it cooling solutions - jaeggi-hybrid.eu
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APPLICATION
IT Cooling Solutions Sustainable hybrid dry cooling of data centres
JAEGGI – The Original
Since 1929, JAEGGI has been engaged in the development, production and sale of heat exchangers. Since 1995 the company has been part of the Güntner Group, a worldwide established manufacturer of components for refrigeration, air-condition-ing technology and industrial applications with a total workforce of 2,600 people. Our production facilities in Europe, America and Asia secure us direct market ac-cess and spare parts service worldwide.
JAEGGI places economic efficiency and environmental protection on an equal foot-ing. Our products and services make an active contribution to lowering your oper-ating costs and conserving resources.
Our coolers are tested for hygiene conformity and aerosol emissions. The ISO 9001 quality management system, carried out by the Swiss Association for Quality and Management Systems SQS, guarantees our customers premium quality and maxi-mum reliability anywhere in the world.
All fluid cooling technologies for data centres and server rooms
For over 80 years, the Güntner Group has been manufacturing heat exchangers for refrigeration and air condition-ing. Our reliable and innovative products make us one of the industry’s leading component manufacturers. With our diverse technologies and our consulting expertise we can supply the optimal fluid cooler for every application. For IT cooling applications this means a high level of operational reliability plus a short payback period due to low operating costs.
Technologies
Güntner Group
dry sprayed adiabatic hybrid Multiple circuit coil
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Sustainable dry cooling for data centres
The growing number of computer applications, mobile data, internet services, cloud computing, etc., also increase the demands placed on data centres as regards both quantity (data storage, transmission speed, processing power) and qual-ity (efficiency, resource consumption, emissions).
And the energy consumption relating to cooling the data centre while in operation is already be-tween 30 and 50 %. This means that the elec-tricity consumed by data centres is responsible for around 2 % of global CO2 emissions – just as much greenhouse gas as the entire aviation sector. At the same time, the industry does have a considerable potential for reducing electrici-ty demand by investing in efficiency-enhancing measures on the infrastructure side. On average, 50 % of the electricity consumed by data centres is used for air conditioning, dissipating waste heat and maintaining an uninterruptible power supply (UPS).
Modifications in these areas can be carried out efficiently and without jeopardising the availabili-ty of the IT processes. And this can reduce both costs and CO2 emissions. This is where JAEGGI and its hybrid dry coolers offer future-oriented technology as their contribution to greener data centres.
Increased demand alongside a mandated reduction in CO2 emissions
Growing need for cooling
Cool
ing
need
s, C
O 2 em
issi
ons
More efficient use of energy CO2 emissions must be reduced
MAXIMUM EER
YEAR ROUND (PARTIAL PUE)
(ENERGY EFFICIENCY RATIO)
Success factors in data centre planning
REDUNDANCY
INFR
ASTR
UCTU
RE E
FFIC
IEN
CY)
(POWER USAGE EFFECTIVENESS)AN
D ENERGY
RESO
URCE
AVAILABILITY
DCiE
(DAT
A CE
NTR
E
LOW pPUE ACHIEVABLE ALL LOW PUE ACHIEVABLE
SAVING WATER
EFFI
CIEN
CY
2010 2020
Growing need for cooling
Cool
ing
need
s, C
O 2 em
issi
ons
More efficient use of energyCO
2 emissions must be reduced
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Efficient system design with refrigeration chillers
A typical application for free cooling is the pro-vision of cold water for cooling data centres and servers. This makes it possible to reduce the operating load hours of the refrigeration chillers, so saving a significant proportion of the energy costs.
Year-round low dry cooling temperatures ensure efficient operation of the refrigeration chillers and a high EER (COP).
Chiller operation
Operating a refrigeration chiller raises the thermal load to a higher temperature level and then uses the hybrid dry cooler in dry or wet operation to dissipate the waste heat to the environment. There is potential for increased efficiency primarily in the energy-efficient operation of the refrigeration chiller and the water-efficient and energy-efficient operation of the hybrid dry coolers.
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Efficient system design using free cooling
Free cooling can be used to cover a large pro-portion of the installation’s annual operating hours.
In this diagram, you see a conventional plant design that uses hybrid dry coolers (in free cooling operation) for the direct dry cooling of the servers.
