Refrigerants for commercial

refrigeration applications

June 2011

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 Contents Research has shown that properly designed and maintained
systems using HFC refrigerants provide the lowest GWP and
Executive summary ........................ 2
zero ozone depletion. They are also a safe and cost-effective
Introduction and background ........................ 2
solution that will serve us well into the future.
Environmental drivers ........................ 3
Regulations and timing ........................ 5 In this paper, the long-term, non-ozone-depleting replace-
Criteria for refrigerant selection ........................ 6 ments for hydrochlorofluorocarbon (HCFC) R-22 are also
discussed. The experience to date shows that these alterna-
Chlorine-free refrigerants (HFCs) ........................ 7
tives, when used in optimized systems, provide performance
Halogen-free refrigerants ....................... 11 superior to the baseline HCFC refrigerant. Other refrigerant
System design considerations ....................... 12 choices, such as carbon dioxide and hydrocarbons, are also
Service considerations ....................... 14 discussed, along with their relative merits to HFCs.
Future direction ....................... 15
Emerson Climate Technologies is committed to providing
Glossary of terms ....................... 16
solutions that improve human comfort, safeguard food and
Appendix ....................... 17 protect the environment. We recognize that this is a difficult
Executive summary balance, but remain optimistic. We are confident that we can
develop solutions that provide efficient commercial refrig-
The refrigeration industry has supported global efforts to eration without compromising our global environment. The
protect the environment by phasing out chlorine-containing following paper discusses the factors that we feel are most
refrigerants in accordance with the Montreal Protocol. These important for meeting this challenge.
actions have significantly cut chlorine in the atmosphere and
are starting to repair the ozone layer. DISCLAIMER
Use only refrigerants and lubricants approved by and
Today, there is more attention on climate change and in the manner prescribed by Emerson. In some circum-
reducing greenhouse gases. Carbon dioxide is by far the most stances, non-approved refrigerants and lubricants may be
significant greenhouse gas, produced mainly by burning fossil dangerous and could cause fires, explosions or electrical
fuels for electrical generation and transportation. Since refrig- shorting. For more information, contact Emerson and your
eration equipment consumes energy, energy-efficient designs original equipment manufacturer (OEM).
are important to reducing carbon dioxide production.

If refrigerant gas escapes from a system, it can also contrib- Introduction and background
ute to direct global warming. System manufacturers and Scientific data supports the hypothesis that chlorine from re-
contractors are working hard to contain refrigerant leaks. frigerants has depleted the earths ozone layer and is linked
to a rise in skin-related diseases1. The air conditioning and
For a refrigerant to be considered a long-term option it must
refrigeration industry has supported global efforts to protect
meet three criteria it must be safe; it must be environmen-
the environment by introducing non-chlorine-containing
tally friendly; and it must provide excellent performance
refrigerants. The Montreal Protocol, established in 1987
benefits thus resulting in zero ozone depletion with low
Global Warming Potential (GWP). and later revised, provides guidelines for individual country
legislation, setting timetables for the phase-out of chlorine-
Several non-halogen substances, including ammonia, carbon containing refrigerants. Today, 196 nations have become
dioxide and hydrocarbons, will also work as refrigerants. All party to the Montreal Protocol.
these substances can be refrigerants for the right application
if the system can be designed to meet key selection crite- The effort started with an emphasis on cutting chlorofluoro-
ria. Component and equipment manufacturers continue to carbon (CFC) refrigerants. Work in the late 1980s and early
research how these refrigerants perform in systems. 1990s centered on eliminating CFCs which were used in
foam blowing, cleaning and refrigeration applications and
Hydrofluorocarbons (HFCs) are non-ozone-depleting, non- centrifugal chillers for air conditioning. By the end of 1995,
flammable, recyclable and energy-efficient refrigerants of developed countries stopped producing CFCs, and they are
low toxicity that are used safely worldwide. Although HFCs no longer used in new equipment today. These actions have
are the best environmental and economic choice today, the
significantly reduced atmospheric chlorine and are starting
global sustainability of HFCs requires a focus by the industry
to repair the ozone layer.
on refrigerant containment and energy efficiency.

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 In 1997 the Kyoto Protocol, signed and ratified by many sun. Depleted ozone allows more ultraviolet light to reach
nations around the world, focused attention on the impact the surface, negatively affecting the quality of human, plant,
of human activity on climate change. As a result, there is animal and marine life.
now more attention on global warming. Although the Kyoto
Scientific data verifies that the earths ozone layer has been
Protocol does not apply to the United States, our industry has
depleted. The data also verify that a major contribution to
worked to lower the impact of refrigerants on climate change
ozone depletion is chlorine, much of which has come from
with higher-efficiency refrigerants and system designs.
the CFCs used in refrigerants and cleaning agents.
In 1997 the Air-Conditioning and Refrigeration Institute (ARI)
Research has shown that even the chlorine found in R-22
finished a major international testing program entitled the
refrigerants can be harmful to the ozone layer. The need to
Alternative Refrigerants Evaluation Program (AREP). The
protect the earths ozone has resulted in new government
AREP report indentified several suitable HFC replacements
regulations and HFC refrigerants. Since HFCs are chlorine
for HCFC R-22. In the USA and Europe, these HFC replace-
free, they will not damage the ozone layer.
ments are already being widely used. Some of these replace-
ment refrigerants have different operating characteristics Climate Change
than HCFC R-22, but they all eliminate chlorine and potential
According to the National Academy of Scientists, the tem-
ozone depletion, leaving climate change as the focus for
perature of the earths surface has risen by about one degree
future regulations and control.
Fahrenheit (0.5 degree Kelvin) in the past century2. There is
evidence that suggests that much of the warming during the
Environmental drivers
last 50 years is because of greenhouse gases, many of which
There are two factors important to the discussion of the are the by-product of human activities. Greenhouse gases
environmental impact of refrigerants: ozone depletion and include water vapor, carbon dioxide, methane and nitrous
global warming. oxide, and some refrigerants. When these gases build up in
Ozone depletion the atmosphere, they trap heat. The natural greenhouse ef-
fect is needed for life on earth, but scientists believe that too
The ozone layer surrounding the earth is a reactive form of much greenhouse effect will lead to climate change. Figure 1
oxygen 25 miles above the surface. It is essential for planetary shows the mechanism of this global warming process.
life, as it filters out dangerous ultraviolet light rays from the

The greenhouse effect

Some of the infrared radiation passes through the atmosphere, and

some is absorbed and re-emitted in all directions by greenhouse
gas molecules. The effect of this is to warm the earths surface and
lower atmosphere.

Some solar radiation is reflected Infrared radiation

Solar radiation by the earth and the atmosphere. is emitted from
passes through the the earths surface.
clear atmosphere.

Most radiation is absorbed

by the earths surface
and warms it.

Figure 1

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 Carbon dioxide (CO2) is one of the major greenhouse gases. power used. Higher energy efficiency of some refrigerants
Vegetation is the primary generator of CO2, along with natu- can lower the indirect effect and offset a somewhat higher
ral organic materials decomposing. GWP.

