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Data Center Alabushevo Zelenograd SEZ Russia
Precision air conditioning
casestudyCS_14002_GB
IT Cooling case study
Casestudy Data Center Alabushevo Zelenograd SEZ Russia
2
RC GROUP S.p.A. ● CS_14002_GB
INDEX
1 INTRODUCTION ............................................................................ 3 2 DATA CENTER ALABUSHEVO ........................................................ 4
2.1 DATA CENTER NUMBERS ............................................................... 5 3 CLIMATE CONDITIONS AND COOLING SYSTEM ................................ 6 4 ENERGY CONSUMPTION MANAGEMENT .......................................... 7 5 PRECISION AIR CONDITIONERS ................................................... 10
5.1 CHILLED WATER AIR CONDITIONERS NEXT CW ............................... 11 5.1.1 PLUG FAN .................................................................................. 11 5.1.2 FINNED COILS HEAT EXCHANGER ................................................. 12 5.1.3 MICROPROCESSOR CONTROL SYSTEM ......................................... 12 5.1.4 EXTRA-CIRCUIT SYSTEM ............................................................. 12 5.2 DIRECT EXPANSION AIR CONDITIONER NEXT DX ............................ 13
6 LIQUID CHILLERS ....................................................................... 14 6.1 SCREW COMPRESSORS .............................................................. 14 6.2 SHELL AND TUBE EVAPORATOR ................................................... 15 6.3 CONDENSING COILS & FREE-COOLING .......................................... 15 6.4 CONDENSING SECTION FANS & FREE-COOLING ............................. 16 6.5 MICROPROCESSOR CONTROL SYSTEM ......................................... 16 6.6 FREE-COOLING OPERATING MODE ............................................... 17 6.7 MECHANICAL REFRIGERATION ..................................................... 17 6.8 FREE-COOLING .......................................................................... 18
Casestudy Data Center Alabushevo Zelenograd SEZ Russia
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RC GROUP S.p.A. ● CS_14002_GB
1 INTRODUCTION
Once again RC Group shows its excellence to ensure functionality and safety in air-conditioning in
large capacity IT systems.
This is the case of modern and innovative Data Center of Alabushevo at Zelenograd SEZ (Special
Economic Zone), where RC Group, whose technological proposal, accompanied by a detailed
global energy survey has been permanentely approved, has applied the best of its technology
systems and equipment able to satisfy the needs of the complex allowing the functional
management with the least energy consumption.
Zelenograd is the Russian locality where, since 1958, the Soviet electronics industry is based on,
and is still one of the most important centers of electronics, microelectronics and hi-tech of modern
Russia.
The city, whose name can be literally translated into English as "Green City", is located 35 km
north-west of Moscow and 15 km from Sheremetyevo international airport.
Zelenograd is designed as a city of the future. It has enormous potential: economic zone,
innovative producer-oriented sites, highly qualified management, advanced technical University,
considerable intellectual resources. Zelenograd is considered the smartest city in Europe:
more than half of the adult population has a higher education degree.
The territory of "Zelenograd" SEZ is divided into two main areas:
• An industrial area "Alabushevo (150.0 hectares) including a scientific and industrial area,
where is situated the Data Center of Radius Group, an ancillary infrastructure area and a
recreational area.
• Another area in which are situated the Innovative complex of Moscow University and the
Institute of Electronic Technology (5.15 acres).
MOSCOW
Alabushevo
Casestudy Data Center Alabushevo Zelenograd SEZ Russia
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RC GROUP S.p.A. ● CS_14002_GB
2 DATA CENTER ALABUSHEVO
The Alabushevo Data Center design solution takes into account all the sector’s applicable
regulations requirements. The centers’ engineering infrastructures meet completely Tier III security
requirements provided by Uptime Institute, the sector’s most authoritative independent
consultancy organization. The reliability is designed to achieve 99.98% of operational continuity,
which means no more than one hour of downtime per year.
Picture 1 – Alabushevo building: on the coverage twelve air cooled liquid chillers GLIDER FREE of RC Group are placed (rendering)
Equipment and customer data are protected by uninterrupted power systems, backup power
supplies based on diesel generators with no less than 8 hours of battery autonomy, receiving
precision air-conditioning systems of last generation technology (RC Group), physical security, fire
protection systems and automatic monitoring to videos and access control systems.
