High Performance Homes in Saudi Arabia Revised … · High Performance Homes in Saudi Arabia...

High Performance Homes in Saudi Arabia

Revised Passivhaus Principles for Hot and Arid Climates

A Thesis

Presented to the Faculty

of Philadelphia University

in Partial Fulfillment of the Requirement for Degree of

Master of Science in Sustainable Design

By

Mohammad A. Alshenaifi

May 2015

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© 2015 Mohammad A. Alshenaifi

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ABSTRACT

The aim of the study is to achieve a net-zero energy home in Saudi Arabia in

order to limit the risk associated with the high energy consumption and CO2 emissions.

The Passivhaus concept is taken into consideration to achieve the goal of the study, as

the concept was initially developed to create high-performance homes in cold climates.

However, the Passivhaus did not achieve the same level of performance in hot and arid

climates when compared to what have been achieved in cold climates. The study will

discuss first the potential improvements in energy performance using the Passivhaus

standard in hot and arid climates, and explore the potential to achieve the goal of this

study.

Based on the results of the analysis of the proposed Passivhaus, the Passive

Down-Draft Evaporative Cooling (PDEC) will be implemented into the design with the

goal of increasing the energy efficiency of the building. PDEC is a passive evaporative

cooling strategy that cools the warm fresh air by the evaporation of water. The strategy

will not make the building airtight, which would be counter to one of the Passivhaus

principles. Based upon the success of the PDEC performance, this study suggests that

the Passivhaus principles should be revised for hot and arid climates.

This study provides a proposal of a potential net-zero energy house in Saudi

Arabia. Upon the success of the study, the Passivhaus design for hot and dry climates

would be an ideal means to significantly reduce the high energy consumption in Saudi

Arabia.

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ACKNOWLEDGEMENTS

My parents, even when I am very far from you, I always feel you near me, and

your prayers for me. I attribute the success in everything in my life to you. Thank you for

supporting me through thick and thin.

My wife, in every step during my study, I have been inspired by you, and I am

sure you will continue to inspire me in everything I will do in the future. Thank you for

being such a positive force in my life, for everything you have provided me since the first

day we met, and for your patience.

Professor Fleming, thank you so much for being such a wonderful leader,

teacher, and great supporter since our first meeting. The knowledge and experience I

have gained from you are so valuable to me.

Professor Fryer, thank you for helping me with every step in this project, and for

listening to me generously. This study will not have been accomplished without your

support, help, and valuable knowledge.

To all my teachers past and present, thank you for providing the path to achieve

my goals.

Thanks also to all my classmates in the Sustainable Design Program. Every

great moment I have spent at Philadelphia University was great because of you.

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TABLE OF CONTENTS

ABSTRACT ............................................................................................... iii

ACKNOWLEDGEMENTS ......................................................................... iv

LIST OF TABLES ..................................................................................... vii

LIST OF FIGURES ................................................................................... viii

LIST OF ABBREVIATIONS....................................................................... xi

CHAPTER 1: INTRODUCTION .................................................................. 1

The Need for Net-Zero Energy Homes in Saudi Arabia......................................................... 1

Building Consumption in Saudi Arabia .......................................................................................... 2

The Case of the Passivhaus for Hot and Dry Climates ......................................................... 4

CHAPTER 2: THE PROBLEM ................................................................... 6

The Passivhaus as a Solution .............................................................................................................. 6

The First Passivhaus in the Middle East: Qatar ........................................................................ 7

The Desert Passive House, Hereford, AZ ................................................................................... 10

LeBois House, Lafayette, LA .............................................................................................................. 11

CHAPTER 3: THE PROBLEM EVALUATION ......................................... 14

CHAPTER 4: THE ANALYSIS AND DESIGN PROPOSAL ..................... 17

The Site ............................................................................................................................................................ 18

The Orientation and Form Analysis ............................................................................................... 21

The Baseline Design ................................................................................................................................ 25

The Case of the Passivhaus ............................................................................................................... 33

Optimized Building Envelope ............................................................................................................ 33

Daylighting and High Efficiency Lighting and Appliances .............................................. 37

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High Efficiency Air Conditioning System ................................................................................... 40

Onsite Solar Photovoltaic .................................................................................................................... 41

Passive House Energy Performance ............................................................................................. 41

Evaporative Cooling ................................................................................................................................ 43

Energy Performance ................................................................................................................................ 54

Supply Temperature ................................................................................................................................ 59

Case Studies ................................................................................................................................................ 63

The New Stock Exchange in Malta ............................................................................................. 63

Zion National Park Visitor Center ............................................................................................... 66

Passive Down-Draft Evaporative Cooling in Saudi Arabia ......................................... 69

Case Studies Summary .................................................................................................................... 71

CHAPTER 5: CONCLUSION ................................................................... 72

BIBLIOGRAPHY ...................................................................................... 76

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LIST OF TABLES

TABLE 4-1: Building Spaces and Their Areas……………………………………………...25

TABLE 4-2: First Floor Spaces and Their Total Areas…………………………………….26

TABLE 4-3: Second Floor Spaces and Their Total Areas………………………………...27

TABLE 4-4: Potential Air Supply Temperature from the PDEC System…………………61

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LIST OF FIGURES

FIGURE 1-1: SA Oil Consumption since 1980………….……………………………………1

FIGURE 1-2: Energy Consumption by Sector in Saudi Arabia…………………………….2

FIGURE 1-3: Picture shows the lack of thermal insulation in typical residential

buildings construction in Saudi Arabia……………...………………………...3

FIGURE 1-4: The Passivhaus Concept developed in 1996 by Dr. Feist………………….5

FIGURE 2-1: Perspective of the two buildings, Passivhaus villa and baseline villa……..9

FIGURE 2-2: 3D floor plan for the designs and PV panels covering the

Passivhaus roof………………………………………………………………….9

FIGURE 2-3: The Desert Passive House in Hereford, AZ ......................................…...10

FIGURE 2-4: The LeBois House in Lafayette, LA………………………….………..…….12

FIGURE 2-5: 3D drawing showing the compact design of the house with

the mechanical system………………………………………………………..12

FIGURE 3-1: CO2 emissions have been increasing since 1980…………………………15

FIGURE 3-2: the expected energy generation from non-fossil fuel sources

until 2032…………………………………………………………………….....15

FIGURE 4-1: Hail is located in the north Region of Saudi Arabia………………………..18

FIGURE 1-2: The Site is Located in a Farming Area 15 Mi. North of the

City of Hail……………………………………………………………………...18

FIGURE 4-3: The site is located inside a farm and some pictures of the site ...….…...19

FIGURE 4-4: Weather history in 2014………………………………………………………20

FIGURE 4-5: Weather history in 2013………………………………………………………20

FIGURE 4-6: Prevailing wind directions over the entire year……………………….……21

FIGURE 4-7: Fraction of time spent with…………………………………………….……..21

FIGURE 4-8: The weather tool in Ecotect suggest the best orientation

to be south………………………………………………………………...….22

FIGURE 4-9: Forms and solar radiation analysis for five different forms………….……23

FIGURE 4-10: The annual shadow range in the courtyard and a graph

from the National Renewable Energy Laboratory………………………..24

FIGURE 4-11: the First Floor of the baseline design...…………………..….…….……... 26

FIGURE 4-12: the Second floor of the baseline design………………………….….…….27

FIGURE 4-13: Section A of the baseline design…………………………………….…….28

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FIGURE 4-14: Section B of the baseline design……………………………….………….28

FIGURE 4-15: Section C of the baseline design………………………………….……….28

FIGURE 6-16: South Elevation of the baseline design………………………….………..29

FIGURE 4-17: North Elevation of the baseline design…………………………………….29

FIGURE 4-18: East Elevation of the baseline design……………………………………..29

FIGURE 4-19: West Elevation of the baseline design………………………………….....30

FIGURE 4-20: Detail plan of a typical wall and column structure in Saudi Arabia……30

FIGURE 4-21: Detail section of a typical envelope in Saudi Arabia…………………..…31

FIGURE 4-22: Percentage of energy use per use type………………………………..….32

FIGURE 4-23: Detail plan of the optimized wall based on the PHI recommendations..34

FIGURE 4-24: Section detail shows a typical Passivhaus wall……………………..……35

FIGURE 4-25: 3D detail shows the building envelope with the different materials

applied to it……………………………………………………………...…….36

FIGURE 4-26: The family space in the first floor…………………………………...……...38

FIGURE 4-27: The family space in the Second floor………………………………..…….38

FIGURE 4-28: The North West room………………………………………………….…….39

FIGURE 4-29: Energy consumption of lighting and appliances………………………….39

FIGURE 4-30: Potential energy savings in cooling loads from High Efficient AC

System………….……… …………………………………………………….40

FIGURE 4-31: Annual EUI……………………………………………………………………42

FIGURE 4-32: Annual CO2 Emitted…………………………………………………………42

FIGURE 4-33: Potential Energy Consumption for Each Use Type between Baselines

Case and Passive House……………… ………………………….…….42

FIGURE 4-34: PDEC Concept……………………………………………………………….44

FIGURE 4-35: Roof Plan and the Cooling Towers Locations…………………………….45

FIGURE 4-36: Cooling Towers in the First Floor……………………………………….….46

FIGURE 4-37: Cooling Towers in the Second Floor…………………………………….…46

FIGURE 4-38: Cooling Towers at the Top………………………………………………….47

FIGURE 4-39: Section A……………………………………………………………………...47

FIGURE 4-40: Section D………………………………………………………………….…..48

FIGURE 4-41: Section C………………………………………………………………….…..48

FIGURE 4-42: South Elevation……………………………………………………………....48

FIGURE 4-43: North Elevation……………………………………………………………….49

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FIGURE 4-44: East Elevation………………………………………………………………..49

