How to have installations with both high performance and low GWP impact? The newest solutions for the various types of format prove that now natural refrigerants and efficiency can coexist.

1. Natural efficiency: available now!
Andreina Figuera
NSM Retail
March, 2017

2. Frost-trol & Partners
W o r k s h o p s
EuroShop 5th-9th March 2017
CAREL
 CAREL is a world leader in control solutions for air-conditioning,
refrigeration and heating, and systems for humidification and evaporative
cooling.
 We design our products to bring energy savings and reduce the
environmental impact of machinery and systems.
 Our solutions are used in commercial, industrial and residential
applications.
 Our mission of high efficiency solutions summarises the model that CAREL
has adopted, both the starting point and the final objective that enclose the
entire process, from conception to production and marketing of our
systems.

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W o r k s h o p s
EuroShop 5th-9th March 2017
Agenda
1. Most Common supermarket installations.
2. Main drivers on the selection of the type of installations.
3. Natural efficiency available now.
3

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W o r k s h o p s
EuroShop 5th-9th March 2017
1. Most common supermarket installations.
The food conservation systems that are normally taken into account are
among the following ones:
1. Traditional MULTIPLEX refrigeration system .
2. CASCADE MULTIPLEX refrigeration system with DX (normally with
R134A) MT cycle and subcritical CO2 LT cycle.
3. BOOSTER MULTIPLEX refrigeration system with CO2 MT & LT cycle.
4. Secondary loop system.
5. Distributed compressor system (aircooled or watercooled).
6. Distributed watercooled self contained inverter driven display case
system.
1. Most common
supermarket

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A traditional MULTIPLEX refrigeration
systems comprises at least two compression
racks (one for Medium Temperature and one
for Low Temperature applications); each fitted
with multiple compressors in parallel
connected with common piping to the display
cases and cold rooms on one side and to the
remote condensers on the other side.
The multiplicity of compressors (normally
from 3 to 6), working with a common suction
and delivery pressures, allows to get a simple
capacity control by switching and/or
sequencing them.
The wide and complex piping network
contains a massive quantity of refrigerant (in
average approx 2,5 lb/kBtuh) and, being
mostly realized in copper with brazed
junctions and connections, is prone to
frequent leaks (up to 25% per year of the
overall content), difficult to detect for the
presence of necessary insulation material
and costly to repair and to replenish.
• Traditional MULTIPLEX refrigeration system
1. Most common
supermarket

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This system has an overall architecture similar to a
traditional system (two compressor racks, one for MT
applications, one for LT ones) but with two basic
differences:
1. The refrigerant of the LT circuit is carbon dioxide
(CO2) working in a subcritical cycle;
2. The condensation of LT circuit is achieved in a
special evaporator belonging to the MT circuit low
pressure side; the cooling capacity of the MT
compressor is sized to absorb the heat rejected by
the LT cycle condenser.
The main advantages of this solution are:
• Low environmental impact due to refrigerant GWPs
(1300 for R134A; 1 for CO2);
• High efficiency of R134A working in the MT circuit;
• Low compression ratio in the LT circuit compressor
rack.
Drawbacks:
• Lower efficiency of CO2 subcritical cycle vs. HFC
refrigerants at equal conditions.
• Cascade MULTIPLEX refrigeration system with DX (normally with
R134A) MT cycle and subcritical CO2 LT cycle.
1. Most common
supermarket

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In this system the high pressure hot gas is delivered by
the compressor rack to the aircooled gas heat
exchanger where it is cooled and, through a pressure
reduction valve, conveyed at an intermediate pressure to
a common receiver partially as a gas (hence sucked by
the MT compressor) and partially as a liquid.
From there the liquid refrigerant is sent through the
piping network and the expansion valves to all display
cases and walk-in coolers (both MT & LT).
The refrigerant sucked from LT evaporators by the LP
rack (at ≈ -25°F ≡ 181 psig) is compressed and delivered
to the HP compressor rack suction side together with the
refrigerant evaporated in the MT display cases (at ≈
14°F ≡ 370 psig).
The overall weight of refrigerant and the annual leakage
rate are of the same order of magnitude of a traditional
system.
To the great advantage of an ultra-low environmental
impact the following negative aspects are associated:
• Low efficiency (decreasing with the average outdoor
temperature increase);
• Higher capital investment;
• High level of competence required.
• Booster MULTIPLEX refrigeration system with CO2 MT &
LT cycle.
1. Most common
supermarket