The infrastructure engineering project is used to stop any system, for scheduled maintenance work,
without stopping the main technological process. Regular scheduled maintenance works, are the
key to the data center's operational sustainability.
The modular design of the building makes possible to provide customers with a full range of
outsourcing services information infrastructure.
The cooling system made by RC Group is optimized for high density racks through equipment with
up to 12 kW cooling capacity.
The project solution of data center is designed to minimize power losses and, at the same time, the
energy use.
As a result of a greater energy efficiency of the data center’s engineering systems, we require:
equipment optimization to reduce the server energy consumption by 38%; the power systems’
optimization to reduce UPS and PDU and its energy consumption by 51%; the cooling systems’
optimization to reduce power consumption by producing cooling only for 72% of the requirements.
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RC GROUP S.p.A. ● CS_14002_GB
2.1 DATA CENTER NUMBERS
buildings n. 3
space of each building m2 4.366
total space of buildings m2 13.098
total occupied area m2 10.000
offices area m2 1.472
total covered area m2 16.541
server racks per module n. 406
total server racks n. 1.218
total redundancy level of data center TIER III+
chilled water air conditioners n. 108
direct expansion air conditioners n. 9
free-cooling liquid chillers with pumping group n. 12
cooling capacity MW 18
total capacity MW 21
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RC GROUP S.p.A. ● CS_14002_GB
3 CLIMATE CONDITIONS AND COOLING SYSTEM
The project plant considers that the major thermal loads are those produced by the data center IT
equipment. External Thermo hygrometric conditions affect almost exclusively the functioning of
liquid chillers. The area of application of cooling equipment is conducive to the effective use of
direct and indirect free-cooling systems. For this reason all liquid chillers installed on the
Alabushevo building coverage are supplied with free-cooling system for cooling or pre-cooling plant
water when the external air temperature is particularly rigid.
The table shows the Alabushevo extreme and medium air temperature conditions that are similar
to those of Moscow. The table shows clearly how it is possible to dispose the thermal load of the
complex even with free-cooling system in January, February, March, November and December
without the use of the electric compressors.
Table I – The table shows the values of temperature and relative humidity of Moscow. Daily average for month cooling load values are related to local data center needs in twenty-four hours of every day of every month.
Working time
Temperature MAX
Temperature MIN
Medium temperature
MAX
Medium temperature
MIN
Relative humidity
MIN
Relative humidity
MAX
Medium cooling load
Month °C °C °C °C % % kW
Jan 0,7 -18,0 -5,2 -10,2 60,1 93,0 8.400,0
Feb 2,9 -17,9 -3,1 -10,1 54,9 97,0 8.400,0
Mar 7,3 -12,4 0,0 -4,6 54,0 88,9 8.400,0
Apr 15,4 -6,3 9,5 1,5 51,4 89,7 8.400,0
May 24,1 -0,6 18,2 7,2 41,7 85,9 8.948,8
Jun 26,6 2,8 20,6 10,6 50,5 55,9 9.400,2
Jul 28,0 5,3 22,1 13,1 52,8 93,2 9.800,2
Aug 26,0 3,3 20,1 11,1 55,9 97,0 9.400,2
Sep 19,9 -0,9 13,9 6,9 58,7 93,7 8.617,2
Oct 12,9 -7,9 6,9 -0,1 65,8 97,0 8.400,0
Nov 6,2 -11,6 0,3 -3,7 69,6 97,0 8.400,0
Dec 2,7 -16,0 3,2 -8,2 66,1 97,0 8.400,0
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RC GROUP S.p.A. ● CS_14002_GB
4 ENERGY CONSUMPTION MANAGEMENT
The careful evaluation of energy consumption of all units installed in Alabushevo guides better the
business products choice. Cooling groups can be managed using control devices to reduce the
total load, either in parallel or in sequence. In the first case, they will always be all active, at least up
to a reduction of the building required total load equivalent to the minimum capacity of each units.
In the second case, to shrink the building's request, individual units will stop progressively.
