Passive Cooling Through Plants - Dissertation

DISSERTATION Year: 2020-21 Batch No. 18

PASSIVE COOLING THROUGH PLANTS

Undertaken by: Krittika Uckoo Enrollment No.: 16E1AAARF40P050 V Year B.Arch (B)

Prof. PUSHPAK BHAGWATI Prof. ARCHANA SINGH GUIDE COORDINATOR

Aayojan School of Architecture ISI-4, RIICO Institutional Block, Sitapura, Jaipur-302022

APPROVAL The study titled “Passive Cooling through Plants” is hereby approved as an original work of Krittika Uckoo, enrollment no. 16E1AAARF40P050 on the approved subject carried out and presented in manner satisfactory to warrant its acceptance as per the standard laid down by the university. This report has been submitted in the partial fulfillment for the award of Bachelor of Architecture degree from Rajasthan Technical University, Kota.

It is to be understood that the undersigned does not necessarily endorse or approve any statement made, any opinion expressed or conclusion drawn therein, but approves the study only for the purpose it has been submitted.

December, 2020 Jaipur

EXTERNAL EXAMINER 1

Prof. K.S. MAHAJANI PRINCIPAL

EXTERNAL EXAMINER 2

Prof. ARCHANA SINGH COORDINATOR

ii

DECLARATION I, Krittika Uckoo, here by solemnly declare that the research work undertaken by me, titled ‘Passive Cooling through Plants’ is my original work and wherever I have incorporated any information in the form of photographs, text, data, maps, drawings, etc. from different sources, has been duly acknowledged in my report.

This dissertation has been completed under the supervision of the guide allotted to me by the school. Further, whenever and wherever my work shall be presented or published it will be jointly authored with my guide.

KRITTIKA UCKOO V Year B.Arch (B) Aayojan School of Architecture, Jaipur

CERTIFICATE This is to certify that the research titled, Passive Cooling through plants is a bonafide work by Krittika Uckoo of Aayojan School of Architecture, Jaipur. This research work has been completed under my guidance and supervision in a satisfactory manner.

This report has been submitted in partial fulfillment of award of BACHELOR OF ARCHITECTURE degree from Rajasthan Technical University, Kota.

This research work fulfills the requirements relating to the nature and standard laid down by the Rajasthan Technical University.

Prof. PUSHPAK BHAGWATI Guide Aayojan School of Architecture,Jaipur

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ACKNOWLEDGEMENT

As I complete my dissertation, I would like to be grateful to the people without whose support, I would not have been able to make it so far. Their recurring words of encouragement and inputs have enabled me to stay focused and have a deeper comprehension of the subject.

Foremost, I would like to thank my institution and Principal & Director, Prof. K.S. Mahajani for providing a conductive college environment and proficient faculty members.

I extend my thanks to the Dean of Academics, Prof. N.S. Rathore for giving me a chance to take up the dissertation and thesis topic of my interest and providing me advice and time throughout the course of my undergraduate education.

My sincere thanks to the subject co-ordinator, Prof. Archana Rathore, and all other guides, for their time, valuable and insightful inputs during the reviews and discussions.

Most importantly, I am grateful to my dissertation guide, Prof. Pushpak Bhagwati, for always being supportive and delivering his valuable advice, encouragement, and helpful assessment throughout the course of the work. His recommendations and instructions have enabled me to assemble and finish the dissertation effectively.

I would like to express my gratitude to Prof. Madhura Yadav , Director of Manipal University, Jaipur for permitting me to study the campus.

I would especially like to thank my family for constantly motivating and supporting me throughout these tough times and helping me make it through. A big thanks to my parents for accompanying me through the case study. I would also like to thank my friends Ridhima Bhogra, Pranaya Gupta and Radhika Somani for their constant support and valuable inputs.

Krittika Uckoo V Year B.Arch. (B) Aayojan School of Architecture, Jaipur

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ABSTRACT Issues of energy consumption and extensive fuel supply for large scale buildings such as an institutional one are creating a big threat to the environment and also being expensive at the same time. The massive use of air conditioners and other cooling appliances used for maintaining a comfortable indoor thermal temperature is one of the issues which can be solved. A simple and very efficient way to reduce energy consumption is using the site surroundings and vegetation for cooling.

Energy and landscape are critical constituents in the physical development of a built environment. Energy conservation and landscape quality have been widely acknowledged as important parameters in the design of buildings, surroundings, and built-up areas. The study will be focusing on the perfect strategies for the planning and placement of plants and trees around the building to achieve maximum passive cooling. To understand the subject deeply a small study has been done at an initial stage, on energy transfer mechanism which takes place between plants and nature.

Further two case studies concerning the two different climatic zones, hot and dry and composite, have been studied and taken reference from. The simulations of the case studies have been recorded through simulation software called DesignBuilder. Simulations related to the affect of plantations on the building in the form of shading efficiency, internal temperature, relative humidity and change appliances load has been recorded. Analysis depending upon two parts which are the whole building simulation and the other consist some application based simulations. Further, the study is completed by stating the conclusions on the resulting data of thermal simulation, and recommendations are made for the same.

v

CONTENTS

Page No.

Approval ii

Declaration iii

Certificate iii

Acknowledgement iv Abstract v

Contents vi-vii

List of illustrations viii-xi

CHAPTER 1: INTRODUCTION

1-4

1.1 Background of the study

1 1.2 Criteria of selection 2 1.3 Hypothesis 3 1.4 Aim 3 1.5 Objectives 4 1.6 Scope 4 1.7 Methodology 4

CHAPTER 2 : THERMAL PARAMETERS 2.1 Climate 2.2 Energy transmission 2.2.1 Convection 2.2.2 Conduction 2.2.3 Radiation 2.2.4 Evapotranspiration 2.3 Thermal comfort parameters

5-10 6 6

10

CHAPTER 3 : PLANTS FOR PASSIVE COOLING 11-19 3.1 Background 12 3.2. Case study 1: Manipal University, Jaipur, Rajasthan. 12 3.2.1 Effect of Shading of plants 3.2.2 Wind reduction and channeling 3.2.3 Evapotranspiration 3.2.4 Radiation 3.3. Case study 2: Nalanda University, Rajgir,Bihar.

