Volume 7, Issue 1
Carrier Engineering Newsletter
New Refrigerants Impact Standards and Codes
The HVAC industry has gone through tremendous growth and a great number of changes since its inception
in the early 1900s. Not only have the hardware and technology evolved, but also the refrigerants used in
them. Most, if not all, of the changes have been driven by a need to improve the safety of the end users
either directly when technicians or other people come into contact with the equipment, or indirectly by affecting
the environment.
Manufacturers, design engineers and legislators have addressed various issues and continue to do so today.
Refrigerants transitioned rst from toxic, ammable and unstable substances to safer ones in the form of
CFCs and HCFCs. However, they were found to harm the environment by thinning the ozone layer and were
gradually banned by the United Nations Environment Programme (UNEP) Montreal Protocol. They were
replaced by HFCs, but HFCs were also found to have problems because they were greenhouse gases which
contributed to global warming. Refrigerants are now being regulated by an amended version of the Montreal
Protocol called the Kigali Amendment.
This newsletter will discuss the Montreal Protocol and its amended version, along with their implementation at
the US federal and state level, EPA’s strategy for implementation and new emerging refrigerants.
Refrigerants in the HVAC Industry
The rst attempts at using the vapor compression cycle in
refrigeration and air conditioning relied on available substances
at the time. These substances, while able to perform in the
system as required to produce cooling, had a number of
negative aspects including high toxicity, high ammability (or
both) and a chemical instability that resulted in the creation
of dangerous by-products when they were released and/
or burned. Several fatal accidents and severe injuries were
reported during the early days of HVAC system development.
It is important to note that today’s engineering know-how
needed to mitigate safety concerns has vastly improved.
CFC and HCFC Refrigerants: History
and Environmental Issues
Thomas Midgley, under the direction of Charles Kettering
at the General Motors Research Labs, is credited with
the invention of the refrigerants known as Chloro-Fluoro-
Carbons (CFCs) in 1928. CFCs and their close relatives,
the Hydro-Chloro-Fluoro-Carbons (HCFCs) were the safest
non-ammable and non-toxic alternatives to the refrigerants
that were then commonly used. CFCs and HCFCs, such
as CFC-11, CFC-12 and HCFC-22 for example, almost
completely replaced the common ammable and toxic
refrigerants used until then, such as Sulfur Dioxide (SO
2
),
Methyl Chloride (CH
3
Cl) and Ammonia (NH
3
). These new
refrigerants began to be manufactured by the DuPont
Company under license from General Motors under the trade
name Freon.
®
In 1932, the Carrier Engineering Corporation
released its rst unit using Freon as its refrigerant.
CFCs and HCFCs were safe from a ammability and toxicity
standpoint; however, in 1974, Frank Rowland and Mario
Molina suggested that due to the high stability and lifetime
of CFCs and HCFCs they were able to travel to the upper
layers of the atmosphere, in particular the stratosphere,
where they would decompose due to exposure to UV light
and release chlorine atoms. They also proposed a chemical
reaction whereby the free atoms of chlorine would eventually
break up ozone molecules (O
3
) thus reducing the amount
of ozone in the stratosphere. This reduction of ozone was
responsible for what was termed the ozone hole that was
forming over the earth’s South Pole (see Figure 1).
Stratospheric Ozone plays an important role in human
quality of life, since it lters a great portion of the UV-B rays
entering the atmosphere (see Figure 2) and prevents them
from reaching the surface. Excessive UV-B light is linked
with adverse health effects ranging from moderate like
sunburn to more severe such as eye cataracts, skin aging
and cancer, immune system suppression and macular
degeneration among others.