Free cooling operation
In free cooling operation, the energy-intensive refrigeration chiller is switched off and the entire thermal load is dissipated directly to the environment via the hybrid dry cooler in dry or wet operation. There is potential for increased efficiency primarily in the water-efficient and energy-efficient operation of the hybrid dry coolers.
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Temperature requirements for data centres
Sufficient cooling in the data centre is essential to its survival. If the IT hardware is not reliably cooled, its availability can no longer be guaranteed and the equip-ment may even be physically damaged. To prevent this happening and to ensure high availability, it is very important to dissipate energy from the server rooms. However, aiming at temperatures that are too low expends a great deal of effort in cooling and dissipating energy to the environment, which is neither economi-cally nor ecologically sensible. The required level of dry cooling is determined primarily by the IT equipment and cooling technology used.
The latest edition of the 2011 ASHRAE Handbook – HVAC Applications recommends desirable temperatures for data centres categorised as classes A1 to A4 (see il-lustration below). The recommended temperature range for class A1 is 18 – 27 °C, and the permissible range goes up to 32 °C. The two illustrations below contain graphic representations of the recommended and per-missible temperature ranges.
Relative humidity
Clas
s A4
Perm
issib
le ra
nge
Clas
s A3
Perm
issib
le ra
nge
Clas
s A2
Pe
rmis
sible
rang
e
Clas
s A1
Pe
rmis
sible
rang
e
Classes A1 – A4 Recommended
range
Dry bulb temperature in °C
Abso
lute
hum
idity
– g
wat
er p
er k
g of
dry
air
Satur
ation
tempe
rature
in °C
Illustrations: hx diagram for humid air showing the classes used in the 2011 ASHRAE Handbook – HVAC Application
Cambridge University, UK
Recommended range according to 2011 ASHRAE
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450
350
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50
-50
-12 -6 0 6 12 18 24 30 36
-12 -6 0 6 12 18 24 30 36
450
350
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-50
450
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-50
-12 -6 0 6 12 18 24 30 36
-12 -6 0 6 12 18 24 30 36
450
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24°C
32°C
18°C
27°C
Chiller HTKDRY
Heat source
24°C
32°C
18°C
27°C
Chiller HTKWET
Heat source
24°C
23°C
17°C
18°C
HTKDRYChiller
Heat source
24°C
23°C
17°C
18°C
HTKWETChiller
Heat source
Effects of temperature levels on energy and water consumption
In the illustrated system which is equipped with a refrigeration chiller and can also be operated in free cooling mode, the energy can, depending on the outside temperature, be dissipated to the environment directly via the dry cooler.
Annual temperature Frankfurt am Main | Data centre temperature = 18 °C
Annual temperature Frankfurt am Main | Data centre temperature = 32 °C
Free coolingHTK dry
Free coolingHTK dry
Free coolingHTK wet
Free coolingHTK wet
RM mode (HTK dry/wet)
RM mode (HTK dry/wet)
Free cooling operation
Chiller operationwith dryhybrid cooler
with dryhybrid cooler
with wethybrid cooler
with wethybrid cooler
Annual temperature variation showing the classes for the modes of operation
In the system in the example, with 1 MW cooling capacity, the annual temperature variation shown gives the tem-peratures up to which the indicated operating modes can be used. If the data centre needs extremely low tempera-tures, then the use of free cooling operation is very limited. The refrigeration chiller will already need to be activated when the outside temperature is low. The refrigeration chiller can save energy only with the lowest possible return temperatures from the dry cooler. If the temperature in the data centre is 32 °C, this system configuration can still be used in free cooling operation to dry cool the IT equipment, provided the outside temperature does not exceed 25 °C.
Energy consumption of refrigeration chiller
Energy consumption of dry cooler
Water consumption of dry cooler
Free cooling with dry cooling -
-
Free cooling with evaporative cooling
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Operation of a refrigeration chiller with dry cooling
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Operation of a refrigeration chiller with evaporative cooling
Incr
easi
ng e
nerg
y co
nsum
ptio
n
The structural diagrams show all possible operating modes for the entire dry cooling system.