17 vi

3.3.1 Effect of Shading of plants 3.3.2 Wind reduction and channeling 3.3.3 Evapotranspiration 3.3.4 Radiation

CHAPTER 4: ANALYSIS AND ENERGY SIMULATIONS

20-36

4.1 Analysis of the case studies as a whole.

21 4.1.1. Hot and Dry climate 4.1.2. Composite climate 4.2 Analysis based on design applications 31 4.2.1. Orientation 4.2.2. Density 4.2.3. Height and width/spread 4.2.4. Multiple shading/ centre to center distances 4.2.5. Shape of trees and shrubs 4.2.6. Types of plants

CHAPTER 5 : CONCLUSION AND RECOMMENDATIONS 5.1. Conclusion 5.2. Recommendations 5.2.1. North 5.2.2. South 5.2.3. East / West

37-45 38 38

5.2.4. Generic - Application based BIBLIOGRAPHY xii GLOSSARY OF TERMS xiii

vii

LIST OF ILLUSTRATIONS Figure

Illustration Title

Page No.

Source

Chapter 1: Introduction 1.1

Graph showing total final energy consumption in institutional buildings, 2000-2018

1

IEA https://qz.com/741554/the-globalenvironmental-impact-of-airconditioning-is-big-and-will-get-evenbigger/

1.2

Cooling through air conditioners

1.3

Cooling through plants

2

https://www.theguardian. com/cities/2018/aug/15/ what-heat-proof-city-look-like

1.4

Graph showing Energy supply in institutional buildings (India – 1990 - 2018)

2

IEA

1.5

Graph showing Energy consumption in institutional buildings (India – 1990 - 2018)

3

IEA

2

Chapter 2: Thermal Parameters 2.1

Jaipur, India, Sun path and seasons graph

6

https://www.gaisma.com/en/ location/jaipur.html

2.2

Illustration showing the thermal energy transfer from outdoor to indoor

7

Author

2.3

Illustration showing conduction effect through a lattice attached directly to the wall.

7

Author

2.4

Illustration showing convection effect by trees

8

Author

2.5

Illustration showing evapotranspiration by trees and how they make the environment cooler.

9

Author

2.6

Illustration showing reflection, transmission, and absorption of surfaces.

9

Author

2.7

Illustration showing thermal comfort.

9

Author

Manipal University, Jaipur, Rajasthan.

12

Author

Proposed campus plan

12

GRIHA

3.3

Existing campus plan

12

Google Earth

3.4

Campus plan with green area

13

Author

3.5

Manipal University campus view

13

Author

13

Author

Chapter 3: Passive cooling through Plants 3.1 3.2

3.6

Table : Energy Consumption of existing block

viii

3.7

Academic block view

13

Author

3.8

Academic block plan with surrounding plantations

14

Author

3.9

Shading for pavements

14

Author

3.10

Date palm trees used for shading in south.

15

Author

3.11

Bamboo trees used to shade the staircase shaft

15

Author

Badam trees used to shade exterior facade.

15

Author

3.13

Shading trees used for wind channeling

16

Author

3.14

Curry tree plantation in the courtyard

16

Author

3.15

Ground cover for absorbing more heat radiations

16

Author

3.16

Nalanda University Campus plan

17

Earthscapes

3.17

Nalanda University Campus plan, showing density of plantations.

17

Earthscapes

3.18

Nalanda University site section showing density of plantations.

17

Earthscapes

3.19

Site level shading through trees

18

Earthscapes

3.20

Wind reduction and channeling, Nalanda University

18

Earthscapes

3.21

Evapotranspiration through plants in parking zone

19

Earthscapes

3.22

Radiation and absorption

19

Earthscapes

3.12

Chapter 4: Analysis and Energy Simulations 4.1

CASE 1 : Building without plantations around.

Academic Block , Manipal University, Jaipur.

21

Author

4.2

Site weather data of Manipal University , Jaipur.

22

Design Builder (simulation)

4.3

CASE 2 : Building with existing plantations.

Academic Block , Manipal University, Jaipur.

23

Author

CASE 3 : Building with existing and additional plantations. Academic Block , Manipal University, Jaipur.

24

4.4

4.5

Simulated data of all three cases on the basis of internal temperature, relative humidity and latent load.

Author

25

Design Builder (simulation)

4.6

CASE 1 : Building without plantations. Nalanda University.

27

Author

4.7

CASE 2 : Building with existing plantations Nalanda University.

28

Author

ix

4.8

CASE 3 : Building with existing and additional plantations, Nalanda University.

4.9

Simulated data of all three cases on the basis of internal temperature, relative humidity and latent load.

4.10

North

4.11

28

Author

29

Design Builder (simulation)

