCs) and toxic (NH3)

rerigerants decrease.

CO2

is also a leading candidate as an alternative to R-134a in

automotive air conditioning as the latter will be phased out in

new car models in the EU rom 2011.

Europe where these heat pumps are used or combined hot

water and space heating.

CO2 is also used as a secondary uid in low temperature

applications as it can reduce the energy consumptions or

pumps and tube dimensions in indirect cooling systems.

The use o indirect systems is increasing as it reduces the

Sub critical CO2

Refrigerant inside: NH3

or HFC


CO2

Pump

Standard chiller

Refrigerant inside: NH3

or HFC


F. 1.9 CO2 in subcitica opeation in cascade ithhdocabon, ammonia, o HFC eieant.

F. 1.10 CO2 as seconda fuid in an indiect sstem.

1.4.4 HFc AlteRnAtives Used in new And RetRoFitted systems witH new oil

sUmmARyHFcHFCs ae b a the most common epacement o HCFCs in ne equipment and a ide ane o such equipment

has been aaiabe on the maket o the past 15 eas.

The eatie hih gwP o HFCs hae inceased the pessue on ndin atenaties ith oe impact on cimate and

the deeopment eots hae inceased as cimate chane has become the numbe one enionmenta chaene.

The auments used in aou o HFCs ae that the can be used sae and cost eectie in a appications hee

CFCs and HCFCs hae been used ith minima technica chanes. As the ocus on cimate chane inceased, this

aso esuted in an inceased ocus on ene ecienc. In man appications the ene ecienc o todas HFCs


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tHe only mARket segments where ODS have been

replaced widely by non-HFC alternatives are domestic

appliances and some plug-in display cases that have

changed rom R-12 to isobutane (R-600a). In markets whereammability and toxicity have been considered difcult

and/or costly to handle saely the transition has been to

HFCs. As new technologies are developed and mature and

more technicians receive training and become amiliar with

non-HFC alternatives, these not-in-kind alternatives can be

expected to increase their market share. As the HFCs are not

compatible with traditional rerigeration oils the introduction

o HFC normally requires a change to ester-oils (e.g. PAG-oils

are used with R-134a in the automotive sector). There is a

special range o HFC rerigerants called drop-in or service-

blends that are tailored to allow the use o HFCs with

traditional mineral oils by adding a component to address oiltransport characteristics (see service blends below).

In most R-22 applications the two dominating HFC

alternatives or new installations are R-407C and R-410A.

The ormer is closest to R-22 in terms o capacity and

pressure. Provided the change to an ester oil has been made,

R-407C gives a similar capacity and perormance as R-22 but

presents a special characteristic. As it is a zeotropic blend i.e. it has a gliding temperature during condensation and

evaporation (glide) - it is less suitable or some applications.

R-410A was introduced later and it requires redesign to

handle the higher pressure but has an advantage o higher

capacity and insignicant glide. R-407C has lost a signicant

part o its initial markets to R-410A, but is still the preerred

solution in several segments such as small- and medium-

sized chillers and water/brine heat-pumps. R-410A, on the

other hand, has taken most o the market in smaller air

conditioning systems o unitary and split type.

In commercial applications that traditionally used R-12 andR-502, R-22 is normally replaced by R-404A/R-507.

In some traditional R-22 segments such as larger chillers

R-134a has taken a signicant market share.

sstems is much hihe than that o the HCFCs sstems the ae epacin. In man sectos thee ae equiements

on minimum eciencies epessed as Seasona Ene Eciencies, o eampe. In some makets, the oenment

oes ta eemptions o subsidies to hih ene ecienc soutions.

In most appications the ene consumption i be the majo contibuto to oba amin om a rAC sstem.

TEwI (see Abbeiations and denitions) as e as the lie Cce Anasis (lCA) o cost and enionmenta impact ae

impotant actos to conside hen compain dieent atenaties.

