Low-GWP, Energy-Efficient HCFC Replacement Technologies in the Refrigeration and Air Conditioning Sector

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 ?