FIGURE 4-45: West Elevation……………………………………………………………….49

FIGURE 4-46: South Perspective…………………………………………………….……..50

FIGURE 4-47: North East Perspective……………………………………………….……..50

FIGURE 4-48: South East Perspective……………………………………………….……..51

FIGURE 4-49: 3D Detail Shows the Structure and System of the Cooling Towers.…...52

FIGURE 4-50: 3D Section Shows the PDEC through the Living Room and Bedrooms……………………………………………………………………..53

FIGURE 4-51: 3D Section Shows the PDEC through the Family Spaces…..……….....53

FIGURE 4-52: Air Flow (CFM) – South East……………………………………………….56

FIGURE 4-53: Air Flow (CFM) – South West…………………………………...………….56

FIGURE 4-54: Air Flow (CFM) – North East………………………………………………..57

FIGURE 4-55: Air Flow (CFM) – North West……………………………………………….57

FIGURE 4-56: Air Velocity – Through East Cooling Tower and Living Room…………..58

FIGURE 4-57: Air Velocity – Through Cooling Towers and Family Area………………..58

FIGURE 4-58: Air Velocity – Through Cooling Towers and Operable Windows…….....59

FIGURE 4-59: Dry-Bulb Temperature……………………………………………………….60

FIGURE 4-60: Wet- Bulb Temperature……………………………………………………...61

FIGURE 4-61: Comparison between Dry-Bulb Temperature and Potential

Air Supply Temperature……………………………………………………..62

FIGURE 4-62: Passive Cooling Strategies in The New Stock Exchange……………….64

FIGURE 4-63: Floor Plan of One of the Buildings in The Torrent Research

Center…………………………………………………………………………65

FIGURE 4-64: Section through the PDEC System in the Torrent Center………………65

FIGURE 4-65: Natural Ventilation Concept in the Zion National Park

Visitor Center…………………………………………………………………66

FIGURE 4-66: Comparison between a Baseline Model and the Developed

Case Using PDEC System in Zion Center………………………………...67

FIGURE 4-67: Section through the PDEC in the Riyadh Case Study…………………...69

FIGURE 4-68: The Location of the PDEC in the Floor Plan of the Case Study………..70

FIGURE 5-1: The Potential to Reach Net-Zero Passive House………………………….74

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LIST OF ABBREVIATIONS

AIA: The American Institute of Architecture

ASHRAE: American Society of Heating, Refrigerating & Air-Conditioning Engineers Inc.

ACH50: Air Changes per Hour at 50 Pascal

CHGC: Solar Heat Gain Coefficient.

EIA: U.S. Energy Information Administration.

EPA: US Environmental Protection Agency.

OPEC: Organization of the Petroleum Exporting Countries

SEEC: Saudi Energy Efficiency Center.

K.A.CARE: King Abdullah City of Atomic and Renewable Energy.

PHIUS: Passive House Institute in the United States.

PDEC: Passive Down-Draft Evaporative Cooling

NREL: National Renewable Energy Laboratory

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CHAPTER 1: INTRODUCTION

The Need for Net-Zero Energy Homes in Saudi Arabia

In April 2010, King Abdullah bin Abdul-Aziz Al Saud established an initiative

entitled King Abdullah City for Atomic and Renewable Energy (K●A●CARE). The aim of

creating this city is to build a sustainable future for Saudi Arabia and to face the

challenges associated with the significant demand for fossil fuel and increasing CO2

emissions.

In 2014, Saudi Arabia was ranked the number one oil consuming nation in the

Middle East, and 12th in the world with total consumption of approximately 3 million

barrels per day (bbl/d) (EIA, 2015). This is almost double the nation’s consumption in

2000, because of its strong economic and industrial growth. The nation’s oil

consumption, as shown in figure 1-1, has been increasing since 1980. Furthermore, the

fossil fuel demand is expected to increase from 3 million bbl/d in 2010 to 8.3 million

bbl/d by 2028 (K.A.CARE, 2015). The direct burning of crude oil for power generation

contributes significantly to this increase, with an average consumption of 0.7 million

bbl/d in the last few years during the summer alone.

FIGURE 2-1 SA Oil Consumption Since 1980

Source: EIA, 2015

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Along with its high energy consumption, Saudi Arabia also produced the 10th

largest volume of CO2 emissions in the world in 2014 (EIA, 2015), which represents 57

percent of world’s greenhouse gas emissions which are a known cause of global

warming which could further exacerbate the energy problem for the nation in the future

(EPA: BODEN, MARLAND, & ANDRES, 2010).

Building Consumption in Saudi Arabia

Buildings are major contributor in energy use with more than 50% of the total

energy consumed in Saudi Arabia, according to the Saudi Energy Efficiency Center

(SEEC, 2013). In 2011, buildings consumed approximately 80% of the total electricity

generated, of which 51.2% is used by residential buildings, and air conditioning

represents 70% of the total national electrical demand (SEEC, 2013)

Based on the information and data mentioned earlier, it is apparent that buildings

in Saudi Arabia are designed and constructed without regard to how they will respond to

their environment when the energy source they rely on is depleted. The currently low

Commercial 12.2%

Governmental 15.1%

Residential 51.2%

Industrial 17.9%

Agricultural 2.6%

Building

78.5%

Source: SEEC & K.A.CARE, 2013

FIGURE 1-2 Energy Consumption by Sector in Saudi Arabia

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cost of electricity bills, the lack of thermal insulation, and the absence of sustainable

standards in the construction industry has led to an assortment of low quality buildings

in the nation’s existing built environment. At the present time, there is no standard

criteria for buildings to raise the level of quality and efficiency. Almost 70% of buildings

in SA are not thermally insulated (SEEC, 2013). Figure 1-3 shows a typical home

structure in Saudi Arabia.

The rapid increase in energy consumption needs an immediate and serious

strategy in order to reduce building consumption until sustainable sources for energy

generation are found. This study recommends that the strategy take into consideration

and focus on the residential sector since it represents the majority of energy consumed

in the nation. Creating more high-performance homes in Saudi Arabia will significantly

reduce the risks associated with the increasing consumption of fossil fuel and related

CO2 emissions. This approach could be achieved through two major steps. First,

FIGURE 1-3: Picture Shows the Lack of Thermal Insulation in Typical Residential Buildings Construction in SA

Source: www.alriyadh.com, 2015

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creating buildings that are more responsive to their environment in order to minimize the

energy consumed. Second, relying on sustainable sources of energy in order to achieve

self-sustained homes.

The Case of the Passivhaus for Hot and Dry Climates

Since the study will focus on developing High-Performance homes for hot and

arid climates, the case of the Passivhaus will be taken into consideration as it was

initially developed for homes in Germany. The Passivhaus concept traces its roots back

to 1988 by Dr. Wolfgang Feist and Bo Adamson (Trubiano, 2013). The first approval of

the concept was in 1990 through their first project, the Kranichstein Passive House, in

Darmstadt, Germany (Passive House Institute, 2015). In 1996, the Passivhaus Institut

was founded as a research group led by Dr. Feist with an interdisciplinary group of

architects, engineers, and construction professionals who work together to develop

energy-free architectural design principles (Trubiano, 2013). Figure 1-4 gives an

overview of what a typical Passivhaus looks like.

A typical Passivhaus, as described in the Passivhaus Institut (figure 1-4), must

be designed and built based on the developed five principles which are as follows:

1. The building should be super-insulated with continuous insulation through its

entire envelope.

2. The building should be designed with minimal thermal bridging.

3. The building envelope is extremely airtight.

4. It employs high-performance windows (typically triple-paned).

5. The building is operated with a heat recovery ventilator and uses a minimal

space conditioning systems.

http://passipedia.passiv.de/passipedia_en/examples/residential_buildings/single_-_family_houses/central_europe/the_world_s_first_passive_house_darmstadt-kranichstein_germany

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The Passivhaus concept could be an ideal solution to create sustainable homes

in Saudi Arabia. However, since the Passivhaus concept was initially developed for cold

climates, it will not have the ability to be directly implemented in hot and arid climates,

and revising Passivhaus principles adapted to hot and arid climates would therefore be

the ideal approach to achieving net-zero energy homes in Saudi Arabia.

Source: Passivhaus Institut, 2015

FIGURE 1-4 The Passivhaus Concept Developed in 1996 by Dr. Feist

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CHAPTER 2: THE PROBLEM

The Passivhaus as a Solution

Passivhaus standards were initially developed in Germany to increase buildings’

efficiency in cold climates. Hundreds of Passivhaus homes have been successfully built

around the world (Trubiano, 2013) since the Kranichstein Passive House. This 1990

project is a multi-family house designed and built based on the principles mentioned

earlier. The house was oriented to maximize the desired solar gain for its climate. The

roof, walls, and floor were insulated using polystyrene. A heat recovery system was

incorporated with 80% efficiency. Using these passive strategies a higher level of

efficiency was achieved.

Although the Passivhaus Institute states that these principles work effectively in

hot climates, it is apparent how these principles cannot be directly mapped to hot

climates. Several passive cooling strategies are not taken into consideration when

applying these principles in hot climates. To illustrate that, evaporative cooling is a

passive cooling strategy and requires direct or indirect natural ventilation. The passive

cooling with the direct natural ventilation cannot be implemented when one of the

principles is the building being airtight. Airtightness is an effective strategy to keep the

desired temperature as long as possible in a building. Instead, an evaporative cooling

strategy such as cooling towers could achieve higher level of effectiveness in hot and

arid climates. This strategy uses much less energy than mechanical cooling, with

energy savings ranging between 30% and 90% (Lechner, 2009). As a result, expanding

the Passivhaus principles for their use in hot and dry climates could achieve a higher

level of performance.

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The direct implementation of the Passivhaus principles in hot and arid climates

will not achieve the same level of effectiveness as they have achieved in cold climates.