31

Author

South

31

Author

4.12

East / West

31

Author

4.13

South-west / South-east

32

Author

4.14

Site plan with 2:1 density ratio

32

Author

4.15

Site plan with 1:1 density ratio

32

Author

4.16

Site plan with 1:2 density ratio

32

Author

4.17

South - 15m

33

Author

4.18

South - 12m

33

Author

4.19

South - 2m

35

Author

4.20

East /West - 15m

35

Author

4.21

East /West - 12m

35

Author

4.22

East /West - 2m

35

Author

4.23

Table : Shape of trees and shrubs

34

Author

4.24

12m heighted @ 16m c/c

35

Author

4.25

12m heighted @ 10m c/c

35

Author

4.26

12m heighted @ 6m c/c

35

Author

4.27

15m Heighted - @ 20m c/c

35

Author

4.28

15m Heighted - @ 16m c/c

36

Author

4.29

15m Heighted - @ 10m c/c

36

Author

Chapter 5: Conclusions and Recommendations 5.1

Larger trees placed om north side

39

Author

5.2

Small shrubs placed on north side

39

Author

5.3

Large trees for south shading

39

Author

x

Author

Round top for shading

9

5.5

Palm trees for top shading

39

Author

5.6

1.5m green ground cover stretch

40

Author

5.7

Shading eff. 10%

40

Author

5.8

Deciduous trees for winter sunlight

40

Author

5.9

Shading eff. 50%

41

Author

5.10

Columnar shape crown for east / west side

41

Author

5.11

Large and tall trees should not be used

42

Author

5.12

Shading eff. 15%

42

Author

5.13

Combination of shrubs and trees

42

Author

5.14

6m green ground cover stretch

43

Author

5.15

Evergreen trees to placed at east / west

43

Author

5.16

Site plan with 1:1 density ratio

44

Author

5.17

Wind flowing through the courtyard

44

Author

5.18

Warm air converted to cooler air due to evapotranspiration

44

Author

5.19

Trees as wind screen

45

Author

5.4

xi

CHAPTER 1

INTRODUCTION 1.1 Background of the study 1.2 Criteria of selection 1.3 Hypothesis 1.4 Aim 1.5 Objectives 1.6 Scope 1.7 Methodology

Passive cooling through plants

1.1 BACKGROUND Energy costs and environmental concerns have made it more important than ever to find ways to reduce energy consumption. As a developing nation the consumption of energy will continue to increase and it is important to improve the energy efficiency of our built environment. This will greatly benefit the environment, the owners and users of buildings. There are many ways to improve the energy efficiency of the built environment in which the passive ways works the best.

Passive technologies, with respect to building orientation, fenestrations , roof insulation, evaporative cooling, natural ventilation have a major role in producing a comfortable thermal temperatures. Passive cooling could be best achieved through on-site sources such as the surrounding environment and vegetation to control of space cooling and space heating.

1.1 : Graph showing total final energy consumption in institutional buildings, 2000-2018 X-axis - Year ; Y-axis - Percentage

Above graph 1.1 showing the energy consumption for various purposes in an institutional building, where the results clearly states that the major consumption is for the purpose of space heating. Problem such as space heating which contributes to the environmental imbalance and discomfort for people can easily and effectively solved by a strategic vegetation plantation for the buildings.

The potential of remodeling campuses of educational institutions to deliver on sustainability is gigantic . As of 2013, India has 45 central universities, 318 state universities, 185 state private universities, 129 deemed to be universities, 55 autonomous institutes of national importance, and 37,204 registered colleges. To illustrate, this translates, in terms of energy, into the emission of 231 million tonnes of equivalent carbon dioxide (eCO2) per annum approximately.

If surrounding designed and managed well with basic plantation strategies for effective cooling, these campuses can show how even a city can operate within the bounds imposed by finite land, water, and energy resources, material, green spaces, and biodiversity, and also reduce energy consumption.

1

Passive cooling through plants

1.2 CRITERIA OF SELECTION Improved living standards and the increased population in developing countries contribute to a drastic increase in energy consumption in India. An increase in the urban population by 1% has been reported to increase energy consumption by 2.2%.

An annual energy consumption increase of 30% by the year 2020 was predicted by the International Energy Agency in 2008. A study demonstrated that the anticipated increase in building energy consumption was mainly because of the use of airconditioning, where it has become a necessity. Landscaping and plantation cannot totally stop the use of HVACs but strategically placement of plants can eventually lead to less or a reduced energy consumption through HVAC. The above mentioned text can be illustrated by fig. 1.3 and fig. 1.3 where two different ways of achieving comfort conditions inside a building can be witnessed creating a wide difference in energy consumptions.

1.2 : Cooling through air conditioners

1.3 : Cooling through plants

Energy consumption can be reduced by two techniques—conservation and efficiency measures taken at an initial state. Energy conservation refers to reducing of energy consumption by using less of an energy service. Efficient-energy use refers to using less energy for a constant service. It involves a smart approach in the buildings for natural sunlight, ventilation and maintaining the ideal room temperature. Conducting an energy audit is the first step towards identifying opportunities to reduce energy and related costs.

1.4 : Graph showing Energy supply in institutional buildings (India – 1990 - 2018)

2

Passive cooling through plants

1.5 : Graph showing Energy consumption in institutional buildings (India – 1990 - 2018)

Graphs displayed above speak about the energy supply and consumption in institutional buildings of India from the year 1990 - 2018. Interpretations can be made that both the data are on a constant increment which implies that an action is to be taken to reduce the energy consumption at an initial stage.

Energy efficiency use : The consumption of electricity includes the application of lighting, electrical appliances, machinery, and air conditioning systems, which are now widely used.

The role of air conditioning systems in composite and hot and dry climates is using the energy for cooling as well as for heating.

Growth in the use of air conditioning has increased in institutional buildings in India from 13251 units in 1970 to 253399 in 1991. This figure is predicted to reach about 1511276 in the year 2020.

Maximizing shade, channeling wind and evapotranspiration from vegetation potentially could significantly contribute to cooling the built-up and therefore saving energy. If vegetation is planted in sufficient amounts and strategic locations around areas, it will reduce heat gain to a building, but also produce evapotranspiration, thus reducing the temperature at the micro-climatic scales.

1.3 RESEARCH QUESTIONS 1. What are the form of energies which affects the building and how?

2. What is passive cooling and how can it be achieved through plants?

3. How much energy can be saved through strategic plantation in and around a building?

1.4 HYPOTHESIS A systematic placement of plants around the buildings can yield substantial savings in energy consumption and result in passive cooling.

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Passive cooling through plants

1.5 AIM To study the different types plantation patterns and techniques which helps in achieving passive cooling in a built structure.

