MAXIMIZING NATURAL VENTILATION BY DESIGN IN · PDF fileMAXIMIZING NATURAL VENTILATION BY...

MAXIMIZING NATURAL VENTILATION BY DESIGN IN LOW RISE RESIDENTIAL BUILDINGS USING WIND CATCHERS IN THE HOT

ARID CLIMATE OF UAE

by

Rashed Khalifa Al-Shaali

A Thesis Presented to the FACULTY OF THE SCHOOL OF ARCHITECTURE

UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements of the Degree

MASTER OF BUILDING SCIENCE

August 2002

Copyright 2002 Rashed Khalifa Al-Shaali

UNIVERSITY OF SOUTHERN CALIFORNIA

The Graduate School

University Park

LOS ANGELES, CALIFORNIA 90089-1695

This thesis, written by

…………………………………………………..

Under the direction of h…………….. Thesis

Committee, and approved by all its members,

Has been presented to and accepted by The

Graduate School, in particular fulfillment of

requirements for the degree of

……………………………………………….

……………………………………………….

Dean of Graduate Studies

Date ……………………..

THESIS COMMITTEE

………………………………………………..

Chairperson

………………………………………………..

………………………………………………..

ii

Acknowledgements

First of all, I would like to thank Allah (God) for granting me patience that

carried me through all the difficult times. Second, I would like to thank my father

and mother, the most wonderful friends I have ever had and loved, for all the

sacrifices, caring and guidance and for giving me such a wonderful sister and

brothers. The list of people whom I want to thank is very long. However, I would

like to value the following people for their indispensable help:

Professor Pierre Koenig, my chief advisor, for his ultimate and important

support, direction, encouragement and patience.

Professor Marc Schiler, for his guidance, support and forbearance through

out all the study period and for opening the doors of opportunities when I thought

that all of them are closed.

Professor Ralph L. Knowles, for his assistance, kindness and for always

reminding me of the spiritual side of Architecture.

Professor Murray Milne, for providing me with all the necessary computer

documents and his immediate and positive responses to my questions.

I would also like to especially thank my friend Ahmad Al Awar for his

incessant help, as well as Nasser Al-Shaali, Khalid Al Hammadi, Zainab A. Al-

Rustamani and Dr. D. E. Ordway for their assist and kindness.

Last but not least, I would like to thank my wife Amal for her support and

love that carried me smoothly through a lot of difficult time and for giving me the

best gifts I have ever had, our children Khalifa and Reem.

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Table of Contents

Acknowledgements_________________________________________________________i

List of Figures____________________________________________________________vi

Abstract_________________________________________________________________xi

1 UAE _______________________________________________________________ 1 1.1 Physical features _________________________________________________ 1 1.2 Climatic conditions _______________________________________________ 2 1.3 Housing ________________________________________________________ 2 1.4 Social needs and demands__________________________________________ 3 1.5 Environmental and cultural issues ___________________________________ 3

1.5.1 Vernacular architecture styles_____________________________________ 4 1.5.2 Environmental sense and consideration _____________________________ 4

1.6 Wind and wind catchers ___________________________________________ 5 REFERENCES: _________________________________________________________ 6

2 Climatic Data and Analysis ____________________________________________ 7 2.1 Writing TMY2 Data Format ________________________________________ 7

2.1.1 What is TMY2 Data ____________________________________________ 7 2.1.2 TMY2 Data Format ____________________________________________ 7 2.1.3 Calculating the Missing Data _____________________________________ 8

2.1.3.1 Direct Beam Solar Radiation __________________________________ 8 2.1.3.2 Total Horizontal (diffused) Solar Radiation_______________________ 9 2.1.3.3 Dew point outdoor air temperature_____________________________ 10

2.2 SCRAM _______________________________________________________ 10 2.2.1 What is SCRAM Data _________________________________________ 10 2.2.2 SCRAM Data Format__________________________________________ 11

2.3 Climatic Data Charts ____________________________________________ 13 2.3.1 City of Abu Dhabi ____________________________________________ 13

2.3.1.1 Temperature Range ________________________________________ 13 2.3.1.2 Temperature + Relative Humidity _____________________________ 14 2.3.1.3 Wind Velocity Range_______________________________________ 15 2.3.1.4 Bioclimatic Timetable ______________________________________ 16 2.3.1.5 Psychrometric Chart________________________________________ 17

2.3.2 City of Al-Ain________________________________________________ 18 2.3.2.1 Temperature Range ________________________________________ 18 2.3.2.2 Temperature + Relative Humidity _____________________________ 19 2.3.2.3 Wind Velocity Range_______________________________________ 20 2.3.2.4 Bioclimatic Timetable ______________________________________ 21 2.3.2.5 Psychrometric Chart________________________________________ 22

2.4 Wind Roses ____________________________________________________ 23 2.4.1 City of Abu Dhabi ____________________________________________ 23 2.4.2 City of Al-Ain________________________________________________ 25

iv

REFERENCES: ________________________________________________________ 27

3 Wind and Ventilation ________________________________________________ 28 3.1 Wind Characteristics_____________________________________________ 28

3.1.1 Wind near the Ground _________________________________________ 28 3.1.2 Wind in an Urban Environment __________________________________ 30 3.1.3 Wind Flow __________________________________________________ 30

3.2 Natural Ventilation for Thermal Comfort _____________________________ 31 3.2.1 Removal of Excess Heat________________________________________ 32 3.2.2 Cooling Effect over the Human Body _____________________________ 32 3.2.3 Cooling the Structure __________________________________________ 33

REFERENCES: ________________________________________________________ 35

4 Historical Precedents ________________________________________________ 36 4.1 Hot and Arid Zones ______________________________________________ 36

4.1.1 The Malqaf __________________________________________________ 38 4.1.2 The Badgir (Barjeel)___________________________________________ 43 4.1.3 Wind Scoops_________________________________________________ 49

4.2 Design Examples of Wind Catchers _________________________________ 51 4.2.1 Qatar University in Doha _______________________________________ 51 4.2.2 Concept drawings_____________________________________________ 54

REFERENCES: ________________________________________________________ 57

5 Setting the Variables_________________________________________________ 60 5.1 Hypothesis_____________________________________________________ 60 5.2 When to use Natural Ventilation ____________________________________ 60

5.2.1 City of Abu Dhabi ____________________________________________ 61 5.2.2 City of Al-Ain________________________________________________ 78

5.3 Model Drawings and Testing Environment____________________________ 96 5.3.1 Helium Bubble Generator_______________________________________ 96 5.3.2 Drawings ___________________________________________________ 96

6 Wind Catcher with Different Sizes and Outlets__________________________ 103 6.1 1/3 Wind Catcher ______________________________________________ 104

6.1.1 Case 0 _____________________________________________________ 104 6.1.1.1 Speed 1_________________________________________________ 105 6.1.1.2 Speed 2_________________________________________________ 106 6.1.1.3 Speed 3_________________________________________________ 106



6.1.4 Case 3 _____________________________________________________ 119 6.1.4.1 Speed 1_________________________________________________ 119 6.1.4.2 Speed 2_________________________________________________ 120

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6.1.4.3 Speed 3_________________________________________________ 121 6.2 1/2 Wind Catcher ______________________________________________ 125





6.3 Full Length Wind Catcher________________________________________ 145 6.3.1 Case 0 _____________________________________________________ 146

6.3.1.1 Speed 1_________________________________________________ 146 6.3.1.2 Speed 2_________________________________________________ 147 6.3.1.3 Speed 3_________________________________________________ 147




6.4 Additional Tests________________________________________________ 163 6.4.1 Wind catcher with Smaller Opening______________________________ 163 6.4.2 Wind Catcher in the Middle of the Windward Façade ________________ 166

6.5 Suggestion ____________________________________________________ 167

7 Future Work ______________________________________________________ 170

8 Bibliography ______________________________________________________ 171

vi

List of Figures

Figure 1-1 United Arab Emirates Map .............................................................................................. 1 Figure 2-1 Scram Data Format........................................................................................................ 11 Figure 2-2 Abu Dhabi 1997 Temperature Range ............................................................................. 13 Figure 2-3 Abu Dhabi 1997 Temperature + Relative Humidity........................................................ 14 Figure 2-4 Abu Dhabi 1997 Wind Velocity Range .......................................................................... 15 Figure 2-5 Abu Dhabi 1997 Bioclimatic Timetable ......................................................................... 16 Figure 2-6 Abu Dhabi 1997 Psychrometric Chart............................................................................ 17 Figure 2-7 Al-Ain 1997 Temperature Range ................................................................................... 18 Figure 2-8 Al-Ain 1997 Temperature + Humidity ........................................................................... 19 Figure 2-9 Al-Ain 1997 Wind Velocity Range ................................................................................ 20 Figure 2-10 Al-Ain 1997 Bioclimatic Timetable ............................................................................. 21 Figure 2-11 Al-Ain 1997 Psychrometric Chart ................................................................................ 22 Figure 2-12 Abu Dhabi 1997 Wind Rose ........................................................................................ 23 Figure 2-13 Abu Dhabi 1991, 92, 93, 94, 95, 97, 98 and 99 Wind Rose ........................................... 24 Figure 2-14 Al-Ain 1997 Wind Rose .............................................................................................. 25 Figure 2-15 Al-Ain 1995, 96, 97, 98 and 99 Wind Rose .................................................................. 26 Figure 3-1 Typical Record of the Wind Velocity near the Ground .................................................. 28 Figure 3-2 Wind Patterns (a) Constricted by Topography. (b) Above and Below Tall Buildings. (c)

Around large Buildings. ........................................................................................................ 29 Figure 3-3 Effect of Terrain on Wind Velocity Profiles ................................................................... 30 Figure 3-4 Wind Pressure around Building ..................................................................................... 31 Figure 3-5 Wind Pressure Drives Cross Ventilation......................................................................... 31 Figure 3-6 Heat Generated and lost (approximate) by a person at rest (rh fixed at 45%)................... 33 Figure 3-7 Isocomfort Curve........................................................................................................... 34 Figure 3-8 Isocomfort Curve Parametrized as a Function of the air velocity..................................... 34 Figure 4-1 Wind Tower in the Middle East ..................................................................................... 36 Figure 4-2 Catching Efficiency for Different Wind Catcher Designs................................................ 37 Figure 4-3 Roof plan of the Fu'ad Riyad house in Cairo, showing the malqaf with sectional details.. 38 Figure 4-4 Section of the Fu'ad Riyad house showing the malqaf..................................................... 39 Figure 4-5 Section of a modern villa designed for Saudi Arabia showing the use of malqaf.............. 39 Figure 4-6 Section through the hall of Muhib Ad-Din Ash-Shaf'i Al-Muwaqqi showing the malqaf

and central location of the hall............................................................................................... 40 Figure 4-7 Arrows indicate the direction of airflow; arrow length corresponds to airspeed. The

measurements where made on 2 April 1973 by scholars from the Architectural Association School of Architecture in London. All wind and airspeeds are given in meters per second. ..... 40