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Kältemaschine [h]
Freecooling benetzt [h]
Freecooling trocken [h]
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Economic impact of data centre temperature
Calculating the operating load hours for the year makes its impact on their distribution apparent. The proportion of free cooling mode increases as the data centre temperature increases.
Proportion of operating load hours spent in free cooling dry/wet/refrigeration chiller operation, depending on the data centre temperature
Free cooling dry
Data centre temperature in °C
Prop
ortio
n of
the
oper
atin
g lo
ad h
ours
Free cooling wet
Refrigeration chiller operation
Location London (UK)
Data centre temperature 18 °C 32 °C
Free cooling dry 3 h 0.03 % 5,332 h 61 %
Free cooling wet 21 h 0.24 % 3,150 h 36 %
Refrigeration chiller 8,737 h 100 % 279 h 3 %
Energy consumption of the refrigeration chiller 498 MWh ‑98 % 9 MWh
Energy consumption of the dry cooler 58 MWh 2 % 59 MWh
Total water consumption 4,533 m3 66 % 7,520 m3
Total costs (at 0.1/kWh; €4/m3) €73,740 ‑50 % €36,937
When we calculate the operating costs for energy and water, we can also see the commercial effect of the data centre temperature. Increasing the data centre temperature to 32 °C would enable the operating costs for dry cooling to be reduced by 50 %. This reduces the total energy consumption by almost 98%.
High-yield investment
Saves money, saves resources
Unlike conventional cooling towers, choosing hybrid dry coolers from JAEGGI gives you a resource-efficient unit that rapidly pays for itself.
This system uses around 70 to 90 % less water than a conventional cooling tower, which represents a worth-while saving – particularly for such a long-term durable product.A representative comparison between a wet cooling tower and a hybrid dry cooler from JAEGGI was compiled on the basis of a system in use at a production facility in London, operating three shifts with a year-round con-stant load of 1,000 kW. In this system, the cooling water temperature was brought down from 38 °C to 28 °C.
During cooler periods or under partial load, the JAEGGI HYBRIMATIC control operates the coolers entirely dry, i.e. dissipating heat to the ambient air purely by convection. Only when dry operation is unable to achieve the required cold water temperature, does it automatically switch in
the wetting cycle. In this particular example, the switch point for dry operation is at an ambient temperature of 18 °C.
At the London site, the water consumption of the hybrid dry cooler over a period of one year (i.e. water lost to evaporation and used for blowdown at 3-fold concentra-tion) was 1,350 m3 with a wastewater volume of 450 m3. If a wet cooling tower had been installed instead, this would have consumed 15,693 m3 of fresh water and generated 5,231 m3 of wastewater. As you see, in this example, using hybrid dry cooling reduced the water consumption by over 90 %.
ConclusionPurchasing a hybrid dry cooler not only saves you enor-mous operating costs, it also protects the environment and our dwindling resources – of which water is also one. In this example, investing in the HTK had already paid for itself after 2 years
Water saved by a JAEGGI HTK compared to a conventional cooling tower
554,370 €
177,310 €
40,000 €
Cooling tower
JAEGGI HTK
years
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%Kältemaschine [h]
Freecooling benetzt [h]
Freecooling trocken [h]
3230282624222018
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Data centre cooling without compressor refrigeration
If the refrigeration chiller represents a substantial investment in the plant design and is a majorenergy consumer, alternatives are also interesting.
Which features may be of interest to planners? – Location of the installation Annual temperature variation – Data centre temperatures – Minimising heat transfer processes
Two possible options are briefly introduced here:
Cooling wall
The hybrid dry cooler is connected to the cooling wall directly, without an intermediate circuit. The cooling wall deals with cooling the data centre interior.
Advantages – No intermediate circuit – Lower temperature transfer losses – Higher circulation temperatures in the dry cooling circuit
Server rack backplane cooling
The hybrid dry cooler is connected to the water-cooled racks directly, without an intermediate circuit. The air entering the rack is heated by the IT equipment and cooled again before it leaves.
