CO2: The Inconvenient Truth
There are now better technologies than
CO2 for retail refrigeration systems

Introduction
Articles have been published over the last 12-18
months raising doubts about the green credentialsof CO2 (R-744) as a refrigerant due to its inherent
poor energy efficiency.
This raises the questions of why did the industry choosea relatively high total emissions technology to comply
with the European F-Gas Regulation and should othertechnologies be considered before deciding on which
low GWP option provides the lowest environmental
impact and best value for money.
From a climate change emissions perspective, it’s obviousthat any significant leakage of the high GWP R-404A(3922) easily outweighs any energy efficiency benefits seen
over using CO2 (R-744). Of course, the issue when choosing
CO2 (R-744) technology is that the equipment is morecomplex, more expensive and less energy efficient.
This contributes to a higher 10-year Life Cycle Cost,
but the EU F-Gas Regulations primary focus is low GWP
not cost, so CO2 (R-744) appeared to be a good choice...

BUT IS IT REALLY?

2Is there a better option
than CO2 (R-744)?
Although CO2 (R-744) achieves the primary objective of lowering
the total emissions below R-404A levels, apart from matching cooling
performance, CO2 (R-744) does not necessarily meet any of the otherdesired criteria.
Clearly there is room for improvement in the technology choice.
Very low GWP A2L refrigerants such as Opteon™ XL20 (148) andOpteon™ XL40 (239) have been commercially available since 2016,
with the first commercial application installed in October 2017 at
Park Cake Bakeries in Oldham (UK). This raised the profile of thisalternative technology and led to interest from retailers for use insupermarket refrigeration. The use of Opteon™ XL refrigerants is nowa reality with installations made during 2019 by the large retailer
ASDA (part of the Walmart Group) and Central England Co op inthe UK, meaning the use of the very low GWP Opteon™ XL range
is now a valid choice for retailers to consider.

3

10-Year Total
Emissions

Sevilla, Spain

Helsinki, Finland

2000
1500

1000500(R-454C)

IHX))+44

L20X

2pt
eon

™

OOscritCX
P4n™
eoTranptO(R0-7(RR-4-44904AA)
C-4(RL20Xpteon™

)+TranscritCO2O

44-7(R54omlCleParal(R0P4on™
pteOp)
49-4-4RXX
L2n™
eoptOAA044C)

r-450+4)-74(R2OtC

scri(REj-4P40(RRX™
onpteOecto4904AA)

0Tr
anThis combined with improved energy performancedelivered by Opteon™ XL refrigerants result in thetotal emissions being 12-13% lower in Sevillaand Leicester, and even in the cooler low carbon
power generation location of Helsinki, 6-8% lower
than those produced from the use of the equivalent
optimal CO2 (R-744) technology.

Leicester, UK2500-4Using an annual leak rate (ALR) of 5%, a level
achieved by responsible retailers across Europe,
the very low GWP of Opteon™ XL20 andOpteon™ XL40 greatly reduces the contributionof direct refrigerant emissions.

10-Year Total Emissions (TeqCO2) comparison for a standard supermarket format(~2000m² sales area with design loads of 160 kW medium temperature/30 kW
low temperature)

10-Year Total Emissions (TeqCO2)

A study performed by Wave Refrigeration, basedon their own practical experience working with
ASDA and other international retailers, looked at
the use of the very low GWP Opteon™ XL products
compared to the various available CO2 (R-744)
technologies, namely FGB/Booster, internal heatexchanger (IHX), parallel compression and Ejector.
Wave considered standard and small sized
supermarkets (~2000m2 and 300-500m2 retailarea) in 3 locations representing the range ofclimatic conditions found across Europe (Helsinki,Finland, Leicester, UK & Sevilla, Spain).

Figure 1

10-Year Direct Emissions (5% ALR)

10-Year Indirect Emissions
410-Year Life
Cycle CostLeicester, UK

Helsinki, Finland

1600
1400
12001000800600400200B)F
G4444-7-7(R(RCO

22O
CXOpteon™

)I54-4(RL20-7HX)
CA04
R44-4)F
GomlC(R2OCO2(RC-74Bp)
le54-44)

Paral(RR

L20X™
onpteOCCA04-4)FG44-7(R2OC-74O2(RBrecto+4)

0L2Xon™

Ej-4(RR-45404CA)

0pteCombining these elements give significantly lower
10-year Life Cycle Costs i.e. 11-13% lower inSevilla and Leicester, and even in the low-cost
power generation location of Helsinki, 5-7% lower
than using the equivalent optimal CO2 (R-744)
technology.

Sevilla, Spain

OThe study deduced that the use of the Opteon™ XLtechnology provides the lowest CAPEX (up to 11%lower) and maintenance costs (up to 15% lower),
but the most significant cost saving over a 10-year
period is from the lower energy consumption(up to 15% lower).

10-Year Life Cycle Cost (Thousands, €) comparison for a standard supermarket
format (~2000m² sales area with design loads of 160 kW medium
temperature/30 kW low temperature)

10-Year Life Cycle Cost (Thousands, €)As there is now an alternative low emissions
technology to match or reduce total emissions fromCO2 (R-744) technologies, the cost element now
becomes a relevant and important consideration.

Figure 2CAPEX

Maintenance

Energy Expenditure5Inconvenient ornot, the truth is...

Figure 310-Year total emissions vs 10-year LCC and CAPEX comparison between
Opteon™ XL and R-744 Technologies for a standard supermarket located inSevilla, Leicester & Helsinki

The inherent lower energy efficiency and complexityof CO2 (R-744) systems has left many question
marks as to whether this technology is indeed
the best choice.

10-Year Total Emissions (TeqCO2) / kW

11CO2 (R-744) FGB/Booster Spain

CAPEX

109€ 229 k € 248 k€ 267 k€ 288 kOpteon™ XL40 (R-454A) Spain
CO2 (R-744) + Ejector Spain

8CO2 (R-744) FGB/Booster UKOpteon™ XL20 (R-454C) Spain

7Opteon™ XL40 (R-454A) UK

CO2 (R-744) + Parallel Comp UK

6Opteon™ XL20 (R-454C) UK

5Opteon™
XL40 (R-454A)
Finland433400CO2 (R-744) FGB/Booster Finland
CO2 (R-744) + IHX Finland

Opteon™ XL20 (R-454C) Finland

3900

4400

4900

5400

5900

6400

6900

The introduction of very low GWP Opteon™ XL
refrigerants has been proven to be a viable
alternative to R-404A and CO2 (R-744) in bothstandard and small supermarket refrigeration
applications.
The practical experience from installations haveshown improved energy performance, whilst
maintaining similar equipment costs, maintaining
system simplicity and reliability compared withR-404A, with the lowest 10-year life cycle cost,lowest 10-year total emissions and lowest cost per
TCO2e reduction when compared to the optimum
CO2 (R-744) technology choice over a wide rangeof climatic conditions.

10-Year Life Cycle Cost (Thousands, €) / kW

Looking for a compliant Low GWP solution?
Opteon™ XL refrigerants, why would you
choose anything else?

The information set forth herein is furnished free of charge and based on technical data that Chemours believes to be reliable. Chemours makes no warranties, express or implied, and assumes no liability in connection
with any use of this information. Nothing herein is to be taken as a license to operate under or a recommendation to infringe any patents or patent applications. ©2020 The Chemours Company FC, LLC. Opteon™ andany associated logos are trademarks or copyrights of The Chemours Company FC, LLC. Chemours™ and the Chemours Logo are trademarks of The Chemours Company.

6