SELECTED TOPICS IN HIGH RISE MECHANICAL DESIGN

1 NORR | SWEGON ACADEMYT oronto and DubaiShangri-la HotelFEBRUARY 2011 SELECTED TOPICS IN high RISE MECHANICAL DESIGNS imcoe TowersINTRODUCTIONT opicA discussion on MECHANICAL building systems DESIGN practices in tall buildings. We will draw upon our experiences in building DESIGN in urban Canada, (specifically Toronto and surrounding region) and the Middle East, (specifically Dubai and the GCC).ThesisThere are many factors which influence building DESIGN choices not just SampleHigh rise residential, hospitality and commercial facilitiesINTRODUCTIONT orontoSettled the 17th centuryCapital of the province of OntarioBusiness capital of CanadaSprawling metropolis on the north shore of Lake OntarioPopulation of million Climate of 4 seasonsSchizophrenic summerGorgeous AutumnModerate winter with very cold periodsNon existent springToronto Temperature hTemperature (oC)Temperature ( C ) ( C ) MeanTemperature ( C ) 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 million (mostly expatriates)Climate: two seasons: Hot summers up to 50 C with high humidity.

2 Spring and fall are more pleasant +/- 30 CWinter has lows of 15 C with occasional rainAbu Dhabi Temperature Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecMonthTemperature (oC)Temperature ( C ) ( C ) MeanTemperature ( C ) Why What How and BecauseWhy- 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 ofINTRODUCTION How - Achieve the why with the what under the influences of: BecauseClimateInternational standardsRegional regulationsInvestor/Developer financial expectationsLong term vs short term thinkingMarket forces Vendors availability in the market Labour costs Material costs Contractor habits.

3 CapabilitiesMaintenance likelihoodRegional habitTypes of ownershipEngineer s position in the marketAesthetic and functional project goals including shapeINTRODUCTION Physical RealitiesWater in a typical 10 story building exerts a pressure of bar10 Stories10 barINTRODUCTION A tall building can be considered to be a collection of shorter buildings10 Stories10 Stories10 Stories10 Stories10 Stories10 StoriesINTRODUCTION Water in a 30 story tall building exerts a pressure of 3 x 10 story = 3 x bar = 10 bar10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 bar10 barINTRODUCTION 10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 StoriesHigh pressure zone Medium pressure zonesPressure breaksINTRODUCTION Medium pressure zones10 Stories10 Stories10 Stories10 Stories10 Stories10 StoriesHigh pressure zone Heat exchanger pressure break10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 StoriesUpper building zonePressure breaksINTRODUCTION Medium pressure zones10 Stories10 Stories10 Stories10 Stories10 Stories10 StoriesHigh pressure zone 10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 StoriesWater storage tank pressure breakPressure breaksINTRODUCTION Water, waste and other fluids move up and down the vertical axis.

4 Pressure considerations must be can move orders of magnitude greater amount of energy than heating and cooling energy up and down a building requires less shaft space with water than with Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 Stories10 StoriesINTRODUCTION In consideration of the foregoing we will examine the following MECHANICAL DESIGN issues:Plumbing SystemsLife SafetyHeating, Ventilation & Air ConditioningEnvelope ConsiderationsPLUMBING SYSTEMSW ater SupplyDubaiLegacy of unreliability, On site storage mandatoryRoof top tanks strongly incentedConcrete construction allows for extra weight of waterTanks on a building roofTanks on a building roofPLUMBING SYSTEMSW ater SupplyTorontoRobust and developed infrastructureGenerally reliable 4 -6 barUp to 5 +/- stories no supplementary pumping is requiredMunicipality takes responsibility for water supply adequacy, quality.

5 SYSTEMSS ystem pressure regulationEvery 30 stories of residential buildingResults in 10 bar additional pressureOptimal delivery pressure of bar Maximum 5 barPressure regulation is necessaryPLUMBING SYSTEMSD omestic Hot WaterDistributed tank type electric gasDistributed tankless gas electricCentral supply gas electric Solar hot water Dubai water chillingHot water from cold water tapsCold water from hot water tapsPLUMBING SYSTEMS Domestic hot water recirculation in high rise10 Stories10 StoriesPLUMBING SYSTEMSD rainage and VentingTorontocomprehensive regulatory frameworkwell understood standard of practicevendors / designer/ authorities alignedDubairudimentary regulatory frameworkvarious international standards, BS, North American, EN, Chinesevendors / designers / authorities not well alignedVenting: not well understoodInstallation of traps and floor drains habitDual stack mandatoryPLUMBING SYSTEMSTall building drainageHydraulic jump lowest floors of a drainage riser must not be connected directly to the high building riserLIFE SAFETYNFPA 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 bar residual pressure requiredTorontolow rise building directly suppliedfire pumps supplied from back up emergency powerseparate sprinkler & standpipe pumps (usually)