Advantages – No intermediate circuit – Lower temperature transfer losses – Higher circulation temperatures in the dry cooling circuit – Increases the free cooling potential
– Increases the free cooling potential – Low pressure drop Δp leads to lower fan power
– Very small region with higher air temperature (and only inside the rack)
– Very small regions with high air speed (and only inside the rack)
– No false floor needed
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Hybrid dry coolers – Plume-free – Minimal sound emission – Maximum power density – Coated heat exchangers – Low consumption of water and energy – Short payback period thanks to low operating costs
– Absolute operational reliability, even with high outdoor temperatures
– Achieves a PUE of < 1.22 – Can achieve cooling water temperatures that are lower than the ambient temperature.
– Calculation of the amortisation, taking into account:
Up-to-date climate data Annual temperature variation Load profile
Fans – Fan units with
industrial fans for low noise and high efficiency
standard motors with premium efficiency
or
EC technology
Transportation/bringing‑in
– Highly resistant to torsion – Unit up to 5.45 m long without lifting beam – Unit longer than 5.45 m with lifting beam
Hybrid dry coolers High Performance
Combination of dry cooling and evaporative cooling
Sophisticated equipment technology and high-quality materials
Proven system to maximise savings in operating costs
Maximum operational reliability
Long service life
HYBRIMATIC – Intelligent control saves operating costs – Monitors all important parameters – Trouble-free, efficient operation – Manages wetting water system – Reports errors and issues operating messages – Communicates with building management systems
– A number of bus systems are available – Optimised for water-saving operation
HYBRIMASTER control: – Controls multiple hybrid coolers installed in parallel for a high degree of energy efficiency and water savings
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thermowave plate heat exchanger
Compact, powerful heat exchangers between the primary and secondary circuit
No glycol-carrying pipes in the building or the server room
Compact, powerful plate heat exchangers – High level of energy efficiency due to small temperature differences
– Excellent fouling resistance due to high turbulence and smooth surfaces
– Highly fail-safe thanks to proven technology – All parts in contact with water are made of stainless steel
Easy to install and service – Compact construction – Easy cleaning – Easy maintenance
Wide range of applications – Capacity of 50 – 1000 kW – Various plate geometries – Optimised pressure drops
Member of the Güntner Group – Everything from a single source – Easy processing – Precise design
Primary circuit (water/glycol)Secondary circuit (water)
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SAP St. Leon RotSAP is a leading provider of business software that was founded in 1972, with headquarters in Walldorf (Germany) plus sales and development locations in over 50 countries around the world. The hybrid dry coolers are used for dry cooling the refrigeration chillers and for free cooling. In St. Leon Rot, SAP operates over 24 hybrid dry coolers with a total capacity of 30 MW.
Equinix AM3 Amsterdam With more than 95 IBX data centres in 31 major business centres, Equinix is one of the world’s leading providers of data centre services, connecting over 4,400 customers and partners worldwide. Equinix AM3 Science Park in Amster-dam uses an innovative concept based on 100 % water – without any chemicals or biocides – geothermal aquifer storage plus hybrid dry cool-ers from JAEGGI (HTK Hybrid High Performance). Equinix AM3 won thewon the Green Data Centre Award in 2012.
Data centre of a major international telecommunications company
This cloud data centre is currently the larg-est data centre in Germany and began op-eration in 2014. Cooling the server rooms calls for a capacity of 18 MW. 12 JAEGGI hybrid coolers of type HTK were installed for free cooling operation. Increasing the temperature of the cooling water and using hybrid cooling ena-bles the free cooling units to operate for nearly 8,000 hours per year without using the refriger-ation chiller.
References
xDC Swisscom WankdorfSwisscom’s Wankdorf data centre of is one of the most modern and efficient in the world. Its IT equipment oc-cupies a floor space of 4,000 m2, seven modules each consuming 600 kW, and reaches peak energy efficiency (PUE = 1.2) by virtue of its excellent efficiency, modular structure and the innovative cooling system that uses no compression refrigeration.
Year-round cooling is guaranteed using only free cooling with JAEGGI hybrid coolers. Part of the waste heat is also used to heat neighbouring residential properties.
JAEGGI provided the installation’s 8 HTK1.8/7.8 dry coolers with a total capacity of 6 MW, and is proud to be a part of this high-efficiency concept.
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JAEGGI Hybridtechnologie AGHirschgässlein 11CH-4051 BASEL
www.jaeggi-hybrid.eu
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