1.6 OBJECTIVES 1. To study the conditions required for introducing passive cooling in a built form.

2. To study the effective plantation patterns and techniques for reducing heat gain and enhancing heat loss in a building.

3. To analyze and compare the amount of efficiency plants can provide for passive cooling in the buildings with quantitative data.

1.7 SCOPE AND LIMITATIONS 1. The scope of the study is limited to the incorporation of passive cooling only through plants and no other techniques.

2. The study will focus on passive cooling techniques in composite and hot and dry climatic zones.

3. The study will focus on institutional buildings of height limited to a range of 10-12m.

1.8 METHODOLOGY S.No .

1.

2.

3.

Objectives

Data Required

-To study the conditions required for introducing passive cooling in a built form.

-Energy transfer pattern, climate, impact of passive cooling on buildings, insulation techniques.

- landscaping pattern, function of plants with respect to thermal comfort.

Secondary sources: Research papers, books, internet, journals.

- Designs which use landscape for passive architecture and their performance.

Secondary sources: Case studies and works of landscape architects like Ravindra Bhan, Geoffery Bawa, Prabhakar Bhagwat Website - NZEB, GRIHA, IGBC. Primary sources: Interviews

-To study the effective plantation patterns and techniques for reducing heat gain and enhancing heat loss in a building.

- To analyse and compare the amount of efficiency plants can provide for passive cooling in the buildings with quantitative data.

Source

- Combining obtained data for analysis and comparison.

- Quantitative data and graphical analysis.

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CHAPTER 2

THERMAL PARAMETERS 2.1 Climate 2.2 Energy transmission 2.2.1 Convection 2.2.2 Conduction 2.2.3 Radiation 2.2.4 Evapotranspiration 2.3 Thermal comfort parameters

Passive cooling through plants

2.1 CLIMATE Passive cooling design thoroughly counts in the climatic and thermal conditions of a distinct area where a passive building is to be constructed. The description of climate includes statistics and the averages, such as the day to day or year to year variations.

The study will be focusing on two major climatic zones that are – composite and hot and dry. These climate zone are responsible for the selection of vegetation distribution combined with average annual and monthly temperatures, and the seasonality of precipitation. Building orientation and placement of plants greatly depends upon the climatic zone which influence the sun path and wind directions.

Both the climates mentioned above need heating and cooling to maintain thermal comfort in the indoor temperature, due to extreme summers and extreme winters seasons.

2.1 : Jaipur, India, Sun path and seasons graph

Thermal parameters of a region depends upon the sun path and eventually the tilt of the earth. Parameters such as sun direction, wind direction, wind speed, solar radiations, relative humidity greatly affect the thermal zone. To move forward with the passive designs with respect to a particular climatic region above mentioned parameters should be studies properly and incorporate in the designs.

2.2 ENERGY TRANSMISSION AND THERMAL COMFORT PARAMETERS Local climate effects the rate of heat gain from buildings by contributing to heat flows throughout our environment also called as sensible heat flow. There are three ways that heat can be transmitted through any medium: conduction, convection and radiation.

Heat flows through the materials or building fabric from which a house is built. The primary heat transfer paths between a building and the external environment are: conduction through walls, roofs, doors, and windows (glazed); solar radiation directly penetrating through windows; and sensible and latent heat gain from air exchange.

6

Passive cooling through plants

2.2 : Illustration showing the thermal energy transfer from outdoor to indoor

2.2.1 Conduction Heat flows through the materials or building fabric from which a house is built.

The primary heat transfer paths between a building and therefore the external environment are- conduction through walls, roofs, doors, and windows (glazed); radiation directly penetrating through windows; and sensible and latent heat gain from air exchange. Cooling occurs when the heat is removed from the source and transferred by molecular conduction to another location.

Insulation retards the transfer of heat by conduction. Insulation can be accomplished by interposing a the substance of low conductivity between the source of heat and cooler zones.

2.3 : Illustration showing conduction effect through a lattice attached directly to the wall.

Plants directly attached to a surface which is most vulnerable to gain heat through conduction, breaks the incident radiation, reduce conductivity of the surface and hence increases cooling effect.

7

Passive cooling through plants

2.2.2 Convection Convection is caused by temperature difference or forced air motion generated by wind or fans. Convective heat transfer takes place when the building is infiltrated by wall surfaces, when the outdoor air flows through the interior space. If the ambient temperature is different from the temperature of any element of the interior space, convective heat transfer takes place. Energy dissipated through convection varies with shape and size: lobed leaves are more efficient in dissipating energy than entire leaves; small, narrow leaves are more efficient than large, broad leaves.

2.4 : Illustration showing convection effect by trees

Placement of trees near the building screen the hot and cold winds and creates leeward sides and windward sides. Air movement also cools buildings by carrying heat out of the building as warmed air and replacing it with cooler external air. Large trees help to difficile warm winds during summers and cold winds during winters, which helps in controlling and balancing the internal temperatures.

2.2.3 Radiation and Evapotranspiration Evaporation of perspiration is the most effective physiological cooling process. It requires air movement and moderate to low humidity (less than 60%). Evaporation is the transformation of a liquid to a gas. Thus evaporation has a cooling effect. The rate of evaporation depends upon: Water available at the surface - The degree to which that surface is heated - The humidity of the overlying air 8

Passive cooling through plants

- Air motion Roughly half of the energy absorbed by a tree is used for evapotranspiration. Most of the rest is lost by radiation and convection. Only a very small amount is stored in the plant.

Evaporation is therefore an effective passive cooling method, although it works best when relative humidity is lower (70% or less during hottest periods) as the air has a greater capacity to take up water vapour. Rates of evaporation are increased by air movement.

2.5 : Illustration showing evapotranspiration by trees and how they make the environment cooler.