6 Dubaialways pumpedelectric fire pump backed up by direct diesel driven fire pumpresults in combined sprinkler and fire standpipe systemsLIFE SAFETYHigh Building Pressure Control orifice platesApplication of sprinklers sometimes not well understoodExample: pendant sprinklers in exposed applicationsPendant sprinkler headsPendant sprinkler headsUpright sprinkler headUpright sprinkler headLIFE SAFETYS moke ControlSmoke control specifically mandated for high buildingsDefinition of high building Isolation of fire floorextraction from fire floorpressurize floor above and belowdifferential pressure of 12 Papressurize stairwellStairwell PressurizationMust supply at various points in the stairwell so that backpressure at exit doors is less than 133 N HEATINGH eatingElectric Low first cost but high operating costDistributed hot water Very commonDistributed gas Not common due to safety concernsDistributed steam Currently not commonAir source heat pumps Not compatible with very cold climatesWater or ground source heat pumps Commonly appliedDubai No heating HEATINGH eatingTall Building hot water supply to.

7 Perimeter radiationreheat of branch air terminalsHEATINGH eatingTall Building hot water supply to:perimeter radiationreheat of branch air terminalsoverhead radiation fan coil unitsHEATINGH eatingTall Building hot water supply to:perimeter radiationreheat of branch air terminalsoverhead radiation fan coil unitsUnit heaters and convectorsHeat pumpsHEATINGH eatingBuilding hot water is typically supplied from a central hot water plant which consists of boilers, distribution pumps and piping tall buildings pressure zoning is necessary to keep the installation economical since high pressure piping and components are more practice is to DESIGN the heating system at minimum supply water temperature and maximum difference between the supply and the return in order to increase system efficiency. This must be optimized against system water temperature is directly proportional to the output capacity of the heaters in the building spaces.

8 Supply water is often scheduled against outside air pumps combined heating and cooling systems HEATINGH eatingHeat source Ground connected geothermalheating boilerHeat sink Ground connected geothermalCooling towerIndividual heat pumps are connected via a piping and water circulation systemDistributed compressors have noise and maintenance disadvantagesVENTILATION Fresh Air SupplyToronto/Dubai: ASHRAE standards are a unifying normBoth Toronto and Dubai have months of the year when natural ventilation is not possibleDubai ventilation shaftsTorontoFiltered, heated, cooled, humidifiedHeat recovery if dedicated fresh air system FREE COOLING when combined with system supply airDemand control just now starting to be utilizedDubaiSand trap, filtered, cooled, de-humidifiedHeat recovery norm (mandatory)Heat wheels, heat pipesConstant volume demand control starting to be utilizedSpace humidity is an issueVENTILATION HUMIDITY CONTROLV entilation required to maintain comfort conditions in winter will require that moisture be added to fresh air supply to ensure that building is maintained at adequate humidity humidity results in occupant discomfort and health issues and static electric shock problemsMitigationAdd steam to air stream (energy to evaporate water provided by boiler)Add atomized water to air stream (energy to evaporate water provided by air handling system )

9 Reduce load with heat wheel latent heat recoveryVENTILATION Building ExhaustsCommercial kitchen exhaustsregulated under NFPA 96grease fires are very dangerous16 gauge welded duct in fire rated enclosureCanadian authorities terminate m above roof level Special filtration technologies remove grease relaxes NFPA 96 requirementsVENTILATION Building ExhaustsResidential Kitchen ExhaustResidential Kitchen ExhaustNot regulated by NFPA 96 UAE culturally inclined to fried foodsVENTILATION Building ExhaustsResidential Kitchen ExhaustResidential Kitchen ExhaustNot regulated by NFPA 96 Culturally inclined to fried foodsSolution indirect central exhaustVENTILATION Washroom exhausts Central extraction is common in both Toronto and DubaiTraditional 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 Toronto high rise residential solution individual toilet/kitchen extraction fans controlled from light switch, ducted directly outside.

10 Brick fa ade can accept grilles even if Architects do not want these low cost. Curtain wall solutions in Dubai cannot high rise Residential ExhaustsDemand control extractionKitchenBathroomLaundryAIR CONDITIONINGT orontoUnitary equipment rather than Air cooled chillers for smaller buildingsSplit AC not common for larger commercial or residential buildings(New advances in refrigerant circuits serving multiple zone units)AIR CONDITIONINGC hilled Water SupplyTorontoMost larger buildings utilize water cooled chiller plantsDeep lake coolingDeep lake coolingAIR CONDITIONINGC hilled Water SupplyDubaiAir cooled chillersWater cooled chiller plantsDistrict cooling plants and distributionAIR CONDITIONINGAir Conditioning Commercial BuildingsVariable Air VolumeConstant air supply temperatureVary air flow quantity to maintain space temperatureConstant Air VolumeVary supply air temperature to maintain Space air temperatureAIR CONDITIONINGAir Conditioning Commercial BuildingsDubaisome VAVhorizontal fan coil units installation complexity maintenance issues low floor space impact improved floorplate efficiency Meat locker effectAIR CONDITIONINGAir Conditioning Commercial BuildingsToronto Variable Air VolumeCentral Units Large units located in MECHANICAL rooms Conditioned supply and