Seasonal energy consumption in two different possible plant managers, were calculated based on
the monthly average of thermo hygrometric conditions in Moscow (189 metres above sea level)
shown in table II which are invoked the statistical-based climate data available from the web1.
Each month features a day type, whose temperature profiles (T) and relative humidity profiles (RH),
hour by hour, are reconstructed on the basis of the equation:
Text = Text max * (1 - kn) + Text min * kn (1)
e:
RH = RHmax * kn + RHmin * (1 - kn) (2)
where the coefficients kn are marked hour by hour and return a dry bulb minimum temperature dry
bulb at 05:00 a.m. and a maximum temperature at 03:00 p.m. (vice versa for relative humidity).
Maximum and minimum values of the equations 1 and 2, on the other hand, correspond to the
averages of maximum and minimum values of month-to-month as from statistical tables, while
extreme temperature conditions are not taken into account. Each month is, therefore, characterized
by an average temperature statistics, with a daily temperature range corresponding to the
difference between the average of the maximum and the average of the minimum.
The profile of the building's cooling load is calculated with the following equation:
(3)
where:
DesignLoad cool is the design heat load in cooling mode and expresses the peak load of the shell
to which you should refer to in the choice of chillers. It is therefore related to the
climatic conditions of the project, which should be the harshest of the installation
location.
CL0 is the constant contribution, not influenced by time (because they multiplied ku), or
other factors. Corresponds to the fraction of endogenous load strapped to
machinery with continuous operation 24hrs/24hrs. Back to express the minimum
load always on, just like data center applications.
ku is the time factor, expressed as a percentage. When is canceled, expresses the
load reset (turned off unless it is different from zero CL0). The value considered to
vary, depending on the time, all load conditions included in bracket.
1 The most used source is www.weatherbase.com.. 2 Cooling load ratings from “Energy analysis for RC Group units”- SPECTRUM Manual ©2013 RC Group SpA Valle Salimbene Pv.
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RC GROUP S.p.A. ● CS_14002_GB
kw is a constant (= 1) for plant on (ku > 0), and (= 0) for plant off (ku = 0)
CL1 is the load process, little influenced by climatic conditions (for application of
comfort, it is recommended that this value is zero). CL2 is the comfort loaded, mainly at the level of employment (latent loads, lighting)
and, largely, separate climatic conditions.
DCL is the reference value for the thermal indentations (thermal exchanges between
the building envelope and the outer environment).
Text is the outside air temperature at dry bulb (°C).
Tcl is the temperature to which reverses the sign of the heat exchange between
building envelope and the external environment.
Tch is the maximum temperature used for calculations: it corresponds to the average
of the maximum of all months of the year.
The total energy consumption evaluation is based on the compressors absorption of : all groups of
chillers throughout their operating period, the fans both during mechanical refrigeration and free-
cooling and the primary fluid’s circulation pump: water and ethylene glycole.
The refrigerant load adjustment of various refrigeration units is performed sequentially, in order to
progressively stop the chillers keeping those in operation able to work at their maximum capacity.
This solution allows to have a decent energy saving towards a system worked in parallel, in which
most of the units continue to work with a very low single load.