Radiation impinging on an opaque surface is reflected or absorbed. Radiant heat loss is also important, both physiologically and psychologically. It involves direct radiation to cooler surfaces. Radiation and absorption of heat and light depends upon the texture of the surface from which the light gets radiated. A soft, smooth or a polished surface radiates of reflects more heat than a rough or an irregular one, therefore a surface carpeted with ground covers such as grass, hedges, shrubs etc radiates less heat and absorb more, resulting in effective cooling.

2.6 : Illustration showing reflection, transmission, and absorption of surfaces.

9

Passive cooling through plants

2.3 THERMAL COMFORT PARAMETERS Thermal comfort is defined as the condition of mind which expresses satisfaction with the thermal environment. Thermal comfort concerns the interior temperature of rooms, including maintaining and distributing it evenly, and air quality.

Factors affecting comfort for people (human thermal comfort) are outlined in Design for climate and include both physiological and psychological factors.

To be effective, passive cooling needs to cool both the building and the people in it.

The thermal sensation is linked to the intensity of solar radiation, orientation of windows, and surface reflectance from the walls. The aim in buildings, with regard to thermal comfort conditions, is to achieve internal thermal neutrality for the occupants and assure their comfort, using minimal power consumption for heating and cooling.

Although considerations relating to thermal comfort in building design are mostly for indoor climate, the outdoor climate should be taken into consideration to achieve the occupants’ comfort and reduce energy consumption.

2.7 : Illustration showing thermal comfort.

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CHAPTER 3

PLANTS FOR PASSIVE COOLING 3.1 Background 3.2. Case study 1: Manipal University, Jaipur, Rajasthan.

3.2.1 Effect of Shading of plants 3.2.2 Wind reduction and channeling 3.2.3 Evapotranspiration 3.2.4 Radiation 3.3. Case study 2: Nalanda University, Rajgir,Bihar.

3.3.1 Effect of Shading of plants 3.3.2 Wind reduction and channeling 3.3.3 Evapotranspiration 3.3.4 Radiation

Passive cooling through plants

3.1. BACKGROUND Thermal energies, the energy transfer and their movement, exists in the nature. These energies are very much responsible for the process of heat gains and the heat loss in buildings. Vegetation affects building energy use directly by modifying the thermal interaction between a building and its surrounding environment.

Design objectives are organized by energy transfer processes: • Prevent Heat Gain Through Convection • Encourage Heat Loss Through Convection • Prevent Heat Gain Through Conduction • Encourage Heat Loss Through Conduction Two case studies having different climatic zones have been selected and studied observe how the placement,profile,heights and other parameters of plants affect the building.

3.2. MANIPAL UNIVERSITY, JAIPUR, RAJASTHAN. Location : Dehmi Kalan, Jaipur Site Area : 20 Acres (Total 66 Acres) Built up Area : Academic Block – 35,668.6 m Principal Architect - Sundaram Architects Landscape Architects - Master plan Landscape Architects Green Building Design Certification - Terra Viridis Environmental Design Consultancy 3.1 : Manipal University, Jaipur, Rajasthan.

Manipal University was completed in the year 2014 in October. The Academic and Administrative buildings of Manipal University Jaipur (MUJ) have been awarded a 5-star rating by GRIHA (Green Rating for Integrated Habitat Assessment).Manipal University is the first university in India

3.2 : Proposed campus plan

3.3 : Existing campus plan

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Passive cooling through plants

Proposed blocks

Existing building blocks - 20 Acres

Area with plantations - 10 Acres approx 50% of site area

3.4 : Campus plan with green area

3.5 : Manipal University Campus view

Manipal campus has a average of 50% green density around the building blocks. The existing campus consist of four major blocks that are, Administration block, academic block A, academic block B, and a Dinning hall. All the four blocks are efficiently covered from the surround with dense layers of trees, shrubs and ground cover.

BLOCKS

BUILT UP AREA

AIR CONDITIONED AREA

NON AIR CONDITIONED AREA

Admin Block

2,11,131 sqm

10,060 sqm

11,053.1 sqm

Academic Block

35,668.6 sqm 17,764.6 sqm 3.6 : Table: Energy consumption of existing blocks.

18,904 sqm

A separate thermal simulation study is done for the academic block A, as the block has been approved by IGBC rules and regulations. The academic block is studies carefully keeping in mind the surrounding plantation patterns. Energy consumption reduction observed from table 2.4 • Admin block consumes 81.5% less energy.

• Academic block consumes 72.9% less energy (occupancy - 1000/day) • Campus 76.14% less energy consumption.

(Source : GRIHA)

3.7 : Academic block view

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Passive cooling through plants

3.8 : Academic block plan with surrounding plantations

Academic block is surrounded by a green stretch of trees, shrubs and ground covers from all four sides. A canteen area which has a semi-open space divides the courtyard into two parts. Both the courtyards are covered with green grass patches and consist of small heighted trees.

3.2.1 Effect of Shading of plants Palm trees and large heighted sheesham trees shading the

pavements or the streets to help students and faculty move in a cooler zone.

3.9 : Shading on pavements

14

Passive cooling through plants

Date Palm Trees used on south direction, at the very exterior part of the green stretch. A series of date palm trees heighted 3m placed at a distance of 6m centre to centre for multiple shading on the pavements as well as the front facade.

3.10 : Date palm trees used for shading in south.

3.11 : Bamboo trees used to shade the staircase shaft

Bamboo trees were used to shade the semi-open staircase shaft and the exterior facades. Bamboo being thin and tall trees provides shade and even allow fresh air to pass through them.

3.12 : Badam trees used to shade exterior facade.

Badam trees (Terminalia catappa) were used to shade east facade.

Badam trees are of nearly with round shaped foliage and contains large, dark colored leaves.

15

Passive cooling through plants

3.2.2 Wind reduction and channeling

3.13 : Sheesham trees used for wind channeling.

Large trees such as sheesham are planted at the edge of the road to protect the building from direct warm winds in summers and cold winds in the winters. These trees also protects the building from harsh thunder storms. Sheesham trees attaining maximum height of 18m were places at a distance of 5m centre to centre.