Many Passivhaus projects were built in cold climates and are either net-zero energy or

net-zero ready buildings. However, to date no net-zero energy Passivhaus projects

have been built in hot climates (PHIUS, 2014).

To better understand the success of the Passivhaus in hot climates, three case

studies are analyzed in this study in order to evaluate its level of effectiveness. These

case studies are the existing Passivhaus projects that were built in hot climates and

include: The first Passivhaus in the Middle East, in Qatar; The Desert Passive House in

Hereford, Arizona, and the LeBois House in Lafayette, Louisiana.

The First Passivhaus in the Middle East: Qatar

The first and the only Passivhaus project in Middle East to date was built in 2013

in Qatar. Qatar is located in the Arabian Peninsula and is known for its very hot and

very humid weather. The average dry-bulb high temperature is 105 °F (40 °C) with dew

point temperature of 80 °F (24.7 °C). Many days throughout the year exceed these

points. The weather conditions are reversed from those in Europe where the

Passivhaus concept was developed.

The main purpose of this project is a demonstration project compared to a

standard Qatar villa, to inspire the creation of more sustainable homes. The project

consists of two single family villas, which were designed to be occupied by two similar

families with two young children. The first villa, the Piassavas villa, has a total area of

2153ft 2 (200m

2) and was designed and built based on the Passivhaus guidelines and

standard. The expected annual energy use intensity (EUI) for the Passivhaus is

8

11.1kWh/ft2/yr. (120 kWh/m2/yr.). The envelope is constructed with 14.5 in. (370 mm) of

polystyrene to ensure a super insulated and airtight envelope. Triple panel glazing was

chosen to minimize solar heat gain through windows. A mechanical ventilation system

with energy recovery is used to provide fresh air and to minimize air infiltration. In

addition to that, 2200 ft 2 (205 m

2) of photovoltaic panels cover the roof and provide

shading for the roof and exterior walls (Bryant, Amato, Law & Al Abdulla, 2013).

The second Villa was built next to it, based on typical Qatar standards. It was

built as a baseline and reference in order to compare it with the Passivhaus standard, to

measure the difference in energy usage between the two homes. It is similar in terms of

the architectural design, building orientation, and total square footage. The villa has a

shading structure which covers only two of its exterior walls including the entrance.

Figure 2-1 and 2-2 show the architectural design of the two villas and the Piassavas

villa is apparent with the photovoltaic covering the roof (Bryant, Amato, Law & Al

Abdulla, 2013).

With all the Passivhaus strategies being applied, the project aims include

achieving 50% annual energy reduction, 50% water reduction, and 50% reduction in

CO2 emissions compared with the baseline villa. The question that is raised here, since

there are many Passivhaus homes in cold climates that achieved net-zero energy, why

the developers of this project did not aim to achieve that? The aim was not even close

to what could have been achieved through the Passivhaus Principles. The success of

the Passivhaus in cold regions around the world could be reflected in the developers’

goals in Qatar. The logical reason that the developers in Qatar set these goals lower is

likely the very hot weather, which requires massive cooling loads

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FIGURE 2-1 Perspective of the Two Buildings, Passivhaus Villa (Right) and Baseline Villa (Left)

FIGURE 2-2 3D Floor Plan for the Two Design and PV Panels Covering the Passivhaus Roof (Lower Right)

Source: Qatar Foundation, 2013

Source: Qatar Foundation, 2013

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The Desert Passive House, Hereford, AZ

Hereford, Arizona is located in the southwestern part of the United States. The

city has a hot and semi-arid climate. The hot season lasts from May to September with

an average high temperature of 94°F. The cold season lasts for three months, during

the period from the end of November to the end of February, with an average high

temperature of 66 °F (Weather Spark, 2015).

The Desert Passive House is a single family house. It is certified by the Passive

House Institute in the United States (PHIUS). The house has an airtight envelope with

0.59 ACH50 and meets all the US Passive House requirements. However, according

the Passive House Institute, the project did not reach net-zero energy with the Passive

House strategies and the use of Photovoltaics (PHIUS, 2014). This house provides

another example that Passivhaus principles could not have the ability to achieve the

same level of effectiveness in hot climates. The house consumes much less energy

compared to a standard house in Arizona with an annual EUI of 25.9 kBtu/ft2/yr. Figure

2-3 shows a picture of the house with the solar photovoltaic array on the roof (PHIUS,

2014).

Source: PHIUS, 2015

FIGURE 2-3 The Desert Passive House in Hereford, AZ

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LeBois House, Lafayette, LA

Lafayette, Louisiana is located in the deep south of the United States. The city

has hot-humid climate. During the hot season, the average high temperature is 85°F.

The cold season lasts approximately less than three months from December 1st to

February 21st with an average high temperature of 66 °F (Weather Spark, 2015).

The LeBois House is a single-family house with total floor area of 2190 ft2. The

house was designed and built employing the Passive House principles developed by

the Passive House Institute in the United States. The envelope is thermally well

insulated with R-28 insulation in the walls and R-55 in the roof. The envelope is

designed to minimize air infiltration with airtightness of 0.55 ACH. Based on PHIUS

recommendations, double panel glazing windows with U-0.18 and solar heat gain

coefficient of 30% were chosen

The Passive House Planning Package (PHPP) is a simulation software

developed by the Passivhaus Institute, and was used to run the energy simulation for

the house. The software predicted the primary energy consumption would not exceed

37.03 kBtu/ft²/yr. (116 kWh/m²/yr.). However, the monitored performance results

revealed a greater number, which was 58 kBtu/ft²/yr. (184 Kwh/m²/yr.). Based on the

actual result, the EUI is approximately 50% greater than the PHPP projections.

For the LeBois House, the results were not only lower than what has been

achieved in cold climates, but also lower than what was expected using the PHPP tool.

It is clear that the Passivhaus strategies when applied in the climate conditions in

Lafayette did not yield the expected energy improvement.

12

FIGURE 2-4 The LeBois House in Lafayette, LA

FIGURE 2-5 3D Drawing Showing the Compact Design of the House with the Mechanical System

(Source: PHIUS, 2014)

(Source: PHIUS, 2014)

13

These three case studies are the existing Passive House projects that have been

built in hot climates. Some of the information was gathered from the Passive House

Institute in the US that is published on their website as well as by contacting them

directly. Information that was noted in the case study of the Qatar Passivhaus was

gathered from previous research conducted by governmental organizations in Qatar.

The analyzed case studies give an overview of the potential energy savings by applying

the Passivhaus principles in hot climates.

Implementing the Passivhaus principles directly in Saudi Arabia will not achieve

the net-zero energy in order to encounter the current energy challenges in Saudi Arabia.

When referring to the success of the Passivhaus in cold climates, it will be an ideal

concept as a starting point with the hope of achieving greater energy savings in the

future. Rethinking about passive cooling strategies could improve building efficiency in

Saudi Arabia. Another project, the Showcase House in Phoenix, Arizona, is a

successful example of house built in hot climates and used passive cooling strategies.

The Showcase House was not built based on the Passivhaus principles; however, the

house achieved better EUI when compared with the previous case studies. The total

EUI of this house went down to 9 kBtu/sf/yr. The designer took into account using

natural ventilation to cool the house (AIA, 2015).

14

CHAPTER 3: THE PROBLEM EVALUATION

Saudi Arabia is a developing country and facing a significant increase in energy

demand. In the short-term, it is not yet a major problem with the wide availability of fossil

fuel, which is the primary energy source in the country. However, fossil fuel is not a

sustainable source to rely on, and at some point in the future oil will reach its breaking

point. Nowadays, while Saudi Arabia has total reserves of approximately 265.8 billion

barrels (OPEC, 2015), if the average daily production in SA continues at the same level

until 2050, the country will use approximately 144.5 billion barrels, which is roughly 54%

of its current total oil reserves. This is not yet considered a major problem as the total

reserves have increased since 1980 with the discovery of new oil fields, however, fossil

fuel is not a sustainable source regardless of how long it may last.

With SA’s growing population, by 2032 the energy increasing energy

consumption is expected to become a significant problem. The government expects the

electricity demand to exceed 120 Gigawatts. The average daily consumption of fossil

fuel in the country is expected to grow from 3.4 million bbl/d to 8.3 bbl/d in 2028

(K.A.CARE, 2013). Unless energy conservation principles and sustainable sources of

energy are implemented, the country will face a shortage in less than 20 years.

The other serious problem is the dangerous increase in CO2 emissions. CO2

represent approximately 57% of greenhouse gases, which contribute to the risks

associated with global warming (EPA, 2010). Figure 3-1 shows the rapid increase of

CO2 emission in Saudi Arabia since 1980 (EIA, 2015).

15

The government of Saudi Arabia plans to offset the increasing energy

consumption through the King Abdullah City for Atomic and Renewable Energy

(K.A.CARE). The aim of the city is to generate 50% of electricity from non-fossil fuel

sources by 2032. K.A.CARE plans to achieve that gradually as shown in figure 3-2.

Source: EIA, 2015

FIGURE 3-1 CO2 Emissions Have Been Increasing Since 1980

Figure 3-2: The Graph Shows the Expected Energy generation from non-fossil fuel sources until 2032

Source: K.A.CARE, 2013

16

The establishment of K.A.CARE seems to be a great beginning towards a

sustainable future. Nevertheless, alternative sustainable energy sources are not enough

to offset the total energy demand. Developing energy conservation principles, and

energy-conscious designs and projects will significantly limit the risks associated with

increasing energy demand and CO2 emissions.