Figure 4-8 Malqaf with wetted baffles and a wind-escape. Design by Hassan Fathy ........................ 41 Figure 4-9 Details of the malqaf with wetted baffles........................................................................ 42 Figure 4-10 Barjeel details.............................................................................................................. 43 Figure 4-11 Mohamed Sharif house, first floor................................................................................ 44 Figure 4-12 Wooden doors and opening.......................................................................................... 45 Figure 4-13 Interior view of the Wooden doors and openings.......................................................... 45 Figure 4-14 Shaikh Saeed house (North Elevation) ......................................................................... 46 Figure 4-15 Shaikh Saeed house (East Elevation)............................................................................ 46 Figure 4-16 Shaikh Saeed house (Courtyard view) .......................................................................... 46 Figure 4-17 Traditional Square Barjeel ........................................................................................... 47 Figure 4-18 Unusual cylindrical Barjeel.......................................................................................... 47 Figure 4-19 The Barjeel Closed to Block Undesirable Wind............................................................ 48 Figure 4-20 A fort in the City of Ajman uses the Barjeel for Natural Ventilation ............................. 48 Figure 4-21 Wind scoop, Hyderabad, Sind, Pakistan ....................................................................... 49 Figure 4-22 Wind Scoops facing the prevailing wind ...................................................................... 49 Figure 4-23 Scoops in Pakistan at different levels ........................................................................... 50

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Figure 4-24 A picture from the roof ................................................................................................ 51 Figure 4-25 Section/Elevation of Humanities Faculty Modules ....................................................... 51 Figure 4-26 An External Picture of the Wind Catchers .................................................................... 52 Figure 4-27 A picture from the courtyard........................................................................................ 52 Figure 4-28 Qatar University (Phase 1), Kamal El-Kafrawi ............................................................. 53 Figure 4-29 Ariel View of Qatar University .................................................................................... 53 Figure 4-30 From above: Wind tower; monodirectional wind tower and scoop; multidirectional wind

tower and scoop; combined wind tower and scoop ................................................................. 54 Figure 4-31 Day and Night reverse wind directions......................................................................... 55 Figure 4-32 Concept Drawings for rotating wind scoops ................................................................. 56 Figure 5-1 Hours to Block Natural Ventilation in Abu Dhabi .......................................................... 61 Figure 5-2 January Wind Rose........................................................................................................ 62 Figure 5-3 February Wind Rose...................................................................................................... 63 Figure 5-4 March Wind Rose.......................................................................................................... 64 Figure 5-5 April Wind Rose ........................................................................................................... 65 Figure 5-6 May Wind Rose............................................................................................................. 66 Figure 5-7 June from Midnight to 7am Wind Rose.......................................................................... 67 Figure 5-8 June from 15pm until Midnight Wind Rose.................................................................... 68 Figure 5-9 July from Midnight to 7am Wind Rose .......................................................................... 69 Figure 5-10 July from 3pm to Midnight Wind Rose ........................................................................ 70 Figure 5-11 August from Midnight to 7am Wind Rose.................................................................... 71 Figure 5-12 August from 2pm to Midnight Wind Rose.................................................................... 72 Figure 5-13 September from Midnight to 7am Wind Rose............................................................... 73 Figure 5-14 September from 2pm to Midnight Wind Rose .............................................................. 74 Figure 5-15 October Wind Rose ..................................................................................................... 75 Figure 5-16 November Wind Rose.................................................................................................. 76 Figure 5-17 December Wind Rose .................................................................................................. 77 Figure 5-18 Hours to Block Natural Ventilation in Al-Ain .............................................................. 78 Figure 5-19 January Wind Rose...................................................................................................... 79 Figure 5-20 February Wind Rose.................................................................................................... 80 Figure 5-21 March Wind Rose........................................................................................................ 81 Figure 5-22 April Wind Rose.......................................................................................................... 82 Figure 5-23 May from Midnight to 8am Wind Rose........................................................................ 83 Figure 5-24 May from 3pm to Midnight Wind Rose........................................................................ 84 Figure 5-25 June from Midnight to 7am Wind Rose........................................................................ 85 Figure 5-26 June from 5pm to Midnight Wind Rose........................................................................ 86 Figure 5-27 July from Midnight to 7pm Wind Rose ........................................................................ 87 Figure 5-28 July from 5pm to Midnight Wind Rose ........................................................................ 88 Figure 5-29 August from Midnight to 7am Wind Rose.................................................................... 89 Figure 5-30 August from 5pm to Midnight Wind Rose.................................................................... 90 Figure 5-31 September from Midnight to 7am Wind Rose............................................................... 91 Figure 5-32 September from 4pm to Midnight Wind Rose .............................................................. 92 Figure 5-33 October Wind Rose ..................................................................................................... 93 Figure 5-34 November Wind Rose.................................................................................................. 94 Figure 5-35 December Wind Rose .................................................................................................. 95 Figure 5-36 Helium Bubble Generator ............................................................................................ 96 Figure 5-37 Side and Top View of the Model.................................................................................. 97 Figure 5-38 1/3 Wind Catcher, Top View, Section and Front View ................................................. 98 Figure 5-39 2/3 Wind Catcher, Top View, Section and Front View ................................................. 99 Figure 5-40 Full Length Wind Catcher, Top View, Section and Front View .................................. 100 Figure 5-41 Leeward Elevation with different Apertures ............................................................... 101 Figure 5-42 General Setup of the Experiments .............................................................................. 102 Figure 6-1 Model Position in respect to the Wind Catcher ............................................................. 103 Figure 6-2 1/3 Wind Catcher Front Axonometric View ................................................................. 104

viii

Figure 6-3 Case 0 Back Axonometric View .................................................................................. 104 Figure 6-4 Six Frames Combined ................................................................................................. 105 Figure 6-5 Four Frames Combined ............................................................................................... 105 Figure 6-6 Five Frames Combined................................................................................................ 106 Figure 6-7 Two Frames Combined................................................................................................ 106 Figure 6-8 Five Frames Combined................................................................................................ 107 Figure 6-9 Case 0 3D Drawing ..................................................................................................... 107 Figure 6-10 Case 0 Side View ...................................................................................................... 108 Figure 6-11 Speed Vs Location..................................................................................................... 108 Figure 6-12 Case 1 Back Axonometric View ................................................................................ 109 Figure 6-19 Six Frames Combined................................................................................................ 109 Figure 6-27 Seven Frames Combined ........................................................................................... 110 Figure 6-33 Five Frames Combined.............................................................................................. 110 Figure 6-40 Six Frames Combined................................................................................................ 111 Figure 6-46 Five Frames Combined.............................................................................................. 111 Figure 6-47 Case 1 3D Drawing ................................................................................................... 112 Figure 6-48 Case 1 Side View ...................................................................................................... 112 Figure 6-49 Speed Vs Location..................................................................................................... 113 Figure 6-50 Case 2 Axonometric Back View ................................................................................ 114 Figure 6-58 Eight Frames Combined ............................................................................................ 114 Figure 6-63 Five Frames Combined.............................................................................................. 115 Figure 6-73 Nine Frames Combined ............................................................................................. 115 Figure 6-81 Five Frames Combined.............................................................................................. 116 Figure 6-88 Five Frames Combined.............................................................................................. 116 Figure 6-89 Case 2 3D Drawing ................................................................................................... 117 Figure 6-90 Case 2 Side View ...................................................................................................... 117 Figure 6-91 Speed Vs Location..................................................................................................... 118 Figure 6-92 Case 3 Axonometric Back View ................................................................................ 119 Figure 6-98 Five Frames Combined.............................................................................................. 119 Figure 6-101 Two Frames Combined............................................................................................ 120 Figure 6-108 Five Frames Combined............................................................................................ 120 Figure 6-114 Six Frames Combined.............................................................................................. 121 Figure 6-115 Case 3 3D Drawing.................................................................................................. 121 Figure 6-116 Case 3 Side View..................................................................................................... 122 Figure 6-117 Speed Vs Location................................................................................................... 122 Figure 6-118 Speed Vs Cases ....................................................................................................... 123 Figure 6-119 Speed Vs Cases ....................................................................................................... 124 Figure 6-120 Speed Vs Cases ....................................................................................................... 124 Figure 6-1211/2 Wind Catcher Front Axonometric View .............................................................. 125 Figure 6-122 Case 0 Back Axonometric View............................................................................... 126 Figure 6-128 Five Frames Combined............................................................................................ 126 Figure 6-134 Six Frames Combined.............................................................................................. 127 Figure 6-139 Four Frames Combined............................................................................................ 127 Figure 6-140 Case 0 3D Drawing.................................................................................................. 128 Figure 6-141 Case 0 Side View..................................................................................................... 128 Figure 6-142 Speed Vs Location................................................................................................... 129 Figure 6-143 Case 1 Axonometric Back View............................................................................... 130 Figure 6-150 Seven Frames Combined ......................................................................................... 130 Figure 6-159 Eight Frames Combined........................................................................................... 131 Figure 6-164 Bubble Speed 0.95 m/s ............................................................................................ 131 Figure 6-165 The Bubble Exiting from the Bottom Opening and other Bubbles following the same

Path .................................................................................................................................... 132 Figure 6-166 Some Bubbles Exit using the Bottom Opening and some Bubbles head Upwards...... 132 Figure 6-167 Bubbles headed Upward creating a Vortex ............................................................... 133

