The UNEP 2010 report focuses on low-GWP refrigerants to replace HCFCs and emphasizes the need for energy-efficient technologies in refrigeration and air conditioning. It discusses ongoing transitions from HFC-134a to HC-600a in domestic refrigeration and highlights the use of hydrocarbons and CO2 as alternatives in commercial applications. The report also addresses challenges in the industry, such as the ongoing reliance on high-GWP refrigerants and the need for further research into acceptable low-GWP options for air conditioning and chillers.

1. UNEP South America Regional Workshop
Low-
Low-GWP, Energy-Efficient HCFC Replacement Technologies in the
Energy-
Refrigeration and Air Conditioning Sector
Update of the 2006 2010 UNEP Refrigeration and
Air-conditioning Technical Options Report
Air-
22nd – 23rd April, 2010, Bogota, Columbia
Lambert Kuijpers
[Daniel Colbourne]

2. 2006 2010 UNEP RTOC Report
Overview
• Introduction
• Chapter 2 refrigerants
• Chapter 3 domestic refrigeration
• Chapter 4 commercial refrigeration
• Chapter 5 industrial refrigeration
• Chapter 6 transport refrigeration
• Chapter 7 air conditioners and heat pumps
• Chapter 8 water-heating heat pumps
• Chapter 9 chillers
• Chapter 10 vehicle air conditioning
• Chapter 11 refrigerant conservation

3. 2006 2010 UNEP RTOC Report
Introduction
• From 2006 to 2010 report
– Major focus is on low-GWP alternatives
– Especially in relation to phase-out of HCFCs/R22
– Minimising Climate Impacts (Decision XIX/6)
– Alternatives will applied for HCFCs that should minimise impacts
on the environment, including on the climate
– Climate “gains” realised if GWPs are lower and if the energy
efficiency is comparable or lower
– Decision XXI/9 (MOP-21)
– Requires report to illustrate the efficiency, cost and availability of
the low-GWP alternatives

4. 2006 2010 UNEP RTOC Report
Domestic
• Two well-known refrigerant, HFC-134a and HC-600a
• Conversion still ongoing from HFC-134a to HC-600a
(could also be done under the Clean Development
Mechanism); market share HC-600a is growing
• The low-GWP option is HC-600a
• HC-600a has low pressure which has favourable aspects
for the noise production of the refrigerator
• HC-600a is a very efficient refrigerant (high Tcrit)
• There is no advantage to change to any short lived (HFC)
compounds (flammable) for any reason

5. 2006 2010 UNEP RTOC Report
Commercial refrigeration
• In stand-alone products a change from HFC-134a to HCs
is occurring, but also to CO2 (small amount) (Coca Cola
greening of vending machines is mainly HCs now)
• Condensing units (cooling equipment at bakeries,
butchers, smaller shops) uses HCFC-22 (in particular in
A5), HFC-134a and R-404A
– first difficulty is the conversion away from HCFC-22 here
– difficulty also lies in the low costs, which do not make it
possible to compete when introducing low-GWP solutions
– subsector is slightly moving towards HCs and ammonia
(Japan);
– CO2 not considered in this subsector

6. 2006 2010 UNEP RTOC Report
Commercial refrigeration
• Centralised systems in supermarkets
– Vary from 20 kW to 1 MW in capacity
– Use of high-GWP refrigerants (e.g. R-404A with GWP 3900)
will not be part of a sustainable future
– Indirect systems often with carbon dioxide in the secondary
circuit
– Low pressure CO2 cascade systems, with choices for several
refrigerants in the primary circuit (from HFCs to HCs and
ammonia)
– Two stage CO2 systems becoming more common

7. 2006 2010 UNEP RTOC Report
Unitary
• Globally, air-cooled air conditioners and heat pumps --ranging
in size from 2 to 420 kW
– Comprise a vast majority of the AC market below 1,500 kW capacity
• Nearly all air-cooled AC and heat pumps manufactured prior
to 2000 used HCFC-22
• Air-cooled AC & HPs generally fall into four distinct categories
– small self-contained air conditioners (window- and through-wall)
– non-ducted or duct-free split residential and commercial
– ducted split residential
– ducted commercial split and packaged