17

CHAPTER 4: THE ANALYSIS AND DESIGN PROPOSAL

This chapter discusses a proposal provided to improve the efficiency level of the

Passivhaus in hot and arid climates in order to accomplish the goals of the study. The

goals of this study include:

• Creating sustainable homes through designing buildings that are more

responsive to the environment

• Revising the Passivhaus standard for hot and arid climates, to take into

consideration new passive cooling strategies

• Achieving net-zero homes for hot and arid climates

• Using solar energy as the main source of energy

• The proposed house design could be an initial step to move towards an overall

sustainably built environment for the future

The process followed to reach the goals will include a design of a single family

house for a Saudi family, the Passivhaus principles applied to the design, a revised

Passive House design, and finally an energy analysis and comparison between the

Passivhaus case and the developed proposal. The first step will include a site analysis

and a design used as a baseline based on a typical Saudi standard. In the second step,

the Passivhaus principles will be applied to the baseline design. An energy simulation

will be made to estimate the level of performance in the climate of Saudi Arabia. In the

third step, the Passive Downdraft Evaporative cooling strategy will be incorporated into

the Passivhaus design, aiming to achieve a higher level of performance and to reach

net-zero energy. Finally, air movement analysis, air velocity analysis and previous case

studies will be analyzed as well to measure the potential improvement in performance.

18

The Site

The site is located in Hail province, SA as shown in figure 4-1, 4-2 and 4-3. Hail

is located in latitude 27.6° and longitude 41.6°. The location is a farming area located 15

mi. (25 km) north of the city of Hail. This location provides an ideal setting, providing

typical weather conditions that are not affected by surrounding buildings.

FIGURE 4-1 Hail Is Located In the North Region of Saudi Arabia

Source: Google Maps

FIGURE 3-2 The Site is Located in a Farming Area 15 Mi. North of the City of Hail

Source: The Saudi Network, 2015

19

The climate of Saudi Arabia is known for its low relative humidity and very high

temperature during the summer. The weather data of the study is based on historical

weather records from 1978 to 2014 (Weather Spark, 2015). The weather observations

in the last two years can be seen in Figure 4-4, 4-5, 4-6, and 4-7. The key climatic data

for the study is as follows:

• From April to October the temperature is high

• The average high temperature during the hot season is 103 °F

• The prevailing winds come from:

o South: 13% of the time

o North: 12% of the time

o South West: 12% of the time

o North East: 11% of the time

• In 2014:

o The highest average was recorded in April with 9 mi/h

o The lowest average was recorded in September with 6 mi/h

Source: Google Maps

FIGURE 4-3 The site is located inside a farm, with some pictures of the site

20

Wind Direction

Average Low Temperature

Average High Temperature

Colored Temperature

Diagram

Temperature Range

Wind Direction

Average Low Temperature

Average High Temperature

Colored Temperature

Diagram

Temperature Range

FIGURE 4-4 Weather history in 2014

FIGURE 4-5 Weather history in 2013

Source: Weather Spark, 2015


21

The Orientation and Form Analysis

This study concentrates on the design of a single family house, with orientation

and form being important initial design decisions. Privacy also plays an important role

when designing a home in Saudi Arabia, which will be explained in more detail below.

The simulation software Ecotect was used in order to find out the ideal orientation for

the house. The weather tool in Ecotect suggests that 172.5o (south) is the ideal angle

to orient the house (Figure 4-8).

FIGURE 4-6 Prevailing Wind Directions over the Entire Year


FIGURE 4-7 Fraction of Time Spent with Various Wind Directions


22

After considering the best orientation for the house, several forms were analyzed

using the simulation software Sefaira and Ecotect to find the ideal form with the lowest

solar radiation when designing the house. These forms include a square, rectangle,

square configuration with a courtyard in the middle; a rectangle with courtyard in the

middle; and finally a u-shaped form with a courtyard located in the south. The analysis

reveals that the basic rectangular form has the lowest annual EUI. The square and u-

shaped forms has almost the same EUI, while the square and rectangular shapes with

courtyards were the worst. When shading devices were applied to the lowest three

forms, the u-shaped form was the most affected form and the EUI decreased by 7.2%.

The rectangular form was the least affected form with only a 3.1% decrease. The

analysis of the five different forms can be seen in figure 4-9.

Source: Weather Tool - Ecotect

Figure 4-8 The Weather Tool in Ecotect Suggest the Best Orientation to Be South

Source: Weather Tool -

Ecotect

23

SHADING NO SHADING % Of

Improvement

5.9

%

3.1

%

7.2

%

FIG

UR

E 4

-9

Fo

rms a

nd

So

lar

Rad

iation

An

aly

sis

fo

r F

ive

Diffe

ren

t F

orm

s

So

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are

: S

efa

ira

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co

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24

Although the rectangular shape was the most effective shape, the u-shaped form

was chosen for several reasons. The first and most important reason is privacy. Privacy

in Saudi Arabia is very important for religious and traditional purposes. As a result,

courtyards are known in the culture of Saudi Arabia to create homes with more privacy.

The second important reason is minimizing east and west windows. Among all the four

orientations, buildings located in the 27o latitude absorb most of the solar radiations in

the building from the east and west walls (NREL, 1996). The u-shaped design will help

avoid windows in the east and west façades and minimize glare as well. Windows that

would be on the eastern and western sides will be relocated in the courtyard as needed.

In addition, when a courtyard is incorporated into a building design, it connects the

inside and outside environment, and creates an aesthetically pleasing experience.

FIGURE 4-10 The Annual Shadow Range in the Courtyard and a Graph Shows How Much Solar Radiation Absorbed From the East and West Facades

Source: NREL, 1996 – Software: Ecotect

25

The Baseline Design

The house was designed to fit a large family of 8 occupants. The design is a two

story U-shaped house with a courtyard located in the south. The house has two

separate entrances. The first entrance is the family entrance, located on the north side

of the house. The other entrance is the guest entrance, which is located on the east

side. The building has a total length of 66 feet and width of 43 feet. The total built area

is 3770 ft2 (350 m2). The size of the house considered to be average and fits most of the

residential lots in Saudi Arabia. The first floor is 2 feet higher than the ground level. The

floor-to-floor height is 10 feet while the total height of the building is 25 feet taking into

account the height of the parapet. Several spaces are included in the house which are

normally found in a typical Saudi house. Table 4-1, 4-2, and 4-3 show the different

spaces in the house with their areas while the model drawings can be seen from figure

4-11 to 4-19.

TABLE 4-1 Building Spaces and Their Areas

Level Room Area ft2

1st & 2nd Family Spaces 590

1st Living Room 190

1st Winter Room 218

1st Guest Room 263

1st Dining Room 121

2nd Bedrooms 894

1st Kitchen 222

1st & 2nd Toilets 300

2nd Office 80

26

TABLE 4-2 First floor spaces and their total areas

Space Number Name Area ft2

1 Guest Room 263

2 Living Room 190

3 Family Space 405

4 Dining Room 121

5 Winter Room 218

6 Kitchen 222

7 Guest Toilet 63

8 Family Toilet 60

9 Courtyard 485

1

2

3

6

5

8 7

9

A

B

C

4

FIGURE 4-11 First Floor

27

TABLE 4-3 Second Floor Spaces and Their Total Areas

Space Number Name Area ft2

1 Master Bedroom + Toilet 372

2 Bedroom + Toilet 282

3 Bedroom + Toilet 225

4 Bedroom+ Toilet 225

5 Family Space 185

6 Office 80

1

3

5

4

2

6 A

B

C

FIGURE 4-12 Second Floor

28

FIGURE 4-13 Section A

TABLE 4-14 Section B

FIGURE 4-15 Section C

29

Figure 4-16 South Elevation

Figure 4-18 East Elevation

Figure 4-17 North Elevation

30

The building model was designed with a more “business as usual” design and

construction in Saudi Arabia, with the envelope and glazing properties based on typical

construction standards in the state. Figure 4-20 and 4-21 show a typical wall and roof

construction in Saudi Arabia.

FIGURE 4-19 West Elevation

Figure 4-20 Detail Plan of a Typical Wall and Column Structure in Saudi Arabia

31

Concrete

Concrete Beam

FIGURE 4-21 Detail Section of a Typical Envelope in Saudi Arabia

Source: www.alriyadh.com

32

The core materials used in the design are concrete for the roof and slabs, and

CMU for the walls. The construction properties of the design are as follows:

• Total R-values

Floor: R-15 ft2⋅h⋅°F/BTU (U-0.36 W/m2K)

Walls: R-15 ft2⋅h⋅°F/BTU (U-0.36 W/m2K)

Roof: R-15 ft2⋅h⋅°F/BTU (U-0.36 W/m2K)

• Single panel glazing with:

Total U-value: 0.42 BTU/h⋅ft2⋅°F (2.4 W/m2K)

Solar heat gain coefficient (SHGC): 60%

• Airtightness: 5 ACH ( about 0.5 cfm/ft2)

• Thermal Mass: 19 BTU/°F

Using Sefaira, the estimated total energy consumption of the house was 258,890

kBTU with a EUI of 69 kBTU/ft2/yr. (217 kWh/m2/yr.). The potential total carbon emitted

was 97,141 lbs CO2. ooling demand represents 70% of the home’s total energy

consumption (Figure 4-22). This data acts as a reference for the energy performance of

the developed cases, which will be explained in detail in the following sections.

Cooling70%

Heating6%

Lighting16%

Appliances8%

Hotwater0.001%

FIGURE 4-22 Percentage of Energy Use per Use Type

33

The Case of the Passivhaus

In this section, the Passivhaus principles will be applied to the design to ascertain

the potential improvements in energy performance when Passivhaus requirements are

implemented. In the first step, the building envelope will be optimized to meet the

Passivhaus requirements. Second, maximizing daylight and selecting high efficient

lighting and appliances will be explored, to minimize energy requirements for the house.

Third, a high-efficiency HVAC system will be incorporated to reduce the energy

consumed for heating and cooling. After that, a photovoltaic system will be installed on

the roof to generate energy for the house. Finally, an energy simulation will be

conducted to measure the potential improvements in the energy performance. The

result will reveal if the Passivhaus requirements are enough to reach net-zero energy

for this house at the designated site. Sefaira, Ecotect, and Radiance design tools will be

used to simulate the energy performance and daylighting analyses.