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Figure 6-168 Nine Frames Combined ........................................................................................... 133 Figure 6-173 Four Frames Combined............................................................................................ 134 Figure 6-174 Case 1 3D Drawing.................................................................................................. 134 Figure 6-175 Case 1 Side View..................................................................................................... 135 Figure 6-176 Speed Vs Location................................................................................................... 135 Figure 6-177 Case 2 Axonometric Back View............................................................................... 136 Figure 6-184 Six Frames Combined.............................................................................................. 136 Figure 6-191 Six Frames Combined.............................................................................................. 137 Figure 6-197 Five Frames Combined............................................................................................ 137 Figure 6-206 Eight Frames Combined........................................................................................... 138 Figure 6-207 Case 2 3D Drawing.................................................................................................. 138 Figure 6-208 Case 2 Side View..................................................................................................... 139 Figure 6-209 Speed Vs Location................................................................................................... 139 Figure 6-210 Case 3 Axonometric Back View............................................................................... 140 Figure 6-216 Six Frames Combined.............................................................................................. 141 Figure 6-222 Five Frames Combined............................................................................................ 141 Figure 6-228 Six Frames Combined.............................................................................................. 142 Figure 6-229 Case 3 3D Drawing.................................................................................................. 142 Figure 6-230 Case 3 Side View..................................................................................................... 143 Figure 6-231 Speed Vs Location................................................................................................... 143 Figure 6-232 Speed Vs Cases ....................................................................................................... 144 Figure 6-233 Speed Vs Cases ....................................................................................................... 144 Figure 6-234 Speed Vs Cases ....................................................................................................... 145 Figure 6-235Full Length Wind Catcher Front Axonometric View ................................................. 145 Figure 6-236 Case 0 Axonometric Back View............................................................................... 146 Figure 6-241 Five Frames Combined............................................................................................ 146 Figure 6-246 Five Frame Combined ............................................................................................. 147 Figure 6-250 Three Frame Combined ........................................................................................... 147 Figure 6-251 Case 0 3D Drawing.................................................................................................. 148 Figure 6-252 Case 0 Side View..................................................................................................... 148 Figure 6-253 Speed Vs Location................................................................................................... 149 Figure 6-254 Case 1 Axonometric Back View............................................................................... 150 Figure 6-260 Five Frame Combined ............................................................................................. 150 Figure 6-266 Five Frame Combined ............................................................................................. 151 Figure 6-271 Six Frame Combined ............................................................................................... 151 Figure 6-272 Case 1 3D Drawing.................................................................................................. 152 Figure 6-273 Case 1 Side View..................................................................................................... 152 Figure 6-274 Speed Vs Location................................................................................................... 153 Figure 6-275 Case 2 Axonometric Back View............................................................................... 153 Figure 6-281 Five Frame Combined ............................................................................................. 154 Figure 6-287 Other Bubbles taking a Different Path ...................................................................... 154 Figure 6-288 Bubbles Exiting the Model....................................................................................... 155 Figure 6-289 Seven Frame Combined........................................................................................... 155 Figure 6-294 Bubbles Grouping together to Exit ........................................................................... 156 Figure 6-295 Six Frame Combined ............................................................................................... 156 Figure 6-296 Case 2 3D Drawing.................................................................................................. 157 Figure 6-297 Case 2 Side View..................................................................................................... 157 Figure 6-298 Speed Vs Location................................................................................................... 158 Figure 6-299 Case 3 Axonometric Back View............................................................................... 158 Figure 6-306 Six Frame Combined ............................................................................................... 159 Figure 6-311 Five Frame Combined ............................................................................................. 159 Figure 6-315 Three Frame Combined ........................................................................................... 160 Figure 6-316 Case 3 3D Drawing.................................................................................................. 160 Figure 6-317 Case 3 Side View..................................................................................................... 161

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Figure 6-318 Speed Vs Location................................................................................................... 161 Figure 6-319 Speed Vs Cases ....................................................................................................... 162 Figure 6-320 Speed Vs Cases ....................................................................................................... 162 Figure 6-321 Speed Vs Cases ....................................................................................................... 163 Figure 6-322 1/3 Wind Catcher with Smaller Intake Opening........................................................ 164 Figure 6-323 Eighteen Frames Combined with Fan Speed No.1 .................................................... 164 Figure 6-324 Six Frames Combined with Fan Speed No.2............................................................. 165 Figure 6-325 Six Frames Combined with Fan Speed No.3............................................................. 165 Figure 6-326 1/3 Wind Catcher in the Middle of the Windward Façade......................................... 166 Figure 6-327 Front View .............................................................................................................. 166 Figure 6-328 3D Drawing............................................................................................................. 167 Figure 7-1 Curved Wind Catcher .................................................................................................. 170 Figure 7-2 Openings on the Opposite Wall.................................................................................... 170

xi

Abstract

This research studies natural ventilation in a residential building using

different wind catcher sizes and exhausts to maintain a comfortable environment that

would reduce energy consumption in a hot arid zone.

All the simulated airflow tests were performed on a 1:48 scale model of a

building 14’ wide, 28’ long and 10’ high. A wind catcher with three different sizes

was built and tested. All three sizes had the same section but varying lengths, which

represented 1/3, 1/2 and all of the windward façade. The leeward façade was used as

an exhaust in two general configurations: the first configuration used the entire

façade as an outlet (10' X 14'), while the second used an opening of 4' X 14' placed at

varying locations. A Helium Bubble Generator was used to investigate the air speed

and pattern inside the model. The device produces neutrally buoyant bubbles filled

with helium. The bubbles follow the air flow streamlines. The tests were recorded

using a Digital camcorder.

All the wind catcher sizes showed an acceptable air speed inside the model.

The major distinction was in the plan exposure area, where it becomes narrower as

smaller wind catcher is used. On the other hand, this type of wind catcher can not

provide sufficient air flow for cooling the ceiling. In addition, if the same exhaust

was used with different fan speeds the air pattern will remain the same.

1

1 UAE

1.1 Physical features

Established on 2nd of December, 1971, the United Arab Emirates is a

federation of seven emirates: Abu Dhabi, Dubai, Sharjah, Ajman, Umm al-Qaiwain,

Ras al-Khaimah and Fujairah.

Comprising an area of 83,600 square kilometers, the country lies between

latitudes 22°–26.5°N and longitudes 51°–56.5°E. It is bordered to the north by the

Arabian Gulf, to the east by the Gulf of Oman and Sultanate of Oman, to the south

by the Sultanate of Oman and Saudi Arabia, and to the west by Qatar and Saudi

Arabia.

The UAE has 700 kilometers of coastline, including 100 kilometers on the

Gulf of Oman. Along the Arabian Gulf coast are offshore islands, coral reefs and salt

marshes, whilst stretches of gravel plain and barren desert characterize the inland

region.1

Figure 1-1 United Arab Emirates Map2

2

1.2 Climatic conditions

The UAE lies in the arid tropical zone extending across Asia and North

Africa. Climatic conditions in the area are strongly influenced by the Indian Ocean.

This explains why high temperatures in summer are always accompanied by high

humidity along the coast. There are noticeable variations in climate between the

coastal regions, the deserts of the interior and mountainous areas. Prevailing winds,

which are influenced by the monsoons, vary between south or southeast, to west or

north to northwest, depending upon the season and location. Average rainfall is low

at less than 6.5 centimeters annually, more than half of which falls in December and

January. 1

1.3 Housing

In 1985 Government spending on housing stood at 20.1% of total

government expenditure. By 1993 this had climbed to almost 30%. There has been a

noticeable improvement in overall housing standards within the UAE.

The Abu Dhabi Department of Social Services and Commercial Buildings

had 504 buildings and villas under construction in Abu Dhabi and Al Ain in mid

1995 and was studying 417 new projects.

The Department has constructed 40,000 housing units since its inception in

1976. The Department's investments rose from Dh 79 million in 1976 to Dh 11

billion in 1993.

All the Municipal authorities in the UAE have provided important housing

schemes and government funding has been substantial. In addition a number of

3

schemes funded by personal contributions have been undertaken. Among these is the

scheme for construction of 2,000 houses for UAE nationals, financed by the

President Sheikh Zayed bin Sultan Al Nahyan.3

1.4 Social needs and demands

One of the major UAE Government projects is the Housing Ministry's

building of neighborhoods for citizens. The Ministry established the project in

fulfillment of a personal order from the president of the UAE.

Natural ventilation and day-lighting is neglected in the design of these houses

because of two main reasons:

• The Energy (mainly electricity) is very cheap at 8.97 fils/kwh (0.02

US$) because of government support for the prices of Gas.4

• There is modest (almost none) awareness of environmental issues.

Nearly all the new neighborhoods and houses ignored the cumulative

knowledge that shaped the form and style of old houses. Old houses had a lot of

respect for Natural Forces, mainly Sun and Wind, which underpinned two major

traditional elements, the courtyards and cooling towers.

1.5 Environmental and cultural issues

UAE is a unique case when it comes to the mix of ethnic groups living on its

soil. According to CIA publications (1982), Citizens form only 19% of the

population, Iranian and other Arabs 23%, South Asian 50%, other expatriates 8%.

These percentages have been more or less sustained up to this year.5

4

The unbalanced structure of the population, along with relaxed environmental

laws, caused setbacks in two major and notably related topics:

1.5.1 Vernacular architecture styles

This style is drawing its last breath, mostly for aesthetic reasons, but more

importantly because of no understanding of natural forces that was the key factor to

building in that style. The deterioration of Vernacular styles is due mainly to the

implementation of designs from other cultures that are not suitable for climatic

conditions in the UAE, which gives rise to the second topic.

1.5.2 Environmental sense and consideration

More than half of the population is transient, living in the UAE for a short

period of time, which makes them less interested in environmental and power

savings issues. This and slack laws make it the perfect combination to produce the

following for a country with only 3 million inhabitants (Based on International

Energy Agency (IEA) and (EIA) International Energy Annual 1999):

• Total Energy Consumption (1999E):

1.9 Quadrillion Btu* (0.5% of world total energy consumption)

• Energy-Related Carbon Emissions (1999E):

32.2 million Metric tons of carbon (0.5% of world total carbon

emissions)

• Per Capita Energy Consumption (1999E):

652.7 million Btu (vs. U.S. value of 355.8 million Btu)

5

• Per Capita Carbon Emissions (1999E):

11.2 metric tons of carbon (vs. U.S. value of 5.5 metric tons of

carbon)

• Renewable Energy Consumption (1998E):

0.71 Trillion Btu* (0% increase from 1997)6

1.6 Wind and wind catchers

Through recent history, generally two groups of people lived in two very

different divisions in UAE. These two dominions searched for possible survival

methods; one colonized in the desert area and became cattle breeders (Bedouin),

forcing them to move from an oasis to another looking for plants and water for them

and their animals. The other group became fishermen and the sea became their major

source of life, either by going into long fishing trips or traveling to other countries

for trading purposes.

Understanding the wind was a major survival tool for Bedouin as it was for

fishermen. The Bedouin predicted the rare seasons of rain that was very much

dictated by wind movement. They were also warned by the warm winds that dried

their bodies of valuable and scarce water. The direction and time of wind was a

matter of life and death for the fishermen and their starving families also. This very

careful trial-and- error process gave a jump-start in building wind towers and

orienting them in the right direction.