© Carrier Corporation 2019 www.carrier.com/commercial
Figure 1: A depiction of the ozone hole
Figure 2: Effect of the stratosphere’s ozone layer ltering UV-B light
2 www.carrier.com/commercial
(from https://www.climate.gov/sites/default/les/OzoneProject-Layers_lrg.png, an NOAA site)
UV-A
UV-B
S
t
r
a
t
o
s
p
h
e
r
e
ozone concentration (Dobson units)
100 220 500
s
a
t
e
l
l
i
t
e
s
w
a
t
h
ozone hole
ozone molecules
(trillions per cm
3
)
40 km
10 km
elevation
6,000 km
60
South America
Antarctica
(from https://www.climate.gov/sites/default/les/OzoneProject-Layers_lrg.png, an NOAA site)
3 www.carrier.com/commercial
The Montreal Protocol
After Rowland and Molina’s discovery, the United Nations
Environmental Programme (UNEP) organized a series
of meetings of scientists and representatives from around
the world that culminated in the signing of the “Montreal
Protocol on Substances that Deplete the Ozone Layer” in
1987. This treaty is considered as the most successful
international agreement ever sponsored by the United Nations.
It has been signed and ratied by every participating country
and is enforced worldwide. The agreement is responsible for
the gradual elimination of all CFCs and HCFCs everywhere
in the world. In the US, the only HCFC still in production
is R-123 but it will be phased out completely by the end of
2019. No new piece of equipment will be built in the US
using either CFCs or HCFCs starting in 2020. This is the
case also for every other developed country and many
developing countries (referred to as article 5 countries in
the treaty). The usage of CFC/HCFC even in developing
countries has been drastically reduced and will be completely
eliminated within a relatively short time. In practical terms, it
means that except for a very few cases, only the CFCs and
HCFCs already made or imported can be used for servicing
older units, but no new refrigerants of these types can be
manufactured.
Hydro-Fluoro-Carbon (HFC)
Refrigerants
Due to the ban on production of CFCs and HCFCs, the
industry began using HFCs. HFCs, such as R-134a and
R-410A for example, are also uorocarbons, but they do
not contain any chlorine atoms in their molecular make
up and thus do not destroy the ozone layer. HFCs are
considered 3rd generation refrigerants and were intended
as the solution tor eplace all applications of CFCs and
HCFCs in new equipment.
Natural Refrigerants
Another group of refrigerants, while not new, is enjoying
renewed interest in the industry: natural refrigerants. The
group is made up of refrigerants that are not synthetized as
uorochemicals are, but rather extracted or rened from
naturally occurring sources. The most common ones are
ammonia (NH
3
), propane (C
3
H
5
) and carbon dioxide (CO
2
).
The main advantage to using them is that they pose a
minimal risk to the environment if they leak from a system:
they cause no ozone depletion and have very low global
warming potential. As a disadvantage, their use may require
special mitigation for high ammability, toxicity or high
operating pressures.
Ammonia (R-717): Typically used in large industrial or
commercial refrigeration settings, but can also be found in
some chiller applications and even some small appliances.
It is incompatiblewith copper and its initial cost is high. It is
ammable and toxic. It has good capacity and efciency and
a strong smell detected at very low ppm levels. The use of
ammonia has been growing in selected applications.
Propane (R-290): A hydrocarbon (HC) that can be used in a
wide variety of refrigeration and air conditioning applications,
much like R-22. One of its biggest downsides is its high
ammability, rated A3 by ASHRAE. This limits its maximum
charge to 150 grams in the US. It is low cost.
Carbon Dioxide (R-744): This refrigerant is used in very
low temperature cascade systems or as a secondary loop
uidwhere it is seeing an increase in use, as in supermarket
refrigeration. It suffers rapid performance degradation with
increased condensing temperatures but recent technology
advances, such as those seen in Carrier’s CO
2
OLtec
®
refrigeration products, help overcome this issue.
Global Warming and
the Greenhouse Effect
The Intergovernmental Panel on Climate Change (IPCC), an
intergovernmental body of the United Nations, published a
report in 1995 indicating that man-made greenhouse gases
(GHG) were responsible for global warming. Refrigerants, in
particular HFCs, were deemed as GHGs and contributors to
the greenhouse effect warming up the earth (see Figure 3).
