the impact of increasing temperatures in transition zones...

Proceedingsof9thWindsorConference:MakingComfortRelevantCumberlandLodge,Windsor,UK,7-10April2016.NetworkforComfortandEnergyUseinBuildings,http://nceub.org.uk

The impact of increasing temperatures in transition zones inAbuDhabi onthermalcomfort

TiaKansara1

1UniversityCollegeLondon,UK,[email protected]

AbstractThe applicationofwestern comfort standards to buildings in theArabianGulf has resulted inmass-use air-conditioning.BuildingsarecooledtotemperaturesthatareexcessivecomparedtohistoricexpectationsinAbuDhabi. This paper raises the question ofwhether these thermal conditions are appropriate. If not, is therescopeforadjustmentof indoorstandardstobroadenthermalcomfortparameterswhilstretainingthermallysatisfiedoccupants.Thispaperinvestigatestheentrancelobby,aformoftransitionzone,cooledidenticallytooccupied zones, that provides occupants with a bridge between external and internal environments. Iftransitionzoneshavedifferentcomfortconditionstosteadystateenvironments,theymayallowoccupantstoacclimatize before reaching their destination inside the building.. In 2012, twenty existing mixed-use, casestudy buildings were tested using passive methods to widen comfort parameters indoors. Buildings weremeasured to provide occupant feedback from an intervention of raising the indoor transition zonetemperatureby1ºC.Apreinterventionandpostinterventionsurveywasusedintheentrancetransitionzone.Theresultsshowtherearesomechangesinbuildingsthatcanbeassociatedtotheinterventionstudy.

Keywords:ThermalComfort;TransitionZone;AbuDhabi;

1 IntroductionThewidening of the indoor thermal comfort parameters could lead to an opportunity tostudy how to improve the performance of existing buildings in Abu Dhabi using simpletechniquesofchangingthetemperature insidethetransitionzone.Meanwhile,occupantsmayprovidefeedbackforapotentialchangeinbehaviourtowardacceptingmoreambientenvironments. Thermal comfort is the psychophysical experience of one’s immediateenvironment. Transition zones aredesigned tobe steady-state environmentsbut theydonot need to be designed to deliver steady-state conditions. There is little empiricalinformation about how much time is spent in transition zones and more information isrequired. This shows, that on average, occupants do not spendmore than 10minutes intransitionalareasandas such the traditionalmethodofPredictedMeanVote (PMV)maynotbeapplicabletothermalcomfortassessmentsinAbuDhabi.

The transition zones bridge the external and internal environments of the building. Theexchangeof air between theoutdoors and indoors is a significant factor in these spaces.These spaces are currently cooled continuously throughout the year. Further analysis isneeded to understand how the thermal comfort in these areas may be tested and bywideningthecomfortparameterswhatimpactthismayhaveonoccupantreceivedcomfort.

Windsor Conference 2016 - Making Comfort Relevant - Proceedings 278 of 1332

2 LiteratureReview2.1 TransitionZonesTransition areas may be characterised by their physical location; features (glazing wallsorientationandfenestration);varyinglevelsofaccesstothepublic,workersandresidents;occupancy (schedules and use) and their fluctuating thermal parameters. Chun et aldescribethreeparticulartypesoftransitionalenvironments(Chun,Kwok,&Tamura,2004),theseare:TYPE1:A transitional spacescontainedwithinabuilding,whereconditionsareconstantlymixedaspeoplemoveinandoutofthebuilding.

TYPE2:Anattachedcoveredspaceconnectedtothebuilding(balcony)

TYPE3:Aseparatespacewithnoattachmentstobuildings(busstations)

Types 1 and2 are areas that are influencedby theoutdoor climatewhilst architecturallybound to the building. Pitts description of transitional areas includes entrance zones,circulationzones,andzonesof longer residence (Pitts,2013).Pittsargues there isaweakseparation between the external and internal environments in the entrance zones. Hissuggestion is towidenthePMVtooperatetheentrancezonebetween+0.5to -0.5 (Pitts,2013).Occupantspassthroughavarietyofthermalenvironmentsastheyjourneythroughabuilding. These are referred to as thermal step changes. The largest step change in AbuDhabiisbetweentheexternalenvironmentinthesummerseasonandtheentrancezone.Theentrancetransitionareashaveafunctionmoreakintofreerunningspacesbecauseofthelinktotheexternalenvironment.HereMETvaluesareexpectedat1.7-2.0(Pitts,2013).Despite the numerous features of transition zones, the focus should be on the entrancezonewhere there is a high rateof infiltration from theoutdoors andoccupants expect ashort transit, see Fig. 2.1. This is typically where heat exchange between man andenvironment does not reach steady-state but the increased thermal flexibility improvescomfort(Humphreys&Nicol,1998)andtheincreaseinperceivedcontroldeliversahigherrateofoccupantsatisfaction(Williams,1995).