Burning fossil fuels also adds CO2 to the atmosphere. Fossil Direct global warming is an issue only if the refrigerant leaks
fuels are used in power plants around the world to produce or is released from the refrigeration system; thus, refrigerant
electricity for vital social needs. According to the U.S. Energy containment in the system is the key to cutting the direct
Information Administration, nearly 30 billion metric tons global warming effect. The best way to do this is with low-
of energy-related carbon dioxide were produced in 20073. charge system designs, the quick repair of all leaks and the
In comparison, total annual HFC production globally is less recovery of refrigerant during service operations.
than 0.001 percent of this figure. It is estimated that HFCs
Indirect global warming is a function of the efficiency of any
will contribute no more than three percent of greenhouse
piece of equipment. In a refrigeration system, the compres-
gas emissions by 2050. Energy-efficient refrigeration equip-
sor efficiency, system design, and thermodynamic and
ment saves energy and cuts energy-related carbon dioxide
heat-transfer properties of the refrigerant affect the energy
emissions.
efficiency of the equipment. Indirect global warming takes
Total Equivalent Warming Impact (TEWI) into account the energy efficiency, and the power source.
Global Warming Potential (GWP) is a direct measure of Electrical generation can come from fossil fuels, hydropower
global warming that considers only the direct effect of the or nuclear power. The implication is that a less efficient sys-
refrigerant as a greenhouse gas when it escapes into the tem uses more electricity, and thus has a higher TEWI.
atmosphere. Essentially, all alternatives to R-12 and R-502 It is likely that global warming will be important in driving
have substantially less direct GWP and are, therefore, con- the trend to more efficient refrigerants, as energy consump-
sidered a move in the right direction. As a result, refrigerants tion is the main contributor to global warming by most
with a Global Warming Potential (GWP) of less than 4,000 equipment. In dealing with the changing refrigerant environ-
have been accepted; however, some European countries are ment, Emerson has adhered to a strategy that permits us to
using 2,000 as a maximum GWP (reference GWP for R-11 = serve our markets with products that provide performance,
4,000)4. reliability and minimum risk, while moving as rapidly as pos-
The refrigeration industry developed TEWI to measure the sible to chlorine-free alternatives.
impact of various activities on global warming. TEWI is wide-
ly accepted as the best measure of global warming, because
it accounts for greenhouse gases from direct emissions of Refrigerant options
operating fluids together with the sizable energy-related
Refrigerant Type GWP
CO2, as seen in Figure 2. This global warming calculation
R-12 CFC 10900
includes the effects of system efficiency and the source of
the electricity (coal, nuclear, hydroelectric) and the direct ef- R-502 CFC 4700
fect of the refrigerant when it escapes into the atmosphere. R-22 HCFC 1810
The number varies according to the leakage rate and type of R-134a HFC 1430
R-404A HFC 3922
R-407A HFC 2107
Global warming impact
R-407C HFC 1774
R-410A HFC 2088
R-422A HFC 3143
R-422D HFC 2729
R-32 HFC 675
R-1234yf HFO 4
HC-290 Propane 20
R-717 Ammonia 0
R-744 Carbon Dioxide 1
Figure 2 Figure 3

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 TEWI and refrigerants it is likely that most commercial refrigeration applications
Global warming is a significant consideration in the selection will stay with HFC options, such as R-404A, R-507, R-134a,
of future refrigerants. Some refrigerants have a higher direct R-407C and R-410A. The efficiency performance and cost ad-
GWP than others; however, direct global warming alone can vantages of these refrigerants outweigh the disadvantages
be misleading in understanding the effect of various refrig- associated with higher pressures and direct GWP.
erant alternatives. TEWI helps to assess the climate-change Emerson Climate Technologies supports TEWI and expects
impact fairly, as it takes into account the direct (refrigerant that this measurement tool will become the representative
emissions) and indirect (system power consumption/ef- criterion in selecting future refrigerants. Using the right
ficiency) effects in evaluating global warming. Todays HFC refrigerant in energy-efficient refrigeration equipment can
refrigerants appear to be good options when comparing the lower greenhouse gas emissions.
total global warming impact to that of halogen-free refriger-
ants. Regulations & Timing
The Montreal Protocol was revised to call for a production
TEWI highlights the need to control leaks to reduce global
phase-out of HCFC refrigerant applications by 2020; howev-
warming from the refrigerant. As shown in Figure 3, indirect
er, concerns about the proximity of the production cap and
global warming that which can be best dealt with by using
the impact of Environmental
higher-efficiency refrigerants and the design of higher-
efficiency systems can have a far greater impact than Protection Agency (EPA) regulations have caused many
direct global warming. Refrigerant that does not get into the end-users and OEMs to work on system redesigns to cutout
atmosphere does not cause global warming. HCFC refrigerants. As shown in Figure 4, allowable HCFC
production levels drop with time, with the next significant
The Kyoto Protocol was established in 1997 in response to
cut planned in 2020.
global warming concerns. Developed countries are chal-
lenged with cutting greenhouse gases by an average of 5.23 The Montreal Protocol supports HCFCs to aid in the transi-
percent from 1990 levels between the years 2008 and 2012. tion from CFCs; however, HCFC consumption will be limited
The protocol focuses on six gases, which it views as being relative to historic usage of CFC and HCFC on an ozone-
considered and controlled as a total package. These gases depletion weighted basis, during the transition. The EPA
include CO2, CH4, N2O, HFCs, PFCs and SF6. has established U.S. regulations, which control future use of
HCFCs according to a schedule that the agency and industry
As we consider the refrigerants available to manufacturers
believe is right.
and the potential global warming impact of each, we believe

HCFC phaseout timeline

Figure 4

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 The EPA is monitoring continually the U.S. compliance with The components of a refrigerant mixture are chosen based
the Montreal Protocol and has developed a schedule to on the final characteristics desired. These characteristics
monitor progress toward the total phase-out of HCFCs. The could include vapor pressure, transport properties, lubricant
United States Clean Air Act established regulations for imple- and material compatibility, thermodynamic performance,
menting this phase-out. After 2010 chemical manufacturers cost, flammability, toxicity, stability and environmental
may still produce R-22 to service existing equipment, but properties. The proportions are chosen based on the exact
not for use in new equipment. Equipment manufacturers in characteristics desired in the final product.
the United States must not produce new systems using R-22.
ARI established AREP to evaluate refrigerant alternatives.
In 2020 use of existing refrigerant, including recovered and
More than 180 AREP reports were approved and released
recycled refrigerant will be allowed beyond 2020 to service
to the public when the committee finished testing in 1997.
existing systems, but chemical manufacturers will no longer
This testing led to the widespread use of HFC refrigerants to
be able to produce R-22.
replace R-22.
In the European Union, the F-Gas Regulation5 took effect
Safety
as of July 2007. It requires leak inspections, leak-detection
systems, recovery, and training and certification. Manufac- As the air conditioning and refrigeration industries move
turers must comply with the requirements on labeling and away from the few CFC and HCFC refrigerants still in circu-
leak checks. The effectiveness of the F-Gas Regulations will lation, the safety of new refrigerants must be considered.
be reviewed in 2011. See EPEEGlobal.org for further details. Refrigeration safety issues fall into four major areas:

