Low GWP Alternatives
This guidance is for organisations affected by the 2014 EU F-Gas Regulation (517/2014). The F-Gas
Regulation creates controls on the use and emission of fluorinated greenhouse gases (F-Gases)
including HFCs, PFCs and SF6. The 2014 EU F-Gas Regulation replaces the 2006 Regulation,
strengthening all of the 2006 requirements and introducing a number of important new measures.
The 2014 F-Gas Regulation includes a significant phase down in the supply of HFCs to the EU market
– by 2030 there will be a 79% cut in supply
. The phase down will force end-users of HFCs to find alternatives that have a much lower global warming impact. This Information Sheet provides guidance for HFC users about the use of low global warming potential (GWP) alternatives. We provide general background to the selection of low GWP alternatives and specific details for different market sectors.
GWPs of HFCs in current use
The global warming potential (GWP) of a fluid is a measure of its contribution to global warming
compared to the most common greenhouse gas, carbon dioxide (CO2). The GWP values used in the
2014 F-Gas Regulation are based on the UN IPCC’s 4th Assessment Report, as listed in Annex I of the
Regulation. The GWP of CO2 is 1. The GWPs of common HFCs in current use are between 750 and
The HFC phase down is based on “GWP-weighted” amounts of HFCs. It is interesting to note that the
average GWP of all the HFCs used in 2012 was approximately 2,000. To achieve a 79% reduction in
GWP-weighted sales over the next 15 years, the average GWP of HFCs and their alternatives sold in
2030 will need to fall to around 4002
This will be achieved by:
a) Using non-HFC alternatives with ultra-low GWPs that are not part of the HFC phase down
b) Using new HFC products with much lower GWPs than those currently used.
HFC 404A: 3,922: Supermarket and industrial refrigeration
HFC 227ea: 3,220: Fire protection systems
HFC 410A: 2,088: Air-conditioning
HFC 407C: 1,774: Air-conditioning
HFC 134a: 1,430: Refrigeration, air-conditioning, foams, aerosols
HFC 365mfc: 794: Foams
Why are HFCs so widely used?
It is useful to note that HFCs are in widespread use because they have a number of properties that are
well suited to their end use applications. In particular, the fact that the commonly used HFCs are nonflammable
and non-toxic makes them easy to use.
It is important to recognise that the physical properties required vary because the range of end uses
is so broad. HFCs are used for many applications including refrigerants, foam blowing agents, aerosol
propellants and solvents. HFCs are well suited to this wide range of end user requirements as they
form a large family of fluids providing a wide range of different physical properties.
Fluid properties that affect selection of alternatives
The process of selecting an alternative fluid is complex and must take into account many different
properties. Some of the most important are:
a) Basic suitability to the relevant application (e.g. as a refrigerant, foam blowing agent etc.)
b) Impact on energy efficiency (especially for refrigerants and foam blowing agents)
e) Suitable operating pressure
f) Good materials compatibility (e.g. with metals, flexible seals, lubricants)
g) Reasonable cost.
As a general rule, HFCs used in current applications have a better set of properties than the available
alternatives – if the alternatives were better, then market forces would lead to their adoption. This is
illustrated by the fact that in some markets there has already been widespread voluntary uptake of
low-GWP alternatives where there has been a good commercial driver (e.g. hydrocarbons used in
domestic refrigerators, in aerosols for personal / domestic products and in certain types of
The HFC phase down will force a move to lower GWP alternatives. In many cases end users will need
to adapt to the use a fluid with slightly less favourable properties (e.g. use of a flammable fluid in place
of a non-flammable HFC). It is expected that, for particular uses, these difficulties will be overcome
as the fluid and equipment suppliers develop new products and codes for their safe operation. It is
likely that HFCs will get more expensive as the phase down restricts supply – this will create a better
commercial case to use alternatives, which currently may be more expensive to use.