6

REFERENCES:

1 United Arab Emirate. The official site for the Ministry of Information and Culture in the UAE. The Country. 29 Jan. 2002 <http://www.uaeinteract.com/uaeint_main/yearbook/yr_country/002country03.asp >. 2 The University of Texas library Online. United Arab Emirates Map. 15 Jan. 2002 <http://www.lib.utexas.edu/maps/middle_east_and_asia/unitedarabemirates.jpg> 3 The Emirates Center For Strategic Studies and Research. Housing. 5 Jan. 2002 <http://www.ecssr.ac.ae/00uae.socialhousing.htm>. 4 United Arab Emirate. The official site for the Ministry of Information and Culture in the UAE. CMS Energy Signs Taweelah A2 Deal 3 Jun. 2002 <http://www.uaeinteract.com/uaeint_main/newsreport/19981004.htm>. 5 Central Intelligence Agency. United Arab Emirates. 20 Dec. 2001 <http://www.odci.gov/cia/publications/factbook/geos/tc.html>. 6 Energy Information Administiration. United Arab Emirates. 22 Dec. 2001 <http://www.eia.doe.gov/emeu/cabs/uae.html>.

7

2 Climatic Data and Analysis

2.1 Writing TMY2 Data Format

2.1.1 What is TMY2 Data

The TMY2s (Typical Meteorological Year) are data sets of hourly values of

solar radiation and meteorological elements for a 1-year period. Their intended use is

for computer simulations of solar energy conversion systems and building systems to

facilitate performance comparisons of different system types, configurations, and

locations in the United States and its territories. Because they represent typical rather

than extreme conditions, they are not suited for designing systems to meet the worst-

case conditions occurring at a location. Yet, it can be a good tool for architects to

understand the weather they are trying to design for.1

2.1.2 TMY2 Data Format

CLIMATE CONSULTANT is a computer program. It only reads weather

data if it is in the following format:

MMDDHHBBBBBHHHHHTTTTKKKKWWWWCCZZZ

MM Month 01 to 12

DD Day 01 to 31

HH Hour 01 to 24

BBBBB Direct Beam Solar Radiation in kilojoules per square meter

HHHHH Total Horizontal Solar Radiation in kJ/sq m

TTTT Dry-bulb outdoor air temperature in degrees C times 10

8

KKKK Dew point outdoor air temperature in degrees C times 10

WWWW Wind speed in meters per second times 10

CC Sky cover in tenths (00 to 10)

ZZZ Wind direction in degrees from north

Every line represents an hour, which will result in an 8760 lines of data that

represent the TMY2 year.

2.1.3 Calculating the Missing Data

The weather data I obtained from the United Arab Emirates was missing

some major components such as:

• Direct Beam Solar Radiation

• Total Horizontal Solar Radiation

• Dew point outdoor air temperature

2.1.3.1 Direct Beam Solar Radiation

Direct radiation is rays that we get directly from the sun and is capable of

casting shadow.2 The sun's radiation for a day is represented by a sine curve. The

area under the curve is the sum of the direct beam radiation of the day which is the

radiation data format I got from the UAE. In order to change it to an hourly data I did

the following calculation:

A = M t1 ∫ t2

(sin π t / ∆ t) dt3

Where, A is Area under the curve

M is the Maximum amplitude

9

t1 ،t2 is time of start and end of radiation.

t is the time in hours with t = 0 representing midnight.

∆ t is the overall time of sun-shine (t2-t1).

From this equation and knowing the area under the curve (the sum of the direct beam

radiation of the day) we can obtain M (Maximum amplitude)

M = A / t1 ∫ t2 (sin π t / ∆ t) dt

= A * π / N * 2

Where, N is the number of sun exposure hours, which of course differ each day of

the year. Therefore, I considered the 21st as a typical day for the month.

After obtaining the Maximum amplitude we can get the amplitude at any

given hour using the following equation:

Y = M sin (π t / ∆ t)

Y is the amplitude at any given hour.

t is the time in hours with t = 0 representing midnight.

∆ t is the overall time of the sun-shine (t2-t1).

2.1.3.2 Total Horizontal (diffused) Solar Radiation

As solar radiation passes through the earth's atmosphere, part of the radiation

is intercepted by dust particles and dry air while other parts may be absorbed by the

ozone on the upper levels and by water vapor in the surface near the ground. The

result would be a scattered radiation in all directions4, which is most noticed in a

cloudy day, where the clouds block all the direct beams of the sun and there is no

obvious or well-defined shadow.

10

We can obtain the total horizontal radiation from direct radiation using the

following equation:

Global horizontal Gh = Direct normal x Cos (zenith angle) + scattered radiation

Also Gh= Direct normal x Sin (horizontal angle) + scattered radiation

2.1.3.3 Dew point outdoor air temperature

Dewpoint calculated from Dry Bulb Temperature and Relative Humidity

B = (ln (RH / 100) + ((17.27 * T) / (237.3 + T))) / 17.27

D = (237.3 * B) / (1 – B)

Where:

T = Air Temperature (Dry Bulb) in Centigrade (C) degrees

RH = Relative Humidity in percent(%)

B = intermediate value (no units)

D = Dewpoint in Centigrade (C) degrees5

2.2 SCRAM

2.2.1 What is SCRAM Data

The SCRAM (MET144) format is essentially a reduced version of the

traditional CD-144 format. CD-144 refers to the "Card Deck 144 format". The

SCRAM (MET 144) format consists of fewer weather variables. The file is

composed of one record per hour, with all weather elements reported in a 28-column

card image.6

11

2.2.2 SCRAM Data Format

1-5 Surface Station Number

6-7 Year

8-9 Month

10-11 Day

12-13 Hour

14-16 Ceiling Height (Hundreds of Feet)

17-18 Wind Direction (Tens of Degrees)

19-21 Wind Speed (Knots)

22-24 Dry Bulb Temperature (Degrees Fahrenheit)

25-26 Total Cloud Cover

27-28 Opaque Cloud Cover

Figure 2-1 Scram Data Format5

Surface Station Number - The WBAN number identifying the NWS surface

observation station for which hourly meteorological data are input to the met

processing program .

Year, Month and Day of Record - Identifies the year, month and day during which

the meteorological data were observed. Only the last two digits of the year are

reported .

12

Hour - Identifies the hour of the meteorological data observation. Hour is based on

the 24-hour clock and is recorded as 00 through 23. Times are Local Standard Time

(LST) and are adjusted in PCRAMMET to the 01 - 24 clock in which hour 24 is the

same as hour 00 of the next day .

Ceiling Height - The height of the cloud base above local terrain and is coded in

hundreds of feet .

Wind Direction - The direction from which the wind is blowing, based on the 36

point compass, e.g. 09=East ،18= South, 27=West, 36=North, 00=Calm .

Wind Speed - The wind speed measured in knots (00=Calm) .

Dry Bulb Temperature - The ambient temperature measured in whole degrees

Fahrenheit .

Cloud Cover - There are two cloud cover parameters, opaque cloud cover and total

cloud cover in the SCRAM meteorological data files.5

13

2.3 Climatic Data Charts

2.3.1 City of Abu Dhabi

2.3.1.1 Temperature Range

The temperature range for Abu Dhabi can be plotted using Climate

Consultant. (See Figures 2-2 through 2-10)

In summary, the year can be classified into three main groups:

• Group 1: The hottest months, May, June, July, August and September where

the temperature mean value exceeded the comfort zone range.

• Group 2: The Moderate months from November through March that showed

moderate temperatures plotted around the human comfort zone.

• Group 3: April and October, which were the transmission months to and

from the hot 5 months mentioned in group 1.

Figure 2-2 Abu Dhabi 1997 Temperature Range

14

2.3.1.2 Temperature + Relative Humidity

A typical day for Abu Dhabi with dry-bulb temperature and relative humidity

level can be plotted using Climate Consultant. (See figures 2-11 through 2-19)

The same three temperature groups (discussed in section 2.3.1.1) can be

noticed here also with a high humidity level all through the year with a RH

difference that can reach 40% sometimes between day and night.

Figure 2-3 Abu Dhabi 1997 Temperature + Relative Humidity

15

2.3.1.3 Wind Velocity Range

The wind velocity range for Abu Dhabi can be plotted using Climate


The wind low and high average velocities for all the years showed a very

similar pattern that ranged from 2.5 to 15 mph. In addition, there was an irregular

pattern of the record high speeds which is most probably caused by occasional

storms.

Figure 2-4 Abu Dhabi 1997 Wind Velocity Range

16

2.3.1.4 Bioclimatic Timetable

The bioclimatic timetable for Abu Dhabi can be plotted using Climate


According to the following charts, there are three categories of months:

• 1st Category from October 15 through March 15: The day and night is in

the comfortable temperature range.

• 2nd Category from March 15 through June 15 and from September 15

through November 15: The nigh only is in the comfortable

temperature range.

• 3rd Category from June 15 through September 15: The overheated period

lasts 24 hour.

Figure 2-5 Abu Dhabi 1997 Bioclimatic Timetable

17

2.3.1.5 Psychrometric Chart

The Psychrometric chart for Abu Dhabi can be plotted using Climate


There is almost a 20'F difference in dry-bulb temperature between day and

night. In summer, the change in absolute humidity values was greater than the other

seasons while in winter only a change in relative humidity appeared with a constant

absolute humidity value.

The charts suggest that the effective strategy would be ventilation (zone 6)

coupled with high mass and night ventilation (zone 7&8), all under sun shading

(zone 5). Furthermore, there are some months (like July and August) that are too hot

and humid for such strategies to work successfully

Figure 2-6 Abu Dhabi 1997 Psychrometric Chart

18

2.3.2 City of Al-Ain

2.3.2.1 Temperature Range

The temperature range for Al-Ain can be plotted using Climate Consultant.

(See Figures 2-47 through 2-52)

In summary, the year can be classified into three main groups:

• Group 1: The hottest months, May, June, July, August and September where

the temperature mean value exceeded the comfort zone range.

• Group 2: The Moderate months from November through March that showed

moderate temperatures plotted around the human comfort zone.

• Group 3: April and October, which were the transmission months to and

from the hot 5 months mentioned in group 1.

