Methodology for the Evaluation of Natural Ventilation in ... - Cham

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temperature of the air was the same as the temperature leaving the south half of the model. Thisimplied that some of the air from the atrium entered the second floor and warmer air exited at theceiling level. The data presented are for the stacks open case, which explains why there wassignificantly warmer air at the ceiling measurement point. In the heated zone, the temperaturepattern was similar for all of the wind speeds used (Figure 79). For each case, coolertemperatures were recorded at the mid-height of the heated zone. The actual temperaturecorresponded to the temperature of the exiting air from the ground and first floor south zones.Since there were no heating loads in the atrium space, the air exiting the south zones was driveninto the two zones on the north half of the model by the wind force. The air from the atriumspilled over the railing into the heated zones on the north half of the building, while warmer airexited at the ceiling level for both floors (Figure 69). Airflow visualization carried out forseveral different wind speeds verified this explanation for the temperature variation in the heatedzone (Figure 70) as did the CFD simulations (Figure 71). In Figure 77 and Figure 79, the coolestair temperatures correspond to the exiting air temperatures from the south half of the model,where the wind-driven air is entering the model. However, the heat sources at the floor andsome amount of radiation to the ceiling causes the thermocouples near the floor and ceiling torecord higher temperatures. Some of the cooler air enters into the first floor north half of themodel over the railing, causing cooler temperature measurements near the floor. There is someamount of jet flow, introducing the cooler air at the mid-height of the space. These flow patternswere visible with the airflow visualization technique and also provided with the CFDsimulations.Figure 70. Airflow Patterns for Reduced-Scale Air Model with Stacks Open: Combined Wind-Buoyancy Case144
Figure 71. Airflow Patterns for Combined Wind-Buoyancy Driven Flow at 0.5 m/s3.532.521.55m/s4m/s3m/s2m/s1m/s1.5m/s0.5m/s0.7m/s10.5020.2 20.4 20.6 20.8 21 21.2 21.4 21.6 21.8 22Figure 72. Combined Wind-Buoyancy Full Model Ground Floor Scaled TemperatureStratification at Column145
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Thesis Committee:Leon R. Glicksman,
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Table of ContentsTable of Contents
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7.1.3 Full Model Case .............
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Figure 41. Wind Direction Data for
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List of TablesTable 1. Energy End U
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Table 64. Comparison of Dimensionle
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Chapter 1.0IntroductionEnergy consu
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insulated building envelopes with t
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energy usage and efficient design.
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Figure 3. European Patent Office Bu
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selecting boundary conditions) to e
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2.2.1 Buoyancy-Driven VentilationVe
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Figure 7. Neutral Pressure Level fo
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Combined wind-buoyancy flow is more
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design. The depth of natural ventil
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of cooling required by 30 percent o
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considered when determining how the
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environmental conditions are examin
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As natural ventilation is prevalent
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Chapter 3.0Evaluation of Prototype
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Figure 12. Interior Atrium ViewFigu
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Table 8. Prototype Building Window
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Figure 15. HOBO® H8 Series Tempera
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Finally, airflow visualization was
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only is the airflow almost never at
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Table 10. Window Bag Device Measure
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Mon 7-21Tue 7-22Wed 7-23Thu 7-24Fri
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12:00 AM1:00 AM2:00 AM3:00 AM4:00 A