Optimized Building Envelope

The building envelope was optimized based on the Passivhaus requirements.

The Passive House Institute in the United States has developed climate specific

recommendations for each climate zone. The current Passive House recommendations

for hot and dry climates have been applied to the building envelope. The major

differences in the envelope from the baseline case in the materials used, R-values, and

U-values. When compared with a typical Passivhaus building built in cold climates, walls

with lower R-values are recommended to reach the desired improvement in the building

envelope in hot climates. Windows with higher U-values and lower SHGC are also

recommended in such climate. These recommendations are not only benchmarks, but

34

also cost-effective values. Figures 4-23, 4-24 and 4-25 show a plan, a section, and 3D

detail for the optimized envelope. The envelope properties are as follows:

Total R-value for:

o Floor: R-35 ft2⋅h⋅°F/BTU (U-0.16 W/m2K)

o Walls: R-35 ft2⋅h⋅°F/BTU (U-0.16 W/m2K)

o Roof: R-40 ft2⋅h⋅°F/BTU (U-0.14 W/m2K)

• Glazing:

o Double panel windows

o Total U-value: 0.27 BTU/h⋅ft2⋅°F (1.55 W/m2K)

o Solar heat gain coefficient (SHGC): 30

• Shading for south windows & courtyard

• Thermal Bridge Free Construction

• Airtightness: 0.6 ACH (0.050 cfm/ft2)

• Thermal Mass: 19 BTU/°F

Stud

FIGURE 4-23 Detail Plan of the Optimized Wall Based On the PHI Recommendations

35

Source: Passipedia, 2015

Concrete Beam

Floor Insulation

FIGURE 4-24 Section Detail Shows a Typical Passive

Source: Passipedia, 2015

36

FIG

UR

E 4

-25

3D

De

tail

Sh

ow

s th

e B

uild

ing

En

ve

lop

e w

ith th

e D

iffe

ren

t M

ate

ria

ls A

pp

lied

37

The two layers of insulation, polyurethane and rigid, along with the continuous

concrete structure, minimize the thermal bridging through the envelope and provide the

airtightness of the building. Additionally, the thick layer of concrete masonry unites

creates a high thermal mass envelope. With the optimized envelope, the annual EUI is

reduced from 69 kBTU/ft2/yr to 51 kBTU/ft2/yr. with total energy savings of 26%. The

carbon emissions from this household energy use is reduced by 24.5% from 97,141 lbs

CO2 to 73270 lbs CO2. For the Passive House design, the cooling loads are reduced

by 36% from 158,669 kBTU to 100,183 kBTU and the heating loads are reduced by

53% from 13,923 kBTU to 6,484 kBTU. The higher reduction in heating loads reveals

that Passive House recommendations for the building envelope design are more

effective when it comes to minimizing heating loads.

Daylighting and High Efficiency Lighting and Appliances

Maximizing daylighting was taken into consideration when designing the house.

The u-shaped design maximize sun light and minimizes glare. The daylighting analysis

was conducted on a summer day at 12pm (figure 4-26, 4-27 and 4-28). The results

show that the amount of sunlight in the family room in the first floor is higher than 300

lux, which is enough for reading purposes. Other places in the house receive a

significantly greater amount of daylight. After that, high performance lights and

appliances were chosen for the building during the simulation process. The lighting

power density and plug load power density were set to 0.2 W/ft2. These values are

considered to be high-efficient lighting and appliances (ASHRAE, 2013). Figures 4-29

shows a comparison of the energy consumption between a standard lighting power

density and the improved case.

38

FIGURE 4-26 The Family Space on the First Floor

Source: Ecotect &

Software: Ecotect & Radiance

FIGURE 4-27 The Family Space on the Second Floor


39

FIGURE 4-28 The Northwestern Room


0

5000

10000

15000

20000

25000

30000

35000

40000

Lighting Appliances

kB

TU

Baseline High Efficient Lights and Appliances

FIGURE 4-29 Energy Consumption of Lighting and Appliances

Software: Sefaira

40

In conclusion, approximately 70% of the house is naturally well lit during daytime

hours. This amount of light was achieved without placing windows in the west façade,

and only one window for the guest room in the east. Lighting loads are reduced by 66%,

and appliance loads are reduced by 33%. The annual EUI decreased by 13% from 69

kBTU/ft2 To 60 kBTU/ft2 while the carbon emitted reduced by 14% from 97,141 lbs CO2

to 83,277 lbs CO2.

High Efficiency Air Conditioning System

This aspect of the design process relies significantly on mechanical engineers.

Due to the limited personal knowledge about designing an air conditioning and HVAC

system for the house, the simulation software Sefaira was used to find out the potential

energy savings that could be achieved from a high efficiency HVAC system. The

software allows designers to insert the basic data of a mechanical system used in the

house. The inputs were set as a high efficiency mechanical system with ventilation

recovery. Based on the analysis results from Sefaira, a high efficiency HVAC system

could achieve 20% energy savings, a 16.7% CO2 reduction, and the cooling loads

could be reduced by 24%. Figure 4-32 shows a comparison of energy consumption

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

Baseline High Efficient AirConditioning system

FIGURE 4-30 Potential Energy Savings in Cooling Loads from High Efficiency HVAC System

41

between a standard AC system and a high-efficiency energy recovery ventilation (ERV)

system.

Onsite Solar Photovoltaic

Onsite solar photovoltaic panels are placed on the roof to generate energy. In

this high efficiency design case, almost all of the area that is exposed to the sun in the

roof is covered with PV panels. The total area of the PV panels is 646ft2 (60m2). The

PV’s efficiency is 15%, which considered average. This amount of PV panels could

generate up to 48,264 kBTU. The total energy consumption of the baseline case could

be reduced by 26% when using onsite PV’s alone.

Passive House Energy Performance

After applying all the Passive House strategies, an energy simulation was

conducted to measure the projected performance improvements of the house, and then

to find out the potential of achieving net-zero Passive House in hot climates.

Based on the energy simulation, the Passive House strategies along with with

the PV system have helped to achieve significant reductions in the home’s energy

consumption. The total energy consumption decreased by 71% from 258,890 kBTU to

74,891 kBTU. Without the PV system, the annual EUI of the Passive House dropped

from 69 kBTU/ft2 to 33 kBTU/ft2 with a total projected energy savings of 52%. When the

PV system was added to the house, the annual EUI went down further to 20 kBTU/ft2

(Figure 4-31), and the carbon emissions are reduced by 70% from 97,144 lbs CO2 to

28,958 lbs CO2 (Figure 4-32). The cooling loads are still dominating the total energy

consumption, representing 71% of the total energy consumed. The cooling loads are

reduced by 54% while heating loads are reduced by 72% (Figure 4-33). So it is

42

apparent how the Passive House strategies are more effective when it comes to

reducing heating requirements than cooling requirements.

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

Cooling Heating Lighting Appliances Hotwater

kB

TU

Baseline Passive House

FIGURE 4-33 Potential Energy Consumption for Each Use Type between Baseline Case and Passive House

0

20,000

40,000

60,000

80,000

100,000

120,000

Baseline Passive House Passive House withPV's

lbsC

O2

FIGURE 4-32 Annual CO2 Emitted

69

3320

0

20

40

60

80

Baseline Passive House Passive Housewith PV's

kB

TU

/ft2

FIGURE 4-31 Annual EUI

43

Although significant improvements have been achieved, the Passive House

principles did not accomplish a net-zero energy house. This analysis confirms the

results and information from the case studies analyzed in Chapter 2, expecting that the

Passive house could achieve a high level of efficiency in Saudi Arabia although the

results were similar to what the Passive House achieves in cold climate regions. As a

result, the developed case that will be discussed in the next section will take into

consideration other cooling strategies with the aim of reaching a net zero energy

Passive House.

Evaporative Cooling Passive Down-Draft Evaporative Cooling

Direct evaporative cooling is considered to be more effective in hot and arid

climates as it increases the relative humidity in the air during the cooling process. It

basically provides cooling to the spaces with much less energy when compared to

traditional mechanical systems. This strategy could be achieved by passing the outside

air through a water medium to a building. This strategy cools the air by evaporation, as

well as increasing the moisture in the air.

Cooling Towers

Passive Down-Draft Evaporative Cooling (PDEC), or cooling tower, is one of the

most effective evaporative cooling approaches. The PDEC system is basically designed

to capture winds at the top of the tower, then cools the hot air by water evaporation

before it enters the building (Figure 4-34). The energy consumed in this strategy is only

the energy needed to pump water to the top of the tower. This strategy could achieve

between 30% and 90% energy savings in the cooling loads depending on the design

(Lechner, 2009).

44

Since cooling loads represent most of the energy consumed, the PDEC will be

implemented in the design in order to decrease the cooling demand and reach a net-

zero energy Passive House. However, the PDEC relies significantly on natural air to

cool the building, and the mechanism of the PDEC contradicts one of the Passive

House principles, of airtightness. By applying PDEC, the house will be open to external

air and the building will not be airtight. As a result, if this strategy achieves higher

performance, the Passive House principles should be revised for hot and arid climates

in order to better meet the needs of such climate.

The house was designed for a large family with four bedrooms. At least two

cooling towers are needed to deliver cooled air to each space in the house. The cooling

towers are positioned in the east and west side of the house. These locations allow the

cooling towers to supply every space in the house with fresh and cooled air. Each tower

FIGURE 4-34 PDEC Concept

Source: The Center for Global Ecology, Stanford, CA

45

is 8x4 ft., and has water sprays at the top. There are four openings with louvres at the

top of each tower to control and capture winds. The cooled air will be delivered to the

different spaces in the house through smaller openings in each room. Fans are optional

and should be located at the top of the towers to control air velocity as needed. On the

roof, a long clerestory is located between the cooling towers to improve the air

circulation in the house. The clerestory location is right above the family space on the

second floor. A part of the 1st floor family area is a double high space. The design of the

cooling towers and clerestory will allow cool air to enter through the cooling towers and

leave through the clerestory after it cools the spaces. Figures 4-35 to 4-48 show plans,

sections, elevation, and 3D views of the house after incorporating the PDEC to the

design.