Figure2:1Conceptoftransitionalenvironmentsindoorsandoutdoors

2.2 ThermalComfortinTransitionZonesThermal comfort is the human psychological sense of satisfaction in one’s physicalenvironment.Researchdividesintosubjective(satisfaction,productivity,health,wellbeing,and approval) and objective factors (Temperature, Humidity, Air speed, Clothing Factor -CLO and Metabolic rate - MET). The physical, physiological and increasingly the


psychologicalconstructshavedeterminedbothquantitativeandqualitativeparametersofthermal comfort. Although the quantitative measurements are favoured (Meir, I. A.,Motzafi-Haller,W., Krüger, E. L.,Morhayim, L., Fundaminsky, S. andOshry-Frenkel, 2007)thereremainsanopportunitytoresearchqualitativemeasuresofsubjectivestates.

Theheatbalancemodel isbestused ina steady-stateenvironment;however, transitionalzones are by definition, not steady-state environments. They are areas that connectoccupantstotheoutdoorsandindoors,aswellasconnectingoccupantsbetweendifferentsteady-stateenvironmentsindoors.Furtherarticulationoftheneedsofthetransitionzonesmay close the gap,which exists between the design-stage and actual construction of thebuilding’s thermal environment. It is rare to find indoor environments that have uniformconditionsthroughoutthebuilding(Schiavonetal.,2014,p.329).Traditionalheatbalancemodelsuseasinglesetofconditionstocompareoccupantexperiencesandtheresult isavarietyofresponseseventhoughoccupantmaybewearingthesamelevelofclothingandactivityandexposedtothesamezone(Schiavonetal.,2014,p.329).

Mechanical control of the physical environment to standardise indoor comfort hasdominated comfort research (RichardDeDear, 2012). Despitework to introduce thermaldelight to highlight the significance of broadening the parameters of thermal comfort(Heschong,1979),environmentalengineeringapplicationsofcomfort,suchasheatingandcooling,arethemainfocusofthebuildingindustry(Fanger,1970,p.14).Fanger’sanalysisshows that applying an inter-disciplinary approach to comfort, including heat and masstransfer,thermalphysiology,psychophysics,ergonomics,biometeorology,architectureandtextile engineering, one can increase the understanding of ones immediate environment.These evaluations are useful to learn from in order to construct better buildings in thefuture.

There is littleempirical informationabouthowmuchtime isspent intransitionzonesandmore information is required.Researchcompletedby theauthor in2011showed thatonaverage,occupantsdonotspendmorethan10minutesintransitionzones.Ifthisisthecaseonawiderscale,thetraditionalmethodofPMVmaynotbeapplicabletothermalcomfortassessmentsandissupportedbytheworkofSchiavonetal.suggestingtraditionalmodelsare “far from reality during building operation and in building performance simulations”(Schiavonetal.,2014,p.329).

The adaptivemethod of thermal comfort analysis requires a building to be passively, ornaturally ventilated. The transition zones are cooled continuously throughout the year.Often thismeans, there is no scheduling of air conditioning and the adaptivemethod ofthermalcomfortmaynotbeapplicabletothetransitionzonesindoors.However,ofthetwotransition zone connectors, the space that bridges the indoors to the outdoors is ofsignificantconcernastheairexchangewiththeoutdoorsisatitshighest.

Thermalcomfort theory recognises that there isnoexactsetcondition thatwill satisfyalloccupants, as each occupant has a distinct perception of ‘too hot’, ‘too cold’, and‘comfortable’. One’s perception is fed by feelings, reasoning and how we react to ourenvironment. Theobjective in designing a common thermal environment is to satisfy themajorityofoccupantsandtominimisethosewhoaredissatisfied.PMVstudieshavebeenusedintransitionzonesbutduetotheshortperiodoftimespentinsuchnonsteadystateenvironments,thecontinuationofPMVmaynotbeideal.