Overview of Available Alternatives
It is worth noting that there are no alternatives currently being proposed with GWPs in the 10 to 140 range.
Ideally there should be maximum use of ultra-low GWP alternatives. There are a number of such fluids
available, although they all have safety and practicality issues. Ammonia, hydrocarbons (HCs) and CO2 have all been available for many years and are increasing in market share
in some applications.
HFOs (hydro-fluoro-olefins) are newly introduced fluids. Like HFCs they consist of carbon, fluorine and
hydrogen. A key difference is that they are unsaturated molecules – this means they have a double
bond between 2 carbon atoms. This gives them much lower GWPs than HFCs. However, most HFOs
have a small degree of flammability (referred to as “mildly flammable”), which makes them more
difficult to use than non-flammable HFCs. HFOs were first introduced for commercial use in around
2013 and there should be growing commercial availability from 2015.
A number of HFO/HFC blends are also under development. These are being formulated to provide
properties similar to current HFCs but with much lower GWPs. Mildly flammable HFO/HFC blends are
available with GWPs between around 140 and 700. To create non-flammable blends the GWPs are
higher, in the 600 to 1,400 range.
Ammonia: GWP0: Toxic and mildly flammable. Good option for large refrigeration applications
Hydrocarbons(HCs): GWP3 to 5: Highly flammable. Already used in aerosols, foams and small refrigeration systems.
CO2: GWP1: High operating pressure (for refrigeration): Already used in foam, fire protection and
HFOs: GWP1 to 9: New family of fluids. Most are mildly flammable.
HFC32: GWP675: Mildly flammable. Already being used for small air-conditioning systems.
HFO / HFC blends: GWP140 to 700: Mildly flammable. Various blends being proposed, but not fully commercialised yet.
HFO / HFC blends: GWP600 to 1,400: Non-flammable blends under development.
HFC 134a GWP1,430, HFC 407F GWP1,825, HFC 407A GWP2,107: Various HFCs in this GWP band will be useful short-term alternatives for very high GWP refrigerants such as HFC 404A – but in long term other alternatives will be needed.
Energy Efficiency is Crucial
When purchasing a new refrigeration, air-conditioning or heat pump system or when selecting a
suitable insulation foam it is important to maximise the energy efficiency. During the life cycle of
products of this sort it is the energy related CO2 emissions that dominate the overall greenhouse gas
emissions. It is counter-productive, from an environmental perspective, to use an ultra-low GWP
alternative but have to sacrifice energy efficiency. Always try to ensure that the low GWP alternative
that you select has equal (or preferably better) energy efficiency to the best high GWP option available
on the market.
Domestic Refrigeration – Low GWP Alternatives
After the phase out of CFCs in 1995 the domestic refrigeration market used HFC 134a as the main
alternative. However, from around 2000, hydrocarbons (HCs) were introduced and they are currently
the dominant refrigerant in this market. With refrigerant charges of under 0.15 kg the flammability
issues related to use of HCs have been overcome.
A small proportion of large refrigerators and freezers, particularly imported models, still use HFC 134a.
Under the 2014 F-Gas Regulation the use of any HFC with a GWP above 150 will be banned in this
market from January 2015.
Two alternatives are likely to be used:
a) Where possible, HCs will be used as these are well established in this market.
b) If flammability issues are especially important (e.g. a very large refrigerator with a charge
above 0.15 kg) then HFOs may be adopted.
Commercial Refrigeration – Low GWP Alternatives
The commercial refrigeration market makes use of 3 main types of system:
a) Small hermetically sealed systems (refrigerant charge typically 0.1 to 0.5 kg)
b) Condensing units (split systems with refrigerant charge typically 2 to 10 kg)
c) Central pack systems (large systems with refrigerant charge typically 50 to 150 kg)
It is also important to note that this market uses 2 distinct temperature levels for chilled and for frozen
products – that can affect the best refrigerant selection.