The most common HFC atenaties in ne appications and etots ith chane o oi to a poo este oi ae:

Spit and unita ai conditionin units r407C and r410A

Heat pumps r134a, r407C and r410A

Dispa cases and sma sstems r134a and r404A/r507

Chies, ai conditionin r134a, r407C and r410A

Chies, commecia r134a and r404A/r507

Centa sstem commecia r404A/r507

Industia r404A and r507

Out o the HFC eieants isted aboe on r410A equies components desined o sinicant hihe pessue.

Seice bends intended o use in eistin sstems ae isted in the net section.

th ru pra a ua ru h a ah a a

hh r .


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tHe FiRst so cAlled R-22 drop-in alternatives or serviceblends was the R-417A, but lately R-422A, R-422D, R-424A,

R-427A, R-428A and R-434A have been launched to oer

alternatives tailored to general or specic R-22 applications.

Almost all service blends (except R-427A) have a similar

sUmmARy HFc seRvice BlendsSeice bends ae deeoped to oe a dopin technoo that oes cost as compaed to chanin the oi,

hich is equied, hen adoptin the same HFC atenaties used in ne sstems.

retot is the tem oten used to descibe the pocedue in hich the eieant and the oi ae chaned (and, i nec

essa, cetain pats o the equipment ae aso epaced). In this epot,etot ees on to this pocedue and not to

the one usin seice bends. Most seice bends ae popieta poducts maketed as a ocost, eastouse soution,

so sometimes the technicians usin them do not hae a u undestandin o thei chaacteistics and imitations.

To oecome the need to chane to este ois hen ODS ae epaced b HFCs, a numbe o seice bends hae been

deeoped to epace the HCFCs. One component (oten a hdocabon), hich chanes the chaacteistics o the oi

eieant mitue in the sstem, is added. These atenaties ae sod ith the adantae that the oe a cost eectie

option to epacin ODS. A chane in eieant i esut in a chane in the chaacteistics o the oi hich aect oi

tanspot and ubicit. It is ecommended that beoe an decision to intoduce a seice bend is taken, an eauation be

conducted to detemine hethe the sstem i be sinicant aected b the chane in oi tanspot and ubication.

The st citeia hen eauatin options o epacin HCFCs is to dene the status o the eistin sstem. Aas

check that the eistin sstem is in sucient ood shape to justi the equied inestment.

Inestment, een i imited, in equipment that is about to ai is a aste o mone. The ene ecienc and histoica

eakae ates ae impotant actos to conside beoe an decisions ae made. I the equipments condition is such

that epacement ith a seice bend is deemed the best option, additiona measues to be taken in connection ith

the chane shoud aso be eauated in ode to minimie eaks and etend the equipments ie time.

The seice aaiabiit duin the emainin ie time o the equipment shoud be ensued to aoid that a utue

ack o aaiabiit oces additiona inestments. The numbe o bends oeed on the maket makes the stoae o

seice quantities a chaene o the seice poides uness some standadisation occus in the maket.

Beo ae the most common consideed seice bends o epacin r22.

r417A r22 repacements taetin sma diect epansion sstems

r422A r502 and o tempeatue r22 epacement

r422D r22 repacements in o eampe chie appications

r424A r22 repacements taetin sma diect epansion sstems

r427A r22 repacements

r428A r502 and o tempeatue r22 epacement

r434A r22 repacements in o eampe chie appications

r438A r22 repacement taetin a ide ane o opeatin conditions

1.4.5 HFc seRvice Blends Used in existing systems

approach in composition where one or two componentsare added (oten hydrocarbon). This part o the blend

composition is extremely soluble in the oil which results

in the viscosity o the oil not increasing when the HCFC is

replaced with a non-soluble HFC. This strategy has proved


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problems that should be avoided. Several actors should

be taken into account when evaluating the service blend

option and when deciding to what extent case studies can be

considered relevant or the applications under consideration.

tecHnicAl inFoRmAtionFar r b apa, coP a har praur h r b ar:

The component (oten a hdocabon) absobed b the oi does not make the oi miscibe ith the eieant, but it adjusts

the iscosit to be moe simia to the od oi/eieant mitue o hich the compesso as desined and to impoe oi

tanspot, paticua in the eapoato and suction ine hee a thicke oi inceases the isk o poo oi etun. Since in

most cases the component intoduced to decease the ois iscosit is a fammabe substance, thee ae imits on ho much

o this component can be added beoe thee is a isk o eposion, especia i eakae outside the equipment occus.

