The use of CO2 in Europe as refrigerant in commercial refrigeration is getting more and more common. Starting from the big compressor rack for hypermarket, then with small and cost effective solution for small supermarket, now the attention of the industry is moved to small condensing unit for C-Store and very small formats. The technology applied in the compressor rack application is not directly applicable in the condensing unit world, historically driven by initial cost and ease of use. CAREL is offering now a full solution for CO2 transcritical condensing unit able to guarantee - Energy efficiency thanks to specific components able to work at very high pressure but specifically design for such small capacity - DC compressors technology to further improve the energy efficiency not reachable - Full control of the system to guarantee best perfomances and reliability - Advanced display and remote connection to maximize the ease of use. CO2 transcritical condensing unit are available in the market since years but never getting the appropriate success due mostly to unavailability of adequate components (especially compressors) to correctly place this solution into the market. CAREL already market leader of this application is now proposing a new solution equipped with DC compressors that are able to improve the performances and at the same time reducing overall costs and dimensions of the whole unit. This speech informs about the excellent key performance factors of BLDC technology in this application and explains the specific control and system demands.

1. High efficiency CO2 transcritical DC condensing unit
Giovanni Tonin
BU Retail Solutions,
Sales&Marketing Process

2. Condensing unit regulation
EUROPE Ecodesign “Directive 2009/125/EC (Energy Related Product,
ERP) ”
Minimum COP (coefficient of performance) for units with rated capacity
lower than 5 kW, minimum SEPR (seasonal energy performance ratio) for
units with rated capacity between 5 and 50 kW.
USA DOE “CFR 2015 Title 10 part 431”
Limitation are applied to the entire system: condensing unit and refrigeration
units. Requirements are different according to the type of refrigerated units.
EUROPE “ F-GAS regulation No. 517/2014”
Stationary refrigeration and air-conditioning equipment,
HFCs with GWP≥2500 unacceptable from 2020
USA “EPA SNAP Rules”
Remote condensing units
New: HFC-227ea, R-404A, R-407B, R-421B, R-422A, R-422C, R-422D, R-428A,
R-434A, R-507ª unacceptable from 2018
Japan “Act on Rational Use & Proper Management of Fluorocarbons”
Condensing unit and refrigerating unit
Target GWP < 1500 from 2025
China under definition
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved

3. CO2 condensing unit scenario
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved

4. Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved
CO2 condensing unit application
Hypermarket – Supermarket
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 reductionNOW

5. CAREL Hecu sistema
New efficiency frontier
Food quality
Innovation suitable for all
Always connected
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved

6. New efficiency frontier
DC inverter technology
The compressor with DC motor allows considerable energy saving as operation is optimum at part loads.
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved
On-Off cycling is not efficient as the
refrigeration circuit needs time to reach the
nominal efficiency. Part load conditions (i.e.
25%) won’t allow to reach nominal efficiency.
Average efficiency is low.
This area represents the increase of
efficiency at part load. It’s bigger with a wider
BLDC capacity range
Refrigeration plant is working for the largest
part of the time at low partial load

7. New efficiency frontier
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved
ADAPTIVE WORKING
CONDITION
Smooth Lines
• Continuous superheat set point modulation according to real unit demand
• Dynamic modulation of cooling capacity results in no more off cycles
• Stable product temperature and less defrost needs
• High efficiency and stability with CAREL EEV
SH
set
Regulation temp.
Integrated Solution for System Optimization
§ Continuos superheat modulation: Smooth Line
§ Floating Suction for self adapting working conditions
Dynamic SH setpoint

8. New efficiency frontier
Floating Suction & Compressor speed modulation
• Continuous suction pressure set point modulation
• Optimum and stable control suction pressure control
• Compressor ON-OFF cycles reduced to the minimum
• High efficiency and stability with CAREL power+
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved
REAL TIME
SYNCHRONIZATION
Dynamic Suction
setpoint

9. Innovation suitable for all
Unique controller board
For BLDC compressor management and
CO2 valves management, both high
pressure and flash gas valves
Advanced DC compressor driver
For an efficient and variable speed
compressor driving and optimal
performance at partial load
Electronic expansion valves
For a calibrated injection and precise
regulation of gas cooler and receiver
pressure
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved
Fully
integrated
and
compact
solu3on
ALL
in
ONE

10. Innovation suitable for all
Maximum
ease
of
use
Easy set-up and optimisation
• Wizard start-up procedure for a
simplified unit configuration
• Pre-setting of the main parameters
and probes to reduce
commissioning timing
Extremely fast commissioning
• Automatic preconfiguration of the
system network (refrigerated cases
and condensing unit)
• Optimised default parameters with
extensive laboratory tests
Intuitive programming
• Different access profile for different
user
• Simplified menu for a clear
navigation
• PGD and pLD PRO terminal with
full informations
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved

11. Food quality
Full envelope management and optimum compressor control
CAREL testing process approves the use of its inverter with different models
of compressors to ensure completely safe operation in the best possible
conditions.
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved
Advanced oil return features
• By washing the showcases using CAREL E2V expansion valves
• With Speed Boost function
Extreme
reliability
à
no
down
3me

12. Food quality
Highest quality of food preservation combined with high energy efficiency
The condensing unit constantly responds to the cooling demand of each connected unit, dynamically
adapting to current conditions while the E2V valves on each unit control the flow of refrigerant, and the
MPXPRO controllers minimize temperature fluctuations
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved

13. Always connected
Direct data access and
notification
With optimized interface for
different device and configurable
report
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved
GPRS-ETHERNET
Simple and deep MAINTENANCE
Fullly independent access to the
refrigeration unit to maximize the
maintenance experience
Intuitive site navigation
With custom maps and graphics
Easy optimization and higher
service level
With site graphs and trend

14. Always connected
ENERGY CONSUMPTION
Systems comparison and Business Intelligence within all units connected
• Energy dashboard with comparative
analysis
• Analytics for optimal food preservation
• Centralised alarm monitoring
• Remote customized interface
• Geo localization
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved

15. Conclusions
• CO2 DC inverter technology is available in the market now
Any reproduction, modification or distribution of this document, whether in part
or entirely and by any means, is expressly prohibited except upon CAREL's
express prior written permission. 2016 CAREL all rights reserved
• Considerable energy saving results can be obtained by DC technology and advanced
control algorithms
• Both efficiency and refrigerants regulations can be achieved using DC inverter
technology and natural refrigerant CO2
• Reduced down time of the system with advanced envelope control and preventive
actions
• Optimum food preservation with more stable product temperature
• Wide range of remote monitoring systems in order to optimize system performance,
carry out preventive maintenance and analyze energy consumption