Refrigerant decisions are also impacted by other regulations Pressure almost all the new refrigerants operate at a
on product design and application. For example, Underwrit- higher pressure than the refrigerants they replace. In some
ers Laboratories, Inc. (UL) modified the pressure standard cases the pressure can be substantially higher, which means
for refrigerants in air conditioning and refrigeration systems, that the refrigerant can be used only in equipment designed
making it possible to safely apply the higher-pressure refrig- to use it and not as a retrofit refrigerant.
erant alternatives6.
Material compatibility the primary safety concern here
It is important for users to continuously monitor and under- is with deterioration of materials, such as motor insulation,
stand the impact of all the various legislative actions to our which can lead to electrical shorts, and seals, which can
industry. In Europe, refrigerant choices are also impacted by result in leaks.
commercial incentives, such as refrigerant taxes, depending
Flammability Leakage of a flammable refrigerant could
on GWP and energy-efficiency certification schemes.
result in fire or explosions. Many new refrigerants are zeo-
Regardless of regulations, many OEMs have already launched tropes, which can change composition under some leakage
environmentally friendly systems in response to competitive scenarios. So it is important to understand the flammability
pressures. Since 1990, Emerson has developed and released a of the refrigerant blend, and what it can change into under
series of new HFC products to support the industrys need for all conditions.
chlorine-free systems. Products designed to operate with R-
Toxicity during the transition to HFCs, some countries
404A, R-507, R-134a, R-407C and R-410A are now available.
have explored or applied toxic refrigerant options. These
alternatives may offer system performance benefits, but
Criteria for refrigerant selection
they can also be highly dangerous. It is the view of Emerson
The desirable characteristics for a widely used refrigerant that toxic refrigerant options should not be used for com-
include: mercial refrigeration, especially considering that HFCs can
Environmental acceptability deliver the equivalent or better efficiency and performance.
The major refrigerant manufacturers, equipment manufac-
Chemical stability
turers and safety-standard setting agencies, such as UL and
Materials compatibility
the American Society of Heating, Refrigerating and Air-Con-
Refrigeration-cycle performance ditioning Engineers (ASHRAE), have extensively studied and
Adherence to nonflammable and nontoxic guidelines, then rated the safety aspects of proposed new refrigerants
per UL according to each of the factors listed above. The intent is to
Boiling point

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 use only refrigerants that are at least as safe as those being zero ozone depletion and low GWP to be considered a long-
replaced. term option.

Chlorine-free refrigerants (HFCs) HFCs

The selection and approval of acceptable long-term refriger- HFCs, or hydrofluorocarbons, are chemicals used in air
ants is a complex task. The ever-shifting legislative environ- conditioning and refrigeration applications. They are non-
ment, the phase-out of CFCs and HCFCs, the availability of flammable, recyclable, energy-efficient refrigerants of low
alternate refrigerants and many other factors are just a few toxicity that are being used safely worldwide.
of the issues that must be taken into account. Technical and Economic Assessment Panel (TEAP) of the
Based on these factors, Emerson Climate Technologies has Montreal Protocol on Substances that Deplete the Ozone
cited the following key criteria for evaluating and approving Layer reported in 1999 that HFCs are needed for the safe and
HFC refrigerants for use in Emerson products: cost-effective phase-out of CFCs and HCFCs and are essential
substitutes for these products. Also, HFCs are needed to
Global warming should be reviewed, based on the TEWI ap- phase-out HCFCs in developing countries. As replacements
proach; therefore, the combined direct global warming and for less energy-efficient, older equipment, HFC systems
indirect global warming, which varies with energy efficiency, conserve energy and reduce global warming gases at electric
should be less than the refrigerants being replaced. power plants. These systems are being used responsibly,
including recovery and reuse of HFCs to design of HFC-pro-
Safety must be maintained. New refrigerants should be
ducing plants, with the goal of zero HFC emissions.
nontoxic, with a Threshold Limit Value (TLV) minus Time-
Weighted Average (TWA)7 greater than 400 parts per million Substituting HFCs for CFCs has lowered the impact of
(ppm), and nonflammable. If they are not, steps must be greenhouse gas emissions, as HFCs cut total greenhouse gas
taken to ensure that the refrigerants are properly used in release. Current technology has reduced greenhouse gas
equipment and facilities designed to provide adequate discharged by more than 80 percent since 1990. Projections
safety protection. Maximum system pressures must be no show that by 2050, HFC emissions will make up less than two
greater than current acceptable limits for retrofit applica- percent of potential future contributions for all greenhouse
tions. Emerson approves only refrigerants that meet UL gases, as identified in the Kyoto Protocol8.
standards. See Emerson Climate Technologies, Inc. Accepted
Refrigerants/Lubricants (Form 93-11). Depending on the country of use, HFC emissions manage-
ment is being conducted through mandatory recovery and
It is desirable that lubricants work with current oil-control non-regulatory means, voluntary measures and industry-
technology, meet current or improved durability require- government partnerships. This involves engaging jointly
ments and be backwards compatible with mineral-oil sys- in research and communication to find new technologies,
tems. Material compatibility between the new refrigerants, designs and processes to manage HFC emissions and to
lubricants and materials of construction in compressor and enhance product energy efficiency.
system components must be maintained.
The HFCs and equipment being produced for refrigeration
It is highly desirable to have one lubricant solution that appear to be satisfactory for these applications; however,
works with all the alternative refrigerants, including HFC and there are several areas in which they differ from the refriger-
HCFC retrofit chemicals. One lubricant that works with all ants they are replacing:
the approved chemicals makes the service and long-term
refrigerant use easier. They require polyol ester (POE) oil rather than mineral oil.