The earth’s surface is warmed by sunlight that comes through
the atmosphere. At the same time, the earth radiates back
to space some heat in the form of infrared radiation (IR).
A ne balance between the heat coming in and the heat
radiated back maintains a constant average earth temperature.
When excessive amounts of greenhouse gases are present,
they will trap a larger portion of the heat which will no longer
be radiated back out to space. This enhanced greenhouse
effect causes the earth to warm up and raises its average
temperature. It is estimated that even seemingly small
temperature increases (less than 2°F) could have a devastating
effect on climate. Scientists attribute some of the climate
changes we seem to be experiencing to an increase in
the earth temperature.
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Figure 3: How the greenhouse effect works
The greenhouse effect
Infrared
radiation (IR)
is given off by
the Earth...
... most escapes to
outer space, allowing the
Earth to cool...
... but some infrared
radiation is trapped by gases in
the air (including CO
2
),
keeping the Earth warm
enough to sustain life.
ENHANCED
GREENHOUSE EFFECT
2
3
4
Sunlight
passes through
the atmosphere
and warms the
earth.
Increasing levels of CO
2
increase the amount of
heat retained, causing the
atmosphere and Earth’s
surface to heat up.
5
Total Equivalent Warming Impact (TEWI)
It is difcult to evaluate the real effect of a HVAC system to the
environment unless a metric like TEWI is used. Other metrics
such as Life Cycle Climate Performance (LCCP) can be used as
well, but TEWI is the most common one used in the US. TEWI
measures the impact of direct emissions (refrigerant leaking
from a system) and indirect emissions (caused by generation of
electricity at power plants to run a system through its lifetime).
The lower the TEWI, the lower impact on the environment.
Reducing the GWP of a refrigerant works on reducing the
direct emissions portion, while improving a system’s efciency
works on reducing the indirect emissions portion. It is estimated,
as a rule of thumb, that for tight systems such as chillers,
direct emissions account for about 2% of the total, while
indirect emissions account for up to 98%. It is easy to see that
while both portions need to be reduced, the key is to improve
system efciency to gain the most benet from a system
change or redesign. Using a lower GWP refrigerant that will
result in a less efcient system is not sensible and is counter
to the goal of improving the environment. Sensible regulations
will deal with both direct and indirect portions of TEWI.
The Kyoto Protocol
Trying to capitalize on the success of the Montreal Protocol, the
UNEP sponsored a series of meetings of interested parties that
concluded with the drafting of the Kyoto Protocol in December,
1997. The Kyoto Protocol’s goal was to reduce the emission
of any GHGs, including HFCs, to reduce their effect on global
warming. The Kyoto Protocol was signed and ratied by a
number of countries (US did not ratify it), but it was nowhere
near the success that the Montreal Protocol had been, and while
it went into effect, it did not really play a role worldwide since it
was not truly enforced. The Kyoto Protocol’s complexity made
it difcult to verify compliance, to follow, and to enforce.
(from the CO2CRC website at http://www.co2crc.com.au/gallery/general-ccs/)
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Figure 4: Kigali amendment phase down schedule for HFCs by country group.
The Kigali Amendment to the
Montreal Protocol
In spite of the failure of the Kyoto Protocol, the world
community was still interested in curbing GHG emissions.
After a great many discussions, the world parties decided to
amend the original Montreal Protocol to also include GHG
reductions. The agreement, signed in Kigali, the capital of
Rwanda, in October of 2016 set very specic reduction levels
for HFCs measured in carbon dioxide equivalents (CO
2eq
).
It only regulated HFCs and did not eliminate any specic
refrigerants, unlike the original Montreal Protocol that resulted
in the elimination of CFCs and HCFCs. In fact, the new
amendment did not alter the previously set phase-out of
chlorinated refrigerants, which continues to be on track.
The reductions are gradual over approximately 30 years
and differ for countries depending on their development
level. (Developed countries would see the faster reductions,
followed by developing countries, group 1 and group 2).