At the same time the atio beteen oi and eieant i aect ho diuted the oi is, e.. i the oi chae is eatie

sma as compaed to the eieant chae, the oieieant mitue i hae oe iscosit than i the oi content

is sinicant hihe eatie to the eieant chae.

The oi that is cicuated noma has a oe densit than the eieant and i thee ae stabe iquid ees, e.. in the

eceie, tube o she condense, the oi i tend to foat on top o the eieant iquid and can accumuate to an

etent hee the compesso i eentua ai.

In compe eieation sstems thee ae cases that hae been epoted hee the oi accumuated in the

eapoato and suction ines.

In sstems ith tubes ith ifes/ooes to enae tube suace and impoe heat tanse, thee hae been epots

hee heat tanse as dastica aected due to bockin o the ooes ith oi.

Theeoe, the caims that seice bends ae eas to use and do not equie the same caeu eauation as a etot to

standad HFC eieants can oten be questioned.

Some o the dieences in ecommendations beteen suppies o dieent seice bends can pobab be moe

eated to poicies and isk assessment athe than technica dieences beteen the atenaties.

Some compesso and/o eieant manuactues ecommend that akbenene ois be used ith HFC seice

bends and/o that a pat o the od oi is epaced ith este ois. The impotance o cean and d sstems and the

isks associated ith conetin od sstems o oten questionabe condition shoud not be undeestimated. The

consequence o these aspects is not that seice bends cannot be used; athe thei suitabiit shoud be eauated

esus the sstem in question to aoid isk o aiues. The eauation o the dieent commeciaaaiabe options

is dicut to do as objectie inomation is ackin. A suppies o seice bends ae ocusin on success stoies and

thee is a tendenc to t to minimie an concens.

In opeations on mitues o od and ne ois, thee is the isk o a chemica beak don o the oi caused b

contaminants in the od oi. Thee is aso a isk that ne oi i dissoe and tanspot deposits to the compesso.

Suction tes duin the chane oe pocedue can be used to educe this pobem.

to be unctional in many systems, but there also have been

reports o problems in some applications. There is limited

unbiased inormation readily available and it is obvious that

success stories are more widespread than those describing


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wHen evAlUAting AlteRnAtive rerigerants or

dierent applications, careul consideration should be

paid to the oil properties and how they are aected by

the dierent rerigerants. How a rerigerant behaves in a

system is signicantly easier to predict than how the mixture

o oil and rerigerant will behave. It is easy to dene the

properties o a rerigerant or pure oil at dierent pressures

and temperatures. It much more complex to predict and test

lubrication properties in the compressor and oil transport

in the system ater the rerigerant and oil has mixed. The

selection o oil must take into account all aspects to ensure

long term reliability o the system. Many systems have ailed

because end users have not considered the interaction

between the oil and the rerigerant.

1.5 Oils in rerigeration and air conditioningsystems

sUmmARy oils in RAc systemswith a e eceptions, rAC sstems contain an oi to sea and ubicate the compesso. A sma amount o oi i

aas eae the compesso and i be tanspoted aound the sstem (een ith oi sepaatos, a sma amount i

cicuate in the sstem).

In most sstems, oi etun equies that the oi is miscibe ith the eieant. The miscibiit aso deceases the

neatie impact o oi in the heat echanes.

The ois used ith CFCs and HCFCs ae not miscibe ith HFCs, hich makes an oi chane equied to achiee the

same chaacteistics.

The Minea oi (MO), akbenene (AB) and sometimes Poaaoens (PAO) ois used ith CFC o HCFC

eieants ae most common epaced ith Pooeste (POE) ois hen HFCs ae used. Aso Poakene cos

(PAg) ois and Poinethes (PvE) ae used o HFCs. PAg is the oi used in automotie ai conditionin.