Service procedures for equipment should remain simple. Most of the HFCs are mixtures, which can behave
Using refrigerant blends should not require unreasonable differently than pure compounds under some conditions.
service procedures. HFCs have higher vapor pressures than the refrigerants
The performance of new refrigerants should be similar to the they are replacing, which can affect the settings of
refrigerants they are replacing. Regardless of the specifica- controls, valves and safety devices.
tions of individual manufacturers, a refrigerant must have

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 Mixtures R--134a is available from most refrigerant manufacturers.
As mentioned earlier in this paper, refrigerant manufactur-
R-134a has the benefit of being a single-component refriger-
ers have been unsuccessful in developing single-component,
ant and, therefore, does not have any glide. Also, the direct
high-pressure alternatives to CFCs that have zero-ozone-
HGWP of R-134a is low.
depletion potential, adequate performance, good reliability
and safety. So HFC mixtures (also called blends, azeotropes, The disadvantage of R-134a lies in its fairly low capacity
near-azeotropes and zeotropes) are widely used. compared to R-22. To use this refrigerant, all the tubing in
the heat exchangers and between the components a system
Mixtures have advantages and disadvantages when com-
need to be significantly larger to minimize pressure drops
pared to pure substances. Mixtures allow the advantage
and maintain an acceptable operating efficiency. Combined
of tailoring the final refrigerant characteristics for superior
with the greater compressor displacements required, it
efficiency, performance and reliability. Disadvantages of
results in a system that will be more costly than R-22 systems
zeotropic mixtures include the following:
today. The heat-transfer coefficient of R-134a is also lower
Temperature glide Because the composition a zeotrope than that of R-22, and tests show that system performance
alters during a phase change, there is a slight change in degrades with its use.
evaporating and condensing temperature at constant pres-
This may not be the case in larger commercial systems, in
sure. This phenomenon is known as glide. Most zeotropic
which large screw or centrifugal systems are used, and refrig-
mixtures under consideration exhibit low glide. This phe-
erants like R-11 and R-12 were common. Here, R-134a may
nomenon is a little different from similar effects seen with
offer the best solution for a fairly low-investment, simple
single-component refrigerants caused by normal pressure
redesign to HFCs.
drop in the heat exchanger. As a result, little or no effect on
system performance is expected. Emerson laboratory and field trials show that the refrigera-
tion capacity and energy efficiency of R-134a are similar to
Fractionation since the components of a zeotropic mixture
R-12 for medium- and high-temperature applications. At
possess different vapor pressures, under some conditions
evaporating temperatures below -10 degrees Fahrenheit
they may leak from a system at different rates. As a result,
(-23 degrees Celsius), R-134a loses its attractiveness for
the refrigerant composition may change over time, with a
several reasons:
corresponding change in performance.
It experiences significant loss of capacity and efficiency
Zeotropic mixtures available in the marketplace with a glide
compared to R-12.
of less than six degrees Fahrenheit (3.3 degrees Kelvin) ap-
proximate an azeotrope so closely that fractionation should Pressure ratios become high, compromising compressor
not be a serious problem. The only exceptions to this are sys- reliability.
tems that use multiple evaporators or flooded evaporators.
Low side pressures are sub-atmospheric (i.e., vacuum),
To ensure fractionation does not occur during charging, it resulting in system reliability concerns.
is recommended that zeotropic mixtures be liquid charged
rather than vapor charged. Liquid must be removed from the Except for ozone-depletion potential, Emerson believes that
refrigeration cylinder. It then can be flashed through a meter- R-134a possesses the same deficiencies as R-12 and repre-
ing device and charged into the system in its vapor state. sents a step backward for most commercial refrigeration
The refrigerant manufacturers recommendation should be and air conditioning applications. These deficiencies include
closely followed. larger-displacement compressors and larger-diameter tub-
ing compared to that required for use with high-pressure
R-134a refrigerants.
R-134a is the first non-ozone-depleting fluorocarbon
For customers planning to use R-134a, Emerson has devel-
refrigerant to be commercialized. Developed more than 25
oped product lines for applications above -10 degrees Fahr-
years ago to have characteristics similar to R-12, it is used in
enheit (-23 degrees Celsius) evaporator temperatures.
medium- and high-temperature applications in which R-12
had been used. R-134a is used in automotive air conditioning
because of its low hose permeability and high critical tem-
perature. Domestic refrigerator producers also use R-134a.

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 R-404A R-32
Equipment manufacturers use HFC refrigerant R-404A as the R-32 is an HFC refrigerant that is slightly flammable, with
long-term replacement for R-502. R-404A is an excellent low- an ASHRAE 34 flammability classification of A2L. It is best
and medium-temperature refrigerant, because of high en- known as a component in R-410A. R-32 is not currently being
ergy efficiency and zero-ozone-depletion potential. R-404A marketed as a stand-alone refrigerant in North America, but
is a near-azeotropic blend of HFC refrigerants R-125, R-143a is gaining interest in China.
and R-134a. It is commercially available from many sources
R-410A
and is becoming the most popular refrigerant of its class.
R-410A has become the refrigerant of choice for use in resi-
R-507 dential air conditioning applications. Most major residential
This refrigerant is an azeotropic mixture of R-143a and air conditioning manufacturers offer R-410A product lines.
R-125, with characteristics also similar to R-502. Emerson R-410A delivers higher efficiency and better TEWI than other
compressors developed for R-404A (except for a few hermet- choices. The refrigerant also has many benefits that make it
ic reciprocating models) are also approved for R-507. R-404A an ideal refrigerant for use in commercial refrigeration ap-
and R-507 operate at slightly higher pressures and slightly plications.
lower discharge temperatures than R-502.
There are several distinct operational differences between
R-407C R-22 and R-410A refrigerants. R-410A operates at 50 percent
R-407C is a blend of R-32, R-125 and R-134a. Of the higher- higher pressure than R-22; however, the higher pressure
temperature HFC options, R-407C was designed to have allows the system to run at a lower temperature. Because of
operating characteristics similar to R-22. The major concerns these differences, anyone handling these units should get
surrounding R-407C are in its high glide (10 degrees Fahren- training on the technical aspects of the new R-410A systems,
heit) and the efficiency degradation when compared to R-22; where they can learn proper joint brazing and maintenance
however, this refrigerant provides the simplest conversion of tips for this refrigerant.
the HFC alternatives. In systems where glide is acceptable, R-410A is a near-azeotrope composition of 50 percent
R-407C has become a popular option for manufacturers who R-32 and 50 percent R-125. System testing has shown that
want to move quickly to an HFC alternative. In the long run, R-410A delivers higher system efficiency than R-22. R-410A
however, the lower-efficiency performance of this refrigerant evaporates with a 35 percent higher heat-transfer coefficient
may make it a less attractive alternative when compared to and 28 percent lower pressure drop compared to R-22.
R-410A for medium-and high-temperature applications.
Other system performance enhancements have been gained
Care should be taken when applying R-407C in any applica- by sizing for equal pressure drop and reducing the number of
tions in which glide can impact system performance by frac- coil circuits needed to raise the mass flux. The higher density
tionation in flooded-evaporator or multi-evaporator designs. and pressure also permit smaller-diameter tubing, while
Also, R-407C should not be viewed as a drop-in for R-22 maintaining reasonable pressure drops.
systems or applications. Like all HFCs, R-407C requires POE
lubricants, and other system design modifications may be Because systems that use R-410A have been specially
required for R-407C to operate acceptably in R-22 systems. designed to use less tubing and fewer coils, R-410A has
emerged as a cost-effective refrigerant. Fewer materials,
R-407A along with lower refrigerant charge and better cyclic perfor-
R-407A is a blend of R-32, R-125, and R-134a in a 20/40/40 mance, also contribute to the affordability of R-410A.
ratio by mass. R-407A was designed for low and medium
R-410A is considered a high-pressure refrigerant. High-pres-
temperature refrigeration applications. With an IPCC4 GWP
sure refrigerants operate at pressures significantly higher
Value of 2107, R-407A has 54% lower GWP than R-404A.
than those normally seen with refrigerants such as R-22
Manufacturers of this refrigerant claim a good capacity and
and R-502. They cannot be used as retrofit refrigerants with
efficiency match for R-22, making it well suited as a retrofit
existing equipment, but only in new equipment (including
for R-22 in supermarket and food storage applications. Dis-
compressors) specifically designed for them. R-22 compres-
charge temperatures of R-407A will be lower than R-22 but
sors cannot meet UL and industry design standards with
system pressures are higher. Compressor cooling should be
these higher pressures.
taken into account for high ambient operation.

