selected topics in high rise mechanical design

NORR | SWEGON ACADEMY

Toronto and Dubai Shangri-la Hotel

MAY 2010

SELECTED TOPICS IN HIGH RISE MECHANICAL DESIGN

Simcoe Towers

INTRODUCTION

Topic

A comparison of building mechanical practices in hot and cold climates. We will compare mechanical building design in urban Canada, (specifically Toronto and surrounding region) with the Middle East, (specifically Dubai and the GCC).

Thesis

There are many factors which influence building design choices not just climate.

Study Sample

Mid to high rise residential, hospitality and commercial facilities

INTRODUCTION

Toronto

Settled the 17th centuryCapital of the province of OntarioBusiness capital of CanadaSprawling metropolis on the north shore of Lake OntarioPopulation of 3.2 million Climate of 4 seasons

Schizophrenic summerGorgeous AutumnModerate winter with very cold periodsNon existent spring

Toronto Temperature Profile

-15.0-10.0-5.00.05.0

10.015.020.025.030.035.040.045.050.0

Jan

Feb

Mar Apr May Jun Ju

lAug Sep Oct NovDec

Month

Tem

pera

ture

(o C)

Temperature (°C ) Max.Temperature (°C ) MeanTemperature (°C ) Min.

INTRODUCTIONDubai

The business capital of the United Arab EmiratesTrade, Finance, Stocks & CommoditiesRegional travel hubTourist destinationRuled by Maktoum family since the 18th centuryArabian Gulf to the west Population of 1.3 million (mostly expatriates)Climate: two seasons:

Hot summers up to 50º C with high humidity. Spring and fall are more pleasant +/- 30º CWinter has lows of 15º C with occasional rain

Abu Dhabi Temperature Profile

-15.0-10.0

-5.00.05.0

10.015.020.025.030.035.040.045.050.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Tem

pera

ture

(o C)

Temperature (°C ) Max.Temperature (°C ) MeanTemperature (°C ) Min.

INTRODUCTION

Why What How and Because

Why- SafetyHealthFit for purpose (meet comfort or process expectations)Economic viability (financial expectations, time)Effectiveness (Operations and Maintenance, energy efficiency, sustainability)

What - Movement of air, water etcunder the effects of gravity and powered delivery systems, subject to understood principles of heat transfer, fluid mechanics and solid mechanics

How - Achieve the Why with the What under the influences of

INTRODUCTION

How - Achieve the why with the what under the influences of:

BecauseClimateInternational standardsRegional regulationsInvestor/Developer expectationsLong term vs short term thinkingMarket forces• Vendors – availability in the market• Labour costs • Material costs• Contractor – habits, capabilitiesMaintenance likelihoodRegional habitTypes of ownershipEngineer’s position in the marketAesthetic and functional project goals including shape

INTRODUCTION

A building

10 Stories10 Stories 3.3 bar3.3 bar3.3 bar

INTRODUCTION

Some buildings

10 Stories10 Stories 10 Stories10 Stories10 Stories10 Stories

INTRODUCTION

A tall building

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

10 bar10 bar

INTRODUCTION

A taller building

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

INTRODUCTION

A taller building

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

10 Stories10 Stories

INTRODUCTION

In consideration of the foregoing we will examine the following mechanical design issues:

Plumbing Systems

Life Safety

Ventilation

Heating & Air Conditioning

PLUMBING SYSTEMS

Water Supply

TorontoRobust and developed infrastructureGenerally reliable 4 -6 barUp to 5 +/- stories no supplementary pumping is requiredMunicipality takes responsibility for water supply adequacy, quality, etc.

PLUMBING SYSTEMS

Water Supply

DubaiLegacy of unreliability, On site storage mandatoryRoof top tanks strongly incented

Concrete construction allows for extra weight of water

PLUMBING SYSTEMS

Water Supply

DubaiLegacy of unreliability, On site storage mandatoryRoof top tanks strongly incented

Concrete construction allows for extra weight of water

PLUMBING SYSTEMS

System pressure regulationEvery 30 stories of residential buildingResults in 10 bar additional pressure

Optimal delivery pressure of 1.5 – 2.5 bar Maximum 5 bar

Pressure regulation is necessary

PLUMBING SYSTEMS

Domestic Hot Water

Distributed tank type • electric• gas

Distributed tankless• gas• electric

Central supply• gas• electric

Dubai water chillingHot water from cold water tapsCold water from hot water taps

PLUMBING SYSTEMS

Domestic hot water recirculation in high rise

PLUMBING SYSTEMS

Drainage and Venting

Torontocomprehensive regulatory frameworkwell understood standard of practicevendors / designer/ authorities aligned

Dubairudimentary regulatory frameworkvarious international standards, BS, North American, EN, Chinesevendors / designers / authorities not well alignedVenting: not well understoodInstallation of traps and floor drains – habitDual stack mandatory