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RC GROUP S.p.A. ● CS_14002_GB
Working time Ambient temperature Relative
humidity Load Compr. Fans Pumps EER Free
Cooling
MAX MIN Av MAX
Av MIN
MIN MAX Average Sum Sum Sum Average Average
Month h °C °C °C °C % % kW kWh kWh kWh W/W %
Gen 744 0,7 -18,0 -5,2 -10,2 60,1 93,0 8.400,0 0 110.564 75.076 33,67 100,0
Feb 672 2,9 -17,9 -3,1 -10,1 54,9 97,0 8.400,0 0 109.044 67.810 31,92 100,0
Mar 744 7,3 -12,4 0,0 -4,6 54,0 88,9 8.400,0 4.732 189.850 75.076 23,18 99,8
Apr 720 15,4 -6,3 9,5 1,5 51,4 89,7 8.400,0 595.854 194.810 72.654 7,01 58,0
Mag 744 24,1 -0,6 18,2 7,2 41,7 85,9 8.948,8 1.272.546 132.102 79.826 4,49 8,7
Giu 720 26,6 2,8 20,6 10,6 50,5 55,9 9.400,2 1.397.908 119.364 81.848 4,23 0,0
Lug 744 28,0 5,3 22,1 13,1 52,8 93,2 9.800,2 1.539.266 139.116 88.140 4,13 0,0
Ago 744 26,0 3,3 20,1 11,1 55,9 97,0 9.400,2 1.441.964 122.786 84.578 4,24 0,0
Set 720 19,9 -0,9 13,9 6,9 58,7 93,7 8.617,2 1.120.406 127.424 72.654 4,70 13,6
Ott 744 12,9 -7,9 6,9 -0,1 65,8 97,0 8.400,0 353.302 226.236 75.076 9,55 78,0
Nov 720 6,2 -11,6 0,3 -3,7 69,6 97,0 8.400,0 0 179.640 72.654 23,97 100,0
Dic 744 2,7 -16,0 3,2 -8,2 66,1 97,0 8.400,0 0 128.228 75.076 30,74 100,0
Total 8.760 Total 7.725.978 1.779.164 920.468 7,35 52,5
Total 10.425.610
Table II – The table shows the values of energy consumption (kWh) of twelve liquid chillers working in sequence. The evaluation includes energy consumption of compressors, of fans and circulation pumps (water and glycol).
Casestudy Data Center Alabushevo Zelenograd SEZ Russia
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RC GROUP S.p.A. ● CS_14002_GB
5 PRECISION AIR CONDITIONERS
The equipment of Alabushevo data center requires an overall cooling capacity of about 14 MW.
Picture 2 – Part of a data center room (rendering)
In order to satisfy the requests specific equipment, manufactured in the plant RC Group of
Zeccone, in the province of Pavia, has been applied.
• n. 108 chilled water CRAC units NEXT CW;
• n. 9 direct expansion CRAC units NEXT DX.
Picture 3 – Diagram of air distribution system between the Racks rows. Through the floating floor the NEXT units send the filtered and conditioned air in the cold aisle between the rows of Racks (blue arrows). The Racks are downloading the hot air in the hot aisle (red arrow) where there is the suction at the top of the air conditioner.
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RC GROUP S.p.A. ● CS_14002_GB
5.1 CHILLED WATER AIR CONDITIONERS NEXT CW Each of the 108 precision air conditioning units NEXT CW are capable to produce 60kW in cooling
with airflow of about 15,000 m3/h. The chilled water units allow to obtain the best adaptation to
variable load of areas which are dedicated.
Picture 4 – Chilled water close control air conditioners NEXT CW with down-flow air delivery.
NEXT CW are suitable to be installed internally, either directly into the room where they are placed
on the data center equipment, both in an adjacent room: the air distribution is from the bottom
through the plenum between the building floor and the raised floor.
5.1.1 PLUG FAN Each unit is equipped with plug-fans with EC motors able to ensure high energy saving during
operation with reduced airflow.
Picturea 5 – Centrifugal fan (Plug Fan) directly coupled to EC electric motor. (Ziehl Abegg SE – Künzelsau - Germania).
The motor rotation control is obtained with the EC system (Electronic Commutation) that manage
the motor according to the 0÷10V proportional signal coming from the microprocessor control.
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RC GROUP S.p.A. ● CS_14002_GB
5.1.2 FINNED COILS HEAT EXCHANGER The coils are fed with chilled water by copper tubes, aluminum fins and galvanized steel frame fins
with high heat exchange surface and high-efficiency air filters; the two-way valve adjusts the water
flow with proportional control and emergency manual control.
5.1.3 MICROPROCESSOR CONTROL SYSTEM The microprocessor control system allows the operating state and alarm’s management and
monitoring. It includes: a voltage free contact for the general alarm; an operating hour counter of
the main components with maintenance reporting; the function "data logger" for the memorization
of the intervened alarms; flash memory for data storage in case of power failure and menu
management with password protection. There is also the serial communication line for the remote
control.
Picture 7 – Mp.com microprocessor control system (RC Group Spa Valle Salimbene (PV) Italia).
Each units is also equipped with: humidifier, Dehumidification system, and extra-circuit coil.