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 For refrigeration application, R-410A is potentially the most R-152a is being considered as an option to replace R-134a in
efficient refrigerant at medium-temperature conditions automobile air conditioning; however, because of its flam-
(zero to 30 degrees Fahrenheit). Other advantages include mability, R-152a is not a serious alternative for commercial
smaller line sizes and lower pressure drops; however, the refrigeration systems.
system would require design for higher pressures. Potential
R-422 refrigerants
changes in UL requirements may reduce the impact. Testing
at lower temperatures has shown promising results. Re- R-422A, R-422B and R-422D are other HFC refrigerants that
search is ongoing at Emerson to understand the benefits of were developed for replacement of R-22. All R-422 series
this refrigerant in commercial refrigeration. refrigerants have the same blend of refrigerants. The last
letter simply signifies slightly different percentages of the
R-417A refrigerant mixes. R-422 refrigerants are branded as One
R-417A was developed to be a drop-in refrigerant for new Shot or ISCEON 9 series and are a blend of R-125 (85 per-
and service replacements of R-22, while using traditional cent), R-134a (11.6 percent) and R-600a (3.4 percent). The
HCFC lubricants, such as mineral oil and alkyl benzene (AB). hydrocarbon in the mixture was added to enhance oil return.
This refrigerant is branded as ISCEON 59 and Nu-22 The refrigerant manufacturers claim equivalent capacity and
refrigerants and is a blend of R-125 (46.6 percent), R-134a improved efficiency compared with R-22. They further claim
(50 percent) and R-600 butane (3.4 percent). The hydrocar- that R-22 lubricants can be maintained, but recommend a
bon in the mixture was added to enhance oil return. ASHRAE consultation with the system and compressor manufacturer
designates the refrigerant as A1/A1 rated, meaning that it is for current application considerations.
nontoxic and nonflammable. The refrigerant manufacturer
Independent testing of R-422A has shown that its capacity
claims equivalent capacity and improved efficiency com-
is 10 to 15 percent lower than R-22 and R-404A, especially
pared with R-22. It further claims that R-22 lubricants can
in low-temperature conditions. Mass flow of R-422A is even
be maintained, but recommends a consultation with the
higher than R-404A and about 55 percent higher than R-22.
system and compressor manufacturer for current recom-
Pressures of R-422A are similar to those of R-404A and 20
mendations.
percent higher than R-22.
The manufacturers claims about R-417A performance are
Refrigerant changeover guidelines are available from Emer-
not supported by independent test reports. Independent
son that describe the retrofit procedures when transitioning
testing of R-417A has shown between nine and 10 percent
from R-22 to R-422 series refrigerants.
lower system capacity when used as a drop-in refrigerant.
This same testing shows efficiency losses of three to five Future low-GWP fluorocarbon refrigerants
percent. Independent testing of R-417A has also shown
Several refrigerant manufacturers are developing refriger-
significant delays oil return.
ants for automotive air conditioning applications that will
Two more challenges are presented with R-417A. The refrig- meet European Union environmental standards for GWP
erant has a worse GWP rating than R-407C and R-22. As a substances. The most likely candidate to replace R-134a in
blend, R-417A has the same fractionation and glide issues as automotive air conditioning applications is HFO-1234yf, a
R-407C. So a system leak may affect the composition signifi- single-component refrigerant with a much lower GWP than
cantly and, therefore, the properties of this refrigerant. R-134a. These future low-GWP refrigerants are being de-
veloped as non-carbon dioxide alternatives. Other possible
Emerson Climate Technologies does not expect R-417A to fluorocarbon refrigerants under development are two-blend
be a significant HFC alternative to R-22. Refrigerant R-417A azeotropes with HFO and R-32 or R-134a.
has neither been fully tested nor qualified by Emerson and
at this time is not approved for use in our compressors or Halogen-free refrigerants
components.
Ammonia
R-152a Ammonia (NH3) is widely used as a refrigerant in large indus-
R-152a is chemically similar to R-134a, but it is different envi- trial refrigeration plants. As a halogen-free refrigerant, am-
ronmentally. R-152a has a much lower GWP (120 compared monia has the benefit of zero-ozone depletion potential and
to 1,300) than R-134a but is considered ASHRAE A2 flam- no direct GWP; however, its high toxicity limits its applica-
mable. tion to industrial refrigeration applications. In large ammonia

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 systems, the efficiency is the same as similar systems with system at high-temperature conditions. Microchannel heat
R-22 refrigerant. exchangers, gas/suction heat exchangers or CO2 expanders
improve system performance, with some added cost and
Although ammonia is widely available and is a low-cost sub- complexity.
stance, there are significant challenges to applying ammonia
as a refrigerant in commercial refrigeration systems. Ammo- The cost impact of CO2 in transcritical systems is substan-
nia systems have higher discharge pressures than R-22. Oil tial. Because of the higher pressure, modifications are
management becomes a major issue in ammonia systems, required on the compressor shell, valves, rings, terminal
since the oils used are usually not soluble in ammonia. The and seals, and the pressure relief valve and microchannel
low mass flow of ammonia compared to R-22 is an advan- heat exchanger. Performance implications require CSHX, a
tage for large ammonia plants, but becomes a challenge in discharge-pressure regulator valve and a low side accumula-
smaller commercial systems. Also, ammonia is highly cor- tor to control excess charge. Another oil separator is required
rosive on copper materials, so refrigerant lines must be steel, because of oil circulation and return problems. The bottom
and the copper in the compressor-motor windings must be line is a 20 to 30 percent higher final cost for performance
insulated from the gas. levels equal to those of an HFC.