8. 2006 2010 UNEP RTOC Report
Unitary Air Conditioning-Current Situation
Conditioning-
• HCFC-22 was the ideal refrigerant in the past for AC and is
still being massively applied in Article 5 countries.
– The transition away from HCFC-22 is nearly complete (Europe in
2004) or is well underway in most developed countries.
– HFC refrigerant blends R-410A and R-407C have been dominant
replacements for HCFC-22 in all categories of unitary air
conditioners in developed countries.
– Hydrocarbons have been used in some applications, including
lower capacity portable room units and splits
• Most developing countries continue utilising HCFC-22 as the
predominant refrigerant in unitary air conditioning
applications
– The two largest developing country markets China and India

9. 2006 2010 UNEP RTOC Report
Unitary Air Conditioning – HFCs
• R-407C is mostly used as a retrofit refrigerant (requires less
redesign when converting from HCFC-22) and was also used
for new equipment especially in Europe (to facilitate the early
HCFC-22 phase-out for new equipment, 2002)
• R-410A is the most likely refrigerant to replace HCFC-22 in
most applications in the developed countries and requires
significant redesign.
– Article 5 countries may go slightly different routes to phase out R-22
– As many HFC blends containing HFC-125, R-410A shows a capacity
and energy efficiency decrease with higher ambient temperatures
(much more than e.g. HFC-134a or R-290, both having a much
higher critical temperature)

10. 2006 2010 UNEP RTOC Report
Unitary Air Conditioning – HC-290
HC-
• HC-290 is considered as an alternative to HCFC-22,
particularly in low charge applications
– IEC 60335-2-40 has established the maximum charge limits
• Broader use of HCs in unitary air conditioners will be more
difficult, because the many unitary AC have higher charge
– Significant progress made in reducing charges via redesign and
micro-channel HXs
• HC-290 is considered as one of the candidates in the phase-
out process of HCFC-22 in air conditioning in Article 5
countries; full cost implications are not yet established.
• There is a significant research conducted on CO2 (R-744)
systems to address efficiency issues
– It is not yet clear whether this will be a serious candidate

11. 2006 2010 UNEP RTOC Report
Unitary Air Conditioning – future outlook
• The air conditioning industry is currently exploring
alternatives to R-410A and R-407C, which have lower GWP
and/or better TEWI
• Alternatives include: HFC-32, HC-290, CO2, HFC-152a and
possibly HFC-1234yf
• Technical challenges: flammability, toxicity, peak load
efficiency and economic feasibility
• Products with HC-290 have already been developed by
some manufacturers
• The development of products with the other options is
expected to require significant additional research and
development

12. 2006 2010 UNEP RTOC Report
Chillers – Past and Present Refrigerants
• Prior to the Montreal Protocol, chillers used:
– Centrifugal chillers: CFC-11, CFC-12, R-500
– Reciprocating and screw chillers: CFC-12 and HCFC-22 with a few
using R-717 (ammonia)
• Now chillers use these refrigerants:
– Centrifugal chillers: HCFC-123, HFC-134a, HFC-245fa (limited use)
– Screw and scroll chillers: HCFC-22, HFC-134a, R-410A, R-407C
(decreasing)
– Screw and reciprocating chillers – also available with R-717, R290
• HCFC-22 was phased out for use in new equipment in all
developed countries by 1 January 2010 (Europe, 2004)