5.1.4 EXTRA-CIRCUIT SYSTEM The extra circuit system consists of an additional chilled water cooling coil powered by a valve
directly managed through the microprocessor control system.
The additional cooling coil is placed on the air flow upstream the filter section and downstream the
main cooling coil. It is perfectly sized in order to provide with the main cooling coil’s same cooling
capacities, guaranteeing a total back-up.
The interchange between the two cooling systems is done automatically via the microprocessor
control. This system allows to solve easily and in a limited space many plant problems including:
• extra-circuit system fed by well water in emergency to the main refrigerant circuit;
• main cooling circuit is a support for the extra-circuit system connected to the external chiller;
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RC GROUP S.p.A. ● CS_14002_GB
Picture 8 – Air cooling system of an air conditioner. The system includes a main chilled water coils (left) and an emergency auxiliary called "extra-circuit" (right).
5.2 DIRECT EXPANSION AIR CONDITIONER NEXT DX The nine precision air conditioner NEXT DX are able to produce, each, with a cooling 57kW airflow
of about 14,500 m3/h. The units are self-contained, equipped with two compressors in order to
allow a better adaptation to demand loading of areas which are dedicated and plug-fans with
brushless motor electronically commutated (EC) able to ensure high energy savings during
operation with reduced airflow. Cooling coils are refrigerant direct expansion HFC410A, match to
the condenser series Team-Mate produced by RC Group.
Picture 9 – Direct expansion close control air conditioner NEXT DX with down-flow air delivery.
Extra – Circuit System Main cooling circuit
Water flow control valve Water flow control valve
Air flow
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RC GROUP S.p.A. ● CS_14002_GB
6 LIQUID CHILLERS
The demand for cooling of IT rooms is satisfied by the creation of a refrigeration unit consisting of
twelve liquid chillers GLIDER FREE, each of which has been selected to provide 1100 kW of
cooling capacity. Each chiller is equipped with chilled water pumping group.
Picture 10 – GLIDER FREE: air cooled liquid chiller with free-cooling produced by RC Group
6.1 SCREW COMPRESSORS GLIDER FREE, manufactured in the establishments of RC Group in Valle Salimbene in the
province of Pavia, are equipped with semi-hermetic screw compressors with bi-screw technology
and high efficiency screw profile with high peripheral speeds, optimized for refrigerant R134a.
Picture 11 – Screw compressor (Refcomp SpA - Lonigo (VI) Italia).
For a precise control of the cooling capacity supplied, screw compressors are equipped with a
control system of modulating cooling capacity. The lubrication system is equipped with an oil
pressure separator and oil flow switch.
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RC GROUP S.p.A. ● CS_14002_GB
6.2 SHELL AND TUBE EVAPORATOR The shell and tube evaporator, which is expressly designed for R134a refrigerant, is realized with
internal corrugated pipes having a helical profile, intermediate septa positioned to ensure optimal
speed and reduced fluid pressure drops.
Picture 12 – Shell and tube evaporator (WTK SpA - Lonigo (VI) Italia).
The evaporators are characterized by single-circuit water side, and independent circuits, one for each
compressor, on the refrigerant side; coat, head, tube sheet of stainless steel; anti-condensation
insulation closed cell polyurethane; temperature sensor on water inlet and outlet. Each refrigerant
circuit is equipped with its own electronic expansion valve for high performance and system
efficiencies thanks to a timely and accurate response to variations in temperature and pressure.
6.3 CONDENSING COILS & FREE-COOLING In one finned Pack are available the condensing coil and free cooling coil. The tubes are made of
copper and aluminum fins, high efficiency specifically developed to ensure a high heat exchange
coefficient and contained losses. The combination of two factors: special fins tubes, allows to combine
optimally the maximum capacity in relation to the size of the exchanger, minimal refrigerant charge
and the reduction of the air flow necessary for heat exchange.
Picture 13 – Heat exchange finned coils made from copper tubes and aluminium fins full. The finned Pack contains both the part dedicated to the condenser and the free-cooling hydraulic circuit (NAS Srl – Albano Laziale (Roma) Italia).
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RC GROUP S.p.A. ● CS_14002_GB
6.4 CONDENSING SECTION FANS & FREE-COOLING Axial fans with sickle-shaped blades and fan guard are optimized for low noise levels.
