7x24 Exchange 2014 Spring Magazine - page 32

32
7X24MAGAZINE SPRING2014
REFERENCES
ASHRAE. 2011.ASHRAETC9.9ThermalGuidelines forLiquidCooledDataProcessingEnvironments.
Atlanta:AmericanSocietyofHeatingRefrigerationandAirConditioningEngineers, Inc.
ASHRAE. 2006.ASHRAETC9.9LiquidCoolingGuidelines forDatacomEquipmentCenters.Atlanta:
AmericanSocietyofHeatingRefrigerationandAirConditioningEngineers, Inc.
ASHRAE. 2011.ASHRAEHandbook–HVACApplications, chapter34.Atlanta:AmericanSocietyof
HeatingRefrigerationandAirConditioningEngineers, Inc.
CornellUniversity. 2005. LakeSourceCoolingProject.CornellUniversity,
http://energyandsustainability.fs.cornell.edu/util/cooling/production/lsc/
EnwaveEnergyCorporation. 2013.EnwaveServices:DistrictCoolingSystem,
http://enwave.com/district_cooling_system.html
EPA. 2012.WaterUseClassificationsandWaterQualityStandards forSurfaceWaters.Environmental
ProtectionAgency.http://water.epa.gov/scitech/swguidance/standards/
EPRI. 2008.WaterUse inElectricalPowerGeneration.ElectricPowerResearch InstituteReport 1014026.
JohnPeterson is aprofessional engineerwithEYPMissionCritical Facilities, Inc., awhollyowned subsidiaryofHewlett-PackardCorporation.
He canbe reachedat jpeterson@hp.com
MuntherSalim is theGlobal LeadEnergyEfficiency expertwith theHewlett-PackardCorporation.He canbereachedatmsalim@hp.com
Figure6shows
chiller-only
support toassist
withpeakwater
temperaturesor
loadsusing the
river/lakewateras
theheat sink
insteadofacooling
tower.
Figure7presentsan
optionwitha riveror
lakecoolingplant that
canbesized tosupport 100%of the
required load, or less, dependingon the
liquidcoolingclass. Thissystem
configurationasshowncouldsupport
UTITier I&II. Indeed thissystem
presentsagreateropportunity for
economicandenergysavings.
CONCLUSION
Dependingon thedesired locationand
uptime resiliency/availability
requirements, the feasibilityof lakeand
riverwater systemsshouldbe
evaluatedearlyduring thesiteselection
processandsubsequentconceptual
designphase todetermine the lifecycle
cost incomparison to traditional
coolingsolutions. Traditional
mechanical systemshaveseveral
features thatmake themmore
attractive thana riveror lakesource
coolingproject, including familiarity
and flexible location.However, lakeand
rivercoolingarrangementsofferbetter
counter-argumentsbeyond justbeing
more resourceefficient: forexample
lessmechanical coolingequipment to
purchaseandmaintain; lessmechanical
equipment footprint; andzeropotable
waterconsumption.Also lakeand river
coolingcould totallyeliminate theneed
for refrigerationsystemsandglobal
warming refrigerantsat theproject site.
Althoughawaterutility isnotneeded
for riveror lakewatercooling, apermit
from the regulatoryauthority is likely
needed foroperationand thermal
discharge.While thismayseem
daunting to theHVAC industryat first,
the rulesand regulationshavealready
beendeterminedand inmanycaseswill
be lessofan issue than for
manufacturersandutilityplants.While
theefficiency isdependentupon the
water temperatureat the intake
location,mostmodernsystemscanbe
designed tooperatewithhigher
temperaturesand flow rates to reject
thesameamountofheat from the
buildingbeingserved.
Figure6:Chiller only(no cooling tower)with river/lake source cooling
Figure7:River/lake source coolingonly