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In this system each display case and cold room
has its own compressor (speed controlled with
an inverter in order to adjust its capacity
according to the actual requirement) and a water
cooled condenser.
Water is recirculated by a pump between the
internal units and an outdoor package (drycooler or
/and chiller ).
The advantages of this system are:
• ENVIRONMENT RESPECT:
• Extra low content of refrigerant (≈ 10÷20%
vs that of a multiplexed system).
• LOW LEAKAGE RATE (≈ 2%/year),
including display cases and chiller.
• ENERGY SAVING by:
• Virtually no refrigerant pressure drops.
• Self adjusting evaporating temperature.
• Full recovery of condensing heat to
produce sanitary or heating hot water.
• FOOD QUALITY: Smooth temperature regulation
around the set point since the first start up.
• Distributed watercooled self contained inverter driven display case
system.
1. Most common
supermarket

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2. Main drivers on the selection of the type of
installations.
Investment cost
Energy Consumption
Environment impact
Food quality
2. Main drivers on the
selection of the type of

10. Frost-trol & Partners
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EuroShop 5th-9th March 2017
2. Main drivers on the selection of the type of
installations: Energy Consumption
The most common available technologies that increase the energy efficiency
of the equipment used in all types of installations, and thus help to comply with
the normatives, are:
 Electronic expansion valves (EEV).
 Variable capacity compressors.
 Variable frequency drives (VFD).
 Evaporative cooling.
 Electronic fans and pumps.
 Controllers and supervisory systems with energy-efficiency functionalities.
 High efficiency heat exchangers (e.g. micro-channels, flooded).
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2. Main drivers on the
selection of the type of

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EuroShop 5th-9th March 2017
2. Main drivers on the selection of the type of
installations: Environment impact.
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Sector Application GWP limit Year
Plug in Hermetically sealed equipment 150 2022
CDU
Multipack centralized refrigeration systems for
commercial use with a rated capacity of less
than 40 kW is included.
1500 2020
Centralized
system
Multipack centralized refrigeration
systems for commercial use with a rated
capacity of 40 kW or more
150 2022
2. Main drivers on the
selection of the type of
installations
Refrigerant scenario

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EuroShop 5th-9th March 2017
3. Natural efficiency available now
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1.- Selecting a type of installation..
• Optimize the system
• Standardize the components
• Reduce environmental impact
2.- Creating the solution to offer the complete application control to:
Water loop BLDC:
Centralized systems:
compressor pack or
condensing units.
The latest technological developments, allows to have all types of installations with natural
efficiency; it means: installations that can use refrigerants with a low GWP and at the same time
functioning with energy efficiency.
3. Natural efficiency available
now

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Hypermarket – Supermarkets Big -
Medium formats
•Compressor racks, mainly CO2 transcritical
booster
•Natural refrigerant CO2 as standard
•Continuous improvement for energy efficiency
mostly in warm climates
•Carbon footprint reduction
Convenience store – Petrol Station
Small – Extra small formats
•Condensing Units
•Natural refrigerant CO2 available
•Partial load energy efficiency
•Carbon footprint reduction
3. Natural efficiency available now:
Condensing units and centralized systems.
3. Natural efficiency available
now

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EuroShop 5th-9th March 2017 14
3. Natural efficiency available now:
pRack for centralized systems.
The know-how of Carel, on the natural refrigerating applications, allowed
designing specific features inside pRack platform.
Transcritical
3. Natural efficiency available
now

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EuroShop 5th-9th March 2017
3. Natural efficiency available now: pRack for
centralized systems with Co2 trasncritical.
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Evaporative cooling
Subcooler Parallel compression
Ejectors
3. Natural efficiency available
now

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3. Natural efficiency available now:
HECU for Condensing units.
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• Continuous modulation of the
suction pressure set point
• ON-OFF cycles kept to the
minimum
• High efficiency and stability with
CAREL power+
• Continuous modulation of the superheat set point
• Stable product temperature
• High efficiency and stability with CAREL electronic
expansion valve
Real time continuous energy optimization through data communication with refrigerated
unit (MPX PRO).
3. Natural efficiency available
now

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3. Natural efficiency available now:
HEOS for waterloop BLDC systems.
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Plug-in refrigerated units equipped with top DC inverter and modulating EEVs technologies.
Water condenser on-board connected with a water loop system for condenser heat management.
High flexibility and Low ambient impact and Energy saving
3. Natural efficiency available
now

18. Frost-trol & Partners
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EuroShop 5th-9th March 2017
3. Natural efficiency available now:
HEOS for waterloop BLDC systems.
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Environmental friendly
Flexibility
High Efficiency
Food quality
3. Natural efficiency available
now