3.2.3 Evapotranspiration

3.14 : Curry tree (Murraya koenigii) planted in the courtyard for cooling through evapotranspiration

Curry trees and small green grass patches were planted in the courtyard area and around the canteen area. Curry trees heighted 2.5m and consist of small sized leaves which help in evapotranspiration.

3.2.4. Radiation and absorption

3.15 : Ground covers for reflecting less heat radiation and absorbing more heat radiation.

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Passive cooling through plants

Block radiation reflected by adjacent ground and walls through - planted berm wall, Tree Screen, Freestanding Planter Screen, Vine-covered cables, sliding Wall Planter, Hinged Planter Screen, Plant Floor, Unit Paver in Grass, Grass Pavement, Shade Court/ Sun Pocket.

Encourage emission of heat stored by adjacent ground and walls to heat sinks.

3.3. NALANDA UNIVERSITY, RAJGIR, BIHAR. 55-acre campus 7000 population Three primary land-use elements : 1.Academic Facilities 2.student housing 3.advanced agriculture The design integrates sustainable practices at every phase of the project from site planning of the campus through the creation of infrastructure, cost-effective ways to both reduce consumption of natural resources and minimize the dependency of onsite building materials the site planning allows incremental growth while preserving the agricultural and environmental basis of the region.

The whole idea of planning itself demonstrates the integration of the campus into a large ecosystem of the site. The planning AIMS to create a carbon-neutral and zerowaste campus.

3.16 : Nalanda University campus plan.

3.17 : Nalanda University campus plan, showing density of plantations.

Nalanda University campus has plantation area more than the built up areas. As the University is situated near a farm land so a major part of the campus also involves plantations with farm lands as well.

3.18. : Nalanda University site section, showing density of plantations with respect to the built up.

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Passive cooling through plants

3.3.1 Effect of Shading of plants

3.19 : Site level shading through trees, Nalanda University.

Ideas include schooling as well as cleaning of air through the use of selected native plants and Lowered micro-climate around the water bodies.

The plan includes ecological integration with the natural setting, diversity of land uses, and permeability through the site, tens and compact character of the built form, visual cohesiveness, and Scaled compatibility with the surrounding land subdivisions.

Shade keeps the soil around the building cool, which can then act as a “heat sink”.

3.3.2. Wind reduction and channeling

3.20 : Wind reduction and channeling, Nalanda University.

The campus grid is angled to maximize the cooling breezes of the lake. the plan allows for the infrastructure implementations in phases.

More than 75% of the land is open made up of the campus reserves and landscaped public spaces. Trees have also been used to run turbines and generate electricity.

Larger trees direct the strong winds upwards the windmills. Windbreaks are taller than adjacent plants and are usually formed by only one or two rows of trees.

3.3.3 Evapotranspiration Ground cover such as grasses or turf, also have a cooling effect from evapotranspiration.

The temperature directly above ground cover plants can be 5.6 to 8.3°C cooler than above a heat absorbent material.

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Passive cooling through plants

3.21 : Evapotranspiration through plants used in parking zones and street scapes

3.3.4. Radiation and absorption

2.22 : Radiation and absorption

Block radiation reflected by adjacent ground and walls through - planted berm wall, Tree Screen, Freestanding Planter Screen, Vine-covered cables, sliding Wall Planter, Hinged Planter Screen, Plant Floor, Unit Paver in Grass, Grass Pavement, Shade Court/ Sun Pocket.

Encourage emission of heat stored by adjacent ground and walls to heat sinks.

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CHAPTER 4

ANALYSIS AND ENERGY SIMULATIONS 4.1. Analysis of the case studies as a whole.

4.1.1. Hot and Dry climate 4.1.2. Composite climate 4.2. Analysis based on design applications 4.2.1. Orientation 4.2.2. Density 4.2.3. Height and width/spread 4.2.4. Multiple shading/ centre to centre distances 4.2.5. Shape of trees and shrubs 4.2.6. Types of plants

Passive cooling through plants

4.1 ANALYSIS OF THE CASE STUDIES AS A WHOLE. Passively cooling a building placed on the site or a campus, needs a large scale management and thermal calculations. The internal temperatures or the thermal comfort range cannot be decided without the data interpolation of the exterior climate. Thermal comfort can be managed by balancing factors such as the internal temperatures, relative humidity, public occupancies, type of the building, scale of the building, with respect to the exterior climatic zone .

A whole building analysis or simulation is necessary to receive the above mentioned data and calculate the effective results. For the purpose research the whole building simulations are carried out on simulation software - Design Builder. Design Builder helps to determine the thermal simulations of the whole building by comparing the base case with the proposed case. The software needs the inputs such as Building location to identify climate zone, type of the building and scale of the building to associate the data with the occupancy or no. Of people inside the building.

The statistics obtained from the whole building simulation are achieved by simulating plantation and vegetation components with the building and recording its shading efficiency on the facades by the tress.

4.1.1. Hot and Dry climate CASE 1 Calculating Thermal simulations of the academic building block separately.

1. Simulation data without plantations.

2. Comparison of data of energy consumption reduction in the building due to plantations with various other passive techniques such as wall thickness, WWR, etc. of the existing state of the building. (Academic block)

4.1 : CASE 1 : Building without plantations around. Academic Block , Manipal University, Jaipur.

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Passive cooling through plants

Calculating the building block separately without the existing and proposed plantation will provide a base data to compare the other simulations.

Manipal University is a GRIHA 5 star rated campus which incorporates plantations for making it a passively cooled building.

The simulation are recorded on design builder software which works and follows the weather data and standards of ECBC codes and also ASHRAE 90.1. the interpreted carries the u-values, SHGC, transmittance values of plantations situated around the building. All the resulted data is compared with the weather data to the site. Fig consist of the general site simulation data which detail out the relative temperatures, dry bulb temperature, solar radiations, reflections, wind direction and wind movement of the site.