Standards for building construction specify characteristics of the design for steady-stateenvironments. The American Society of Heating, Refrigerating and Air-ConditioningEngineers – ASHRAE (Paliaga et al., 2013) as well as the British Standard/EuropeanStandard/International Standards Organization – BS EN ISO 7730, two of the most-usedstandards,bothdefinecomfortconditions for steady-states.However, separateandmoreappropriate comfort parameters for transitional spaces are lacking in current literature(Hwang,Yang,Chen,&Wang,2008).AbuDhabi’sstandardforthebuiltenvironment-thePearl Rating System (PRS - introduced in 2010 by Emiri Decree) uses ASHRAE, ISO andCharteredInstituteforBuildingServicesEngineers(CIBSE)standardsfordesigningbuildings.

Theseratingsystemsaswellasthe localstatutes lackanytransitionzone-specificcomfortconditions or design parameters. There is also an absence of analytical studies on thetraditional transition zones of the Emirati and international standards are unsatisfactory.Thisplacesthediscussiononthecomfort-designoftheseenvironmentsasatimelyframingofthesubjectinthispaper.Fangermentionedthereare“unhealthyshocks”uponentryintoabuilding(Fanger,1970,p.93).Thisoccursintheentrance,whenonemovesfromthehotoutdoorstotheairconditionedindoors,which isoftenthecase inAbuDhabi,throughoutthe year, but particularly during the summer. There is information on the impacts of thesudden shift in temperature on the occupant, but there is little research on the exactamountoftimeanoccupantspendsinthedifferentpartsofthebuilding’scirculationareasandcorridors.

ISO7730mentionsthePMVisapplicableforanenvironmentafter30minutesofexposure(ISO,2005).ThamandWillem(2010)researchedthetimeframeforchangestobenoticedinthe reduction of whole body thermal sensation. They concluded that most noticeablechangesinthebodycouldbeperceivedwithinthefirsthourofexposureat20ºC(Tham&Willem,2010).Furtherresearchontheexacttimedifferencebetweenstepsaswellasthetimeconstantofthehumanbodyarerequired.

Literature suggests it takes up to 20 minutes to adjust to a steady state environment(Hwangetal.,2008;Nagano,Takaki,Hirakawa,&Tochihara,2005;Ring,deDear,&Melikov,1993).Occupantsspendshorteramountsoftimethanthisintransitionalareas.Therefore,itis inappropriatetousethePMVmodeltocalculatecomfort.Chunetal.arguetransitionalspaces shouldbe consideredas ‘dynamic, variableandunstable’ (Chun,Kwok,&Tamura,2004).Withthisdefinition,traditionalstandardsarefarfromaddressingtherequirementsforthesespaces.Humanscanadjusteffectivelytoadifferentinternalenvironment(deDear,Ring, & Fanger, 1993; Hwang et al., 2008; Nagano et al., 2005). The transition zones arepsychologically and physically halfway between the outdoors and indoors. The design ofsuchplacesshouldbecongruentwiththepatternscreatedwiththesurroundingbuilding,alltoaidtherelationshipwiththeexternalelements(Alexander,1979).

InAbuDhabiitisunlikelytheoccupantswillhavespentmorethan1houroutside,withoutany artificial cooling e.g. walking outside, or in a car without it. This may change theexpectationof cooling they requireuponentry,dependingon their acclimatisation to thesummerheat. In2011,theauthorfoundthattheaveragetimeoccupantspassedthroughthe building to arrive at their destinationwas tenminutes. Further analysis on transitionzones shows how subjectsmove from discomfort to comfort whenmoving from cold towarm environments (Hardy & Stolwijk, 1966). However, the converse where analysis iscompleted on subjects moving from hot environments (outside) to cooler environments(inside)hasyettoberesearched.


