Center for the Built Environment

Many field surveyshaveshownthatnaturallyventilatedbuildingsarefavorabletohumanthermal comfort andmayallowhighercoolingtemperaturesthanair-conditionedbuildings.Recreatingnatural wind characteristicswithamechanicalcoolingsystemmaydiminishthedrawbacksofconventional cooling systemssuchasdraftsandhighenergydemands.Naturalwindcharacteristics(windvelocity, direction, turbulentintensity,temperatureandrelativehumidity)wererecordedinamountain environmentandcorrelatedwiththehumanthermalsensationof48subjects.Naturalwind fluctuation characteristicswereanalyzedusingtheFastFourierTransform(FFT)analysis.Thedynamiccharacter- istics ofnaturalwindwereaveragedthroughthepowerspectrumexponent (β−value),whichrepresents the energydistributionoftheturbulent flowofnaturalwind.Thepowerspectrumexponent (β−value)of the naturalwindwilldecreasewhenthemeanvelocityincreases,whileitwillincreasewhenthe turbulent intensityincreases.Thepowerspectrumexponent (β−value)wascorrelated(Spearman's rank coefficient¼0.56, po0.001)withthermalcomfort.Thepowerspectrumexponent(β-value)forpeople feeling comfortablehasamedianvalueof1.62[1.41–1.80forthe first andthirdquartiles,respectively] and the β−valueforpeoplefeelinguncomfortablehasamedianvalueof1.10[0.97–1.25]. & 2013ElsevierLtd.Allrightsreserved.