Figure 2-7 Al-Ain 1997 Temperature Range

19

2.3.2.2 Temperature + Relative Humidity

A typical day for Al-Ain with dry-bulb temperature and relative humidity

level can be plotted using Climate Consultant. (See figures 2-52 through 2-56)

The same three temperature groups (discussed in section 2.3.2.1) can be

noticed here also with a high humidity level (sometimes 80%) from November

through May. On the contrary, the relative humidity percentages drop to 20% in

April through October during the night and about 45% during the day.

Figure 2-8 Al-Ain 1997 Temperature + Humidity

20

2.3.2.3 Wind Velocity Range

The wind velocity range for Al-Ain can be plotted using Climate Consultant.


The wind low and high average velocities for all the years showed a very

similar pattern that ranged from 2.5 to 18 mph. In addition, there was an irregular

pattern of the record high speeds which is most probably caused by storms that is

more frequently appearing in the city of Al-Ain.

Figure 2-9 Al-Ain 1997 Wind Velocity Range

21

2.3.2.4 Bioclimatic Timetable

The bioclimatic timetable for Al-Ain can be plotted using Climate


According to the following charts, there are three categories of months:

• 1st Category from October 15 through March 15: The day and night is in

the comfortable temperature range.

• 2nd Category from March 15 through June 15 and from September 15

through November 15: The nigh only is in the comfortable

temperature range.

• 3rd Category from June 15 through September 15: The overheated period

lasts 24 hour.

Figure 2-10 Al-Ain 1997 Bioclimatic Timetable

22

2.3.2.5 Psychrometric Chart

The Psychrometric chart for Al-Ain can be plotted using Climate Consultant.


There is almost a 25'F difference in dry-bulb temperature between day and

night. In summer, the relative humidity values decreases although the absolute

humidity value increases.

The charts suggest that the effective strategy would be ventilation (zone 6)

coupled with high mass and night ventilation (zone 7&8), all under sun shading

(zone 5). Moreover, there are some days that are too hot and dry for such strategies

to work successfully.

Figure 2-11 Al-Ain 1997 Psychrometric Chart

23

2.4 Wind Roses


The wind rose can be plotted using WR Plot. (See Figures 2-72 through 2-80)

The prevailing wind for Abu Dhabi is northwest. However, there are some

years that had two prevailing wind direction, northeast, south and southeast.

WIND ROSE PLOT

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WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 2-12 Abu Dhabi 1997 Wind Rose

24

WIND ROSE PLOT

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WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 2-13 Abu Dhabi 1991, 92, 93, 94, 95, 97, 98 and 99 Wind Rose

25


The wind rose can be plotted using WR Plot. (See Figures 2-80 through 2-86)

The prevailing wind for Al-Ain is northwest. However, there are some years

that had two prevailing wind direction, northeast, south and southeast.

WIND ROSE PLOT

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COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 2-14 Al-Ain 1997 Wind Rose

26

WIND ROSE PLOT

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WRPLOT View 3.5 by Lakes Environmental Software - www .lakes-environmental.com

Figure 2-15 Al-Ain 1995, 96, 97, 98 and 99 Wind Rose

27

REFERENCES:

1 The Renewable Resource Data Center . TMY2 User's Manual. 5 Mar. 2002 <http://rredc.nrel.gov/solar/old_data/nsrdb/tmy2/> 2 Kreider, Jan F, and Kreith, Frank. Solar Heating and Cooling: Engineering, Practical Design, and Economics. Washington, D.C.: Hemisphere, 1975, pp 5. 3 Larson, Roland E., and Hostetler, Robert P. Calculus with analytical geometry. Toronto: Heath and Company, 1986, pp 278. 4 Threlkeld, James L., Thermal Environmental Engineering, New Jersey: Englewood Cliffs, 1970, pp 294. 5The University of Arizona. Dewpoint Formulas. 2 Jan. 2002 <http://ag.arizona.edu/azmet/dewpoint.html> 6 The Meteorological Resource Center. Met Data Guide. 4 Jan. 2002. <http://www.webmet.com/MetGuide/SCRAMSurface.html>

28

3 Wind and Ventilation

3.1 Wind Characteristics

Wind is a key design factor for Architects. It can increase the occupant

satisfaction level in a space and make them thermally comfortable. Therefore,

understanding the nature of wind is crucial if the building is to be environmentally

useful.

3.1.1 Wind near the Ground

Wind is a very irregular phenomenon. In the lower layer of the atmosphere,

various obstacles and objects as well as landforms and vegetation cause turbulence.

Turbulence slow the speed of wind in general where obstacles change wind patterns

inducing increasing velocity in some areas, while protects other areas.1

Figure 3-1 Typical Record of the Wind Velocity near the Ground 1

29

Figure 3-2 Wind Patterns (a) Constricted by Topography. (b) Above and Below Tall Buildings. (c)

Around large Buildings.2

30

3.1.2 Wind in an Urban Environment

The friction caused by numerous obstacles that increase the roughness of the

ground affects the wind velocity.

In an urban environment, a reduction of 20% to 30% in the average wind

speed and an increase of 50% to 100% in the turbulence intensity are noticed when

moving from the countryside in addition to the more frequent weak winds.3

Figure 3-3 Effect of Terrain on Wind Velocity Profiles4

3.1.3 Wind Flow

Wind is a direct result of low and high pressure. The sun radiation heats the

equatorial zone which raises the air causing low pressure that invites wind from other

areas with higher pressure. Similarly, flow in a building is mainly introduced by the

different pressures in and around the building.

Wind flow is produced when an inlet is positioned in an area of positive

pressures and outlets are placed in areas of negative pressures. The pressure

differences between the inlet and outlets induce the air to move through a building.5

31

Figure 3-4 Wind Pressure around Building 6

Figure 3-5 Wind Pressure Drives Cross Ventilation5

3.2 Natural Ventilation for Thermal Comfort

Natural ventilation is the movement of air into and out of a space through

openings intentionally provided for this purpose or it is simply the use of outside

cool breezes when possible. The main purpose of natural ventilation is to provide

fresh air and a cooling effect either by replacing the hot interior air or by the motion

itself.7

32

3.2.1 Removal of Excess Heat

Heat is mainly gained in a space by solar radiation and conduction through

the building envelope; it is also generated in the space by different means such as

people, lights, mechanical and electrical systems. As the air temperature increases

the air rises to the top of the space and increases the temperature of the ceiling,

which radiates heat into the space. The removal of this excess heat can decrease the

overall cooling load of the space and move the temperature more towards the

comfort zone.

3.2.2 Cooling Effect over the Human Body

When the body core temperature increases the hypothalamus calls for

changes in our blood distribution system. Because blood carries heat, the blood flow

toward the skin increases which will result in an increase of the sweat glands and

eventually evaporation. When the air molecules pass by the skin it absorbs heat and

will decrease the temperature of the body. Once air and surface temperature

approach the human body temperature (37 'C or 98.6 'F) evaporation becomes more

important and most effective.8

33

Figure 3-6 Heat Generated and lost (approximate) by a person at rest (rh fixed at 45%)8

3.2.3 Cooling the Structure

The air movement over the different surfaces of the interior decreases the

heat gain through convection and long-wave radiation. The faster the air velocity

over the surface, the cooler it becomes. This happens mainly in a strategy termed

nocturnal ventilation or night time flushing, when the day time ventilation is not

possible due to the high day time temperatures of the region. Nocturnal ventilation is

used with high mass building envelope.

The high mass envelope basically stores the heat during the day-time and

delays the heat transfer to the interiors. When the night falls and the wall becomes

ready to transfer heat into the space, wind is driven into the space in order to carry

the heat outside the building. This process decreases the surface temperature of the

interior and makes the space ready for the next day.

34

Figure 3-7 Isocomfort Curve9

Figure 3-8 Isocomfort Curve Parametrized as a Function of the air velocity. 9

Figures 3-7 and 3-8 show Isocomfort graphs with some of the possible

combinations achieved with a ventilation strategy. All the points appearing on the

Isocomfort curve has the same comfort conditions9. Furthermore, the wind becomes

less effective as the temperature reaches 33'C, which means that faster wind velocity

is needed with higher temperatures.

35

REFERENCES:

1 Allard, Francis. Natural Ventilation in Buildings: A design handbook. London: James & James, 1998, pp 11. 2 Bradshaw, Vaughn. Building Control Systems. New York: John Wiley & Sons. 1993, pp 71. 3 Allard, Francis. Natural Ventilation in Buildings: A design handbook. London: James & James, 1998, pp 22. 4 Brown, G. Z., and Dekay, Mark. Sun, Wind and light: Architectural Design Strategies. New York: John Wiley & Sons. 2001, pp17 5 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6, pp 17 6 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6 pp 16 7 Bradshaw, Vaughn. Building Control Systems. New York: John Wiley & Sons. 1993, pp 246 8 Stein, Benjamin, and Reynolds, John S. Mechanical and Electrical Equipment for Building. New York: John Wiley & Sons, 2000, pp 39 9 Allard, Francis. Natural Ventilation in Buildings: A design handbook. London: James & James, 1998, pp 45

36

4 Historical Precedents

4.1 Hot and Arid Zones

Before the industrial revolution, residents of hot arid zones were encouraged

to figure out natural ways to cool their houses and keep them as comfortable as

possible during hot days. In the Middle East, different approaches had been

attempted by dwellers according to different cultural and climate conditions (besides

material availability).

Figure 4-1 Wind Tower in the Middle East1

37

Figure 4-2 Catching Efficiency for Different Wind Catcher Designs2

38

4.1.1 The Malqaf

This wind catcher device is widely used in Egypt. It is mainly a scoop rising

above the building to collect stronger and cooler prevailing wind. Wind is

predominantly driven into large spaces below the Malqaf and then forced out

through openings in the top of a central hall. In addition to the cooling effect over the

body as a result of wind flow, it also removes excess heat that is generated from

occupants. The disadvantages of the Malqaf are that it can only catch the wind from

one direction and it would only have an effect over limited rooms when forced

through the top of the central hall.

Figure 4-3 Roof plan of the Fu'ad Riyad house in Cairo, showing the malqaf with sectional details3

39

Figure 4-4 Section of the Fu'ad Riyad house showing the malqaf4.