Brushless type synchronous EC motor with integrated electronic commutated system and
continuous variation of the rotation speed.
The motor rotation control is obtained with the EC system (Electronic Commutation) that manage the
motor according to the 0÷10V proportional signal coming from the microprocessor control.
Picture 14 – High efficiency axial fan (Ziehl Abegg SE – Künzelsau - Germania).
6.5 MICROPROCESSOR CONTROL SYSTEM MP.COM microprocessor system is completed with graphic display for control and monitor of
operating and alarms status. The system includes voltage free contact for remote general alarm,
Main components hour-meter, non-volatile “Flash” memory for data storage, menu with protection
password and LAN connection.
Figura 15 – Mp.com microprocessor control system (RC Group Spa Valle Salimbene (PV) Italia).
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RC GROUP S.p.A. ● CS_14002_GB
6.6 FREE-COOLING OPERATING MODE
Chillers cool a mixture of water and ethylene glycol to 40% by weight from 12° C to 7° C by means
of the compression system and allow to achieve the same overall cooling capacity even with the
free-cooling coils when the external air temperature is 0° c.
The air moved by fans crosses the free-cooling coil and then the condensing coil of the refrigerant
circuit.
free-cooling coil takes advantage of low air temperature for pre-cooling water returning from the
system before submitting it to the evaporator.
In this way is possible to have a free-cooling that helps in saving electricity, since part of the
refrigerator plant load is supplied from the outside air instead of being supplied totally by the
compressors.
RC Group chillers with free-cooling have three different working modes:
1. normal mode (mechanical cooling);
2. partial free-cooling mode (free cooling + mechanical cooling);
3. total free-cooling mode.
6.7 MECHANICAL REFRIGERATION
In mechanical mode with active compressors, the butterfly valve sends the fluid directly into the
evaporator: the unit works like a traditional liquid chiller.
The microprocessor manages the outlet water temperature by adjusting the capacity of the
compressor and the condenser pressure is controlled by reducing the air flow through the coils
refrigerant gas through modulation of the fans rotation speed.
Picture 16 – During the mechanical cooling mode, the compressors are active and the water returning from the system flows directly into the evaporator.
Condensing coil and free-cooling
Evaporator
Outlet water Inlet water
Butterfly valve
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RC GROUP S.p.A. ● CS_14002_GB
6.8 FREE-COOLING When the air temperature drops by 3° K under water temperature returning from the utilities, the
free-cooling valve feeds the free-cooling coil that pre-cools (partial free-cooling) or cools completely
(total free-cooling) the water before entering the evaporator.
The control logic handles an optimized electrical energy effort to cope with the heat load to be
disposed, minimizing the compressors’ operating time in order to make the most out of free
cooling.
Picture 17 – When the external air temperature reaches a temperature low enough to pre-cool or cool completely the water returning from the system, the fluid flows first in free-cooling coils and, subsequently, in the exchanger and the evaporator.
The water temperature control in free-cooling mode is achieved initially through the progressive
reduction of the fans’ rotation speed. If the cooling capacity in free-cooling is still excessive, the
microprocessor will stop the fans and, in case the capacity supplied by the free-cooling system is
still exuberant the microprocessor will command the free-cooling valve in closing, getting also the
total battery by-pass.
Refrigeration equipment installed at the data center of Alabushevo allow compression mechanical
mode with external air between 35° C and 10° c.
Between an air temperature of 10° C and 3° C the chillers units work with compressors and active
free-cooling batteries managed through two separate refrigerant circuits.
Under 0° C chillers units are able to fully satisfy the load of the building with free-cooling coils only,
limiting in this way power consumption only to the motorized fans assembly functioning.
Condensing coils and free-cooling
Evaporator
Outlet water Inlet water
Butterfly water
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RC GROUP S.p.A. ● CS_14002_GB
Picture 18 – The coefficients of performance (EER) are referred to a single liquid chiller and also take into account the constant consumption of the water circulation pump.
Only Free-Cooling Free-Cooling + Compressors Only Compressors
EE
R (
kW /
kW)
External air temperature (°C)
(EER) of liquid chillers At full load with variable external air temperature