European specic rules that apply to uorinated gases,
known as the F-Gas rules are also shown for reference as
well. (See Figure 4.)
Note that no specic refrigerant is singled out for elimination,
and in fact HFCs are only regulated but not altogether
eliminated. Reductions are based on total carbon dioxide
equivalents (CO
2eq
), which is calculated based on weight of
refrigerant times its GWP (CO
2eq
= wt of refrigerant x GWP).
The treaty needed to be ratied by a minimum of 20 countries
to go into effect, and that threshold has already been met.
The Kigali amendment took effect on January 1st, 2019.
For the particular case of the US, it needs to be ratied by
the Senate with a 2/3 majority; however, it has not been
presented for a vote yet. There is no indication as to if or
when this may happen.
0
10
20
30
40
50
60
70
80
90
100
110
2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 2032 2034 2036 2038 2040 2042 2044 2046 2048 2050
% of Base YearCO
2e
Level
Year
Developed A2 Developing A5 Group 1 Developing A5 Group 2 F-Gas
Based on the Kigali ammendment and F Gas Regulaon
90%
%
90%
60%
70%
80%
70%
20%
50%
15%
30%
20%
100%
European
F-gas
Developed A2
eg. USA, EU,
Japan…
Developing A5-G1
eg. Mexico, China...
Developing A5-G2
eg. India, Kuwait
UAE…
F-gas
% of Base Year CO
2e
Level
Based on the Kigali Amendment and F-gas Regulaon
93%
63%
45%
31%
24%
21%
(from the CO2CRC website at http://www.co2crc.com.au/gallery/general-ccs/)
6 www.carrier.com/commercial
The US EPA SNAP and the Courts
International treaties like the Kigali amendment, even if
approved by the US representatives, are not US law.
Treaties need to rst be ratied by the Senate and then
codied into laws before they can be enforced. The original
portion of the Montreal Protocol was incorporated into the
Clean Air Act (CAA) and enforced by the EPA. However, the
Kigali Amendment has not been ratied or made into a law,
therefore, regardless of whether the treaty has gone into
force or not, it is not binding in the US.
The EPA has a program in place called the Signicant
New Alternatives Policy (SNAP) created under the CAA
and used to regulate the use of refrigerants from a safety
perspective (not performance). SNAP allows the use of
specic refrigerants only in specic types of equipment.
Only matched pairs are legal to use. For example, the use
of R-410A in residential A/C is a SNAP approved match;
however, R-410A in residential refrigeration is not and it
would be illegal to use it that way. For a refrigerant to be
used in a specic application, a petition has to be made to
the EPA, including required supporting information, and the
EPA rules whether the match is approved.
In 2014, the EPA began unilaterally delisting refrigerant/
equipment applications. The agency was trying to take a
proactive role in the regulation of HFCs to reduce their use
in the US. A summary of the changes to the program is
contained in SNAP Rules 20 and 21. One particular case of
the many changes was the delisting of R-134a and R-410A
in chiller applications after 2024, but it did not affect the use
of R-410A in residential A/C at all.
Two large refrigerant manufacturers, Mexichem and Arkema,
sued the EPA in federal court, claiming that it had exceeded
its authority granted by the CAA. The claim was that the CAA
could only be used to regulate ozone depleting substances
but its mandate did not extend to regulation due to global
warming concerns. The EPA lost the original ruling and a
subsequent appeal. The end result is that Rule 20 has been
vacated and Rule 21 is on hold in the Washington DC circuit
courts pending a nal ruling.
The California Air Resources Board (CARB) supported the
EPA during its court battles and pledged to follow the Kigali
Amendment reductions and to adopt SNAP Rules 20 and
21 regardless of the federal court rulings. The California
legislature has passed bill SB1013 called the California
Cooling Act. It adopts all of the provisions of the SNAP rules
and sets additional limits for stationary refrigeration and
A/C equipment based on charge size and refrigerant global
warming potential (GWP) values. Other states such as New
York, Maryland and Connecticut have made similar supporting
statements, but have not issued any specic rules yet.