Figure 4-5 Section of a modern villa designed for Saudi Arabia showing the use of malqaf5

40

Figure 4-6 Section through the hall of Muhib Ad-Din Ash-Shaf'i Al-Muwaqqi showing the malqaf

and central location of the hall6

Figure 4-7 Arrows indicate the direction of airflow; arrow length corresponds to airspeed. The

measurements where made on 2 April 1973 by scholars from the Architectural Association School of Architecture in London. All wind and airspeeds are given in meters per second.7

41

In dryer conditions, Architect Hassan Fathy suggested wetted baffles which

can help reduce the air temperature by evaporation. Air is mainly directed over a

fountain or a basin of still water, to increase air humidity. He also mentioned that

baffles can reduce air flow which can be overcome by increasing the size of the

Malqaf and suspending the wetted matting in its interior.8

Figure 4-8 Malqaf with wetted baffles and a wind-escape. Design by Hassan Fathy 9

42

Figure 4-9 Details of the malqaf with wetted baffles10

43

4.1.2 The Badgir (Barjeel)

This type of wind catcher was developed in Iran around 900 AD11. It is

principally a shaft that rises 3 meters above the building with two partitions placed

diagonally with openings on all four sides.

Figure 4-10 Barjeel details12

The Badgir (Barjeel) would work both as an intake and exhaust at the same

time. Wind is sucked out by the negative pressure that is created in the leeward side

of the tower. When there is no air movement in the region, stack effect would

remove hot air that is generated inside the space below the Barjeel. The Barjeel is

44

mostly positioned in the corner of the building and directly over the place where

people either gather or sleep. The room or space that is ventilated by the Barjeel is

always being situated near the courtyard of the house and uses it as a major exhaust.

The air that is channeled through the barjeel is transferred to other rooms through

wooden doors or openings on the top of the room. These wooden doors will be

closed if the wind reached uncomfortable velocities. (Figure 4-11 and 4-12)

Figure 4-11 Mohamed Sharif house, first floor13

45

Figure 4-12 Wooden doors and opening14

Figure 4-13 Interior view of the Wooden doors and openings15

46

Figure 4-14 Shaikh Saeed house (North Elevation)16

Figure 4-15 Shaikh Saeed house (East Elevation)

Figure 4-16 Shaikh Saeed house (Courtyard view)

47

Figure 4-17 Traditional Square Barjeel

Figure 4-18 Unusual cylindrical Barjeel

48

Figure 4-19 The Barjeel Closed to Block Undesirable Wind17

Figure 4-20 A fort in the City of Ajman uses the Barjeel for Natural Ventilation18

49

4.1.3 Wind Scoops

In high density cities multi-storey buildings are likely to appear which

decreases the wind velocity near the ground. Windows wouldn't be efficient to

provide the necessary air flow for cooling the inhabitants. The only way around this

problem is to reach for the higher wind velocities by rising above the city skyline.

That is exactly what happened in Hyderabad in Pakistan, where the wind

scoops peak over the roofs of the buildings direct air into spaces below multi-storey

houses. Subsequently, the windows act as an exhaust and guide the wind to the

exterior.

Figure 4-21 Wind scoop, Hyderabad, Sind, Pakistan19

Figure 4-22 Wind Scoops facing the prevailing wind20

50

Figure 4-23 Scoops in Pakistan at different levels21

51

4.2 Design Examples of Wind Catchers

4.2.1 Qatar University in Doha

The university was built in the Arabian Gulf area, for this reason the design

came in favor of natural ventilation. The wind catcher that rose above the octagonal

shaped building was the dominating view from every side of the university. Besides

the astonishing view from the courtyards that surrounds these beautiful traditional

elements, the Barjeels give the impression of being guards protecting the adjacent

spaces from harsh environment.

Figure 4-24 A picture from the roof22

Figure 4-25 Section/Elevation of Humanities Faculty Modules23

52

Figure 4-26 An External Picture of the Wind Catchers24

Figure 4-27 A picture from the courtyard25

53

Figure 4-28 Qatar University (Phase 1), Kamal El-Kafrawi26

Figure 4-29 Ariel View of Qatar University27

54

4.2.2 Concept drawings

The effectiveness of the wind tower and wind catcher depends first and

foremost on how much the device can make use of pressure differences created in

and around the building. Furthermore, the microclimate of the region has to be

examined with awareness of other factors that can influence the direction in which

the wind blows from. For example, sites near the sea are subject to reverse wind

direction from day to night as a result of differences in thermal inertia between land

and water. Similarly, sites located in mountain areas would have the same changing

direction of prevailing wind.

Figure 4-30 From above: Wind tower; monodirectional wind tower and scoop; multidirectional wind

tower and scoop; combined wind tower and scoop28

55

Figure 4-31 Day and Night reverse wind directions29

56

Therefore, designers suggested a new breed of wind scoops that can face the

wind and maximize ventilation without any need of a mechanical system, yet, the

new scoop needs a lot of structural balance low friction bearings and a good centre of

gravity in order to rotate easily with weak low velocity wind.30

Figure 4-32 Concept Drawings for rotating wind scoops31

57

REFERENCES:

1 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6, pp25 2 Brown, G. Z., and Dekay, Mark. Sun, Wind and light: Architectural Design Strategies. New York: John Wiley & Sons. 2001, pp 189 3 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp 131 4 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp 130 5 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp 128 6 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp 116 7 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp 117 8 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp59 9 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp 124 10 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp 125 11 Allard, Francis. Natural Ventilation in Buildings: A design handbook. London: James & James, 1998, pp237

58

12 UAE. Dubai Municipality: the Historical Building Section. Elements of Traditional Architecture in Dubai. Dubai: Dubai Municipality, 2000, pp C-(1). 13 UAE. Dubai Municipality: the Historical Building Section. Elements of Traditional Architecture in Dubai. Dubai: Dubai Municipality, 2000, pp A-(8-1). 14 Forman, Werner, Phoenix Rising: The United Arab Emirates Past, present and future. London: The Harvill. 1996, pp 183. 15 Prakash Subbarao, Sheikh Saeed Al Maktoum House. 12 Dec. 2001 <http://www.datadubai.com/saeedh.htm> 16 UAE. Dubai Municipality: the Historical Building Section. Elements of Traditional Architecture in Dubai. Dubai: Dubai Municipality, 2000, pp B-(1-1). 17 Forman, Werner, Phoenix Rising: The United Arab Emirates Past, Present and Future. London: The Harvill. 1996, pp 13. 18 Vine, Peter. UAE in Focus: A photographic history of the United Arab Emirates. London: Trident. 1998, pp 134. 19 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6, pp 26 20 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6, pp 27 21 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986, pp 114 22 Roger Williams University. Qatar University. 2 May. 2002 <http://faculty.rwu.edu/~huk/Kahncaseweb/University%20of%20Qatar/Q1.gif> 23 Brown, G. Z., and Dekay, Mark. Sun, Wind and light: Architectural Design Strategies. New York: John Wiley & Sons. 2001, pp 188. 24 Roger Williams University. Qatar University. 2 May. 2002 <http://faculty.rwu.edu/~huk/Kahncaseweb/University%20of%20Qatar/Q16a.gif> 25 Roger Williams University. Qatar University. 2 May. 2002 <http://faculty.rwu.edu/~huk/Kahncaseweb/University%20of%20Qatar/Q6p.gif>

59

26 Brown, G. Z., and Dekay, Mark. Sun, Wind and light: Architectural Design Strategies. New York: John Wiley & Sons. 2001, pp 188 27 Roger Williams University. Qatar University. 2 May. 2002 <http://faculty.rwu.edu/~huk/Kahncaseweb/University%20of%20Qatar/Q14a.gif> 28 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6, pp 30 29 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6, pp 14 30 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6, pp 34 31 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6, pp 35

60

5 Setting the Variables

5.1 Hypothesis

Wind catchers can be adapted to provide comfort without overly constraining

either development or design possibilities for new housing in hot-arid climates.

5.2 When to use Natural Ventilation

As discussed in section 3.2.2, when the air temperature approaches human

body temperature (37 'C or 98.6 'F), all the cooling effect is credited to evaporation.

Furthermore, heat loss via convection and radiation decreases to a minimum and

eventually becomes nil. In addition, if the temperature rises above 37 'C and the

evaporation rate decreases, the human body will start gaining heat via convection

from warmer air moving around the body.

When air moves over a wet skin, it will without doubt give a cooling

sensation even if the temperature was amazingly high. On the other hand, there was

no scientific way to prove it. Accordingly, the human body temperature was used as

a reference point for ventilation and the assumption that natural ventilation would be

effective only when temperatures are lower than 37 'C was made for this thesis.

Above that temperature, the human body could gain heat from wind.

Year 1997 was chosen as a typical year for both cities to find the optimum

orientation for the wind catcher; an orientation that will collect wind at the right

times (below 37'C) in order to have a positive effect over the comfort zone.

61


Figure 5-1 Hours to Block Natural Ventilation in Abu Dhabi

Hours to block wind would be as follows:

June from 7:00 to 15:00

July from 7:00 to 15:00

August from 7:00 to 14:00

September from 7:00 to 14:00

62

The prevailing wind for Abu Dhabi is northwest which is also the case in the

afternoon period; however, the wind had almost a reverse direction from midnight

through the early morning hours where the wind blows from the south, southeast and

southwest.

WIND ROSE PLOT

Station # 11111 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME1997 Jan 1 - Jan 31Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.64 m/s

COMMENTS

ORIENTATIONDirection(blowing from)

WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-2 January Wind Rose

63

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

6%

12%

18%

24%

30%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Feb 1 - Feb 29Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


2.12 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-3 February Wind Rose

64

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Mar 1 - Mar 31Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


2.24 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-4 March Wind Rose

65

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Apr 1 - Apr 30Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


2.00 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-5 April Wind Rose

66

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 May 1 - May 31Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.77 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-6 May Wind Rose

67

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jun 1 - Jun 30Midnight - 7 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.52 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-7 June from Midnight to 7am Wind Rose

68

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jun 1 - Jun 303 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.61 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-8 June from 15pm until Midnight Wind Rose

69

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

5%

10%

15%

20%

25%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jul 1 - Jul 31Midnight - 7 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.61 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-9 July from Midnight to 7am Wind Rose

70

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

5%

10%

15%

20%

25%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jul 1 - Jul 313 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.65 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-10 July from 3pm to Midnight Wind Rose

71

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Aug 1 - Aug 31Midnight - 7 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.34 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-11 August from Midnight to 7am Wind Rose

72

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Aug 1 - Aug 312 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.83 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-12 August from 2pm to Midnight Wind Rose

73

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Sep 1 - Sep 30Midnight - 7 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.39 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-13 September from Midnight to 7am Wind Rose

74

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Sep 1 - Sep 302 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.60 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-14 September from 2pm to Midnight Wind Rose

75

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Oct 1 - Oct 31Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.78 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-15 October Wind Rose

76

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Nov 1 - Nov 30Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.64 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-16 November Wind Rose

77

WIND ROSE PLOT

Station #11111 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Dec 1 - Dec 31Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.63 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-17 December Wind Rose

78


Figure 5-18 Hours to Block Natural Ventilation in Al-Ain

Hours to block wind would be as follows:

May from 8:00 to 15:00

June from 7:00 to 17:00

July from 7:00 to 17:00

August from 7:00 to 17:00

September from 7:00 to 14:00

79

The prevailing wind for Al-Ain is northwest which is also the case in the

afternoon period; however, the wind had almost a reverse direction from midnight

through the early morning hours where the wind blows from the south, southeast and

southwest and occasionally east.