2.3 AdjustingtransitionzonestemperaturesetpointTheASHRAE standards have been important for the design of healthy, liveable buildings,however, asDeDear suggests, they indirectly promoteexcessively cold temperatures (deDear, 2012). Further research is needed on the changes to the transition zone’s comfortconditions to testhowoccupants react to thesechanges.This isespecially thecase if thetemperature is increased to widen the thermal comfort parameters and reduce energyconsumption. De Dear and Brager (1998) interviewed occupants in Naturally Ventilatedbuildings, their findings showed occupants preferred wider diversity in temperatures tomimictheoutdoors(Brager&deDear,1998).However,thesestudieswereundertakeninnon-airconditionedbuildings,casestudiesusedinthisresearchareallmechanicallycooled.

Theapplicationofwideningthecomfortparametersattheentranceareaofbuildingswherethereiscontactwiththeexternalclimatemayprovefruitful.Testingtheperceivedcomfortofoccupants in these spaces couldprovideanadvancementof knowledgeand literature.According toHuang, Lu andMa further researchwould be needed to identifywhere theconditionsofthecirculationspacescouldchangetoimprovecomfortaccordingto(Huang,Lu, &Ma, 2011). Chun et al. suggests that buildingswith considerable circulatory spacesmay face higher operational costs per unit indoor area in comparison to steady-stateenvironments (Chun et al., 2004). For example, Saleh and Pitts discuss four notionalexamples of geometries to indicate energy use of these spaces (bin Saleh& Pitts, 2004).Theymodelledwhatachangeintemperature(±5ºC)coulddotothetransitionzones.Theresultsoftheirmodelsshowedanotional10%ormoredecreaseinenergyuseovertheyear,if glazing ratio, building configuration and building design are taken into considerationalongside set point changes. There are a number of examples around the world thatillustrate a wider temperature band in buildings. The UK Health and Safety Executive(Corrosion,Of,Steels,&Swimming,2006)suggestsanindoorenvironmentcanrangefrom13-30°C, according to the levelof activity indoors (Nicol,Humphreys,&Roaf, 2012). TheAustralianstandardAS1837-1976(1976)recommendsbetween21-24°CforofficesandtheBritishCouncilforOffices(BritishCouncil,2010)recommendsbetween20-26°Cduringthesummer.

Studies challenging the BS EN ISO 7730: 2005 in Ilam, Iran, found that occupants werewilling to accept comfort at a higher temperature than offered in BS EN ISO 7730: 2005(Heidari&Sharples,2002).Inanexperimentwith18malesand18females,subjectedtoarangeof temperatures of 22-32ºC, Cui et al. found that performanceof theworkerswasgreatlyaffectedbydiscomfort(Cui,Cao,Park,Ouyang,&Zhu,2013).Thetestsshowedthattheoptimumtemperaturerangeforperformancewas22-26ºC.

Schiavonetal.propose indoorsetpointstoremainbetween18ºCand27.3ºC ifoccupantsareallowedtoadapttheirclothingtoachievethermalcomfort (Schiavon,Hoyt,&Piccioli,2014, p. 331). Additionally, if occupants do not have the ability to change their clothes,setpointsshouldremainbetween21.3ºCand25ºC(Schiavon,Hoyt,&Piccioli,2014,p.331).

TheAbuDhabiEnergyCodes,recommendamaximumof22°Cforheatingandaminimum24°C for cooling with a relative humidity of 50% ±5% (International Code Council, 2012Article302.1). InMalaysianoffices, Ismailassessedthemeasuredtemperaturewas23.1ºCbuttheMalaysiancomforttemperaturewasfoundtobe24.6ºC(Budaiwi&Abdou,2013).Jiang and Tovey (2009) modelled indoor thermal comfort by increasing the indoortemperature set point. They found that during the summer a 1ºC increase, from25°C to26°Ccouldleadtoenergysavinginthebuildingof19%inShanghaiand22%inBeijing(Jiang


&KeithTovey,2009).Al-SaneaandZedan’sresearchonincreasingtemperaturesetpointsshowedtherewasacalculatedreductionofyearlycoolingof10%(Al-Sanea&Zedan,2008).Most literature shows the impact of the energy use from the change in the indoortemperaturesetpoint.