Seice o dopin bends ae desined to achiee a behaiou simia to that o HFC/MO o HCFC/MO to aoid

the cost o chanin the oi to a miscibe oi. It shoud be noted that thee i be sinicant dieences that i aect

some sstems consideab.

th r HFc ar hrp a rur ra a prpr ha a ra aur ra.

lae cans o oi that cannot be emptied at one instaation shoud not be used uness oi is moed to a pessue

esse, i.e. a to pot eieant cinde hee it can be kept unde oepessue ith nitoen.


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tHe need to ensure lubrication and oil transport

creates a challenge in RAC systems as the lubricating

properties will vary greatly, depending on operating

conditions. It is thereore not uncommon that compressor

manuacturers will recommend dierent oils or dierent

applications. Neglecting the importance o oil properties

has resulted in a large number o ailures in systems that

use alternatives to R-22 including HFCs, service blends and

hydrocarbons. There have been serial problems in new HFCand new hydrocarbon systems, as well as in connection

with dierent service blends. The oil behaviour in the

rerigeration systems is oten signicantly more complex

and challenging than the rerigerants behaviour.

When a system is modied, it is important to consider how

this will impact lubrication and oil transport. When there is

inormation rom the compressor and/or oil manuacturer,

this should be taken into account. System manuacturers

should be consulted i they are aware o any problems with

their particular system although some do not consider it

to be in their own interest to extend the lie o old (oten

inefcient) equipment or to assume responsibility or advice

that will involve some risk o problems.

Ester oils and HFCs act as a solvent in the system and

there is a risk that debris and contaminants that have

accumulated in the system over time are dissolved

tecHnicAl inFoRmAtions prpr ar b:

lubra prpr ae impotant to ceate a eiabe sstem ith a on ie. The ubication is ston aected

b the eieant in the sstem hen thee is a miscibe oieieant mitue. The miscibiit is impotant due to

the equiement to hae acceptabe oi tanspot thouhout the sstem. The amount o the eieant dissoed

in the oi is aected b pessue and tempeatue, hich means that the ubication aies ith the opeatin

conditions. Sometimes compesso manuactues equie dieent oi based on the opeatin conditions. The

miscibiit o the eieant in oi is an impotant acto to poide the iht ubication popeties hen the

eieant is dissoed in the oi at a pessues and tempeatues that can occu in the compessos opeatin

eneope. Aso, the CFC o HCFC eieant b itse aects the ubication popeties as the choine om the CFC

o HCFC acts as an antiea additie.

cha ab in the sstem in the pesence o eieant and a mateias that coud be used oe the hoe

opeatin eneope. This must aso take into account the pesence o moistue and contaminants that can occu

in a eieation/ai conditionin sstem. This is a ke concen as contaminants dastica decease stabiit. Poo

pactices appied duin manuactuin, instaation and seicin esuts in a deceased ie epectanc o the

sstem. Uness pactices ae impoed, the phase out o ODS i esut in an inceased aiue ate as the ne ois

ae moe sensitie to poo handin. On the othe hand, ith the intoduction o ood seicin pactices, the ie

o rAC sstems can oten be man times hat as epected ith CFC o HCFCs and od seicin methods. mb o rapr. As thee i aas be a sma amount o oi that eaes the compesso ith the

compessed eieant it is essentia to ensue that it comes back. I the oi is not tanspoted aound the sstem, the

compesso i eentua un out o oi and ai. Oi in the heat echanes i aso hae a neatie impact on the

heat tanse and decease the ene ecienc. Noma the oi tanspot pobem i be citica at o eapoation

tempeatues and o capacit and coud occu ate a on time hen the sstem opeates unde specic conditions.

ear pab ith ois is an impotant issue, in paticua in od sstems hee Oins and othe seas

can be aected b a chane o oi. Thee ae some common used mateias ike viton (a tade name o specia

fuoopome oeed b DuPont) that ae not ecommended toethe ith POE and PAg ois. I these ois ae

i

Documents

Alternatives to HFCs in the Refrigeration and Air Conditioning Sector: Practical Guidelines and Case Studies for Equipment Retrofit and Replacement