WIND ROSE PLOT

Station # 22222 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jan 1 - Jan 31Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.82 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-19 January Wind Rose

80

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

5%

10%

15%

20%

25%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Feb 1 - Feb 29Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


2.14 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-20 February Wind Rose

81

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Mar 1 - Mar 31Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


2.30 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-21 March Wind Rose

82

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Apr 1 - Apr 30Midnight - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


2.19 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-22 April Wind Rose

83

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 May 1 - May 31Midnight - 8 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.91 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes -environmental.com Figure 5-23 May from Midnight to 8am Wind Rose

84

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 May 1 - May 313 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.62 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-24 May from 3pm to Midnight Wind Rose

85

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

5%

10%

15%

20%

25%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jun 1 - Jun 30Midnight - 7 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


2.14 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-25 June from Midnight to 7am Wind Rose

86

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jun 1 - Jun 305 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.65 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-26 June from 5pm to Midnight Wind Rose

87

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

6%

12%

18%

24%

30%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jul 1 - Jul 31Midnight - 7 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.71 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-27 July from Midnight to 7pm Wind Rose

88

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

5%

10%

15%

20%

25%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Jul 1 - Jul 315 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.43 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-28 July from 5pm to Midnight Wind Rose

89

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Aug 1 - Aug 31Midnight - 7 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.59 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-29 August from Midnight to 7am Wind Rose

90

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

5%

10%

15%

20%

25%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Aug 1 - Aug 315 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.67 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-30 August from 5pm to Midnight Wind Rose

91

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

6%

12%

18%

24%

30%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Sep 1 - Sep 30Midnight - 7 AM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


2.07 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-31 September from Midnight to 7am Wind Rose

92

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

4%

8%

12%

16%

20%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

�.�� - �.��

PLOT YEAR-DATE-TIME

1997 Sep 1 - Sep 304 PM - 11 PM

DISPLAY

Wind SpeedUNIT

m/s

CALM WINDS


1.64 m/s

COMMENTS

ORIENTATION


WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-32 September from 4pm to Midnight Wind Rose

93

WIND ROSE PLOT

Station #22222 - ,

NORTH

SOUTH

WEST EAST

3%

6%

9%

12%

15%

Wind Speed (m/s)

> ��.��

�.�� - ��.��

�.�� - �.��

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COMMENTS

ORIENTATION


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94

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95

WIND ROSE PLOT

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WRPLOT View 3.5 by Lakes Environmental Software - www.lakes-environmental.com Figure 5-35 December Wind Rose

96

5.3 Model Drawings and Testing Environment

5.3.1 Helium Bubble Generator

The Helium Bubble Generator is a device that produces neutrally buoyant

bubbles filled with helium. The bubbles follow the air flow streamlines and rarely

collide with objects. Additionally, the bubbles will follow laminar and turbulent

airflows.

Figure 5-36 Helium Bubble Generator

5.3.2 Drawings

All the simulated airflow tests were preformed on a 1:48 scale model of a

building 14’ wide, 28’ long and 10’ high.

97

Top View

Side View

Figure 5-37 Side and Top View of the Model

A wind catcher with three different sizes was built and tested. All three sizes

had the same section but varying lengths, which represented 1/3, 1/2 and all of the

windward façade.

98

aa

Top View

Section a-a

Front View

Figure 5-38 1/3 Wind Catcher, Top View, Section and Front View

99

aa

Front View

Section a-a

Top View

Figure 5-39 2/3 Wind Catcher, Top View, Section and Front View

100

aa

Front View

Section a-a

Top View

Figure 5-40 Full Length Wind Catcher, Top View, Section and Front View

101

The leeward façade was used as an exhaust in two general configurations: the

first configuration used the entire façade as an outlet (10' X 14'), while the second

used an opening of 4' X 14' placed at varying locations.

Full Opening (CASE 0)

2' X 2' X 14' (CASE 1)

Top Opening 4' X 14' (CASE 2)

Bottom Opening 4' X 14' (CASE 3)

Figure 5-41 Leeward Elevation with different Apertures

102

Fan

ModelLight Projector

Table

Bubble Output

FanLight Projector

ModelBubble Output

Wall

Side View

Top View

Figure 5-42 General Setup of the Experiments

103

6 Wind Catcher with Different Sizes and Outlets

All the tests were performed with the wind blowing perpendicular to the wind

catcher's façade.

Wind

WindwardLeeward

WindSide View

Top View

Figure 6-1 Model Position in respect to the Wind Catcher

The tests were recorded using a digital camcorder with a 30 frame per second

rate. The duration of each frame is 0.033 second. In short, every 1 inch in the picture

represents 60 inch per second or 0.76 meters per seconds.

The fan had three speeds, as follows:

• Fan Speed 1 = 5 ft/s = 1.5 m/s = 3.4 mph

• Fan Speed 2 = 7.5 ft/s = 2.3 m/s = 5.1 mph

• Fan Speed 3 = 10 ft/s = 3.1 m/s = 6.8 mph

104

6.1 1/3 Wind Catcher

Figure 6-2 1/3 Wind Catcher Front Axonometric View

6.1.1 Case 0

Figure 6-3 Case 0 Back Axonometric View

105

6.1.1.1 Speed 1

Bubble 1

Figure 6-4 Six Frames Combined

Bubble 2

Figure 6-5 Four Frames Combined

106

6.1.1.2 Speed 2

Figure 6-6 Five Frames Combined

6.1.1.3 Speed 3

Bubble 1

Figure 6-7 Two Frames Combined

107

Bubble 2


Figure 6-9 Case 0 3D Drawing

108

Figure 6-10 Case 0 Side View

Case 0

0

0.5

1

1.5

2

2.5

Spee

d m

/s

speed 1 B1 speed 1 B2 speed 2 speed 3 B1 speed 3 B2

Figure 6-11 Speed Vs Location

The general flow of the wind takes an almost direct path to the exit.

However, there is some variation appearing at the top of the model where a region of

positive pressure is forcing the wind into a loop. The air that is pushed to the wall

opposite to the one adjacent to the wind catcher is taking a coil-like shape and ends

up joining either the general flow towards the exhaust or enter the loop on the top of

the model.

109

6.1.2 Case 1


6.1.2.1 Speed 1

Bubble 1


110

Bubble 2

Figure 6-14 Seven Frames Combined

6.1.2.2 Speed 2


111

6.1.2.3 Speed 3

Bubble 1


Bubble 2


112



113

Case 1

0

0.5

1

1.5

2

2.5

Spee

d m

/s



In this case, most of the bubbles are using the bottom opening to exit but with

some difficulty appearing in the form of turbulence. Less turbulence was observed as

the airflow velocity was increased. Furthermore, an increase in velocity forced some

of the airflow to sweep upwards against the back wall, using the top opening to exit.

As for the speed of wind inside the model, the highest speed would be under

the wind catcher which is in the first third. Nevertheless, the wind decelerates and

reaccelerates throughout the model until it reaches the exhaust, where a speed higher

than the one in the middle zone is noticed most of the time. For example, fan speed 2

in this case showed the highest speed for the exhaust.

114

6.1.3 Case 2

Figure 6-21 Case 2 Axonometric Back View

6.1.3.1 Speed 1

Bubble 1

Figure 6-22 Eight Frames Combined

115

Bubble 2


6.1.3.2 Speed 2

Figure 6-24 Nine Frames Combined

116

6.1.3.3 Speed 3

Bubble 1


Bubble 2


117



118

Case 2

0

0.5

1

1.5

2

2.5

Spee

d m

/s



This is the best self adjusting solution observed in this prototype. Compared

to other exhaust types tested, this configuration maintained the narrowest range with

various airflow velocities near the exit. At slower speeds, the air takes a smoother

path to the exit and as the speed increases, the air is slowed due to the sharper path

angles.

Using fan speed 1, the wind takes a smooth path that becomes smoother with

fan speed 2. However, when using speed 3 the wind tends to go downward and starts

to have sharper air flow patterns.

119

6.1.4 Case 3


6.1.4.1 Speed 1


120

6.1.4.2 Speed 2

Bubble 1

Figure 6-32 Two Frames Combined

Bubble 2


121

6.1.4.3 Speed 3



122


Case 3

0

0.5

1

1.5

2

2.5

1 2 3 4 5

Spee

d m

/s

speed 1 speed 2 B1 speed 2 B2 speed 3


123

The velocity of the airflow is high compared with the other cases because the

opening is in the natural airflow direction of the wind, hence that the opening is

smaller than Case 0 which forces the wind to accelerate. Nevertheless, a bigger

positive zone is created to the upper right corner of the creating a large number of

vortexes. Theses vortices are acting against the smooth flow of wind as they become

more affective with higher speeds. Moreover, this type of opening will be obstructed

by furniture since the wind is taking a path closer to the ground but would be a very

good alternative if body cooling was needed the most.

Speed 1

0

0.5

1

1.5

2

2.5

Spee

d m/s

Case 0 Case 1 Case 2 Case 3

Figure 6-38 Speed Vs Cases

124

Speed 2

0

0.5

1

1.5

2

2.5

Spee

d m

/s



Speed 3

0

0.5

1

1.5

2

2.5

Spe

ed m

/s



125

In case 1, the big air velocity differences occurred because air going through

the bottom opening is much faster than the wind exiting through the top opening,

while in case 2 the difference was because of the faster speed of wind in the first part

of the model and the slowed down flow near the exhaust.

Case 3 did not have a noticeably higher air velocity inside the model with

higher fan speeds, which confirms the assumption that higher wind creates more

turbulence inside the model which results in a slower air flow.

6.2 1/2 Wind Catcher

Figure 6-411/2 Wind Catcher Front Axonometric View

126

6.2.1 Case 0


6.2.1.1 Speed 1


127

6.2.1.2 Speed 2


6.2.1.3 Speed 3


128



129

Case 0

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Spee

d m

/s

speed 1 speed 2 speed 3


The larger wind catcher is allowing a greater volume of air into the model. As

a result, airflow is observed to follow a more linear path both in plan and section,

forcing the wind to rise to the upper part of the opening.