2.4 EvaluatingTransitionZonesItiscleartransitionalareasarewidelyconsidereddifferentfromsteady-stateenvironments.PostOccupancyEvaluation,whichhas thus farprovidedmethodofassessing steady-statezoneperformance,occupantsatisfactionandthermalcomfortisavalidmethodtoextendtotransitional environments. Objective and subjective measures in transition zones show avarietyoffactorsthatpointtowardspotentialenergysaving,primarilythisisinwideningthecomfortparameterinthebuilding(Alonso,Aguilar,Coch,&Isalguy,2000;binSaleh&Pitts,2004;Chunetal.,2004;Chun&Tamura,2005;Ghaddar,Ghali,&Chehaitly,2011;Gulec,Cana,&Korumaz,2013;Huangetal.,2011;Hwangetal.,2008;JieKwong&Adam,2011;Kitchari Jitkhajornwanich, 2000; Nakano, 2003; Pitts, 2013). Whilst energy reduction intransitionalareasisthemainfocusforstudiesdoneontransitionzones,themainaimofthispaperisthermalcomfortofoccupantsandtheirapprovalofthesechangestothetransitionzone.Hence,uponwideningthecomfortparametersoftransitionzonesfactorslikethermalapproval of occupants upon immediately entering the building, complements thisinvestigation (Chun & Tamura, 2005; Jie Kwong & Adam, 2011). Transition zones arecharacterised by their location in bridging the indoor and outdoor environment; theiroccupancy time and use; their volume as a percentage of the whole building;architectural/engineeringfeaturesand,forthepurposeofthissection,themethodsusedtoanalysetheirthermalcomfort.

A large percentage of the buildings are often ignored when conducting post occupancyevaluations.TransitionalspacesofferoccupantstemporaryrefugefromtheharshsummerofAbuDhabi. Besides the influence from theexternal climate, theyprepareone for thetightlycontrolled,indoorworkenvironment(Nakano,2003).InAbuDhabi,thestepchangebetween the interior and exterior environment may reach upwards of 20°C. A thermalbuffer,betweennaturalandartificialspaces,ifmanagedwell,maylenditselfincreasingthepreparatory step for occupants as they move to steady-state environments. Literaturestates it isdifficultforoccupantstoachievethermallysteadystates iftheyareexposedtotheseenvironments for less than20minutes (R.J.deDear,Ring,&Fanger,1993;Nagano,Takaki, Hirakawa, & Tochihara, 2005). Steady state environments target specific indoorthermalcriterionindependentoftheexternalenvironment(Nakano,2003).Transitionzonesareyettoberecognisedbyeitherofthetwoinfluentialinternationallyrecognisedthermalcomfort standards (Chun et al., 2004). These are International Organisation forStandardisation(ISO)ortheAmericanSocietyofHeating,Refrigerating,andAirConditioningEngineers-ASHRAE(Nakano,2003).

Theheatbalancemodelofthermalcomfortassumestheoccupantisapassiverecipientofacontrolled thermal environment. The adaptive model of thermal comfort in comparison,empowersoccupantstomaintaincomfortbyself-regulation.WhenFanger’sequationisnotmet, the occupant is experiencing thermal discomfort, in transition zones, this is themajority of the case. The transition zone analysis rests between artificially cooledenvironmentsandnaturallyventilatedbuildings.Theheatbalancemodeldoesnotapplytonaturallyventilatedbuildings.


“(entrance)zonesaresomuchmoreconnectedtotheexteriorambient environment that they should be considered as freerunningspacesandthereforebecategorisedassuch,anduseof adaptive algorithm should be applied (that is based uponexternalcondition)”(Pitts,2013).

Theheatbalancemodels, pioneeredby Fanger’s predictedmean vote (1970)or theNewEffectiveTemperaturepresentedbyGaggeetal.(1971)measurethermalcomfortofsteady-stateair-conditionedindoorenvironments.Buildingtransitionzonesarecontrolledidenticaltothesteady-stateconditionsbecausethereisnotenoughempiricalresearchonwhatthecomfort criteria should be of transition zones. It is also a result of the lack of practicalthermal environment design, which leads to the default use of benchmarks specific tosteady-states(binSaleh&Pitts,2004).

3 MethodtochangetheTransitionZonetemperaturesetpointOccupantadaptationtakesplacewiththeuseofbehaviouralandphysiologicaladjustmentsto maintain body heat balance. Psychological adjustment remains less documented as amethod,despitethesignificanceinitsabilitytoillustratedifferencesbetweenobservedandpredictedthermalsensation(Nakano,2003).

