Analysis of the options to provide cost effective data cooling in Middle East countries.
By Noriel Ong, ASEAN Eng., MIET, PMP, PQP, ATD; Syska Hennessy Group.
Keppel Ltd. 1Q 2024 Business Update Presentation Slides
Data Center Free Cooling in the Middle East
1. Can Data Center Free Cooling Be Utilized in the
Middle East?
Prepared by: Noriel Ong, ASEAN Eng., MIET, PMP, PQP, ATD
3/21/2017
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Objective
• Learning the types of air economizers
• Understanding the typical air economizers
configuration
• Learning the advantages and
disadvantages of each type of air
economizer system
• Understanding of the energy and water
cost impacts of indirect evaporative
cooling system.
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AIR-SIDE ECONOMIZER
Syska Hennessy Group /
AIR-SIDE ECONOMIZER is “a system that has been designed
to used outdoor air for cooling – partially or fully – when outdoor
air meets certain criteria” (ASHRAE).
• DIRECT AIR-SIDE ECONOMIZERS
– the outside air is directly supplied into the white space
– the exhaust heat is reject fully or partially recirculated back
– The outside air could also be cooled by means adiabatic cooling (aka DIRECT EVAPORATIVE
COOLING).
• INDIRECT AIR-SIDE ECONOMIZERS
– The outdoor air does not enter the white space.
– Data center (primary air) is cooled indirectly by the outside air via heat exchanger.
– The primary air/heat exchanger (cold side) could also be cooled by means adiabatic cooling.
(aka INDIRECT EVAPORATIVE COOLING).
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DIRECT AIR-SIDE ECONOMIZER (EXAMPLE)
Syska Hennessy Group /
CONFIDENTIAL MULTINATIONAL TECHNOLOGY COMPANY DATA CENTER PHASE 2
EXPANSION
Project Features
• Tier 2 electrical design
• Tier 2 mechanical design
• Modular design
• Scalable design
• Greenfield site
• 2 data halls, expandable to 5
• Each data hall scalable to 3.6mW of critical
load
• Adiabatic cooling to provide annual average
1.08 PUE
Size
• 186,000sf
L O C K P O R T , N Y
Services Provided
• Mechanical
• Electrical
• Plumbing
• Fire protection
• Fuel Oil
Completion Date
• 2014
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INDIRECT AIR-SIDE ECONOMIZER
(EXAMPLE)
Syska Hennessy Group /
T5 - EL SEGUNDO DATA CENTER
CALIFORNIA
Project Features
• Day 1:
• 5.5MW critical load
• 85,000 s.f. white space
• Day 2 (ultimate):
• 2.95MW critical load
• 110,500 s.f. white space
• Brownfield site
• PUE goal: 1.3
• Rooftop Indirect Evaporative Cooling
Units (no chiller plant)
• Diesel Generators
• Goal of achieving LEED Gold
• 36” Raised Floors
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Risks Summary
Syska Hennessy Group /
Direct Air-Side
Economizers
Direct Evaporative Cooling
Indirect Air-Side
Economizers
Indirect Evaporative
Cooling
Energy Consumption Low Medium
Water Consumption None Medium None Medium
Temperature
Variations
High Medium Low
Humidity Variations High Low
Air Quality Issues High None
Water Quality Issues None Medium None Medium
Complexity High Medium
Regional
Support/Experience
High High Low
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ASSUMPTIONS
Syska Hennessy Group, MENA /
• 1MW data center critical (IT) load. Fully loaded at static conditions.
• Based comparison with Air-cooled chilled water system with variable primary system
and Computer Room Air Handlers (CRAH).
• Data center cabinets are in hot and cold aisle configuration with containment system.
• White Space Supply/Return Air Temp (SAT/RAT)
• 77°F [25°C]/100°F [38°C]
• Power and Water Tariffs are based on the local utility slabs.
• DEWA, ADDC, Qatar KAHRAMAA, Oman MEDC & PAEW, KSA SEC& NWC, Bahrain
EWA, and Kuwait MEW.
• Weather Bin Data based on IWEC 2.
• IDEC Wet Bulb Depression Efficiency =60%
• IDEC Air to Air Heat Exchange Efficiency = 45%
• IDEC primary and secondary(scavenger) fans speed are constant.
• IDEC Dry Operations: =/< 48°F [9°C] DBT OA
• IDEC Wet Operations: > 48°F [9°C] DBT and < 61°F [16°C] WBT OA
• IDEC Partial Free Cooling: > 61°F [16°C] OA
• Both the data center is pressurized by a DOAS
• Analysis focus on white space only.
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CONCLUSIONS
• The case study revealed that Riyadh, Dhahran and Kuwait has the most
free cooling hours among other places in GCC countries that were
evaluated.
• Although the analysis for UAE, Qatar, Bahrain and Oman showed very
limited free cooling hours, savings can still be achieved through partial
free cooling.
• IDEC full and partial free cooling will reduce data center mechanical
energy or overall utility cost.
• More operation cost savings could be realized if the modulation of
secondary(scavenger) fans are accounted for, which is usually the case.
• Increasing the target supply air temperature limit will increase the
number of full or partial free cooling hours.
• Selecting a higher supply air temperature, i.e. 77°F (25°C), will improve
the economics of the economizer without even considering the option
of using the allowable range.
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CONCLUSIONS
• Although the results seem favorable, there are also other
considerations that need to be examined.
• Water scarcity and storage.
• System operation during dust/sand storms.
• Although no known cases of Legionella were recorded, water
treatment may be required.
• Regular maintenance of heat exchangers to mitigate fouling.
• Indirect airside economizer could be an alternative cooling solution in
lieu with IDEC provided that local support will be present in the region.
When the outdoor air is favorable, 100% economization can be utilized. Air dampers are used to adjust the mixture of outdoor air and return air and necessary redirecting of airstreams for an economizer cycle to meet the environmental condition of the data center.
If the outside air temperature is high but lower than the return air, partial free cooling could be utilized. The mechanical cooling will be activated in this case to supplement the cooling deficit available from the outside air.
And if the outside air temperature higher than the return, air in the data center is recirculated and the mechanical cooling will be activated to process the cooling of the return air.
A derivative of the air economizer discussed above that is more energy efficient is one that uses an adiabatic wetted media humidifier/cooling component aka direct evaporative cooler. Evaporative cooling uses water as a medium to cool the air through its evaporation. The adiabatic evaporation of water provides the cooling effect which requires less energy than the typical vapor compression system used for air conditioning.
This schematic shows a central station air-handling unit with the evaporative cooling component located upstream of the refrigeration cooling coil and a blow through supply fan arrangement.