Small Hermetic Systems
Where the refrigerant charge is below 0.15 kg, HCs can be used – a number of commercial hermetic
units are already available with propane refrigerant.
CO2 is an option for larger systems – it is already in use for some large bottle coolers.
It is likely that HFOs, including both 1234yf and 1234ze, will be used for commercial hermetic systems.
The mild flammability of these refrigerants should not be an issue for such small systems.
Commercial Condensing Units
Currently many condensing units use HFC 404A – which has a very high GWP of 3,922. Use of HFC
404A in all new equipment should be avoided with immediate effect.
As an interim, refrigerants such as HFC 407A or HFC 407F can be used in new condensing units for
frozen applications. These have a GWP that is only half that of HFC 404A. For chilled foods, HFC 134a
offers an even lower GWP.
Various much lower GWP options are becoming available from 2014. CO2 has been trialled in some
convenience stores. HCs will not be suitable as the flammability risk is too high for such large
Some of the new HFO / HFC blends can be considered. For chill applications R450A has a GWP of 601
and is non-flammable. If a mildly flammable refrigerant is acceptable, then HFO 1234yf or 1234ze can
be considered – these have GWPs below 10. For frozen food applications the non-flammable options
(e.g. R448A and R449A) have GWPs just under 1400. Mildly flammable blends such as Opteon XL40
and Solstice L40 are under development – these have GWPs of under 300.
Commercial Central Pack Systems
Most central pack systems use HFC 404A – which has a very high GWP of 3,922. Use of HFC 404A in
all new equipment should be avoided with immediate effect.
As an interim, refrigerants such as HFC 407A, HFC 407F, HFC 448A and HFC 449A can be used in new
pack systems for frozen applications. These have a GWP that is only half that of HFC 404A. For chilled
foods, HFC 134a offers an even lower GWP. However, there have already been significant
developments of much lower GWP alternatives, so these interim options can be avoided.
There are now several hundred supermarket pack systems operating with CO2. This is likely to become
a widely used refrigerant for all new central pack systems.
Some supermarkets are using small hermetic HC systems together with a chilled water system to
remove the condenser heat from each hermetic system. As the HC charge of each system can be very
small, the flammability risk is manageable.
It is likely that mildly flammable HFOs and HFO/HFC blends will also be considered for central pack
systems in the future.
Industrial Refrigeration – Low GWP Alternatives
The industrial refrigeration market is especially broad in scope, both in terms of system size and the
temperature level required. Three main types of equipment are used:
a) Large central systems serving several major loads e.g. used for blast freezing and large cold
stores. These systems often contain several tonnes of refrigerant.
b) Large chiller systems, cooling a secondary refrigerant such as glycol which is distributed to a
number of loads. Chillers often contain several hundred kg of refrigerant.
c) Smaller dedicated plants, each serving a single cooling load. These usually contain less than
100 kg of refrigerant.
The majority of industrial plants operate at similar temperature levels to commercial systems e.g. to
produce chilled or frozen food products. However, some industrial plants operate at much lower
temperatures than commercial systems e.g. well below -100oC.
Large Central Industrial Systems
Large central systems are well suited to ultra-low GWP systems. Ammonia is already widely used,
especially in food manufacturing, breweries and cold stores. All purchasers of large industrial plant
with an evaporating temperature above -500C should strongly consider using ammonia.
CO2 is also an interesting candidate for industrial systems, especially if heat recovery (e.g. for
producing process hot water) is a useful secondary objective.
Large central systems below -50oC are more problematic as ammonia and CO2 are unsuitable below
this temperature. It may be necessary to use an HFC in cascade with ammonia. The very low
temperatures required to produce liquid oxygen and liquid nitrogen (around -200oC) are created using
a very sophisticated form of air cycle refrigeration system.
Large Industrial Chiller Systems
Industrial chillers are also well suited to ultra-low GWP refrigerants. Ammonia is already widely used
(e.g. in breweries). New HFO refrigerants including HFO 1234ze and HFO 1233zd will become available
for large centrifugal chillers.