3.1 MethodsinliteratureSome literature suggests a variety of surveys to use in the transition zone. Kong et al.’s(2011)researchcontrolledthetemperatureintheliftlobbyat26ºC.Theexperimentaimedtomeasure human thermal perceptions in enclosed regions. Their experimentmeasuredsubjective (questionnaire: sensation and preference and acceptability) and objectivethermalcomfortinMalaysianeducationalbuildings.Theresearchtookplacein2008,withfour months of surveying between August and November, 113 respondents’ data wascollected.AsplitunitACwasinstalledinthelift lobbyasaninterventionandtemperaturewas maintained using the thermostat. Occupants were not surveyed immediately uponentry but invited only after 30 seconds of waiting for the lift. There was 8°C highertemperaturedifferencebetweentheliftlobbyandsteadystateindoors.Occupantswereat1.2METandbelow,witharestingtimeof30secondsbeforesurveying(JieKwong&Adam,2011).Usingartificialchambers,Chunetal.foundoccupants’thermalcomfortwascloselyassociated toprior exposure to thermal environments (Chunet al., 2004). Long-termandshort-termmeasurementswere taken using objectives thermalmeasurements. They alsosuggestnotusingPMVtodeterminecomfort.InfieldandlaboratoryexperimentsChunandTamuratestedobjectiveandsubjectivemeasurementsonoccupantswalkingintotransitionzones in Yokohama (Chun & Tamura, 2005). The data showed all of 36 subjects werecomfortableandcouldadapttheirthermalsensations“verywidely”(Chun&Tamura,2005).Studiesshow it is important theoccupantsknowwhat to thermallyexpect (Nikolopoulou,Baker,&Steemers,2001).This isbecause itwill influence their clothingchoicesand theirinterpretation or expectation of comfort (Nikolopoulou et al., 2001). Brager (1998) statespsychological adaptation remains the least studied of adaptive mechanisms, which mayexplainthediscrepancybetweentheobservedandpredictedthermalresponses.

Occupantsofsemi-outdoorenvironmentsweremoretolerantofawiderthermalparameterthanthePPDmodelsuggests(Nakano,2003).Pitts(2013)suggestsaninvestigationintothenon-physiologicalstimulionperceptionsofcomfortandtransitionzonesiswarranted.Thismay be in the form of a broad scale parametric study of reaction. Pitts suggest that


broadening of the PMV to between 16ºC-26ºC to ±1.0 and PPD from 10% to 26% undertransitionzoneconditions.Thechallengeisisolatingtheadjustmentstoonlythetransitionzones(Pitts,2013).

AseminalstudyonthermalcomfortintransitionzonesbyJitkhajornwanich(2000)surveysoccupant thermal comfort whilst they move in and out of the main entrance (K.Jitkhajornwanich & Pitts, 2002). The experiment takes place in both winter (1996) andsummer(1997)inBangkok.UnlikeAbuDhabi,Bangkok’shotandhumidtropicalclimatehassmall variation between the seasons (±10ºC). Jitkhajornwanich uses transverse designsurveys to access subjective responses of occupants in transition zones. A total of 1143office workers are surveyed (Kitchari Jitkhajornwanich, 2000). Jitkhajornwanich evaluatesobjectivecomfort;clothinginsulation;metabolicactivities,theSeven-pointASHRAEscaleofthermal sensation; and the Three-point McIntyre scale for thermal preference.Jitkhajornwanich’s results of the surveys show transition zones could be used to prepareoccupantsforthesteadystatesindoorsoroutdoors(KitchariJitkhajornwanich,2000).

A Taiwanese service centre was used to conduct thermal comfort surveys during thesummer (June – September) on guests and staff. The results measured guests and staffenteringandexitingtheentrancezone.Theyfoundanobviousdifferencebetweenstaffandguest levelsof thermal requirements, in thatguestspreferredcoolerenvironments in theentrancearea(Hwangetal.,2008).Allinterviewstookplacebetween10AMand3:30PM,excludingthehourfollowing lunch(whenthemetabolicrateofrespondents isconsideredunsteady).Wheninterviewing,Hwangetal.explainedthemeaningofthequestionsbutdidnotoffersuggestionstobiasoccupantresponses.Therewere587subjectsinterviewed.Thesurveywasprepared inChineseusing transversedesign,11 staffwere interviewed twice-daily during the data collection period. Objective thermal comfort measurements weretakenintwolocations,oneatthemainentrancetheotherinthewaitingareafurtherintothe building. Objective thermal comfort was measured using an omnidirectional hotwireanemometer, a digital thermometer, with a 150mm diameter global thermometer. Theindoorclimatewascontinuouslymeasuredbetween9:30AMand4PMdaily.TheASHRAESeven-pointthermalsensationscaleandMyIntyrepreferencescalewereused.Thesurveyremovedanyonewalkinghastily.Thismeantanyone in the immediateentrancezonewasexcluded.