PLUMBING SYSTEMS

Tall building drainage

Hydraulic jump – lowest floors of a drainage riser must not be connected directly to the high building riser

LIFE SAFETY

NFPA National Fire Protection Associationcommon basis of designwidely acceptedcomprehensive standards on commercial, institutional and

industrial life safety issuesWater supply for fire fightingautomatic sprinkler systemfire hose system 4.5 bar residual pressure required

Torontolow rise building directly suppliedfire pumps supplied from back up emergency powerseparate sprinkler & standpipe pumps (usually)

Dubaialways pumpedelectric fire pump backed up by direct diesel driven fire pumpresults in combined sprinkler and fire standpipe systems

LIFE SAFETY

High Building Pressure Control – orifice plates

Application of sprinklers sometimes not well understood

Example: pendant sprinklers in exposed applications

Pendant sprinkler headsPendant sprinkler heads Upright sprinkler headUpright sprinkler head

LIFE SAFETY

Smoke Control

Smoke control specifically mandated for high buildingsDefinition of high building

Isolation of fire floorextraction from fire floorpressurize floor above and belowdifferential pressure of 12 Papressurize stairwell

Stairwell PressurizationMust supply at various points in the stairwell so that backpressure at exit doors is less than 133 N

VENTILATION

Fresh Air Supply

Toronto/Dubai: ASHRAE standards are a unifying normBoth Toronto and Dubai have months of the year when natural ventilation is not possible

Dubai ventilation shafts

Torontofiltered, heated, cooled, humidifiedheat recovery if dedicated fresh air system“FREE COOLING” when combined with system supply airdemand control just now starting to be utilized

Dubaisand trap, filtered, cooled, de-humidifiedheat recovery norm (mandatory)heat wheels, heat pipesconstant volume – demand control starting to be utilizedspace humidity is an issue

VENTILATION

Building Exhausts

Commercial kitchen exhaustsregulated under NFPA 96

grease fires are very dangerous

16 gauge welded duct in fire rated enclosure

Canadian authorities terminate 1.3 m above roof level

Special filtration technologies remove grease relaxes NFPA 96 requirements

VENTILATION

Building Exhausts

Residential Kitchen Exhaust

Residential Kitchen ExhaustNot regulated by NFPA 96UAE culturally inclined to fried foods

VENTILATION

Building Exhausts

Residential Kitchen Exhaust

Residential Kitchen ExhaustNot regulated by NFPA 96Culturally inclined to fried foodsSolution indirect central exhaust

VENTILATION

Washroom exhausts Central extraction is common in both Toronto and Dubai

Traditional regulations in Dubai required 2 m X 3 m open to air shafts at kitchens and bathrooms – planning nightmare. Exterior plumbing pipes and open to air ventilation.

Common Toronto high rise residential solution – individual toilet/kitchen extraction fans controlled from light switch, ducted directly outside. Brick façade can accept grilles even if Architects do not want these – low cost. Curtain wall solutions in Dubai cannot accommodate.

VENTILATION

High rise Residential Exhausts

Demand control extraction

KitchenBathroomLaundry

HEATING AND AIR CONDITIONING

Heating

ElectricDistributed hot waterDistributed gas

Tall Building hot water supply to:perimeter radiationoverhead radiationreheat of branch terminalsfan coil units

Dubai No heating

HEATING AND AIR CONDITIONING

Chilled Water SupplyToronto

Unitary equipment rather than Air cooled chillers

Water cooled chiller plants

HEATING AND AIR CONDITIONING

Chilled Water Supply

DubaiAir cooled chillersWater cooled chiller plantsDistrict cooling plants and distribution

HEATING AND AIR CONDITIONING

Air Conditioning Commercial Buildings

TorontoVAV • central• compartmentalizedConstant volume / variable

temperatureVariable volume / variable

temperature

Dubaisome VAVhorizontal fan coil units• installation complexity• maintenance issues• low floor space impact • improved floorplate efficiency• Meat locker effect

HEATING AND AIR CONDITIONING

Air Conditioning Residential and Hospitality

Torontohorizontal fan coilvertical fan coils

HEATING AND AIR CONDITIONING

Air Conditioning Residential and Hospitality

Dubaihorizontal fan coil units• installation complexity• maintenance issues• low floor space impact – improved

floorplate efficiency

SUMMARY

Toronto DubaiClimate cold winter harsh summerInternational standardsRegional regulationsInvestor/Developer expectations short term viewLong term vs short term thinkingMarket forces

• Vendors – position in the market• Labour – cost vs materials high labour costs low labour costs• Contractor – habits, capabilities• Maintenance likelihood moderate low

HabitType of ownership ownership not well defined

Engineer’s position in the marketArchitectural and functional goals

SUMMARY

Thank you for your attention

Questions?