A New Generation of Refrigerants: HFOs
In order to cover the gap that a reduction in the availability
of HFCs would create, the HVAC industry has developed a
new generation of refrigerants called Hydro-Fluoro-Olens
(HFO), such as R-1233zd(E) and R-1234ze(E) for example.
They are very similar to HFC refrigerants in their molecular
make-up and share the fact that they also have no Chlorine
atoms that could cause ozone depletion. However, they have
a big difference with HFCs: HFOs have a double bond that
makes the molecule more unstable and drastically reduces
its atmospheric lifetime. It may seem counterintuitive to
use refrigerants that are more unstable; however, that is
not an issue when they are in containment in storage tanks
or in the system itself. The instability occurs only when
the refrigerant is exposed to sunlight if it leaks. Having a
lifetime that is measured in days instead of years means
that the potential effects of these refrigerants as greenhouse
gases is drastically reduced by orders of magnitude. Some
of the GWP values of these new refrigerants are referred to
as “ultra-low” and their GWP in many cases is in the single
digits. However, other HFO refrigerant GWP values may be
much higher.
Many new low GWP refrigerants now coming into the
market are either pure HFOs or blends of HFOs and HFCs.
By mixing selective refrigerants in a blend, it is possible to
achieve certain properties that a single refrigerant could not
achieve on its own. It is also important to note that by having
HFCs as components of these long term refrigerant solutions
shows HFCs are NOT being eliminated and are part of the
global future solution to global warming.
Refrigerant Safety Classications
In order to discuss some of the more notable low GWP
refrigerants in the market, we will review safety classications
as set by ASHRAE’s Standard 34. (See Figure 5.)
The standard evaluates each refrigerant’s ammability
and toxicity and gives it a class referenced as a letter and
number combination. For toxicity it has two classes A: lower
toxicity and B: higher toxicity. The toxicity class is based on
the refrigerant’s Occupational Exposure Limit (OEL) and it
assigns refrigerants with an OEL of 400 ppm or greater
an A and for less than 400 ppm a B. For ammability, the
standard uses data based on the burning velocity (BV),
heat of combustion (HOC) and lower ammability limits
(LFL) of each refrigerant. A class of 1 would be the lowest
ammability and a 3 would be the highest. In recent years,
the second class was broken into 2L and 2. A rating of
2L indicates that while the refrigerant is still considered
ammable, its ammability is much lower than that of a
class 2 or 3.
7 www.carrier.com/commercial
Figure 5: ASHRAE Standard 34 safety classes
Increase Toxicity
Increase Flammability
New Replacement Refrigerants in
the Market
Table 1 illustrates some of the new low GWP refrigerants
emerging in the HVAC market. The list is not all inclusive
but just a sample of the most signicant players with special
emphasis on Carrier systems. Table 1 below shows the
composition of those low GWP refrigerants that are blends.
In addition to the refrigerants above, we will also cover
the single component HFOs R-1234yf, R-1234ze(E) and
R-1233zd(E).
Table 1: Composition in weight percentages of
some low GWP refrigerants
R-454B R-513A R-514A R-1233zd(E) R-1234yf R-1234ze(E)
No No No Yes Yes Yes
R-134a 44%
R-32 68.9%
R-1234yf 31.1% 56% 100%
R-1130 25.3%
R-1336mzz 74.7%
GWP 466631 3.71 1.34 40.97
ASHRAE 34
Rating
A2L A1 B2 A1 A2LA2L
Pure Fluid?
Low Pressure Low GWP R-11
Refrigerant Replacements
R-1233zd(E): A low pressure single component HFO
replacement for R-11 in new system designs. It cannot be
used to retrot R-11 or R-123 machines. It has an ultra-low
GWP of 1.34. It is neither ammable nor toxic so it carries an
A1 ASHRAE safety rating. Being a single component it has no
glide. Another advantage is that it has high efciency. Carrier,
as well as other chiller manufacturers, have announced new
chiller designs with R-1233zd(E). R-1233zd(E) is US EPA
SNAP approved for use in low pressure chillers.