646ft2 PV

System generate

approximately 48264kBTU/yr

Two Cooling Towers 8 x 4ft

Clerestory

FIGURE 4-35 Cooling Towers Locations

46

A

B C D

Cooling towers on the

first floor

FIGURE 4-36 Cooling Towers on the First Floor

FIGURE 4-37 Cooling Towers on the Second Floor

Cooling towers in the

2nd floor

47

A

OR

Fans (Optional) Source: Nature Cool

Source: Zarja, 2015

FIGURE 4-38 Cooling Towers at the Top

FIGURE 4-39 Section A

48

FIGURE 4-40 Section D

FIGURE 4-41 Section C

FIGURE 4-42 South Elevation

49

FIGURE 4-43 North Elevation

FIGURE 4-44 East Elevation

FIGURE 4-45 West Elevation

50

FIGURE 4-47 North East Perspective

FIGURE 4-46 South Perspective

51

The structure of the cooling towers is very similar to the rest of the building. The

only added material is the PTFE Teflon. This material covers the internal part of the

cooling towers. PTFE Teflon is a water resistant material, and has exceptional

resistance to high temperatures. These characteristics make this material an ideal

choice for the cooling towers. The top of the towers have louvres with dust and insect

control devices. Water sprays and fans are located in the top to cool the air. Figure 4-49

shows a 3D detail for the structure of the PDEC system.

The design of the house allows fresh cooled air to enter the house through the

cooling towers, and then leave through two different routes. In the living spaces, the

heavy cooled air will push the warmer air to the top, which will then leave through the

clerestories. Small windows placed in each room are enough to circulate the air in the

room. The concept of the PDEC system can be seen in Figures 4-50 and 4-51.

FIGURE 4-48 South East Perspective

52

FIG

UR

E 4

-49

3D

Deta

il S

ho

ws th

e S

tru

ctu

re a

nd

Syste

m o

f th

e C

oo

ling

To

wers

53

Figure 4-50 3D Section Shows the PDEC through the Living Room and Bedrooms

Figure 4-51 3D Section Shows the PDEC through the Family Rooms

54

Energy Performance

Due to the difficulty in running an energy simulation for a PDEC, the energy

performance analysis was conducted in two steps. In the first step, IESVE, an

integrated building analysis software system was used to study the air velocity and air

movement in the building. After that, the potential air temperature supplied by the

cooling towers will be determined by using an equation that has been developed in

previous research (Phillip, T. & Lau, B, 2013). This analysis will reveal if the air is

moving properly through tower to the building, and the supplied temperatures are at a

comfort zone. After ensuring that the air is moving and the cooling tower approach is

working, several case studies will be analyzed to find out the potential energy savings in

cooling loads from the towers. This analysis will not provide an accurate number for the

energy consumption and energy savings, however, it will provide an overview of how

much can be achieved and how much is needed to reach a net zero energy Passive

House.

IESVE Analysis

The whole model with the two cooling towers was drawn in IESVE. First, the

airflows were analyzed through the cooling towers, clerestory, and windows. The results

show that the towers are able to capture winds from the top and move them down

through the different spaces in the house. In the family spaces a significant amount of

air is rising to the top and leaving through the clerestories. The IESVE software does

not take into account water sprays in the top, so the results show air is moving in and

out of the top of the cooling towers. In the clerestories, some amount of air is entering

the building, which will bring hot air to the house, however, at the moment selected for

55

the analysis, the air was coming from south, and all the clerestory windows were open.

The design of the clerestory will allow more flexibility to open the desired windows

based on the wind direction. To illustrate that, the wind directions used forth time of the

analysis were coming mostly from south. In this case, the south windows in the

clerestory will be closed to prevent the hot winds from entering the building while the

north windows will be opened to push the warmer air out of the building. The results can

be seen in Figures 4-52, 4-53, 4-54, and 4-55 which show the airflow for each space in

the house.

The site and climate analysis in Chapter 3 shows the average wind speed in Hail

ranging between 6 and 9 mi/h. This wind speed is advantageous in terms of taking

advantage of natural ventilation. Air velocity analysis was conducted during the highest

typical wind speed, to find out what maximum wind speed could be flowing through the

cooling towers. The minimum speed is recognized to be calm. During a calm day, the

fans could be used to move the air inside the towers. During the maximum wind speed

when there are gusty winds, the analysis indicates that the air velocity inside the cooling

towers could reach above 10 ft/s. The desired air velocity in a building should range

between 1 and 1.6 ft/s. The results show that the wind speed is much higher than what

is needed. During this situation, the louvres in the top of the cooling towers will be

adjusted to allow enough air entering the building in order to meet the desired air

velocity. Figure 4-54 to 4-60 shows the results from IES from the design proposal.

56

Master Bedroom

Living Space

SW bedroom

Winter Room

1st

Cooling tower

Clerestory

FIGURE 4-52 Air Flow (CFM) - South East

Software: IESVE

Master Bedroom

Living Space

2nd

floor

1st

floor Family space

SW bedroom

Winter

1st

Cooling tower

Clerestory

FIGURE 4-53 Air Flow (CFM) - South West

Software: IESVE

57

NW bedroom

Kitchen

2nd

floor

1st

floor Family space

NE bedroom

Guest Room

2nd

Cooling tower

FIGURE 4-54 Air Flow (CFM) – North East

Software: IESVE

NW bedroom

Kitchen 1

st floor

Family space NE bedroom

Guest Room

2nd

Cooling tower

FIGURE 4-55 Air Flow (CFM) – North West

Software: IESVE

58

FIGURE 4-56 Air Velocity (ft/s) – Through East Cooling Tower and Living

Software: IESVE

FIGURE 4-57 Air Velocity (ft/s) – Through Family Areas

Software: IESVE

59

Supply Temperature

Studies have revealed that a significant reduction in the air supply temperature of

a cooling tower could be achieved. Phillip, T. & Lau, B, 2013 state that “the cooling

potential of a PDEC system is such that a temperature reduction of up to 80% of the

difference between the Dry-bulb and Wet-bulb temperatures is achievable”.

This relationship can be seen in the equation below:

TT=TDB-0.8(TDB-TWB)

Where:

TT = Tower supply air temperature

TDB = Dry-bulb temperature

TWB = Wet-bulb temperature

FIGURE 4-58 Air Velocity (ft/s)

Software: IESVE

60

The high potential reduction in air temperature is achievable in a location with

high dry-bulb temperature and low relative humidity, and the climate conditions of the

Hail site meet this criteria. IESVE provides the dry-bulb and wet-bulb temperatures of

the site for the entire year. Figures 4-59 and 4-60 show the difference between the dry-

bulb and the wet-bulb temperatures at the site. The significant reduction of the wet-bulb

temperatures suggest that a comfortable air supply temperature from the PDEC system

is highly achievable. By using the equation mentioned earlier, six cases through the

year were calculated. These days include the average dry-bulb and wet-bulb

temperatures of the hottest three months. The other three cases represent some of the

hottest days of the year. Table 4-4 and Figure 4-61 show the potential air supply

temperature of the six different cases compared with the dry-bulb temperature.

FIGURE 4-59 Dry-Bulb Temperature

Software: IESVE

61

Time or Month Dry-Bulb

Temperature - ºF Wet-Bulb

Temperature - ºF

Potential Temperature from

Cooling Towers - ºF

June 21st at 2:00pm 105 63 71.4

Aug 6th at 3:00pm 115 66 75.8

June 15th at 3:00pm 106 71 78

Average in June 111 63 72.6

Average in July 113 64 73.8

Average in August 113 66 75.4

FIGURE 4-60 Wet-Bulb Temperature

Software: IESVE

TABLE 4-4 Potential Air Supply Temperature from the PDEC

Source: Alshenaifi, 2015

62

Tithe results of the IESVE analysis show that the air supply temperatures range

between 71oF and 78oF during the worst cases throughout year when the outside

temperature exceeds 100oF. During cooler days or at night, temperatures supplied by

the cooling towers will be even below comfortable zones.

The results of the airflow and air velocity reveal that the two cooling towers were

designed and located properly at the site. The average wind speed at the site is

advantageous, and in some cases, the louvers will work to minimize the air velocity to

the desired speed. During calm winds situations, the fans will work as needed to move

the air inside the cooling towers, and then to the house. The potential air temperature

reduction from cooling towers will lead to a significant reduction in cooling demands. As

a result, achieving the net-zero energy Passive House is highly achievable. After

ensuring that the cooling towers are working properly, several case studies will be

analyzed in the next section to ascertain out the potential energy improvements.

FIGURE 4-61 Comparison between Dry-Bulb Temperatures and Potential Air Supply Temperature

Source: Alshenaifi, 2015

0

20

40

60

80

100

120

140

June 21st at2:00pm

Aug 6th at3:00pm

June 15th at3:00pm

Average in June Average in July Average in August

Dry-Bulb Temperature Wet-Bulb Temperature Potential Temperature from Cooling Towers

63

Case Studies

In this section, several case studies that used PDEC system are analyzed in

order to find out the potential energy reduction in cooling loads. The case studies will

provide the potential minimum and maximum energy reduction using PDEC. Based on

that, the results would be used to estimate the energy saving needed to reach net-zero

energy Passive House. These case studies are analyzed briefly in the following

sections.