Ghaddaretal. (2011) studiedaworkshopat theAmericanUniversityofBeirutduring thesummer.Occupantswereadministeredsurveystorecordtheirlocalthermalsensationandcomfort after three clothing changes. The air temperature of the transition zones rangedbetween 27ºC-30°C. To test for a warmer transition zone on occupant comfort, indoorentrance zone setpoints were increased from 26ºC to 30ºC. The questionnaire askedoccupants theirdemographicandanthropometriccharacterisationandsegmental thermalsensationanddiscomfort(Ghaddaretal.,2011).Anacceptablerangeofcomfort(PMVlessthan0.5)wasachievedbyraisingairvelocityto1.5m/sanddressingoccupantswithhigherpermeablefabric.

Building Heating Ventilation and Air Conditioning (HVAC) are designed to cater for acomfortable indoor environment whilst balancing the system to reduce any negativehealthyaffects.Interventionstudieshaveshownpositiveeffectsonreducingenergyuseintheworkplace(Siero,Bakker,Dekker,&VandenBurg,1996).Neutraltemperaturesofthetransition zone were discussed as a result of four groups under assessment byJitkhajornwanichandPittsinavarietyoftransitionzonesinBangkok,althoughthecitydoes


not have large annual temperature variations (Jitkhajornwanich & Pitts, 2002), theyreportedneutral temperatureswerecomfortable for thesegroupsandalsosuggestedtheuseofair-conditionedandnaturallyventilatedtransitionzonesforfurthertesting.Thefourgroups reported a neutral temperature of 27ºC in the cool season, and of 26.5ºC in thewarmseason(Jitkhajornwanich&Pitts,2002).

Interventionswithintherealmofsocialandenvironmentalpsychologypredominantlyfocusonvoluntarybehaviourchange,ratherthanchangingcontextualfactors, liketemperature.Thismaydetermineoccupantbehaviouraldecisionsandcomparativefeedbacki.e.feedbackabout the performance of the transition zones (Abrahamse, Steg, Vlek, & Rothengatter,2005).GardnerandSternconductedthirty-eightstudies,withinthefieldof(applied)socialand environmental psychology were reviewed, and categorised as involving eitherantecedent strategies (i.e. commitment, goal setting, information, modelling) orconsequence strategies (i.e. feedback, rewards) (Gardner & Stern, 2002). Gardener andStern’s(2002)researchonfeedbackonindividualperformance,relativetotheperformanceofothers,maybehelpfulinreducingbuildingenergyuse(Gardner&Stern,2002).

3.2 InterventionThe aim of the interventionwas to understand the difference between the temperatureincreaseondifferentgroupsofbuildings.Thefollowingsectiondescribesmethodsfoundinliterature asweas eachof the intervention groups. The intervention tookplaceover themonthofAugust2012,where theoccupiedzonetemperaturesetpointwould increaseby1ºC,thusareductionincoolingrequirementby1ºC.InAbuDhabi,infiltrationcouldleadtoincreasedmoisturecontent.Thisisbecauseofthehighlevelsofhumidityoutdoors.Above60% RH indoor mould growth becomes a concern. Interventions were imposed on tenbuildings (5 mixed-use and 5 prestige), a control group of buildings was also kept tocompareresultsbetweenthetwogroup.

InterventionGroup(10)This isthetestgroup,wherea1ºCchange intransitionzonetemperaturewasmade.Thistook place with the researcher physically going around the building and increasing thetemperatureoftheoccupiedzonesetpointwiththepermissionofthebuildingownerandfacilitiesmanagement.