R-514A: A low pressure zeotropic blend (having a range of
boiling points for a given pressure as opposed to an azeotropic
blend that has a unique boiling point) intended to be used as
a replacement for R-123. R-514A can be used to retrot older
R-123 units or in new systems. The refrigerant is non-ammable
but is toxic, although it has lower toxicity than R-123. It is rated
as B1 by ASHRAE. Carrier does not use it, or have plans to
use it, in any of its units. R-514A is SNAP approved for use in
low pressure chillers.
Medium Pressure Low GWP R-134a
Refrigerant Replacements
R-513A: A medium pressure zeotropic blend of a HFO and a
HFC. It has a low GWP of 631, just under 50% that of R-134a
at 1430. It is mostly intended as a retrot refrigerant that can
be used with relatively minor modications in R-134a units.
R-134a units retrotted to R-513A can experience a drop in
capacity and efciency, but the losses can be lessened by
optimizing the unit and its controls to the new refrigerant. Its
safety classication by ASHRAE is A1 (nonammable and
nontoxic) and it is SNAP approved for use in chillers. Carrier
has approved its use in several of its R-134a units. Please
note that although Carrier has approved the use of R-513A in
some of its units, it is not recommending retrots.
R-1234ze(E): A medium pressure, single component HFO
intended as an OEM replacement for R-134a in several of its
applications, in particular, chillers. It has an ultra-low GWP of
0.97. With an ASHRAE safety classication A2L, it is non-toxic
but slightly ammable. Due to building codes, its use is not
allowed in the US; however, Carrier’s European division has
commercial units based on this refrigerant. The refrigerant is
also a component in certain low GWP blends as well. It has a
lower volumetric capacity than R-134a, so a higher mass ow
rate is required; therefore, it cannot be used as a direct retrot
for R-134a unless modications to the unit are made.
R-1234yf: A single component, medium pressure HFO
replacement for R-134a in certain applications. The most
signicant use of R-1234yf is in the mobile A/C market, and
several new car models already use it. R-1234yf is NOT SNAP
approved for use in any chiller application; however, it is used
as a component in low GWP blends such as R-513A.
8 www.carrier.com/commercial
High Pressure Low GWP R-410A
Refrigerant Replacements
Replacing R-410A is one of the toughest challenges for
the industry so far. There does not seem to be any suitable
A1 available replacements for R-410A that matches its
properties and performance. Most of the new candidates
seem to be either ammable, exhibit lower performance or
have compatibility issues. There are no Carrier approved
replacements for R-410A in chillers; however, R-454B
(Puron Advance™) has been announced by Carrier as a
replacement refrigerant for residential and unitary air
conditioning applications.
R-454B: A near azeotropic, low GWP blend of an HFC and
an HFO medium pressure replacement for R-410A. This
refrigerant is not approved for use in any Carrier chillers and
it is not SNAP approved for that application. R-454B has
been approved by Carrier as a replacement for R-410A in
new units but is not approved for R-410A retrots. (See full
announcement posted on the Carrier website). It is marketed
as Puron Advance.™ It has an ASHRAE safety classication
of A2L, so it is nontoxic but slightly ammable. New units
using R-454B are not expected to be commercially available
until the 2023 to 2024 timeframe.
Standards and Building Codes
Standards are established to harmonize requirements and
guidelines when working with HVAC equipment. Refrigerant,
Equipment and Applications standards provide best methods
to use and handle refrigerants, design and install new
equipment or modify existing installations. By following the
standards, engineers are given the tools needed to install,
operate, maintain and modify HVAC systems in the safest
and most economical way. Standards also align information
across installations, trades and sometimes even geographies.
ASHRAE and UL are responsible for most of the standards
used in the US. CEN (European Committee for Standard-
ization) is responsible for EN (European Norms) standards
in Europe. ISO works in conjunction with the international
standard writing bodies and tries to develop a harmonized
standard. There are also many other standard writing
organizations around the world, such as GB for China.