4.2 : Site weather data of Manipal University , Jaipur.

CASE 2 Calculating Thermal simulations of the building block with existing plantations CASE 2 - Comparison of the data on the basis of- Distance of tree from building.

- Area covered by ground covers 22

Passive cooling through plants

- Height of the tree - Precipitation value to the plant - Orientation of the building with respect to trees.

4.3 : CASE 2 : Building with existing plantations. Academic Block , Manipal University, Jaipur.

Thermal simulation data obtained is through the above mention data inputs such as height of plants, area in which the plantation is spread, transmittance value of the tress etc. Plantations near the academic block consist of various types of plants which solves various purposes.

Changes in the simulation data of case 2 when compared with case1 will sharply depend upon shading surfaces due to tress and also screening of the air flow.

Trees help in screening of deviating the hot air during summers and cool air during winters, hence providing a comfortable climate.

CASE 3 Calculating Thermal simulations of the building block with existing plantations and additional plantations.

CASE 3 Parameters - Adding and altering green zones, on the existing building block. Increasing the green stretch on the front of the building, adding green facades etc. and comparing the data with the existing ones.

Comparison of the data on the basis of• Solar shading • Cooling • Thermal comfort analysis • Wind screening

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Passive cooling through plants

4.4 : CASE 3 : Building with existing and additional plantations. Academic Block , Manipal University, Jaipur.

Plantation added for case 3 are a part of the building or which are attached to the built block to gather the data for maximum potential of plants for passive cooling.

The additional parts include the green roofs on the building, planter walls, window planters, berm walls etc.

Major parts of plants have direct cooling affect on the surfaces as they are directly attached to the facades and the roofs. The data and readings acquired from case 3 will only state the maximum potential of the plantation when the practice is used to the fullest and will be useful to compare the basic standard needed for a green building (i.e case 2).

ANALYSIS OF WHOLE BUILDING SIMULATION FOR HOT AND DRY CLIMATE: Three different cases have been simulated on an annual data basis. Major temperature variations in summer and winter solstices have been recorded and compared further in graph 1. The simulated data recorded have been shown in the table bellow (table 4.5). Three different cases have been compared in the bases of three categories that are 1. Internal Temperature 2. Relative Humidity 3. Latent load Latent load will be dependent upon the internal temperature and humidity and comparing the latent load of the cases will instinctively give the energy consumption.

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4.5 : Simulated data of all three cases on the basis of internal temperature, relative humidity and latent load.

CASE STUDY 1 - ACADEMIC BLOCK , MANIPAL UNIVERSITY , JAIPUR

Passive cooling through plants

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Passive cooling through plants

Graph 1: Summer solstice for hot and dry climatic zone comparing the cases.

Graph 2 : Winter solstice for hot and dry climatic zone comparing the cases.

Above obtained graphical data represents the period of summer solstice and winter solstice of hot and dry climatic zones. Comparing the three cases with respect to internal temperature, relative humidity and latent load on the electric consumption.

Inferences from the graph – SUMMER SOLSTICE 1. Internal Temperature – temperature decreases from 40°C in case 1 to 25°C in case 3 2. Relative humidity - relative humidity has a little increase variation from case 1 to case 3.

3. Latent Load – Major variations can be seen in latent load with a decrement in latent load from case 1 to case3 26

Passive cooling through plants

WINTER SOLSTICE 1. Internal Temperature – temperature slightly increases from 22°C in case 1 to 27°C in case 3 2. Relative humidity - increase in relative humidity is observed from case1 to case3 3. Latent Load – slight increase in the latent load is observed. Latent is constant for case 2 and case 3.

4.1.2. Composite climate CASE 1 Calculating Thermal simulations of the academic building block separately.

1. Simulation data without plantations.

2. Comparison of data of energy consumption reduction in the building due to plantations with various other passive techniques such as wall thickness, WWR, etc of the existing state of the building.

4.6 : CASE 1 : Building without plantations. Nalanda University.

Calculating the building block separately without the existing and proposed plantation will provide a base data to compare the other simulations.

Manipal University is a GRIHA 5 star rated campus which incorporates plantations for making it a passively cooled building.

CASE 2 Calculating Thermal simulations of the building block with existing plantations CASE 2 - Comparison of the data on the basis of- Distance of tree from building.

- Area covered by ground covers - Height of the tree - Precipitation value to the plant 27

Passive cooling through plants

- Orientation of the building with respect to trees.

4.7 : CASE 2 : Building with existing plantations Nalanda University.

Thermal simulation data obtained is through the above mention data inputs such as height of plants, area in which the plantation is spread, transmittance value of the tress etc. Plantations near the academic block consist of various types of plants which solves various purposes.

CASE 3 Calculating Thermal simulations of the building block with existing plantations and additional plantations.

CASE 3 Parameters - Adding and altering green zones, on the existing building block. Increasing the green stretch on the front of the building, adding green facades etc. and comparing the data with the existing ones.

Comparison of the data on the basis of• Solar shading • Cooling • Thermal comfort analysis • Wind screening

4.8 : CASE 2 : Building with existing and additional plantations, Nalanda University.

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4.9 : Simulated data of all three cases on the basis of internal temperature, relative humidity and latent load.

CASE STUDY 2 - NALANDA UNIVERSITY , BIHAR

Passive cooling through plants

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Passive cooling through plants

Graph 3 : Summer solstice for composite climatic zone comparing the cases.

Graph 4 : Winter solstice for composite climatic zone comparing the cases.

Above obtained graphical data represents the period of summer solstice and winter solstice of hot and dry climatic zones. Comparing the three cases with respect to internal temperature, relative humidity and latent load on the electric consumption.

Inferences from the graph – SUMMER SOLSTICE 1. Internal Temperature – temperature slightly decreases from 28°C in case 1 to 22°C in case 3.