The New Stock Exchange in Malta

The New Stock Exchange is located in Valletta, Malta. Malta has a mild winter

with an average temperature of 49oF and warm summers with an average of 86oF. The

cooling loads represent a large volume of the total energy consumption. The New Stock

Exchange is an office building with a huge atrium on the middle. The atrium requires

huge mechanical units with large ducts in order to be cooled. The PDEC system was

taken into consideration to cool the atrium along with a cooling coil system for the rest of

the building. The energy consumption for cooling the whole building was approximately

103,924 kWh. By incorporating the PDEC system in the atrium, the cooling loads were

reduced to 54,139 kWh by 48%. Figure 4-62 shows the passive cooling strategy in the

building (WSP Environmental Ltd, 2002).

64

1. The Torrent Research Center

The Torrent Research center is located in Ahmadabad, India. The center is a

large pharmaceutical laboratory with office space as well, and providing natural

ventilation in the building is extremely important. The center consists of 6 buildings, and

the PDEC system is incorporated in only four of them. In each building, the PDEC

system is located above a central corridor separating the offices from the laboratories.

On the long sides of each building, several shafts are built to maximize air circulation

and push the warmer air out of the building. When the outside temperature reaches its

maximum, the PDEC drops the interior temperature between 10 and 14ºC. With the

PDEC, The total savings in cooling demands for the center reached 64% (KANG, D.

2011). Figures 4-63 and 4-64 are plan and section showing how the PDEC system is

working at the center.

FIGURE 4-63 Passive Cooling Strategy in the building using PDEC System FIGURE 4-62 Passive Cooling Strategy in the building using PDEC System

Source: WSP Environmental Ltd, 2002

65

FIGURE 4-63 Floor Plan of One of the Buildings in the Center

Source: Thomas, L. & Baird, G., 2005

FIGURE 4-64 Section through the PDEC system in the Center

Source: Thomas, L. & Baird, G., 2005

66

Zion National Park Visitor Center

The visitor center at the Zion National Park is located in southwestern Utah. The

summer daytime temperatures range between 95º - 100ºF while overnight lows are

comfortable (65º–70ºF). The total area of the building is 8475-ft2 (787-m2). The building

envelope is well insulated to minimize heating and cooling loads. Two cooling towers

are incorporated in the building. Natural air is cooled by an evaporation process using

four wet pads in the top of the towers. Clerestories are designed in the roof to maximize

daylighting and improve the air movement with the cooling towers (Figure 4-65). Most of

the cooling requirements are met by natural ventilation (P. Torcellini, S. Pless, N. Long,

and R. Judkoff, 2004).

FIGURE 4-65 Natural Ventilation Concept in the Zion National Park Visitor Center

Source: Source: NREL, 2004

67

An energy performance evaluation was conducted over a 2 year period. The

annual EUI for the building was 26.9 kBTU/ft2/yr (8.5 kWh/m2/yr). The building

consumes 65% less energy when compared with a building that meets U.S. federal

codes. Passive cooling towers combined with the clerestories were the most effective

strategies to reduce cooling loads. All the cooling demands were met naturally with 93%

energy savings. The remaining 7% was consumed to pump the water to the top of the

towers. Figure 4-66 shows a comparison between a baseline case and the case with

the cooling towers (P. Torcellini, S. Pless, N. Long, and R. Judkoff, 2004).

FIGURE 4-66 Comparison between a Baseline Model and the Developed Case using PDEC

Source: P. Torcellini, S. Pless, N. Long, and R. Judkoff, 2004

68

Primary School Reference Building by the U.S. Department Of Energy

This case study provides an energy performance study of the PDEC by Kang, D

in 2011. The study was a dissertation for a PhD in Architecture at the University of

Illinois at Urbana-Champaign. The building chosen for the study was a one story E-

shaped school provided by the US Department of Energy. The building consists of one

main corridor. The spaces in the building include classrooms, an office, corridors, an

auditorium, a gymnasium, a cafeteria, a kitchen, and a library. The total square footage

of the building is 6,871 ft2.

Two different geographic locations were chosen to run energy simulations using

the PDEC system. The first location is Yuma, Arizona, which has a hot and dry climate.

The second location is Sacramento, California, which has a warm moderate climate. In

the baseline case, the total electricity consumption for cooling was 7100.78 mega joules

in Yuma. In Sacramento, the cooling consumption was lower, as the average

temperature is cooler then Yuma (Kang, D, 2011).

By applying the PDEC to the design, the estimated cooling consumption was

reduced in Yuma by 96.3% to 258.72MJ. In Sacramento, the cooling loads reduced by a

similar percentage, approximately 95.5%.however, the PDEC was more effective in the

Yuma case as it requires much more energy for cooling. Moreover, the increase in

relative humidity in the Yuma case had a positive impact on the energy performance

and reduced all of the cooling loads. The remaining energy consumption in both cases

was only needed used to pump the water to the top of the towers. The expected total

energy consumption in the building with the PDEC system was only 57.3% in Yuma and

44.9% in Sacramento (Kang, D, 2011).

69

Passive Down-Draft Evaporative Cooling in Saudi Arabia

A study has been conducted measuring the performance of PDEC in residential

buildings in Saudi Arabia. The location selected was Riyadh, the capital city. Riyadh is

an ideal location to find out how the PDEC will work since it has similar weather

conditions to Hail. A single family house design was proposed for this purpose. The total

floor area of the house is 1657ft2 (154m2). The house includes three bedrooms, a guest

room, 2 lounges, a kitchen, and a dining room (Toyin Phillip & Benson Lau 2013).

One 1 x 1.5m cooling tower was placed in the middle of the house. The PDEC

was designed to cool most of the spaces, which include the bedrooms, two lounges,

and dining room (Figures 4-67, 4-68). Water mists were placed in the cooling tower to

cool the air. The falling cool air is distributed within the building via windows and doors

between the spaces (Toyin Phillip & Benson Lau 2013).

FIGURE 4-67 Section through the PDEC in the House

Source: Phillip, T. & Lau, B., 2013

70

The study did not analyze the overall energy performance of the house, but

rather focused on the home’s cooling needs. The study was conducted during the

period between April and October (the summer season), and. the proposed PDEC met

the cooling requirements for more than 75% of the required periods. This reveals that

PDEC system is highly effective in Saudi Arabia’s climate.

FIGURE 4-68 The Location of the PDEC in the Floor plan

Source: Phillip, T. & Lau, B., 2013

71

Case Studies Summary

Based upon the potential savings in cooling loads from the PDEC, the Passive

House principles should be revised for hot-dry climates in order to increase the energy

efficiency in those locations. The previous analysis of the case studies, as explained

above, suggests that there is a significant potential to reduce cooling loads by using the

PDEC system. The potential savings in cooling consumptions in the previous case

studies range between 48% to more than 90%. In the case of the Passive House

design, this reduction in the cooling demand greatly contributes to the home’s overall

level of energy performance, and could reach net zero energy Passive House in a hot-

dry climate.

72

CHAPTER 5: CONCLUSION

Saudi Arabia is a top oil consumer in the Middle East, with approximately 3

million bbl/d. This high consumption is expected to increase to 8.3 million bbl/d by 2028

and Saudi Arabia was ranked the 10th largest CO2 producer in the world in 2014.

Buildings represent approximately 51.2% of total energy consumed in Saudi Arabia, and

70% of the total building consumption goes to cooling loads.

Unless immediate sustainable solutions are implemented, the country will face a

serious problem by 2032 with the increasing consumption. The proposed solutions

should take into account energy reduction strategies before looking to alternative,

sustainable energy sources.

The Passivhaus concept could be an ideal solution to face the challenges

associated with increasing building energy consumption. By applying the Passivhaus

principles to a typical Saudi house, a 71% energy reduction was achieved including the

use of photovoltaics. As the Passivhaus principles are able to achieve a higher level of

energy performance in cold climates, revising the Passivhaus principles for hot and dry

climates by applying other passive cooling strategies will achieve a higher level of

performance.

The PDEC system was taken into consideration as a passive cooling strategy to

improve residential energy performance and reach net zero energy in Saudi Arabia.

This strategy relies significantly on natural ventilation by evaporation. However, the

application of this strategy contradicts with the Passivhaus principles, as the building will

not be airtight.

73

Air velocity, air movement, and case study analysis revealed that significant

potential energy savings can be achieved through the PDEC system. The air movement

analysis in IES shows that the PDEC design in the house work effectively, and the

amount of natural air entering the house meets the desired rates. Additional case

studies have shown a significant reduction in cooling loads can be achieved through the

PDEC system.

The total energy consumption of the baseline case was 258,890 kBTU with

annual EUI of 69 kBTU/ft2. Using US Passive House principles for hot and arid climates,

this total energy consumption was reduced to 100,405 kBTU without the use of

photovoltaics. With the use of photovoltaics, the Passive House total EUI went down to

20 kBTU/ft2, resulting in total energy reduction of 71%. Cooling loads in the Passive

House case represent 71% of the total consumption with 71,993kBTU and the

estimated total photovoltaic production is 48,264 kBTU. In order to reach net-zero

energy Passive House, the total energy consumption needs to be reduced by

52,141kBTU, which represents 72% of total cooling demands Based on an analysis of

the case studies, this amount of reduction is highly possible using properly designed

cooling towers (Figure 5-1). When compared with the case studies, the size and design

of the cooling towers in the house could provide enough cooled air to cool the house

most of the time. If the cooling loads are reduced by 90%, which is the typical result in

the case studies, the project could be net-positive energy and even produce

approximately 12,652 kBTU/yr.

74

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75

The results from the study have shown that using passive cooling strategies, a

higher level of efficiency is very possible. Based on the results of this study, PDEC is a

valuable strategy for hot-dry climates. Revising the Passive House principles for each

climate zone would be effective and provide alternative choices to meet the needs of

each climate zone.