Small Dedicated Industrial Systems
These will be the most problematic type of equipment to find a suitable ultra-low GWP refrigerant.
Most existing plants in this category use HFCs such as HFC 404A, HFC 407C and HFC 134a.
It is worth considering ammonia, although many plants in this category are too small to make
ammonia cost effective. CO2 is also an important new option – relatively small CO2 plants are being
used in supermarkets and this technology may be transferable to small industrial systems.
As with commercial refrigeration systems, a key question is whether mild flammability is an issue. In
many industrial plants flammability can be managed, by careful compliance with well-established safe
codes of practice for design, maintenance and operation.
If mild flammability is acceptable then a range of pure HFO or HFO / HFC blends may be applicable.
HFOs 1234yf and 1234ze have properties similar to HFC 134a and have ultra-low GWP (4 and 7
respectively). These could be suitable for medium temperature and high temperature systems (e.g.
with evaporating temperatures above -10oC. Some new mildly flammable HFO / HFC blends are being
developed with properties similar to HFC 404A, with GWPs below 300 (e.g. XL40 and L40). These could
be suitable for lower temperature applications, down to around -50oC.
If a non-flammable refrigerant is required then CO2 is the only ultra-low GWP option. For medium and
high temperature applications HFO/HFC blends such as R450A and R513A may be suitable – these
have GWPs around 600. For lower temperatures it may be necessary to use blends such as R448A and
R449A – these have GWPs around 1400.
As discussed above for large central systems, very low temperature plants (below -50oC) are more
difficult and may require use of an HFC.
Transport Refrigeration – Low GWP Alternatives
Most refrigerated trucks and trailers and refrigerated containers use HFC 404A. They require a nonflammable refrigerant (e.g. due to rules travelling through certain tunnels) and the flexibility to
provide chilled or frozen temperature levels. There are rigorous testing rules (through ATP Regulations) that make development of systems with new refrigerants more difficult in this sector than some other refrigeration sectors.
CO2 is being trialed by some equipment manufacturers and may become the dominant replacement
for HFC 404A. Currently, various other non-flammable options are being considered including R452A
(GWP 2,140), R448A and R449A (GWPs around 1,400) and R407F (GWP 1,825).
For smaller systems (e.g. in delivery vans) a mildly flammable option may be acceptable. Pure HFOs
and blends such as DR7and L40 (GWP below 300) are being trialled. Non-flammable options such as
R407F are also being trialed.
DX Air-Conditioning – Low GWP Alternatives
DX (direct expansion) air-conditioning includes:
a) Small single splits, typically with refrigerant charge in the 1 kg to 3 kg range
b) Larger single and multi-splits with refrigerant charge in the 4 kg to 15 kg range
c) VRV systems with refrigerant charge in the 15 kg to 30 kg range
d) Packaged roof-top systems with refrigerant charge in the 15 kg to 30 kg range
Currently HFC 410A (GWP 2,088) is the dominant refrigerant for all these categories. Older systems
often used HFC 407C.
Hydrocarbons have been proposed for small splits, although the flammability risk is considerable. HCs
may be acceptable for very small splits (e.g. with a refrigerant charge below 1 kg) but are unlikely to
be considered safe for larger charges.
CO2 has also been trialed, but it is very difficult to achieve high enough energy efficiency, especially
as air-conditioning equipment needs to run in hot weather, when CO2 is least efficient.
Pure HFOs are possible where mild flammability is acceptable, although systems would require a much
bigger compressor than those used with HFC 410A, which could add a significant extra cost.