2. Relative humidity - relative humidity has a little increase variation from case 1 to case 3. 15% raise in humidity level could be observed.

3. Latent Load – Major variations can be seen in latent load with a decrement in latent load from case 1 to case3. 36% decrement in latent load from case 1 to case 30

Passive cooling through plants

2 is observed. And 15% decrement from case 2 to case3 .

WINTER SOLSTICE 1. Internal Temperature – temperature slightly increases from 18°C in case 1 to 22°C in case 3.

2. Relative humidity - increase in relative humidity is observed from case1 to case 3, whereas case 2 and case 3 remains constant.

3. Latent Load – slight increase in the latent load is observed. Latent is constant for case 2 and case 3.

4.2. ANALYSIS BASED ON DESIGN APPLICATIONS Following analysis are based on design application which means strategic usage of plants or trees in design with respect to its shading efficiency, humidification, and radiations. The analysis will be considered only for a building of maximum 3 floors or 10m heighted structure.

4.2.1. Orientation Experiments on orientation are done using a specific 15m heighted tree in all the cardinal directions placed at 5m distance from the facade wall or the exterior wall.

The calculations will depend upon the percentage to shade falling on the building.

The data is recorded for peak summer months that are - May , June, July, August and September.

4.10 : North

4.12 : East / West

4.11 : South

4.13 : South-west / South-east

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Passive cooling through plants

4.2.2. DENSITY Density of the plantation on the site with respect to the built up area. Latent load is dependent on the density of the vegetation planted around the site. Density would be considered while planning on a large scale level as in a campus or large site planning.

BUILT UP : PLANTATION - 2:1 LATENT LOAD - 80%

4.14 : Site plan with 2:1 density ratio

BUILT UP : PLANTATION - 1:1 LATENT LOAD - 55%

4.15 : Site plan with 1:1 density ratio

BUILT UP : PLANTATION - 1:2 LATENT LOAD - 30%

4.16 : Site plan with 1:2 density ratio

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Passive cooling through plants

4.2.3. HEIGHT AND WIDTH/SPREAD Height and width of trees and shrubs with respect to the building plays a major role in shading and cooling for the effect of height of trees on the building the distance of plants from the building is takes 5m (constant) and the internal temperature is constant at 28°C. Different height of trees of 15m, 12m, and 5m are taken for two different cases south and east/west facing walls.

HEIGHT

SOUTH

EAST / WEST

15 M

4.17: SHADING EFFICIENCY - 87% INTERNAL TEMPERATURE - 22 °C

4.20 : SHADING EFFICIENCY - 20% INTERNAL TEMPERATURE - 26 °C

4.18 : SHADING EFFICIENCY - 88% INTERNAL TEMPERATURE - 22 °C

4.21 : SHADING EFFICIENCY - 50% INTERNAL TEMPERATURE - 24 °C

4.19 : SHADING EFFICIENCY - 10% INTERNAL TEMPERATURE - 28 °C

4.22 : SHADING EFFICIENCY - 15% INTERNAL TEMPERATURE - 28 °C

12 M

2M

4.23: Table : Height and width

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Passive cooling through plants

4.2.4. SHAPE OF TREES AND SHRUBS

SHAPE

SHADING EFFICIENCY - SOUTH

SHADING EFFICIENCY - EAST / WEST

88 %

20%

76%

86%

20%

70%

25%

65%

55%

55%

4.23: Table : Shape of trees and shrubs

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Passive cooling through plants

4.2.5. MULTIPLE SHADING/ CENTRE TO CENTRE DISTANCES

4.24: 12m Heighted - @ 16m c/c

4.25: 12m Heighted - @ 10m c/c

4.26: 12m Heighted - @ 6m c/c

Shading a longer facade involves multiple trees for multiple shading. Simulations to record accurate centre to centre distances of trees of a particular height have been carried out to calculate the maximum shading efficiency. 12m heighted tree were kept at various distances 6m, 10m and 16m centre to centre.

4.27: 15m Heighted - @ 20m c/c

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Passive cooling through plants

4.28: 15m Heighted - @ 16m c/c

4.29: 15m Heighted - @ 10m c/c

Shading a longer facade involves multiple trees for multiple shading. Simulations to record accurate centre to centre distances of trees of a particular height have been carried out to calculate the maximum shading efficiency. 15m heighted tree were kept at various distances 10m, 16m and 20m centre to centre.

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CHAPTER 5

CONCLUSION AND RECOMMENDATIONS 5.1. Conclusion 5.2. Recommendations 5.2.1. North 5.2.2. South 5.2.3. East / West 5.2.4. Generic - Application based

Passive cooling through plants

5.1. CONCLUSION According to the observations made from the above analysis done through simulation process, the following observations are: • Plants have a cooling effect on the built environment.

• Buildings with the incorporation of plantation in its surrounding have more energy savings the one without.

• Plantations can reduce approximately half or more latent load of the building.

Summer solstice 1. Plants have a major role to play during summer seasons in hot and dry climate.

50% reduction in the internal temperature were recorded.

2. Plants also help to increase the rate of relative humidity inside a building. Therefore reducing the latent load simultaneously.

3.

Winter solstice 1. Plantations around a building does not have a major effect on the building during winter seasons.

2. A minimum difference of 3-5°C is recorded between the exterior and interior temperatures.

3. Plantations only benefit when deciduous trees are used.

• Orientation has the significant role to play. Placing large trees on the south has good effect on shading, whereas a same condition in north does not apply.

Orienting trees in east/west directions provides shading from harsh sun.

• Quality shading is also hugely dependent upon the height and width of the tree or shrub.

• Shape of the tree - oval shaped trees works best for east /west shading

5.2. RECOMMENDATIONS As per the understanding of whole building simulations and some application based analysis done before in the study, few do’s and dont’s can be drawn.

These recommendations are ideas and suggestions that can be modified by a slight change if required.

5.2.1. North

• