The effectiveness of Vertical Greening Systems upon Indoor Thermal Comfort in Buildings

Transcription

1 The effectiveness of Vertical Greening Systems upon Indoor Thermal Comfort in Buildings With special reference to Living Spaces in Cairo, Egypt By Nourhan Magdy Mohamed A Thesis Submitted to the Faculty of Engineering At Cairo University In Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE In ARCHITECTURAL ENGINEERING FACULTY OF ENGINEERING, CAIRO UNIVERSITY GIZA, EGYPT 2012

2 The effectiveness of Vertical Greening Systems upon Indoor Thermal Comfort in Buildings With special reference to Living Spaces in Cairo, Egypt By Nourhan Magdy Mohamed A Thesis Submitted to the Faculty of Engineering At Cairo University In Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE In ARCHITECTURAL ENGINEERING Prof. Medhat Dorra Prof. Khaled Dewidar Prof. Ayman Mahmoud Professor of Architecture Professor of Architecture Professor of Architecture Cairo University Ain Shams University Cairo University FACULTY OF ENGINEERING, CAIRO UNIVERSITY GIZA, EGYPT 2012

3 The effectiveness of Vertical Greening Systems upon Indoor Thermal Comfort in Buildings With special reference to Living Spaces in Cairo, Egypt By Nourhan Magdy Mohamed A Thesis Submitted to the Faculty of Engineering At Cairo University In Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE In ARCHITECTURAL ENGINEERING Approved by the Examining Committee: Prof. Mohamed Tawfik Abdel Gawad Prof. Basil Kamel Prof. Medhat Dorra Prof. Khaled Mohamed Ragheb Dewidar Prof. Ayman Mahmoud Hassan External member Internal member Main Advisor Advisor Advisor FACULTY OF ENGINEERING, CAIRO UNIVERSITY GIZA, EGYPT 2012

4 Engineer: Nourhan Magdy Mohamed Mohamed Date of Birth: 01 / 02 / 1987 Nationality: Egyptian Nourhan.Magdy@Bue.edu.eg Phone. : Address: 23/2. El Shatr El Khamis Men Degla, Maadi Registration Date: 01 / 09 / 2010 Awarding Date: / / Degree: Master of Science Department: Architectural Engineering Supervisors: Prof. Dr. Medhat Dorra Prof. Dr. Khaled Dewidar (Professor of Architecture, Ain Shams University) Prof. Dr. Ayman Hassan Mahmoud Examiners: Prof. Dr. Mohamed Tawfik Abdel Gawad (Professor of Architecture, Faculty of Fine Arts) Prof. Dr. Basil Ahmed Kamel Prof. Dr. Medhat Dorra Prof. Dr. Khaled Dewidar (Professor of Architecture, Ain Shams University) Prof. Dr. Ayman Hassan Mahmoud Title of Thesis: The effectiveness of Vertical Greening Systems upon Indoor Thermal Comfort in Buildings With special reference to Living Spaces in Cairo, Egypt Key Words: Urban Heat Island, Thermal Comfort, Vegetation and Climate, Vertical Greening Summary : Recently, the popularity of vertical greenery is growing in the context of urban landscaping because of its smaller footprint, aesthetic value and heat island mitigation impact, as a part of new technology that allows the use alternative vegetation ie. Green roofs, roof vegetation and green walls. One of the main advantages of this type of vegetation is they can be used without taking precious land space. The thesis is exposed to the potentials of using vertical greening as an integral part of the building process to save energy, where it firstly introduces the environmental crisis and UHI effect globally to identify the impact of vegetation as a sustainable approach for UHI mitigation. After addressing vertical greening types and functional and environmental aspects in general, the study distills these different vertical greening systems applicable to enhance façade thermal performance in terms of indoor thermal comfort. This will be empirically examined by DesignBuilder simulation, to explore the possibilities of improving indoor thermal comfort within the studied types. Then conclude to a set of recommendations for within buildings in Egypt s climatic settings.

5 The Researcher Nourhan Magdy Mohamed Instructor at the Architectural Department Faculty of Engineering The British University in Egypt (BUE) Bachelor Degree of Architecture Faculty of Engineering- Cairo University- 2008

6 Acknowledgment I would like to express my special thanks to the Department of Architectural Engineering in Faculty of Engineering, Cairo University. I am thankful from the depth of my heart to my Supervisors, Prof. Medhat Dora, Prof. Khaled Dewidar, and Prof. Ayman Mahmoud for being so generous to me, with their time, patience, advice and valuable opinion that s lead to the completion of this research. And special thanks to my mother who helped me with her experience and encouraged me. My thanks are further extended to my beloved family and all my friends I care to name. i

7 Abstract In present time, more and more people move into cities. Densification of cities as planning policy together with an intensive urbanization makes urban planners face with the contradictory task of creating a city that is both dense and green. The unstoppable force of urbanization is consuming vast quantities of natural vegetation, replacing them with concrete buildings and low albedo surface. These resulting changes in the thermal properties of surface materials and the lack of evaporation in urban areas, leads to the phenomena known as the urban heat island (UHI) effect. Since the beginning of the twentieth century research into the use of green inside the cities increased substantially. In particular the amount of publications, articles and research focusing on the use of green roofs and green facades has increased in recent years. Nowadays the environmental impact of buildings on inner and outer climate becomes more and more apparent. Where, green buildings are designed to reduce the overall impact of the built environment on human health and the natural environment. Recently, the popularity of vertical greenery is growing in the context of urban landscaping because of its smaller footprint, aesthetic value and heat island mitigation impact, as a part of new technology that allows the use alternative vegetation i.e. green roofs, roof vegetation and green walls. One of the main advantages of this type of vegetation is that they can be used without taking precious land space. The thesis is exposed to the potentials of using vertical greening as an integral part of the building process to save energy, where it firstly introduces the environmental crisis and UHI effect globally to identify the impact of vegetation as a sustainable approach for UHI mitigation. After addressing vertical greening types, functional and environmental aspects in general, the study distills these different vertical greening systems applicable to enhance façade thermal performance in terms of indoor thermal comfort. This will be empirically examined by DesignBuilder simulation, to explore the possibilities of improving indoor thermal comfort within the studied types. Then conclude to a set of recommendations for buildings within Egypt s climatic settings. Keywords: Urban Heat Island, Thermal Comfort, Vegetation and Climate, Vertical Greening. ii

8 Table of Contents Acknowledgement... Abstract... Table of Contents.... List of Tables... List of Figures. Chapter 1: Introduction 1.1 Inception Observations Research Problem Research Significance Research Aims Scope of the Research Research Hypothesis Research Methodology Research Structure... Page i ii iii vii viii Part I: Theoretical Framework Chapter 2: The Effect of Vegetation on Urban Heat Island Mitigation 2.1 Introduction Energy Crisis Heat Climate Change The Urban Heat Island Phenomenon upon Urban Component Background Causes of Urban Heat Island Impacts of Urban Heat Island Increase Energy Consumption Increase Thermal Discomfort Mitigation of Urban Heat Island Effects. 2.5 Impacts of Vegetation on Urban Climate Vegetation Typologies: Green Roof and Green Façades Potentials of Vegetations at Urban Scale Reducing The Urban Heat Island Effect in Large Cities CO2 Retention Reduction of Urban Noise Increased Biomass and Biodiversity Potentials of Vegetation at Buildings Scale iii

9 2.8.1 Thermal Regulation in Buildings... A. Thermal Insulation B. Interaction with Solar Radiation. C. Evaporative Cooling Visual Aspects and Psychological Positive Effect The Use of Vegetation for UHI Mitigation Summary Chapter 3: Vertical Greening Systems 3.1 Introduction Vertical Greening Historical Background Definition of Vertical Greening System Overview of Vertical Greening Description of Vertical Greening Systems Wall Vegetation A. Naturally Grown Vegetation... B. Concrete Panels with Vegetation Green Façades... A. Planted in Planter Boxes... A.1 Green Wall Container System... B. Planted into the Soil... B.1 Modular Trellis Panel System... B.1.1 Green Screen System... B.2 Cable and Wire rope System... B.2.1 Façade Scape System SYS Stainless Rod and Cables Suitable Plants for Green Façades Living Wall Systems (LWS) Pre-Fabricated Living Wall Systems... A. Planter Boxes System... A.1 Green Wave System... B. Foam Based System... B.1 Fytowall-Fytogreen System... C. Mineral Wool Based System... C.1 Wallflore System Insite Living Wall System... A. Felt Based System... A.1 Planting System... A.2 Paramento Vertical Vegetal Suitable Plants for Living Wall Systems Comparative Assessment of Vertical Greening Systems Summary iv

10 Chapter 4: Potentials and Limitations of Vertical Greening Systems 4.1 Introduction Vertical Greening Systems Functional Aspects Potentials of Vertical Greening Systems Moderating Buildings internal temperature via External Shading Creating a microclimate to alter the climate of the city as a whole Improving insulation property in Buildings Variation in the Wind Effect on Buildings Effect on Solar Radiation Air Quality Improvement Reduction of Urban Heat Island Effect Providing Sound Insulation Providing Biodiversity and Natural Animal Habitat Energy Savings Aesthetics and Psychological Potentials Limitations of Vertical Greening Systems Chances of Façade Damage in case of Green Façade Directly to the Wall Maintance of Vertical Greening Systems... A. Green Façades... B. Living Wall Systems Costs of Vertical Greening Systems Irrigation Systems Moisture Problems Summary Part II: Empirical Examination Chapter 5: Empirical Research Design 5.1 Introduction Introduction to DesignBuilder Modelling Approach Setting Up The Initial Model In DesignBuilder Design Builder Output Format Thermal Comfort Examined Variables Plant Cover Type Simulation Plant: Hedera Helix (Common Ivy) Hedera Helix Vegetation Model Air Cavity Between Façade and Vertical Greening System Tested Vertical Greening Systems v

11 Green Façade with Self Climbing Plant Green Façade with Self Climbing Plant on Supporting Grid LWS Based on Planter Boxes LWS Mineral Wool Based System LWS Foam Based System LWS Felt Based System Façade Orientation Pilot Simulation Limitations Summary Chapter 6: Simulation Results and Discussion 6.1 Introduction Simulation Results for Initial Model Simulation Results for Vertical Greening System (A) Simulation Results for Vertical Greening System (B) Simulation Results for Vertical Greening System (C) Simulation Results for Vertical Greening System (D) Simulation Results for Vertical Greening System (E) Simulation Results for Vertical Greening System (F) Comparison of Conducted Simulation Results Summary... Chapter 7: Conclusion and Recommendations 7.1 Introduction Accomplished Objectives Re-examining Research Hypothesis Findings Vertical Greening System Design Option Vertical Greening Proposed Combined System Combined Vertical Greening System Functional Aspect Integration with Building Façade Recommendations Future Research Ending Statement... Bibliography... Appendix vi

12 Table No. List of Tables Title Page 2.1 Design principles for a sustainable compact city International examples for a modular Trellis system International examples for façade scape system Types of plants suitable for green façade Types of plants suitable for Living Wall Systems Overview of all vertical greening system with their characteristics Advantages and Disadvantages of vertical greening systems Improvement of the insulating value of a well greened façade Summary of insertion loss in vertical greening system Range of costs of different vertical greening systems Overview of all vertical greening systems Potentials and Limitations Contribution of different vertical greening systems Proposed dimensions for Living Space as used in simulations Selection criteria of plants for simulation Summary of Hedera Helix Properties Material layers and thermal properties in System (A) Material layers and thermal properties in System (B) Material layers and thermal properties in System (C) Material layers and thermal properties in System (D) Material layers and thermal properties in System (E) Material layers and thermal properties in System (F) Components and Materials for tested Vertical Greening Systems Thermal simulation results for all variables vii

13 Figure No. List of Figures Caption Page 1.1 Houses in Jupilles National Wild Life Federation Green Screens in Tokyo Caixa Forum in Madrid The Green Façade of the Quai Branly & Caxia Forum. 1.6 Research Methodology Research Structure Total Energy Consumption in Egypt. 2.2 Total Global Greenhouse Emission Generalized Cross section of A Typical Urban Heat Island Factors Tends to Influence The Severity of The UHI Effect. 2.5 Guidelines for Architecture Design to reduce the UHI Effect Interferences of the Environment in Relation to the Building Cross section of a sustainable compact city. 2.8 A study in Catalunya shows urban noise difference Relation between urban vegetation, building vegetation and habitats Distribution of temperatures across eastern façade and no ivy Location of instruments in the shaded area of the façade The Institute of Physics, University of Humboldt Example of vegetated facades in MFO Park The Hanging Gardens of Babylon. 3.2 Greenery integrated with the building occupies Hundertwasser house in Vienna. 3.4 Basic distinctions between greening principles 3.5 Diagram of vertical greening systems. 3.6 Diagram of vertical Greening system, including wall vegetation The principle of wall vegetation 3.8 Concrete panels (Growcrete) with plants viii

14 3.9 Diagram of Green Façades principles The principle of plants from an intermediate planter boxes Examples of green facades in planter boxes Green wall container System Structure Principles of green façades rooted into the ground Different examples green façades with self-climbing plants Principles of Green façades on supporting grid Freestanding structures as green façades Façade Scape system Components Examples of Living wall system Diagram of Living wall system (LWS) Categories Examples of LWS indoor applications Principles of living systems Basic principle of living wall system (Planter Boxes) Module of planter boxes system details Technical Details of planter boxes (LWS) Principle of Foam Based System Technical Details of foam based system Vertical detail fytowall-fytogreen system Principle of mineral wool based living wall system Aluminum Fix-lide system for Wallflore panels Wallflore panel with growing medium Principle of felt layers system Principle of felt layers system Black Box Applications of Felt based LWS Paramento System felt Layer and closing cash unit Examples for Paramento System Boston ivy applied directly against the façade in Delft summer Bioshader Experiment Installation Set Sectional view of the Bioshader Experiment Air circulation through streets with vertical greening SO2 concentration measured inside ivy greened façade in Stuttgart-Vaihingen ix

15 4.6 Aesthetics potentials of vertical greening systems in Buildings Sucker roots structure of plants (Hedera Helix) directly to the wall Sucker root structure in natural wall vegetation Bare parts on a felt layer system with dead plants Deterioration of living wall panels Plan of the Simulation model and its Orientation Thermal analysis output in DesignBuilder Typical evergreen ivy leaves The six tested different vertical greening systems concepts Façade orientations tested in the research Details of case models used in DesignBuilder simulations Thermal simulation results for initial Model on 21 st of March Thermal simulation results for initial Model on 21 st of June Thermal simulation results for initial Model on 21 st of September Thermal simulation results for initial Model on 21 st of December Thermal simulation results for system (A) on 21 st of March Thermal simulation results for system (A) on 21 st of June Thermal simulation results for system (A) on 21 st of September Thermal simulation results for system (A) on 21 st of December Thermal Comfort Hours for Initial model and system (A) Thermal simulation results for system (B) on 21 st of March Thermal simulation results for system (B) on 21 st of June Thermal simulation results for system (B) on 21 st of September Thermal simulation results for system (A) on 21 st of December Thermal Comfort Hours for Initial model and system (B) Thermal simulation results for system (C) on 21 st of March Thermal simulation results for system (C) on 21 st of June Thermal simulation results for system (C) on 21 st of September Thermal simulation results for system (C) on 21 st of December Thermal Comfort Hours for Initial model and system (C) x

16 6.20Thermal simulation results for system (D) on 21 st of March Thermal simulation results for system (D) on 21 st of June Thermal simulation results for system (D) on 21 st of September Thermal simulation results for system (D) on 21 st of December Thermal Comfort Hours for Initial model and system (D) Thermal simulation results for system (E) on 21 st of March Thermal simulation results for system (E) on 21 st of June Thermal simulation results for system (E) on 21 st of September Thermal simulation results for system (E) on 21 st of December Thermal Comfort Hours for Initial model and system (E) Thermal simulation results for system (F) on 21 st of March Thermal simulation results for system (F) on 21 st of June Thermal simulation results for system (F) on 21 st of September Thermal simulation results for system (F) on 21 st of December Thermal Comfort Hours for Initial model and system (F) Air temperature readings in 21 st March for six tested systems Air temperature readings in 21 st June for six tested systems Air temperature readings in 21 st September for six tested systems Air temperature readings in 21 st December for six tested systems Differences in air temperature readings between systems A, B, and C Differences in air temperature readings between systems A, B, C, and D Differences in air temperature readings between systems A, B, C, D, and E Differences in air temperature readings between systems A, B, C, D, E and F Differences in air temperature readings between six systems Differences in air temperature readings between six systems in December Applications of LWS to a Blank Wall Applications of Green façade system Cross section of proposed combined vertical greening system Functional aspects and maintance issue of proposed combined system xi

17 CHAPTER ONE INTRODUCTION

18 Chapter 1: Introduction 1.1 Inception CHAPTER ONE INTRODUCTION Building façades constitute the line division between the indoor and the outdoor, participating in the spaces of both sides. Initially, the main role of façades was to provide protection from the climate s inclemencies as well as from other humans or animals 1. As technology made progress façades became more permeable, allowing air and light to pass through them, leading to the very thin façades of glazing buildings. In accordance, façades requirements became more and more complex in order to improve indoor comfort conditions. Accordingly, new aspects in building façades have emerged in order to express the notion of variability and changeability in façade s environmental aspects. One of these aspects is vertical greening which has been developed throughout the last decade, in order to enhance façades functional aspects such as improving insulation in buildings (stabilizing temperature among all seasons) 2. Another potential is improving aesthetics, improving indoor and outdoor climate, reduce the greenhouse gases such as Carbon Dioxide (CO2), Carbon Monoxide (CO) and Nitrogen Dioxide (NO2) as well as increasing ecological values by creating habitats for birds and insects 3. Throughout the years, replacement of vegetated surfaces with paved and impervious surfaces in the urban area have caused the temperature in the area to increase comparing to the surrounding rural area 4. This is due to the paved surfaces absorbs, retain, and reradiate more solar energy than grasses and trees which leads to that the ambient temperature in urban area can be as much as 6ºC warmer than the air in rural areas 5. This process has drawn attention to the role of vegetation in the contribution of energy efficiency through a variety of means such as simple shading by trees, climbing plants or a green 1 Herzog, Krippner, Lang, (2004). Façade Construction Manual. Birkhauser Architecture, Munich, ISBN: Dunnett, N. & Kingsbury, N., (2008). Planting Green Roofs and Living Walls. London: Timber Press, ISBN Köhler, M., (2008). Green façades - a view back and some visions, Urban Ecosyst, Vol.11, pp Yu-Peng Yeh, (2010). Green Wall; the Creative Solution in Response to the urban heat island effect. National Chung-Housing University. Bioscience, pp Wilmers, F. (1988). Green for Melioration of Urban Climate. Energy and Buildings, Vol.11, pp

19 Chapter 1: Introduction roof can help stop a building from over-heating and can so reduce cooling loads by up to 30% 6. Conversely, a layer of vegetation can also reduce heat loss from buildings, and it has been found that protecting a house from wind reduced by 75% and reduced the heating demand by 25% 7. In spite of these important roles that vertical greening plays in enhancing the urban environment, there has been some conflict considering its technical aspects and maintance issues, Thus, this duality will be discussed in this research, to provide a more valid discussion for the technical and functional aspects of different vertical greening systems in buildings. 1.2 Observations One of the driving observations which directed the course of the research is to investigate the emerging practice of vertical greening that contemporary architecture is experiencing. Where, more and more architects are experimenting with diverse ways of introducing greenery to building façades, providing a wide spectrum of different types of vertical greening. This practice, which one might call a boom of vertical greening, is spreading all around the world as the following recent examples reflect, the figures below show examples from Jupilles, France (figure 1.1) to Reston, USA (figure 1.2) to Tokyo, Japan (figure 1.3) to Madrid, Spain (figure 1.4). Figure 1.1Houses in Jupilles, France, 1996, (Available at: Accessed on ) Figure 1.2 National Wildlife Federation in Reston, USA, 2001 (Available at: Accessed on ) 6 Ibid, p Wilmers, F. (1990/91). Effects of Vegetation on Urban Climate and Buildings. Energy and Buildings, Vol , pp

20 Chapter 1: Introduction Figure 1.3 Green Screens in Tokyo, Japan, 2010 (Available at: in-dytham-architecture-green-screen,accessed on ) This observation was particularly valid with a very explicit reference in this context, where leading architects, such as Jean Nouvel, Herzog & de Meuron and Patric Blanc, seem to find in vertical greening a natural response to the current accelerated information society, one which demands a changeable architecture 8. As well as to the emerging need for a carbon neutral architecture, one which demands an environmentally sensible architecture. Architects are exploring the changeable and expressive capacity of vegetation on the façade, fascinated by its faculty to naturally introduce the notion of time, providing an ephemeral dimension: The ephemeral dimension infers a rapport between architecture and ephemeral elements. Vegetation is one of these and is of course very fleeting, very sensitive and very changeable 9 Figure 1.4 Caixa Forum in Madrid, Spain, 2008 (Available at: Accessed on ) Recent buildings illustrate this. In the case of Jean Nouvel, the green façade of the Quai Branly Museum (figure.1.5) in Paris, achieves a spectacular explosion of different plant species, transmit the thickness and heaviness of living walls, and creates diverse green tapestries rich in texture and tonalities of green, and often punctuated by flowers 10. In the case of Patric Blanc, the green façade of the Caixa Forum in Tokyo uses the same moss-type plant to take different inclinations as if it was referred as the sponge, grass-covered topography of the yard Lambertini, A., (2007). Vertical Gardens: Bringing the City to Life. Thames and Hudson, London, 2007.ISBN An interview with Jean Nouvel available on his office website, Available at: Accessed on: L Atelier Vert, Available at: Accessed on: Pedro Arroyo, Caixa Forum. Architecture is architecture. Available at: Accessed on: