Table Of ContentRP-1673
ASHRAE Design Guide for
Tall, Supertall, and Megatall
Building Systems
PPeetteerr SSiimmmmoonnddss
Atlanta
ISBN978-1-936504-97-8
2015ASHRAE.Allrightsreserved.
PublishedincooperationwiththeCouncilonTallBuildingsandUrbanHabitat
ASHRAE
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LibraryofCongressCataloging-in-PublicationData
Simmonds,Peter,1954-
ASHRAEdesignguidefortall,supertall,andmegatallbuildingsystems/PeterSimmonds.
pagescm
Includesbibliographicalreferencesandindex.
Summary:"TheASHRAEDesignGuideforTall,Supertall,andMegatallBuildingSystemsisconcernedwithHVAC,design,
maintenance,andotherfactorsforbuildings300feet(91m)orhigher.Theguidedetailstheproblemsandpossiblesolutionsfor
tall,supertall,andmegatallbuildings"--Providedbypublisher.
ISBN 978-1-936504-97-8 (hardcover : alk. paper) 1. Tall buildings--Design and construction--Handbooks, manuals, etc. 2.
Megastructures--Design and construction--Handbooks, manuals, etc. 3. Building, Iron and steel--Handbooks, manuals, etc. I.
ASHRAE(Firm)II.Title.III.Title:Designguidefortall,supertall,andmegatallbuildingsystems.
TH1611.S532015
720'.483--dc23
2015016066
ASHRAE Staff Special Publications Mark S. Owen, Editor/Group Manager of Handbook and Special Publications
Cindy Sheffield Michaels, Managing Editor
James Madison Walker, Associate Editor
Sarah Boyle, Assistant Editor
Lauren Ramsdell, Editorial Assistant
Michshell Phillips, Editorial Coordinator
Publishing Services David Soltis, Group Manager of Publishing Services and Electronic Communications
Jayne Jackson, Publication Traffic Administrator
Tracy Becker, Graphics Specialist
Publisher W. Stephen Comstock
Anyupdates/erratatothispublicationwillbepostedontheASHRAE
websiteatwww.ashrae.org/publicationupdates.
ThispublicationwassupportedbyASHRAEResearchProjectRP-1673undertheauspicesofASHRAE
TechnicalCommittee(TC)9.12,TallBuildings.TC9.12isconcernedwiththefunction,operation,energy,
andhumansafetyforbuildingsinexcessof300feetinheight.Alsoincludedisthedeterminationof
requirementsrelatedtohydraulics,airflow,infiltration,thermalinsulation,watervaporretarders,envi-
ronmentalcontrol,fireandsmokecontrol,andmaintenance.
ABOUT THE AUTHOR
Peter Simmonds is managing director/principal of Building and Systems Analytics, LLC based in
Marina Del Rey, CA and Hong Kong. He has one Bachelor of Science degree in Mechanical Engineering
andanotherinResearchandDevelopmentfromReadingTechnicalCollege;aMaster’sdegreefromHTS,
Den Bosch, the Netherlands; and a PhD fromT.U. Delft. He has been a member ofASHRAE since 1989
andhastwicechairedTechnicalCommittee(TC)9.12,TallBuildings.Hehasbeeninvolvedinthedesign
andoperationoftall,supertall,andmegatallbuildingsaroundtheworldformorethan30years.Heisalso
a recognized authority in the field of radiant heating and cooling systems.The main goals of his research
and applications have been to understand the heat transfer and performance of radiant systems for both
heating and cooling. His studies related to thermal performance of these systems led to a unique way to
enhance these systems. Publications of his work led to the development of radiant systems in the United
States and are included in theASHRAE Handbook. He received the Carter Bronze Medal from the Char-
teredInstitutionofBuildingServicesEngineersin1993.
He has authored or coauthored more than 60 technical papers, articles, and books and is a member of
several ASHRAE Technical Committees. Peter also teaches graduate and postgraduate architectural stu-
dentsattheUniversityofSouthernCalifornia,LosAngeles.
ASHRAE
ASHRAE, founded in 1894, is a global society advancing human well-being
through sustainable technology for the built environment. The Society and its
membersfocusonbuildingsystems,energyefficiency,indoorairquality,refriger-
ation, and sustainability within the industry.Through research, standards writing,
publishing and continuing education,ASHRAE shapes tomorrow’s built environ-
ment today.ASHRAE was formed as theAmerican Society of Heating, Refriger-
atingandAir-ConditioningEngineersbythemergerin1959ofAmericanSociety
of Heating and Air-Conditioning Engineers (ASHAE) founded in 1894 and The
AmericanSocietyofRefrigeratingEngineers(ASRE)foundedin1904.
1791TullieCircle,NE
Atlanta,GA30329
1-800-527-4723
www.ashrae.org
CTBUH
The Council on Tall Buildings and Urban Habitat is the world’s leading
resource for professionals focused on the inception, design, construction, and
operationoftallbuildingsandfuturecities.Anot-for-profitorganization,founded
in1969andbasedattheIllinoisInstituteofTechnology,Chicago,CTBUHhasan
Asia office at Tongji University, Shanghai, and a research office at Iuav Univer-
sity,Venice, Italy. CTBUH facilitates the exchange of the latest knowledge avail-
able on tall buildings around the world through publications, research, events,
working groups, web resources, and its extensive network of international repre-
sentatives.TheCouncil’sresearchdepartmentisspearheadingtheinvestigationof
the next generation of tall buildings by aiding original research on sustainability
and key development issues. The free database on tall buildings, The Skyscraper
Center, is updated daily with detailed information, images, data, and news. The
CTBUH also developed the international standards for measuring tall building
height and is recognized as the arbiter for bestowing such designations as “The
World’sTallestBuilding.”
S.R.CrownHall
IllinoisInstituteofTechnology
3360SouthStateStreet
ChicagoIL,60616
www.ctbuh.org
www.skyscrapercenter.com
PREFACE
ASHRAE Technical Committee (TC) 9.12, Tall Buildings, has defined a tall building as
onewhoseheightisgreaterthan300feet(91m).AtthetimeofthepublicationoftheHVAC
Design Guide for Tall Commercial Buildings in 2004, there were only about 300 buildings
tallerthan656ft(200m).Thisnumberhadrisento600in2010,anditwaspredictedthatthere
wouldbe765buildingstallerthan656ft(200m)in2012.Since2004,therehasalsobeenan
introductionoftwonewclassesoftallbuildings(CTBUH2015):
(cid:129) Supertall,whicharebuildingstallerthan984ft(300m)
Figure P.1 A tall building more than 984 ft (300 m) in height.
xviii ASHRAE Design Guide for Tall, Supertall, and Megatall Building Systems
(cid:129) Megatall,whicharebuildingstallerthan2000ft(600m)
With the increasing migration of people into cities, tall buildings continue to be in
demand. More specifically, at the time this document was going to press there were
1730buildingsalreadyconstructedaroundtheworldhigherthan328ft(100m),theASHRAE
definition of a tall building in the previous design guide. 80 buildings have been constructed
with designed heights of at least 984 ft (300 m) (CTBUH 2013), and there are 27 buildings
eitherconstructedorindesignwithheightsmorethan1640ft(500m)(theCTBUHdatabase
listsonlybuildingshigherthan1640ft[500m]).
Tallcommercialbuildingspresentaseriesofdesignproblemsthatdifferfromthosefound
inotherprojectsinthebuiltenvironment.ThepreviousHVACDesignGuideforTallCommer-
cial Buildings provided guidance in both understanding the HVAC design problems of tall
commercial office buildings (with heights of 328 ft [100 m] or more) and in detailing their
solutions.
This revision will be of interest to owners, architects, structural engineers, mechanical
engineers, electrical engineers, firefighters, and other specialized engineers and consultants.