Due to the changes in regulations and treaties like the
Kigali Amendment, many of these standards are now
being updated to reect new technologies and products:
ASHRAE Standard 34: A safety standard which has been
modied to include a new ammability subclass: 2L (see
Figure 5). This class is being used for refrigerants that are
still considered ammable and part of class 2, but are at the
lowest risk levels. Standard 34 has also been updated to
assign safety classications to a large number of new
refrigerants considered low GWP that are coming to the
market. While this standard is in continuous maintenance
assigning new safety classications to new refrigerants, its
main body is considered complete.
ASHRAE Standard 15: Application standard that has
recently been completed and modied to deal with the new
ammability subclass, among other changes. While it is
considered complete, it will continue to undergo reviews to
improve it.
UL 60335-2-40: An electrical safety compliance standard
still being modied to incorporate changes due to the new
refrigerants in the market, the new safety ammability
subclass and charge limits for ammable refrigerants.
Work on this standard is not complete.
Update to the Building Codes Revision Process:
Standards are the technical basis upon which codes are
built. Once all the standards are completed, they are taken
up by the groups that write the building codes. They are
responsible for revising and modifying the International
Building Code (IBC), International Fire Code (IFC) and
International Mechanical Code (IMC) that in essence put
the standards into a practical, organized, consistent,
veriable and enforceable set of rules. These rules are
used by engineers, architects, installers and others to design
and install the safest and most cost efcient systems, and by
inspectors that verify compliance. It is important to note that
while some localities (states, counties, cities, etc.) may just
use the IBC, IFC and IMC codes as is, others may modify
them in order to make them stricter or to adapt to a particular
geographical condition or insurance requirement. Building
codes are on a 3-year cycle, which means that for codes to
allow for the use of A2L refrigerants in places where they are
not allowed now (e.g. chillers in occupied buildings), all the
standards need to be nalized by no later than 2021. The
consensus seems to be that we are on track to complete all
the necessary changes in time.
SUMMARY
The HVAC industry has undergone many changes,
especially in the area of refrigerants. The discovery of the
ozone hole led to the gradual banning of all CFCs and
HCFCs per the original Montreal Protocol. The phase-out
is on schedule, and for the US, 2019 is the last year any
unit can be shipped with an HCFC (such as R-123).
New regulations, inspired by the modied Montreal
Protocol and its Kigali Amendment, are focusing on global
warming. There is still a lot of uncertainty as to what the
nal regulatory outcome will be, but it is expected that use
of HFC refrigerants in new chiller equipment will slowly
diminish over time as new HFO and HFO/HFC blends
emerge. It is important to note that new regulations do
not phase out any HFC refrigerants (such as R-134a or
R-410A). HFCs can, and will, be used well into the future
for many different applications. Further complicating the
situation, states in the US are not in agreement with
federal policies and may enact their own set of rules
(California has already done so).
In the case of chillers, it appears that R-1233zd(E) is the
best choice for low pressure systems, with Carrier and
some other OEMs already announcing commercial units for
sale. Alternatives for R-134a, such as R-513A, are available
but come with the potential for lower performance which
can hurt the overall TEWI rating. Due to this, retrots are
not recommended at this time. Replacing R-410A is the
most challenging as many new candidates are ammable,
exhibit lower performance or have compatibility issues.
Their use may need changes in building codes due to
ammability. Research in this area is still ongoing, with
a number of refrigerants being actively evaluated, but
R-454B looks promising.
R-134a and R-410A systems still provide some of the
best overall options from a perspective of environmental
protection and energy efciency. They should be considered
and evaluated when new units are needed.
Finally, work on standards and building codes is progressing
rapidly with the goal of being completed by the end of 2023
when units with new refrigerants may be required by state
and/or federal regulations.
The HVAC industry continues to evolve and Carrier is
always ready for the future.
9 www.carrier.com/commercial