In fan speed 1 and 2, the air accelerates as it exits, while in fan speed 3 it is

noticed that some kind of positive pressure is building up near the exhaust that

results in a slower airflow.

130

6.2.2 Case 1


6.2.2.1 Speed 1

Figure 6-50 Seven Frames Combined

131

6.2.2.2 Speed 2

Bubble 1


Bubble 2

Figure 6-52 Bubble Speed 0.95 m/s

132

Figure 6-53 The Bubble Exiting from the Bottom Opening and other Bubbles following the same Path

Figure 6-54 Some Bubbles Exit using the Bottom Opening and some Bubbles head Upwards

133

Figure 6-55 Bubbles headed Upward creating a Vortex

Figure 6-56 Nine Frames Combined

134

6.2.2.3 Speed 3



135


Case 1

0

0.5

1

1.5

2

2.5

Sp

eed

m/s

speed 1 speed 2 B1 speed 2 B2 speed 3 Figure 6-60 Speed Vs Location

The air pattern near the exhaust did not change at all compared with the

smaller wind catcher. Nonetheless, the airflow velocity increased especially through

the bottom opening and the coverage area expanded both in plan and section.

136

6.2.3 Case 2


6.2.3.1 Speed 1


137

6.2.3.2 Speed 2


6.2.3.3 Speed 3

Bubble 1


138

Bubble 2



139


Case 2

0

0.5

1

1.5

2

2.5

Sp

ee

d m/s

speed 1 speed 2 speed 3 B1 speed 3 B2


140

This exhaust shows again that it is a better option, even with a larger wind

catcher -although the air did not behave the same way as with the smaller wind

catcher, particularly under the wind catcher. The wind is driven further to the exhaust

as the speed increases unlike the smaller wind catcher where the wind is driven

downward. Yet it is still a better alternative because the air flow covers the majority

of the first bottom meter which is very effective for cooling the human body.

6.2.4 Case 3


141

6.2.4.1 Speed 1


6.2.4.2 Speed 2


142

6.2.4.3 Speed 3



143


Case 3

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Sp

eed

m/s



144

An increase of the airflow velocity is observed again in this case in addition

to a larger positive pressure zone in the top of the model. More turbulence is

appearing with increased velocities as well as vortices in the back upper corner of the

model.

Speed 1

0

0.5

1

1.5

2

2.5

Spee

d m

/s



Speed 2

0

0.5

1

1.5

2

2.5

Spee

d m

/s



145

Speed 3

0

0.5

1

1.5

2

2.5

Spee

d m

/s



Very similar to 1/3 wind catcher (section 6.4.1.3), Case 1 and 2 showed again

a wide range in wind velocities. Case 3 with higher wind creates more turbulence

inside the model which result in a slower air flow.

6.3 Full Length Wind Catcher

Figure 6-79Full Length Wind Catcher Front Axonometric View

146

6.3.1 Case 0


6.3.1.1 Speed 1


147

6.3.1.2 Speed 2

Figure 6-82 Five Frame Combined

6.3.1.3 Speed 3

Figure 6-83 Three Frame Combined

148



149

Case 0

0

0.5

1

1.5

2

2.5

3

Sp

ee

d m/s



Due to the large opening in this configuration, a massive amount of air is

blown inside the model. However, the positive pressure in the top of the model

decreases in size as the airflow velocity increases. The vortex that is created under

the wind catcher (bottom left corner) becomes larger and more obvious in

comparison with smaller wind catchers.

150

6.3.2 Case 1


6.3.2.1 Speed 1


151

6.3.2.2 Speed 2


6.3.2.3 Speed 3

Figure 6-90 Six Frame Combined

152



153

Case 1

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Sp

ee

d m/s



The pattern in this case appears to be identical to that observed using smaller

wind catchers with this exhaust. However, this prototype covered all the floor area

from wall to wall which did not happen with smaller prototypes.

6.3.3 Case 2


154

6.3.3.1 Speed 1


6.3.3.2 Speed 2

Figure 6-96 Other Bubbles taking a Different Path

155

Figure 6-97 Bubbles Exiting the Model

Figure 6-98 Seven Frame Combined

156

6.3.3.3 Speed 3

Figure 6-99 Bubbles Grouping together to Exit


157



158

Case 2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Sp

eed

m/s



This case proves again that the pattern near the exit will not be affected by

the size of the wind catcher even though the speed slightly increased.

6.3.4 Case 3


159

6.3.4.1 Speed 1


6.3.4.2 Speed 2


160

6.3.4.3 Speed 3

Figure 6-107 Three Frame Combined


161


Case 3

0

0.5

1

1.5

2

2.5

Spee

d m

/s



162

Speed 1

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Spee

d m

/s



Speed 2

0

0.5

1

1.5

2

2.5

Spee

d m

/s



163

Speed 3

0

0.5

1

1.5

2

2.5

3

Spee

d m

/s



The velocities recorded in the model with fan speed 1 were in a close range.

This means that with slower wind speed the exhaust does not have a lot of influence

over the air velocity inside the model. In fan speed 2 and 3 a greater differences in

velocities is noticed with a lot of similarity between case 1 and 2 with different fan

speeds.

6.4 Additional Tests

6.4.1 Wind catcher with Smaller Opening

This experiment was performed using a smaller intake opening to test if it is

possible to reduce the speed of the wind when it is undesirable.

164

Front View

Section a-a

Top View

a a

Figure 6-114 1/3 Wind Catcher with Smaller Intake Opening

Figure 6-115 Eighteen Frames Combined with Fan Speed No.1

165

Figure 6-116 Six Frames Combined with Fan Speed No.2

Figure 6-117 Six Frames Combined with Fan Speed No.3

As noticed in the previous images, the wind will take a straight path until it

collides with the bottom surface of the model, then move parallel to the floor surface

to the exhaust. In addition, the bubbles are trying to travel up the wind catcher tower

which creates a positive pressure at the bottom end of the tower.

166

6.4.2 Wind Catcher in the Middle of the Windward Façade

This experiment was performed using the 1/3 wind catcher with the bigger

opening but place between the corners of the windward façade.

Figure 6-118 1/3 Wind Catcher in the Middle of the Windward Façade

Figure 6-119 Front View

167

Figure 6-120 3D Drawing

The wind clearly took the middle zone straight to the exit, while the side

sectors were subject to slower airflow with more turbulence.

6.5 Suggestion

• As mentioned in section 4.2.2, the microclimate of the region has to

be examined before starting the design process.

• The longer the house in the direction of the prevailing wind, the more

efficient the air flow becomes inside the building.

• This type of wind catcher will be most efficient when the wind is

perpendicular to the intake opening.

168

• The wind catcher should face northwest to catch the prevailing wind

for Abu Dhabi especially in the afternoon periods.

• The prevailing wind for Al Ain is northwest and south to southeast.

The wind catcher should face northwest because the wind is blowing

repeatedly from northwest in the afternoon period were ventilation is

most needed.

• The small size wind catcher is efficient enough if the designer does

not need the whole floor area to be covered.

• Areas like Abu Dhabi need a higher air change rate due to higher

humidity levels during summer. In other words, the full length wind

catcher is recommended.

• The upper opening (case 2) is –in my opinion- the best exhaust, which

can also be adapted to be used as an intake when wind is blowing

from the other direction. This is mostly the case from midnight until

the early morning hours.

• If the smaller wind catcher is to be used in a building, it is

recommended to be on the west side of the house to reduce the heat

generated from the afternoon sun over the west façade. The air moves

faster and spread wider over the wall adjacent to the wind catcher

which would decrease the temperature of the west wall surface and

the Mean Radiant Temperature.

169

• This type of wind catcher would not be very effective for cooling the

ceiling, so the house would be much better off with a second floor or

a high ceiling with exhaust. Yet, the air that circulates in the upper

part of the room will be sufficient enough to remove excess heat.

170

7 Future Work

For future studies, the same model may be used with the same 1/3 wind

catcher but with a curved bottom rather than the 45 degree angle. This would help to

find out if it is possible for the wind to have more efficient flow over the ceiling. In

addition, the effect of openings on the wall opposite to the one adjacent to the wind

catcher can be studied to eliminate the turbulence that builds up. Also it would be

very useful to see how the 4 sided Barjeel (mentioned in section 4.1.2) would

perform with various exhausts.

Figure 7-1 Curved Wind Catcher

Figure 7-2 Openings on the Opposite Wall

171

8 Bibliography

Allard, Francis. Natural Ventilation in Buildings: A design handbook. London: James & James, 1998

Bradshaw, Vaughn. Building Control Systems. New York: John Wiley & Sons. 1993 Brown, G. Z., and Dekay, Mark. Sun, Wind and light: Architectural Design

Strategies. New York: John Wiley & Sons. 2001 Fathy, Hassan. Natural Energy and Vernacular Architecture: Principles and

Examples with Reference to Hot Arid Climates. Chicago: University of Chicago. 1986

Forman, Werner, Phoenix Rising: The United Arab Emirates Past, present and

future. London: The Harvill. 1996 Kreider, Jan F, and Kreith, Frank. Solar Heating and Cooling: Engineering, Practical

Design, and Economics. Washington, D.C.: Hemisphere, 1975 Lakes Environmental. WRPLOT View software. 3 Jan. 2002 <http://www.lakes-

environmental.com/lakewrpl.html> Larson, Roland E., and Hostetler, Robert P. Calculus with analytical geometry.

Toronto: Heath and Company, 1986 Milne, Murray. Climate Consultant, University of California, Los Angeles, 1991. The Renewable Resource Data Center . TMY2 User's Manual. 5 Mar. 2002

<http://rredc.nrel.gov/solar/old_data/nsrdb/tmy2/> Stein, Benjamin, and Reynolds, John S. Mechanical and Electrical Equipment for

Building. New York: John Wiley & Sons, 2000 Threlkeld, James L., Thermal Environmental Engineering, New Jersey: Englewood

Cliffs, 1970 UAE. Dubai Municipality: the Historical Building Section. Elements of Traditional

Architecture in Dubai. Dubai: Dubai Municipality, 2000 Vine, Peter. UAE in Focus: A photographic history of the United Arab Emirates.

London: Trident. 1998 "Wind Towers: Detail in Building". Battle McCarthy Consulting Engineers. 1999: 6

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