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27-Jul27-Jul28-Jul28-Jul29-Jul30-Ju
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A range of air exchange rates was f
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the windows on the second floor, or
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Total Electric (kWh/m2)Total Gas (k
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movement, Houghton Hall has much le
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Chapter 4.0Modeling and Visualizati
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for future design of similar type b
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lower and upper openings and natura
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the acceptable diffusion rate, or
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applications involving full-scale b
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digital camera with both manually o
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Chapter 5.0Dimensional Analysis and
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u oHgHT2uocu Hpo1Re Ar1Re Pr(5.7)(5
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X HM X HP(5.16)5.3.2 Kinematic Sim
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Radiation was found to have an impa
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height is used for the full-scale b
Page 94 and 95: 6.3 Model Descriptions6.3.1 Physica
Page 96 and 97: Figure 30. Floor Plan of the Protot
Page 98 and 99: Figure 31. North Facade of Model wi
Page 100 and 101: Monitoring data collected from the
Page 102 and 103: By default, there was no accounting
Page 104 and 105: 40-location card inserted into the
Page 106 and 107: 6.5 ExperimentsTo evaluate the mode
Page 108 and 109: modified to determine the impact of
Page 110 and 111: Figure 39. Two Heated Zone ModelWit
Page 112 and 113: minute interval, the model was assu
Page 114 and 115: Figure 42. Cross-Section of Wind-Ge
Page 116 and 117: Table 25. Wind-Assisted Ventilation
Page 118 and 119: Figure 44. Heaters and Zones for a)
Page 120 and 121: Height from Floor (m)Height from Fl
Page 122 and 123: Where V is the outlet velocity, A o
Page 124 and 125: Table 32. Conduction Heat Loss for
Page 126 and 127: a) Air Modelb) Water ModelFigure 50
Page 128 and 129: Height from Floor (m)The temperatur
Page 130 and 131: Height from Floor (m)In the atrium
Page 132 and 133: First NorthUpper Window 0.17 m/s -0
Page 134 and 135: Height from Floor (m)the column at
Page 136 and 137: Height from Floor (m)Height from Fl
Page 138 and 139: Height from Floor (m)3.53.02.52.01.
Page 140 and 141: was less than 12 percent. These val
Page 142 and 143: Table 39. Variation of Outlet Wind
Page 146 and 147: 3.532.521.55m/s4m/s3m/s2m/s1m/s1.5m
Page 148 and 149: 3.532.521.55m/s4m/s3m/s2m/s1m/s1.5m
Page 150 and 151: The average and exhaust internal bu
Page 152 and 153: Table 43. Calculated Wind and Buoya
Page 154 and 155: In the last two lines, for both the
Page 156 and 157: Figure 80. CFD Simulation of the Te
Page 158 and 159: uoyancy case the air from the groun
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Page 162 and 163: windows of naturally ventilated bui
Page 164 and 165: difficult to select the boundary co
Page 166 and 167: simulations are able to do would al
Page 168 and 169: Bordass, W.T., A.K.R. Bromley and A
Page 170 and 171: Linddament, M. 1996. Why CO2? Air I
Page 172 and 173: 172
Page 174 and 175: MODEL: K20-8SERIAL: 10047RECORDER_I
Page 176 and 177: 2 Boiler-3 50.00 C1 N1 1.0 ON ON OF
Page 178 and 179: |PW|DESCRIP |KW |KWH|KVA|KVH|------
Page 180 and 181: 2:5 ;day_ofYr17:P30 ;EOT = 0.000075
Page 182 and 183: 2:3136:P30 ;DUM2 = -0.040891:-4.089
Page 184 and 185: ;7:21 ;input location;8:0 ;mulptipl
Page 186 and 187: ;79:P22 ;EXC w/DELAY (only for dela
Page 188 and 189: 1:45 ;port5 (homeSense)2:31 ;exit l
Page 190 and 191: 13:P95 ;ENDIF14:P95 ;ENDIF15:P3 ;pu
Page 192 and 193: 2:20 ;RH30:P70 ;sample1:12:20 ;RH31
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194
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Five Windows Open: Upper versus Low
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One Window Open: Upper versus Lower
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25 cm / 3 m 24.33 26.62 22.68 22.93
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25 cm / 3 m 24.07 25.26 22.65 22.78
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Two Stacks Open Temperature Stratif
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Stacks Closed Temperature Stratific
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2.3 24.31 24.65 24.781.4 23.35 23.6
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0.6 20.56 20.67 20.94 21.22 21.41 2
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