The major drawback of using ammonia in commercial refrig- The comparably high pressure level and thermodynamic
eration applications is its high toxicity and flammability level. properties of CO2 as a refrigerant have driven system design-
This alone requires unique safety measures that are well ers to consider subcritical CO2 systems. These systems oper-
beyond the scope of most commercial installations. ate much like conventional cascade refrigeration systems. In
a subcritical system, CO2 is used as a direct expanding medi-
Carbon dioxide um in the low-temperature stage, and different options exist
Environmental concerns about the potential direct emissions for the medium-temperature stage. This way compressors
from HFC-based refrigeration systems have led to legisla- in the low-temperature stage are only exposed to pressure
tion and taxation schemes in parts of Europe that favor levels similar to high-pressure air conditioning applications,
the usage of carbon dioxide (CO2) as a refrigerant. CO2 is such as with R-410A. Subcritical operation might be the
given the designation R-744. CO2 is environmentally benign best application of CO2 as a refrigerant for some commercial
compared with other refrigerants, is nonflammable, has low refrigeration applications.
toxicity, is widely available and is a low-first-cost substance.
In summary, CO2 has many technical and cost challenges.
These are the reasons it was one of the original refriger-
The low efficiency and cycle complexity are the main limita-
ants, used nearly 100 years ago. Although thermodynamic
tions; however, CO2 may become used in transport and
performance of a simple CO2 cycle is poor 30 to 50 percent
low-temperature cascade systems, and in some heat-pump
worse than HFCs poor refrigerants such as CO2 tend to
applications. Whether transcritical or subcritical CO2 systems
have good heat-transfer characteristics and respond well to
are considered, CO2 technology cannot be seen as a drop-in
cycle modifications.
replacement for any of the other refrigerants mentioned in
Many CO2 systems are designed for transcritical operation. this paper. Any application of CO2 requires a thorough as-
These systems tend to have lower energy efficiency, com- sessment of system efficiency, TEWI, life-cycle cost, techni-
pared to conventional systems, and the system design is cal feasibility, reliability and safety.9
different from conventional systems. Transcritical operation
Hydrocarbons
means that the CO2 does not condense at the high pressure,
and rather than using using a traditional condenser, a gas The push for halogen-free refrigerants has led manufactur-
cooler is used. The pressures created by CO2 present signifi- ers to investigate hydrocarbons as a replacement for R-22.
cant challenges in its usage. High side pressures are about Propane (R-290) is considered as a replacement, because it is
2,500 pounds per square inch (psi), and excursions can go to a halogen-free substance with no ozone-depletion potential
4,000 psi. This is a technical and cost challenge not only for and low direct GWP. Propane is widely available and is a low-
the compressor, but also for the heat exchangers. cost substance. The operating pressures of a refrigeration
system with propane are similar to R-22. Propane has been
Typical cycle efficiency is 40 percent of the ideal refrigeration applied in systems with low charge less than 150 grams
cycle Carnot15, where the Coefficient of Performance (COP) (10 ounces) and often outside the U.S.
is 2.5, compared with 68 percent (COP 4.2) for an R-134a

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 The disadvantage of propane and all hydrocarbons is that System design considerations
they are highly flammable. System costs are higher because
Emerson has worked with many refrigerant companies to en-
of the required safety measures. Special considerations must
sure that new refrigerants are compatible with new Emerson
be taken for excess pressures and electrical connections, and
components used in the refrigeration industry. Older com-
ventilation to prevent flammable gas mixtures. Commercial
ponents may not be compatible with the new refrigerants
operators do not want to risk the safety-code issues and
and oils, especially those that have been operating in the
litigation risks associated with using propane in a refrigera-
field for more than a decade. Before retrofitting any system,
tion system.
check the manufacturers recommendations.
The refrigeration industry is anticipating U.S. EPA SNAP
Lubricants
approval of R-290 Propane refrigerant for Domestic refrig-
erators and small self-contained Commercial Refrigeration Most manufacturers of hermetic and semi-hermetic com-
equipment soon. Also, several Foodservice operators and pressors have determined that POEs are the best choice of
OEMs are exploring the performance and economics of tran- lubricants for use with HFC refrigerants. Besides providing
sitioning refrigeration applications to HFC-free, or natural superior lubrication with the new refrigerants, POE oil has
refrigerant alternatives over the next several years, both in other advantages that make it attractive for use in refrigera-
the U.S. and globally. The primary benefits of these transi- tion.
tions would be to:
Because POE oil can be used with all refrigerants and is back-
Reduce the Direct Global Warming Potential (GWP) wards compatible with mineral oils commonly used with
of the refrigerant to near zero to significantly mitigate CFCs and HCFCs, it offers the most flexibility in dealing with
the refrigerants impact on global climate change the uncertainties imposed by the CFC issue. For example:

Potentially improve equipment energy efficiency to cut Using POE oil in a new HCFC system will allow the easy
the Indirect GWP of CO2 emissions generated during transition to HFCs, without the expensive, repetitive
electricity production, while using less electricity. flushing procedure needed to remove the mineral oil
from the system.
Employ renewable refrigerant gases which are by-
products of various processes, thus generating a lower During system service, if POE oil is used to replace any
cost and lower carbon footprint refrigerant than todays mineral oil removed from a system, it starts the process
manufactured alternatives to flush the system of mineral oil, so that conversion to
an HFC can be performed with fewer steps later.
The most common natural refrigerant alternatives being
considered for small commercial refrigeration applications POE oil can also be used with the intermediate HCFC
are R-290 Propane and CO2, while new slightly flammable mixtures if they are used to replace CFCs. A mixture of
(A2L Class) chemical blends (i.e., HFO1234yf) are being con- at least 50 percent POE oil in mineral oil provides
sidered as future low GWP options. China is also evaluating excellent lubrication and will start the flushing procedure
an A2L alternative known as R-32 (a component of R-410A). if a switch to HFCs occurs.

Emerson Climate Technologies supports initiatives to apply Regardless of which HFC refrigerant an OEM is considering,
alternate refrigerants and is maintaining several R&D and care must be taken in the design and handling of systems
Engineering programs. To date, Emerson has been involved using these new refrigerants. Although they provide an
in selection and application of R-290 Propane compressors ozone-friendly solution to the industry, HFCs do present new
and condensing units which have been tested and applied in challenges.
UL 471 approved systems and prototype equipment designs
POE oils are an important requirement to ensure the reliabil-
requiring 150 grams or less of propane refrigerant.
ity of the compressor when used with HFCs; however, when
While propane refrigerant can be safely applied in selec- using POE oils, care must be taken to keep the oil dry, be-
tive applications by following specific industry guidelines cause of its hygroscopic characteristics. Proper precautions
and safety practices associated with flammable substances, must be taken in the manufacturing of the system and its
its use for commercial refrigeration in the United States is ultimate installation in the field, to prevent excess moisture
untested and is not yet EPA approved. from entering the system. A properly selected filter drier is
strongly recommended.