13. 2006 2010 UNEP RTOC Report
Chillers using Ammonia and Water
• Using reciprocating compressors, ammonia (R-717) chillers
are available in the 10-1600 kW range
– With screw the range is 100-7000 kW, with scroll the range goes up
to 10,000 kW
– Techniques are available to reduce system volume and charge
– The market for R-717 chillers is likely to grow in the future in regions
where concerns about use of high-GWP refrigerants are strong
– Safety concerns in comfort cooling applications may increase costs
• Water (R-718) applications have been less common for
comfort than process cooling
– Some water chillers are installed in Europe
– Large process cooling chillers have enormous compressor swept
volumes (low density of water)
– Mainly applied in mines (South Africa)
– Higher costs inherent and are associated with large physical size

14. 2006 2010 UNEP RTOC Report
Chillers using Propane and CO2
• Propane (HC-290) is used in chillers (<300 kW) in both
industrial and in larger buildings in Europe
– Some Article 5 countries such as Indonesia, Malaysia, and the
Philippines are applying HC chillers to large space cooling needs
– The use of HC refrigerants in small chillers is likely to grow in the
future where codes and regulations allow
• Several companies started production of R-744 (CO2) chillers
– In cooler climates such as in northern Europe, R-744 chillers are
accepted as alternatives to HFC chillers
– R-744 chillers offer the advantage of being able to use waste heat to
raise water to higher temperatures with higher efficiency than other
refrigerants
– For this application, R-744 heat recovery chillers provide good
efficiency

15. 2006 2010 UNEP RTOC Report
Centrifugal Chillers – low GWP Alternatives
• Centrifugal chillers
– No replacements for HCFC-123 or HFC-134a have been
commercialised yet
– After phase-out for new equipment, HCFC-123 can be produced for
servicing existing chillers
– Hydrocarbons are used in centrifugal chillers in process applications
but not for comfort cooling because of safety concerns with large
refrigerant charges
– Water (R-718) can be used with centrifugal compressors, but
chillers are relatively large
– HFC-1234yf may prove suitable for centrifugal chillers but too early
– It is not clear whether HFC-1234ze will find any use in chillers

16. 2006 2010 UNEP RTOC Report
Industrial and Transport Refrigeration
• Large amount of industrial systems have been and are using
HCFC-22
• HFCs have not been used that much as in other subsectors
• Ammonia and CO2 first candidates, not so many HCs
• Transport refrigeration covers large amount of different
subsectors, from trucks to ships and containers
• HCFC-22 difficult to replace (in particular on ships) and low-
GWP solutions not often easy to introduce
• Use of HFCs (containers), some HCs, but also intermediate
systems (with eutectic salts) in trucks

17. 2006 2010 UNEP RTOC Report
Mobile AC
• MAC was one of the sectors where the conversion to HFC-
134a was complete at an early stage (nA5; A5)
• Candidates for conversion away from HFC-134a originally
were CO2 and HFC-152a; this is the reason for the GWP 150
limit in the EC directive
• Introduction of blends with short lived HFCs in 2005-2007
(however, not successful)
• Change to the HFC-1234yf candidate, which can be used in
HFC-134a systems (no real converting yet)
• German position on “CO2” has not formally changed
• It has become clear that HFC-1234yf will be the future...

18. 2006 2010 UNEP RTOC Report
HCFC Replacement – A5 Factors
• Technical suitability
• Low capital conversion cost
• Low operating cost
• No further conversions required
HCs HFCs CO2/ Unsatur.
NH3 HFCs
Proven technical suitability Yes Yes Yes No
Acceptability Depends Yes Depends Yes/ ?
Low capital conversion cost Depends Yes/? No/? Yes
Low operating cost Yes No Yes No
No further conversions Yes No Yes ??

19. 2006 2010 UNEP RTOC Report
Summary
• HFCs
– Technically suitable for applications
– High GWPs
– High operating costs
– Technology: transitional or not ?
• Natural refrigerants, HCs, NH3, CO2
– Technically suitable for applications
– In most cases good or better performance
– Low operating costs
– Dependent on building and equipment design (acceptability)
• Unsaturated HFCs
– When commercially available in quantities; which ones ?
– Technical suitability for subsectors and (operating) costs ?