The design guide not only focuses on the efforts of designers of the heating, ventilating, and
air-conditioning (HVAC) systems, but also addresses the importance of the design team and
their collective efforts and concerns that are the critical elements in determining the ultimate
solutions to the projected needs of a tall building. This guide addresses design issues for tall
commercial buildings, which are very often mixed use, consisting sometimes of low-level
retail,officefloors,residentialfloors,andhotelfloors.Additionally,themattersdiscussedand
the recommendations and comments that are developed, with various modifications, can be
applied to other project types within the built environment.As buildings get taller, there are
differentclimaticeffectswhichvaryovertheheightofabuilding.Thefaçadebecomesimpor-
tant,notonlybecauseofthebuildingsize,butalsobecauseofhowitrespondstoambientcon-
ditionsandcontributestothebuilding’sheatingandcoolingloads.Thefaçadealsocontributes
todaylightharvesting.
Additionalissuesaddressedinthisguideareasfollows:
(cid:129) Thewaterdistributioniscritical,especiallywith2000ft(600m)plusbuildings.
(cid:129) Elevators have become complicated and are critical when organizing the buildings core,
butnowadaystheycanbeusedforegress.
(cid:129) Plumbingsystemsaredescribedbecausetheyarejustasintricateaswaterdistributionsys-
tems,andthesearedescribed.
Additionally,buildingintelligencepresentsasignificantimpactontallbuildingoperation;
howdothedifferentbuildingsystemstalktoeachotherandoptimizetheirusage?Whatintelli-
genceisprovidedfortenants?Thisisaddressedinthisguide.
Reflecting the addition of these subjects and the coverage of the newer classes of tall
buildings, this new work has been retitled ASHRAE Design Guide for Tall, Supertall, and
MegatallBuildingSystems.
FOREWORD
Tallbuildingshavealwayschallengedtheimaginationofdesignersandtestedthefortitude
ofengineers.Intheendlessquesttomaximizethevalueofrealestate,buildingshaveclimbed
everhigher.Architectsandengineersdeterminehowprogram,structure,andserviceswillsup-
port each other efficiently.And, in each case, it falls to building services engineers to deter-
minehowaspatialarrangementofstackedfloorswillbeventilated,heated,cooled,andhowit
willinteractwiththeenvelopethatsurroundsit.
Tall buildings are exceptional. They require enormous amounts of energy to move their
occupants from floor to floor, exhaust the heat they and their many electronics generate, and
provide chilled air or heat to keep conditions comfortable. They require enormous skill and
efforttosealenvelopesandkeepthemairtightagainsttheelementsandtopreventunpleasant
pressurechangesaselevatorshurtleupanddowntheirlengths.
Tallbuildingsareexceptional,yes—butthisdoesnotmeantheyareexempt.Thatis,they
are not exempt from the self examination and the subsequent campaigns of environmental
engineeringthattheremainderoftheconstructionprofessionhasundertakenwhenitcomesto
low-height structures. For every LEED®-certified or energy-producing tall building, there are
dozens, perhaps hundreds, that continue to follow a protocol that dates from the 1950s—seal
the building, cover it head-to-toe in glass, and air condition it 24 hours a day. For all of the
advanced engineering work that goes into making these astounding structures stand up and
function,fromanMEPstandpointalargenumberofthemaredinosaurs.Forallthetalkabout
iconicity,manyofthesemonolithsarenotbuiltforlongevity.
Itiscommonplacetotalkaboutatallbuilding’sdesignlife(oratleastthoseofitscritical
constituent parts) as being 25, 50, or 100 years.This is somewhat ridiculous, given that there
has never been a tall building of 656 ft (200 m) or greater dismantled at the end of its design
life,(otherthantheeventsof9/11)andsomeofthemarenowcomingperilouslycloseto,and
beyond, this milestone. Recladding in the conventional sense is enormously expensive and
wastefulofmaterials.Weshouldbedesigningfortheages,andthatmeansdesigningenvelopes
andmechanicalsystemsthatcanbereplacedandimprovedovertimeastechnologyimproves,
orashumantoleranceforadversetemperatureconditionsimproves—probablyboth.
That’s why a design guide like this is so important. There is so much research, so much
unrealized potential in both passive and active systems—operable façades, dynamic façades,
energy-generatingfaçades,verticallyvegetativefaçades,evapotranspirativefaçades,etc.—that
embrace,ratherthanresist,naturalenvironmentalconditions.Ofcourse,asolutionforaone-
story building is not going to work for a 100-story building if it is simply copied upwards
100times.Butthefactthattallbuildingsdorequirespecialengineeringinordertoachievethe
same levels of environmental performance as their shorter peers is not a justification for not
xvi ASHRAE Design Guide for Tall, Supertall, and Megatall Building Systems
attempting it; rather it is a call to action to elevate the practice of tall building engineering to
meetthischallenge.
Oneofthemoreinterestingopportunitiesforsuper-andmegatallbuildingsisthestratifi-
cation of climate that exists in any one location with height. Effectively, with the extreme
heights now being achieved in tall buildings, we are designing one building that cuts across
severalclimatezones.Significanttemperaturedifferencesexistbetweenthetopofthebuilding
and the street level. Tall buildings should be exploiting this for their advantage—cool air is
heavier and naturally drops, warm air rises—yet most continue to extrude the same vacuum-
sealedfaçadeupwardsforhundredsofmetres,withalloftheenergyexpenditurethatimplies.
Façades and building systems need to vary with height and reflect the climatic stratification
thatnaturallyoccursalongtheirlength.
Thisisalreadybeingdone,andhasbeendoneformorethan20years—itjusthasn'tbeen
donenearlyoftenenough.Double-skinfaçadeslikethatpioneeredinthe1997Commerzbank
Tower, Frankfurt, perform as environmental “switches” and provide for natural ventilation,
whilemediatingtheindoortemperaturetoalevelthatdoesnotrequire24/7conditioning.New
projectsliketheShanghaiTower,withitslargeatriaandcommunalskygardens,takethisidea
tothenextlevel,asocialaswellasahighlyfunctionalseriesofspaces.
Consider also the potential of those seemingly inexhaustible high-altitude resources—
wind and solar.A handful of buildings have attempted to harness the wind and derive energy
generationbydirectingitthroughsculptedgaps,towardsturbinesintheirmasses,andnumer-
ous skyscrapers now incorporate solar arrays. However the implications of capturing wind
energyatheighthavenotbeenfullyresolved,andistherethepotentialforhigh-risefaçadesto
incorporatesolar/thermaltechnologies,ratherthanjustPVarrays.
Greenwallsofferarangeofbenefits,fromincreasedenergyefficiencytoaestheticappeal
andthereductionoftheurbanheatislandeffect.Thesameexteriorvegetationwefindcharm-
ingonlow-slungcollegiatebuildingscanalsobeexploitedtogreateffectatheight,providing
significantcoolingtothefaçadewhileblockingglare,enhancingthepsychologicalwellbeing
of the occupants, and reducing impact on mechanical systems.Again, this is not a simplistic
projectofextrusionupwards,butitisbeingdone,inplaceslikeOneCentralPark,Sydney,and
theBoscoVerticale,inMilan,Italy.
We’vealsoseensophisticatedmechanical,operablefaçadesthatadjusttosolarconditions,
suchasattheAlBahartowersinAbuDhabi.Othercutting-edgefaçades,liketheDohaTower,
incorporate historic building techniques to reduce thermal gain and thus improve efficiency.
Weshouldbeseeingmanymoreofthese.
One of the most stunning innovations of recent years is also one of the simplest—a tall
buildinginTokyo,theNBFOsakibuilding,usesenvirotranspirationtoshedheatviarain-filled
ceramic pipes that double as brises-soleil. In other words, it “sweats,” and the microclimate
surrounding it benefits from lowered temperatures. Multiply this across a whole city and the
urbanheatislandphenomenonbeginstoseemlessintimidating.
Thesuperlativeachievementsoftallbuildingsintermsofheightandstabilityhaveyetto
befullyrealizedintheMEPdepartment,buttheycanandmustbeiftallbuildingsaretobea
positive force in urban environmental sustainability. There is much research and hard work
ahead of us. Many one-off, bespoke solutions exist around the world, but there are few stan-
dardizedsetsofpractices.Intheworkofourtwoorganizations,ASHRAEandCTBUH,andin
thepagesbeforeyou,liethebasesforbuildingthatexpertise.
Dr.AntonyWood
CTBUHExecutiveDirector
Research Professor, College ofArchitecture, Illinois Institute of Technology, Chicago, and
visitingprofessoroftallbuildings,TongjiUniversity,Shanghai
TABLE OF CONTENTS
Foreword..........................................................................................xv
Preface...........................................................................................xvii
Acknowledgements................................................................................. xix
CHAPTER 1—INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Introduction.........................................................................................1
GeneralOverview....................................................................................5
EnergyStrategies.....................................................................................7
CHAPTER 2—ARCHITECTURAL DESIGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
RealEstateConsiderations .............................................................................9
ArchitecturalConsiderations...........................................................................11
CoreDesign........................................................................................11
ServiceCores.......................................................................................12
Floor-to-FloorHeight ................................................................................17
TheOwner’sInvolvement.............................................................................18
TheArchitect’sInvolvement...........................................................................19
StructuralCoordination...............................................................................19
AlternativeDuctworkDesigns .........................................................................23
LightingSystems....................................................................................24
ConclusionsConcerningFloor-To-FloorHeight ...........................................................25
CHAPTER 3—FAÇADE SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
BuildingOrientation .................................................................................27
FaçadeSystems.....................................................................................28
Shading ...........................................................................................31
GlazingandFaçadesAnalysis..........................................................................31
Infiltration.........................................................................................34
x ASHRAE Design Guide for Tall, Supertall, and Megatall Building Systems
CHAPTER 4—CLIMATE DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
ClimateandtheAtmosphere...........................................................................37
ExtrapolatingGroundDataUpwards ....................................................................37
GeneratingClimateDataatUpperElevations..............................................................37
ClimateModelingUsingMesoscaleNumericalTechniques ..................................................38
ClimaticData(SeeAppendixA)........................................................................39
TheoreticalDiscussionofStackEffect...................................................................39
PracticalConsiderationsofStackEffect..................................................................44
CalculationofStackEffect ............................................................................45
MeanstoMinimizeStackEffect........................................................................47
FurtherMitigationOptions ............................................................................49
CHAPTER 5—INDOOR AIR QUALITY AND THERMAL COMFORT . . . . . . . . . . . . . . . . . . . . 51
ProvideAppropriateAirandQuantitiesforEachRoomorZone...............................................51
EffectivelyDistributeVentilationAirtotheBreathingZone..................................................53
EffectivelyDistributeVentilationAirtoMultipleSpaces ....................................................53
UseDedicatedOutdoorAirSystemswhereAppropriate .....................................................54
UseDemand-ControlledVentilationwhereAppropriate .....................................................54
UseNaturalorMixed-ModeVentilationwhereAppropriate..................................................56
WhyNaturalVentilation? .............................................................................58
VentilationperASHRAEStandard62-2013...............................................................59
ProvideComfortConditionsthatEnhanceOccupantSatisfaction ..............................................61
AdaptiveComfort ...................................................................................62
CHAPTER 6—HVAC SYSTEMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Introduction........................................................................................69
ConsiderationsinSystemSelection......................................................................69
All-AirVariable-Air-VolumeSystem....................................................................70
Low-TemperatureAirVAVSystems ....................................................................72
UnderfloorAirSystems...............................................................................73
Air/WaterSystems...................................................................................76
RadiantCeilings.....................................................................................76
PassiveBeams......................................................................................77
ActiveBeams.......................................................................................77
Variable-FrequencyDrive(VFD)Fan-CoilUnits...........................................................80
Variable-Refrigerant-Flow(VRF)Fan-Coilswith100%OutdoorAirVentilation .................................80
Air-ConditioningSupplySystems—Conclusions...........................................................81
CHAPTER 7—CENTRAL MECHANICAL EQUIPMENT ROOM AND
FLOOR-BY-FLOOR FAN ROOMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
TheAlternativeSystems ..............................................................................83
ComparisonofAlternativeSchemes.....................................................................89
ConstructionScheduleImpact..........................................................................91
OwnerIssues.......................................................................................92
EquipmentConsiderations.............................................................................93
ArchitecturalIssues..................................................................................94