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 R-410A and R-407C are blends and, therefore, exhibit glide loaded). The desiccant must be tested to ensure com-
characteristics. The impact of glide must be considered both patibility with the new refrigerants and lubricants. Filter
in the system design and in servicing the system. Manufac- Driers from Emerson with a maximum of 30 percent
turers must understand and convey to the field the impact activated alumina, is designed for this specific purpose.
of leaks on non-azeotropic mixtures. Systems containing a These are available as hermetic filter driers and as re-
non-azeotropic refrigerant must be liquid charged to ensure placeable core-type products.
that the proper component mixtures are added.
Activated alumina is used in filter driers to remove acids
R-410A refrigerant has higher operating pressures and is from the system. POE oils exposed to excessive mois-
significantly different from R-22; therefore, R-410A systems ture may hydrolyze and produce acids; therefore, small
require special considerations to increase performance and amounts of alumina are used in filter driers recommend-
benefits of the refrigerant. Precautions must be taken to en- ed with POE oils. Molecular sieve filter driers are the best
sure that the heat exchangers and components being used for moisture absorption. With the hygroscopic POE oil
are designed to handle these higher pressures. R-410A has a lubricants, it is important that the filter drier have a high
much lower critical temperature (162.5 degrees Fahrenheit, moisture-absorbing capability. Oversized filter driers
compared to 204.8 degrees Fahrenheit for R-22) which must may become the standard.
be considered when using this refrigerant in units designed
For more information on the EK Filter Drier, please
for high ambient applications.
reference the Appendix.
Compressors
Pressure-control valves
As system manufacturers consider new equipment designs
Many new refrigerants have higher pressures; thus, all
to operate with HFC refrigerants, they are impacted by
pressure controls and pressure-operated valves may
many other changes occurring throughout the industry,
need to be reset for proper operation. Some of the
including several approved and proposed energy-efficiency
controls or valves may even need to be replaced. Pilot-
regulations. New ASHRAE standards mandate increases in
operated valves must be checked to be sure they are op-
efficiency levels across a variety of commercial equipment.
erating properly. The pilot-operated valve, in many cases,
New state and federal energy efficiency standards, along
requires a minimum pressure differential to open, and
with various incentive programs, drive OEMs to periodically
the valve will not operate properly unless this pressure
redesign many of their refrigeration products.
differential is correct. Valves or controls may also need
Over the past decade, Emerson has developed and released to be resized. Other system components will also be
a series of new scroll models to support the industrys need affected by the new refrigerants and lubricants. Consult
for chlorine-free systems. Many products are designed to your equipment manufacturer for guidelines and more
operate with R-404A, R-134a, R-407C or R-410A. There is a information.
wide variety of displacements available for most commercial
Viewing lens/moisture indicator
refrigeration applications.
Moisture indicators on refrigeration equipment provide
This shows the unique flexibility of scroll technology, with early warning to the long-term effects of water dam-
its inherent ability to adapt to higher-pressure refrigerants age and cut repair and maintenance costs. The proper
like R-410A and more standard-pressure refrigerants like moisture indicator must sense and report just how much
R-407C. Although the design challenge is serious, scrolls are water is in the systems circulating refrigerant. An indica-
more easily adapted to higher pressures and are more ef- tor in a sight glass changes color as the moisture content
ficient than other compressor technologies. Most reciprocat- reaches potentially damaging levels. Be sure to choose
ing designs will require extensive retooling and redesigning an indicator that is sensitive enough to alert operators
to handle the higher pressures. early on that moisture levels are rising, allowing correc-
System protection tive action to be taken before serious system damage
occurs.
Filter driers
Filter driers available are compatible with the new refriger- Moisture Indicators from Emerson (HMI, AMI and MIA)
ants and lubricants, as far as materials are concerned. The are able to read moisture levels far below industry
filter drier must be solid core or compacted bead (spring standards. These indicators start to change color at

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 two percent relative humidity (RH), which is a very dry and repair will reduce refrigerant consumption. All refriger-
indication. At three percent RH, the purple caution color ants should be recovered, reclaimed and recycled at the end
starts to appear. Many other indicators do not start chang- of the system life.
ing colors until about seven to eight percent RH; however,
Emerson Climate Technologies developed its ProAct
early detection is critical with HFC refrigerants and POE
Refrigerant Management service to help equipment owners
lubricants. POE oil can hold up to 20 times more moisture
maintain compliance with the EPAs Clean Air Act. The
than the mineral oil used by older refrigerants, which can
service organizes refrigerant-related inventory information
allow corrosive acids to build up and totally destroy a
quickly and easily, lowering refrigerant loss due to leaks or
system.
reduction of inventory. By providing all the proper docu-
Liquid-control device mentation, Emerson helps operators close the loop between
The liquid-control or metering device may be a capillary the technicians and the owners who have the responsibility
tube or a thermal expansion valve, and controls the flow for compliance. The service provides electronic access to
of refrigerant to the evaporator. The liquid-control device all refrigerant data for management, analysis and reporting
will not have to be changed when an R-502 system is purposes, alleviating many hassles and omissions associated
retrofit with R-402A, R-408A, R-404A or R-507. Although with paper tracking.
the capacity of the liquid-control device is almost the
same, the flow capacity of the liquid-control device in an
R-12 system may increase up to 30 percent with the new
refrigerants.
Responsible-use principles

When an R-12 system is retrofitted with either an HCFC

blend or R-134a, the liquid-control device may have to be
changed; however, a properly sized R-12 expansion valve
may work with the new refrigerant by adjusting the evapo-
rator superheat. The capillary tube can, in all probability,
be made to work with the new refrigerant by adjusting the
refrigerant charge. Although most systems can be retrofit-
ted without changing the liquid-control device, the valve
superheat or the system charge must be adjusted. Sys-
tems using expansion valves still require a solid column of
liquid refrigerant at the expansion-valve inlet.

Service considerations
Responsible-use principles
Emerson promotes the idea that responsible use is the key to
safety and environmental stewardship. As already discussed,
HFC refrigerants are the key to energy-efficient refrigera-
tion equipment. But other factors also figure into optimized
energy efficiency (see Figure 5). Prompt maintenance is im-
portant to keeping systems running not only longer, but also
more efficiently. Preventive maintenance routines can help
extend the life of equipment and increase energy efficiency.

Containment is one way to promote the responsible use of

refrigerant. Equipment manufacturers are working to design
systems that require less charge and have fewer leaks. There
can be no direct impact on the environment from any refrig-
erant that is in a well-designed system. Early leak detection
Figure 5

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 Responsible use of refrigerants10

Contain refrigerants in tight or closed systems and

containers, lowering atmospheric releases.

Encourage monitoring after installations to lower direct

refrigerant emissions and to maintain energy efficiency.

Train all personnel in proper refrigerant handling.

Comply with standards on refrigerant safety, proper

installation and maintenance (ASHRAE-15, ISO-5149
and European Standard EN378).

Design, select, install and operate to increase energy

efficiency.

Recover, recycle and reclaim refrigerants.

Continue to improve equipment energy efficiency when

cost effective.

Future direction
The next generation of refrigerants has been established. As
reviewed here, HFCs have low-ozone depletion advantages
over R-22; however, they still have some GWP.

It is important to recognize that this is an evolutionary pro-

cess. Todays HFCs are the next steps, but they are not the
last steps in the process. As technologies develop and new
applications and system designs continue to emerge, other
refrigerants may be developed and applied.

No HFC refrigerant can cause direct global warming if it is

properly contained. In the HVACR industry and in others, we
expect to see more emphasis on refrigerant recovery and leak
prevention in the coming years. As the concern over potential
climate change grows, Emerson Climate Technologies will
continue to work closely with refrigerant and system manu-
facturers, industry organizations and approved regulations to
improve compressor performance, efficiency and reliability,
while reducing environmental impact.

15

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 Glossary of terms
Azeotrope: A blend, when used in refrigeration cycles, that Total Equivalent Warming Impact (TEWI): TEWI inte-
does not change volumetric composition or saturation tem- grates the global warming impacts of equipments energy
perature appreciably as it evaporates (boils) or condenses at consumption and refrigerant emissions into one number,
constant pressure. usually expressed in terms of CO2 mass equivalents. The
calculated TEWI is based on estimates for (1) the quantity of
Blend: A refrigerant consisting of a mixture of two or more
energy consumed by the equipment over its lifetime; (2) the
different chemical compounds, often used individually as
mass of CO2 produced per unit of energy consumed; (3) the
refrigerants for other applications.
quantity of refrigerant released from the equipment over its
CFC refrigerant: A chlorofluorocarbon, containing chlorine, lifetime; and (4) the GWP of that refrigerant, expressed in
fluorine and carbon molecules (CFC R-12). terms of CO2 mass equivalent per unit mass of refrigerant.

Fractionation: A change in composition of a blend by pref- Zeotrope: A blend, when used in refrigeration cycles, that
erential evaporation of the more volatile component(s) or changes volumetric composition and saturation tempera-
condensation of the less volatile component(s). tures to varying extents as it evaporates (boils) or condenses
at constant pressure.
Glide: The difference between the starting and ending
temperatures of a phase-change process by a refrigerant (at
constant pressure) within a component of a refrigerating sys-
tem, exclusive of any subcooling or superheating. This term
is usually used in describing the condensation or evaporation
process.

GWP: Global Warming Potential. This is a measure of how

much a given mass of greenhouse gas is estimated to con-
tribute to global warming. It is a relative scale that compares
the gas in question to that of the same mass of carbon diox-
ide, whose GWP is 1.0.

Halogen-free refrigerant: A refrigerant that does not contain

halogen compounds, such as chlorine and fluorine (hydro-
carbons, ammonia). This is also commonly referred to as a
natural refrigerant, since it is found in nature.

HCFC refrigerant: A hydrochlorofluorocarbon, containing

hydrogen, chlorine, fluorine and carbon molecules (HCFC
R-22).

HFC refrigerant: A hydrofluorocarbon, containing hydrogen,

fluorine and carbon molecules (HFC R-134a).

HGWP: Halocarbon Global Warming Potential. This is similar

to GWP, but uses CFC-11 as the reference gas, where CFC-11
is equal to one (GWP for R-11 - 4,000).

Near-azeotrope: A zeotropic blend with a small temperature

and composition glide over the application range and no sig-
nificant effect on system performance, operation and safety.

Pure compound: A single compound, which does not

change composition when changing phase.

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 Appendix
For more information, the following materials are available
from Emerson on our online product information (OPI)
website, EmersonClimate.com:

Introduction to Refrigerant Mixtures, form number 92-81

Emerson Climate Technologies, Inc. Accepted Refrigerants/

Lubricants, form number 93-11

R-134a, Application Engineering Bulletin AE-1295

Application Guidelines for ZP**K*E Scroll Compressors for

R-410A, Application Engineering Bulletin AE-1301

Refrigerant Changeover Guidelines

(CFC) R-12 to (HCFC) R-401A 93-02

(CFC) R-12 to (HCFC) R-401B 93-03

(CFC) R-12 to (HFC) R-134a 93-04

(CFC) R-502 to (HCFC) R-402A/408A 93-05

(CFC) R-502 to (HFC) R-404A/R-507 94-15

(HCFC) R-22 to (HFC) R-407C 95-14

(HCFC) R-22 to (HFC) R-404A/R-507 2005CC-54

Access the EK Filter Drier and HMI white papers at

EmersonClimate.com.

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 References
1 According to Annika Nilsson in her book Ultraviolet
Reflections: Life Under A Thinning Ozone Layer, related
diseases may include skin cancer and cataract formation.
(Chichester: John Wiley & Sons Ltd., 1996)

2 www.epa.gov/climatechange/

3 http://www.eia.doe.gov/oiaf/ieo/emissions.html

4 http://ozone.unep.org/teap/Reports/TEAP_Reports/
teap-2010-progress-report-volume1-May2010.pdf

5 EPEEGlobal.org , EPEEs FAQ on the F-Gas Regulation

6 The scope of UL Standard 2182.1 contains test

procedures and methods to evaluate refrigerants and
mark their containers according to the extent of the
refrigerants flammability.

7 TLV minus TWA presents a standard for limiting worker

exposure to airborne contaminants. These standards
provide the maximum concentration in air at which it is
believed that a particular substance will not produce
adverse health effects with repeated daily exposure.
They are expressed either as parts per million (ppm) or
milligrams per cubic meter (mg/m3).

8 The Alliance for Responsible Atmospheric Policy,

http://www.arap.org/print/docs/responsible-use.html

9 ASERCOM statement, Carbon Dioxide (CO2) in

Refrigeration and Air-Conditioning Systems (RAC),
June 2006.

10 http://www.arap.org/responsible.html

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 About Emerson
Emerson (NYSE:EMR), based in St. Louis, Missouri (USA), is a
global leader in bringing technology and engineering together
to provide innovative solutions for customers in industrial,
commercial, and consumer markets through its network
power, process management, industrial automation, climate
technologies, and appliance and tools businesses. Sales in
fiscal 2009 were $20.9 billion. For more information, visit
www.Emerson.com.

About Emerson Climate Technologies

Emerson Climate Technologies, a business of Emerson, is
the worlds leading provider of heating, air conditioning and
refrigeration solutions for residential, industrial and commer-
cial applications. The group combines best-in-class technology
with proven engineering, design, distribution, educational
and monitoring services to provide customized, integrated
climate-control solutions for customers worldwide. The
innovative solutions of Emerson Climate Technologies, which
include industry-leading brands such as Copeland Scroll and
White-Rodgers, improve human comfort, safeguard food
and protect the environment. For more information, visit
EmersonClimate.com.

About Emerson Climate Technologies, Inc.

Emerson Climate Technologies, Inc., part of Emerson Climate
Technologies, is the worlds leading compressor manufacturer,
offering more than 10,000 compressor models in a full range of
technologies, including scroll, reciprocating and screw com-
pressor designs. A pioneer in the HVACR industry, the company
led the introduction of scroll technology to the marketplace.
Today more than 56 million Copeland Scroll compressors are
installed in residential and commercial air conditioning and
commercial refrigeration systems around the world. Emerson
Climate Technologies, Inc. is headquartered in Sidney, Ohio.
For more information, visit EmersonClimate.com.

19

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 2005ECT-162 R6 (6/11) Emerson is a trademark of Emerson Electric Co. 2011 Emerson Climate Technologies, Inc. All rights reserved. Printed in the USA.

2005ECT-162 R6.indd 20 6/22/2011 9:03:52 AM