Due to the limit of available data from energy simulations for mechanical and

dynamic systems, further energy simulations for the PDEC are needed to provide more

accurate results. This could be achieved through the development of more advanced

simulation software, and would lead to more research opportunities on this subject. One

of the areas needing further investigation is the water consumption of the cooling

towers. The PDEC uses water as its main source to cool natural air by evaporation,

which requires a significant use of water. Conducting a study in this matter could

provide solutions or water saving strategies supply the PDEC system. Another area for

further research in this subject is passive evaporative cooling for residential

communities. The strategy of the PDEC could also be applied to cool open or semi-

open spaces in residential communities, which l would also have a positive effect in the

energy performance if the outside environment of a community becomes cooler.

76

BIBLIOGRAPHY

AIA, (2015). Environmental Showcase Home. Retrieved 30 April 2015, from http://www.aiatopten.org/node/225

ASHRAE Standard. (2015). Retrieved 4 May 2015, from https://ashrae.iwrapper.com/ViewOnline/Standard_90.1-2013_I-P

Bryant, J., Amato, A., Law, S., & Al Abdulla, A. (2013). Integrated Project and Metering Design for the First Passivhaus in Qatar. ASHRAE.

BODEN, T., MARLAND, G., & ANDRES,, R. (2010). GLOBAL, REGIONAL, AND NATIONAL FOSSIL-FUEL CO2 EMISSIONS. Carbon Dioxide Information Analysis Center (CDIAC) Datasets. doi:10.3334/cdiac/00001_v2010

Colorado Energy. (2015). R-Value Table. Retrieved 22 May 2015, from http://www.coloradoenergy.org/procorner/stuff/r-values.htmInsulated CMU R-Value http://ncma-br.org/pdfs/66/TEK%2006-02C1.pdf

Cbe.berkeley.edu, (2015). The Center for Global Ecology - Cool tower. Retrieved 5 May 2015, from http://www.cbe.berkeley.edu/mixedmode/images/carnegie/Carnegie_cool_tower.html

Dupont. (2015). PTFE Coating, Extrusion, Molding | DuPont™ Teflon ® PTFE. Retrieved 30 April 2015, from http://www2.dupont.com/Teflon_Industrial/en_US/products/product_by_name/teflon_ptfe/

Eia.gov,. (2015). Saudi Arabia - U.S. Energy Information Administration (EIA). Retrieved 21 April 2015, from http://www.eia.gov/countries/country-data.cfm?fips=SA#cde

EPA. (September 9th, 2013), Global Greenhouse Gas Emissions Data. Retrieved from http://www.epa.gov/climatechange/ghgemissions/global.html

Fennell, H., & Haehnel, J. (2015). Setting Airtightness Standards (1st ed., pp. 26-30). North Thetford, Vt: ASHRAE.

Global Greenhouse Gas Emissions Data. (September 9th, 2013). EPA, Retrieved from http://www.epa.gov/climatechange/ghgemissions/global.html

How much of the world’s energy is consumed by buildings? (2015). IEA. Retrieved from http://www.iea.org/aboutus/faqs/energyefficiency/

https://www.google.com/search?rls=com.microsoft:en-US:IE-Address&biw=1920&bih=986&q=Bibliography&spell=1&sa=X&ei=nGc5VeWBMu3fsASUp4CACw&ved=0CBoQvwUoAA

http://www.aiatopten.org/node/225

https://ashrae.iwrapper.com/ViewOnline/Standard_90.1-2013_I-P

https://ashrae.iwrapper.com/ViewOnline/Standard_90.1-2013_I-P

http://ncma-br.org/pdfs/66/TEK%2006-02C1.pdf

http://ncma-br.org/pdfs/66/TEK%2006-02C1.pdf

http://www.cbe.berkeley.edu/mixedmode/images/carnegie/Carnegie_cool_tower.html

http://www.cbe.berkeley.edu/mixedmode/images/carnegie/Carnegie_cool_tower.html

http://www2.dupont.com/Teflon_Industrial/en_US/products/product_by_name/teflon_ptfe/

http://www2.dupont.com/Teflon_Industrial/en_US/products/product_by_name/teflon_ptfe/

http://www.eia.gov/countries/country-data.cfm?fips=SA

http://www.eia.gov/countries/country-data.cfm?fips=SA

http://www.epa.gov/climatechange/ghgemissions/global.html

http://www.epa.gov/climatechange/ghgemissions/global.html

http://www.iea.org/aboutus/faqs/energyefficiency/

77

IEA. (2015). How much of the world’s energy is consumed by buildings? Retrieved from http://www.iea.org/aboutus/faqs/energyefficiency/

KANG, D. (2011). ADVANCES IN THE APPLICATION OF PASSIVE DOWN-DRAFT EVAPORATIVE COOLING TECHNOLOGY IN THE COOLING OF BUILDINGS (PhD of Architecture). Graduate College of the University of Illinois at Urbana-Champaign.

Kang D. and Strand R., (2009). SIMULATION OF PASSIVE DOWN-DRAUGHT EVAPORATIVE COOLING (PDEC) SYSTEMS IN ENERGYPLUS (pp. 369 - 376). Glasgow, Scotland: Building Simulation.

K.A.CARE. (2013). The Vision | King Abdullah City for Atomic and Renewable Energy. Retrieved 23 April 2015, from http://www.kacare.gov.sa/en/?page_id=84

K.A.CARE. (2012). Building the Renewable Energy Sector in Saudi Arabia. Internation Renewable Energy Agency. Retrieved 21 April 2015, from http://www.irena.org/documentdownloads/events/maltaseptember2012/5_ibrahim_babelli.pdf

Lechner, Norbert. (2009). Heating, Cooling, Lightning Sustainable Design Methods for Architecture (p.2)

Nature-cool.com. (2015). Nature Cool Evaporative Cooling Pads. Retrieved 5 May 2015, from http://www.nature-cool.com/

OPEC. (2015). OPEC Share of World Crude Oil Reserves. Retrieved from http://www.opec.org/opec_web/en/data_graphs/330.htm

PHILLIP, T. & Lau, B. (2013). PASSIVE DOWNDRAUGHT EVAPORATIVE COOLING: In 29th Conference, Sustainable Architecture for a Renewable Future. London, UK: University of Nottingham, UK.

Institute, P. (2015). Passivhaus Institut. Passiv.de. Retrieved 19 May 2015, from http://www.passiv.de/en/02_informations/02_passive-house-requirements/02_passive-house-requirements.htm

PHIUS. (2015). PHIUS Certified Projects: The Desert Passive House. Retrieved from http://www.phius.org/projects/1154

Passive House Institute US. (2015). The Desert Passive House. Retrieved from http://phius.westhostsite.com/project_detail.php?id=1154

http://www.iea.org/aboutus/faqs/energyefficiency/

http://www.kacare.gov.sa/en/?page_id=84

http://www.kacare.gov.sa/en/?page_id=84

http://www.irena.org/documentdownloads/events/maltaseptember2012/5_ibrahim_babelli.pdf



http://www.nature-cool.com/

http://www.nature-cool.com/

http://www.opec.org/opec_web/en/data_graphs/330.htm

http://www.passiv.de/en/02_informations/02_passive-house-requirements/02_passive-house-requirements.htm

http://www.passiv.de/en/02_informations/02_passive-house-requirements/02_passive-house-requirements.htm

http://www.phius.org/projects/1154



http://phius.westhostsite.com/project_detail.php?id=1154

http://phius.westhostsite.com/project_detail.php?id=1154

78

Passipedia. (2015). Passivehaus Wall System. Retrieved 22 May 2015, from http://passipedia.org/_media/picopen/ph_suitable_ext_wall_systems.jpg?cache

Qatar Foundation,. (2013). Boost to Green Living as New Figures For Passivhaus Add Up. Retrieved 23 April 2015, from http://www.qf.org.qa/news/299

SEEC. (2013). Saudi Energy Efficiency Center. Retrieved from http://www.seec.gov.sa/2013/03/27/ي بان lang=en?/م

The Rise of the Green Buildings, (Dec 2nd, 2004). The Economist. http://www.economist.com/node/3422965\

Thomas, L. & Baird, G. (2005). Post-occupancy evaluation of passive downdraft evaporative cooling and air conditioned buildings at Torrent Research Center Sydney: University of Technology.

WSP Environmental Ltd. (2002). Passive Downdraught Evaporative Cooling (PDEC) applied to the central atrium space within the New Stock Exchange in Malta. London, UK.

Weatherspark.com,. (2015). Historical Weather For The Last Twelve Months in Ha'il, Saudi Arabia - WeatherSpark. Retrieved 23 April 2015, from https://weatherspark.com/history/32765/2015/Ha-il-Hail-Saudi-Arabia

Zion National Park Visitor Center: Performance of a Low-Energy Building in a Hot, Dry Climate. (2004). the World Renewable Energy Congress VIII and Expo. Denver, Colorado.

Zarja Elektronika,. (2015). Water mist | Zarja Elektronika. Retrieved 5 May 2015, from http://www.zarja.com/en/systems/extinguishing-systems/water-mist/

http://passipedia.org/_media/picopen/ph_suitable_ext_wall_systems.jpg?cache

http://www.qf.org.qa/news/299

http://www.qf.org.qa/news/299

http://www.seec.gov.sa/2013/03/27/مباني/?lang=en

http://www.seec.gov.sa/2013/03/27/مباني/?lang=en

http://www.economist.com/node/3422965/

http://www.economist.com/node/3422965/

https://weatherspark.com/history/32765/2015/Ha-il-Hail-Saudi-Arabia

https://weatherspark.com/history/32765/2015/Ha-il-Hail-Saudi-Arabia

http://www.zarja.com/en/systems/extinguishing-systems/water-mist/

http://www.zarja.com/en/systems/extinguishing-systems/water-mist/

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