A good candidate for a mildly flammable refrigerant is HFC 32 (GWP 675). This is already in widespread
use in the Far East and was being sold commercially in Europe in 2014. HFC 32 systems have the
potential to be more energy efficient than HFC 410A. For small splits a mildly flammable refrigerant
will be acceptable in many circumstances. However, for larger systems (e.g. VRV) there is much work
to be done to prove the safety of refrigerants like HFC 32 and also safety codes may need to be
updated. Other mildly flammable options are becoming available including R447A (GWP 582).
Wherever mildly flammable gases are used, all relevant safety codes must be followed.
If a non-flammable refrigerant is required there are no easy choices at present. HFO blends with
properties similar to HFC 134a are available with a GWP around 600, but these may not produce the
same energy efficiency as HFC 410A.
Air-Conditioning Chillers – Low GWP Alternatives
Currently most small chillers use HFC 410A and large chillers use HFC 134a. Air-conditioning chillers
are usually located in a plant room or in an enclosure that is out of doors, hence in most situations a
mildly flammable refrigerant will be acceptable (note, this may not be the case in certain basement
HFO 1234ze is being trialled in a range of chiller sizes and could become an ultra-low GWP option for
most chillers. Also, HFO 1233zd is being considered for large chillers – it is a low pressure refrigerant
and can be very energy efficient. For small chillers HFC 32 or HFC 447A may be considered.
Mobile Air-Conditioning – Low GWP Alternatives
HFC 134a is the refrigerant used worldwide for MACs in cars and other small vehicles. Other
refrigerants such as HFC 410A may be used in larger systems in buses and trains.
For small MACs it is likely that HFO 1234yf will become the dominant refrigerant. It is mildly
flammable, but most car manufacturers have been satisfied by the safety trials and are launching
models with HFO 1234yf.
HFO 1234yf will also be acceptable for some larger systems. However, if a non-flammable refrigerant
is required there are no obvious alternatives to HFC 410A. See comments above for larger DX
Technical Aerosols – Low GWP Alternatives
Under the 2006 Regulation the use of HFCs in two categories of aerosol was banned. For one
component foam most of the market switched to flammable propellants (such as hydrocarbons) as it
was shown that they were safe to use. For novelty aerosols most of the market switched to HFO
1234ze, as a non-flammable propellant was required.
Most technical aerosols use HFC 134a as a propellant. HFO 1234ze looks to be a suitable candidate
for most applications.
Foams – Low GWP Alternatives
Extruded polystyrene foam (XPS) is currently manufactured using either HFC 134a or CO2. For some
types of XPS foam CO2 is not considered suitable. HFO 1234ze has been successfully trialled for XPS
and in 2014 was in commercial production in some premium foam products.
Polyurethane foam (PU) and similar foams (polyisocyanurate and phenolic) are manufactured using
hydrocarbons (if a highly flammable blowing agent is acceptable) or HFC 365mfc or HFC 245fa. The
use of a number of new ultra-low GWP HFOs (1233zd, 1336mzz and 1233xf) is being trialed.
Fire Protection – Low GWP Alternatives
In the UK HFC 227ea is the dominant HFC in current use. A fluoro-ketone (FK 5-1-12) with ultra-low
GWP has been available for some years and can be used in many applications that might consider HFC
Solvents – Low GWP Alternatives
HFC 4310mee and HFC 365mfc have had some minor use as solvents, although their market is not
widespread. New HFO products, including HFO 1233zd are undergoing promising trials.
The SRAC industry and the world as a whole, now understand that fluorinated gases have a potentially devastating global warming effect when released into the atmosphere.
F Gas regulations have been implemented in order to contain, prevent and thereby reduce emissions of fluorinated greenhouse gases.
On 2nd April 2008, the Commission Regulation 303/2008 set out the requirements for a company certification scheme.
This scheme is specifically for businesses working with F Gas refrigeration, air-conditioning and heat pump equipment containing or designed to contain fluorinated greenhouse gases.
These F Gas Certification requirements are in accordance with Article 5.1 of EC Regulations 842/2006 on certain fluorinated greenhouse gases (the EC F Gas Regulation).