ControlGroup(4)The control grouphad5mixed-usebuildings.No intervention tookplace. Thepurposeofthisgroupwastomaintainagroupofbuildingsconsistentthroughoutthefieldstudythatwouldnotbeintervenedon.

3.3 Pre/PostInterventionSurveyToconductthesurveyofoccupantperceivedcomfortandsatisfaction,theresearcherstoodintheentrancelobbyofthebuildingandsurveyedoccupantsenteringthebuilding.Theaimherewas to capture the effect of thebuildinguponentry. ThePre andPost-Interventionsurvey was conducted using the same questions, where CLO and MET could also becollected. The survey was prepared in English, Hindi, Malayalam, Arabic and included asheetwithCLOandMETestimations.


Figure3:1Transitionzonesurvey

Thequestionnairetodetermineoccupantthermalcomfortin-situ,wasadministeredtwice,before the intervention in July 2012 and again during the intervention in each respectivecasestudybuildinginAugust2012.

4 ResultsThesamplesizesforeachbuildingoftheoccupantsweredeterminedbythetotaloccupantpopulationof thebuilding,without includingexternalguests to thesamplesize,however,guestswereincludedinthesurveyingastheirinteractionwiththecomfortofthetransitionzonewasequallyimportant,seeTable4-1.

Table4-1Summaryofresponseratesofallself-reportedquestionnairesCSB Intervention

GroupOccupancysample ResponsesPreJuly2012 ResponsesPostAug2012

1 InterventionPrestige 600 84 20





6 Control 25 14 57 Intervention 20 7 48 Intervention 32 16 89 Control 32 11 510 Control 32 6 311 Intervention 32 11 312 Intervention 24 15 813 Intervention 30 30 514 Control 32 24 5


The results of the comfort vote show there is a normal distribution around the neutralcomfortfromtheintervention,seeFig.4-1,wherethemajorityofrespondentsshowedtheyarecomfortableinthetransitionzonewitha1ºCintemperaturesetpointusingthethermalsensationscale.

Figure4:1Interventionbuildingcomfortvote,post-intervention,-3=toocold,+3=toohot

Perhapsa1ºCincreaseintemperatureofthetransitionzonewasnotasignificantchangetothe standard comfort of the occupants, in 6 of the 10-intervention building, therewas avisible increase in the comfort satisfaction (1 to 7 scale) of the occupants from the pre-interventionresults.However, in3ofthe4controlbuildingsthisalsohappenedtobethecase. It isunclear in thecontrolbuildings,whether therewasany indirect impactson thebuildingsthatmaynothavebeencaptured,seeTable4-2.Thecomfortablesatisfaction

Table4-2Summaryofmeanself-reportedcomfort,1=unsatisfactory,7=satisfactoryCSB InterventionGroup PreComfortSat PostComfortSat DeltaComfortSat PreComfSatSTD PostComfSatSTD

1 InterventionPrestige 4 4.7 0.7 1.22 0.4

2 InterventionPrestige 4 5 1 1.12 1.5

3 InterventionPrestige 4.1 5.7 1.6 0.94

4 InterventionPrestige 5.4 5.6 0.2 1.1 1.45

5 InterventionPrestige 4.9 4.8 -0.1 1.73 0.47

6 Control 3.8 5 1.2 1.3 1.81

7 Intervention 4.3 4 -0.3 0.86 1.62

8 Intervention 5.6 4.6 -1 1.13 1.28

9 Control 4.9 3.8 -1.1 1.64 1.32

10 Control 3.7 4.3 0.6 1.69 1.33

11 Intervention 3.5 4.3 0.8 1.34 1.41

12 Intervention 3.4 5.6 2.2 0.86 1.26

13 Intervention 5.6 3.6 -2 0.56

14 Control 4.8 5.4 0.6 1.19 1.22


5 ConclusionAn intervention to increase in the transitional zone temperature shows that therewas apositive response from occupants to the comfort satisfaction and comfort vote of theoccupants.Researchsuggeststhereispotentialforfurtheranalysisofthisnon-steady-stateenvironment, which could lend itself as a bridge between the indoor and outdoorenvironments.Literaturesuggeststhereispotentialtowidenthecomfortparameterofthetransitionzone,fromtheperspectiveoftheoccupant,thereisabroadscaleofcomfortthattheoccupantmanages.

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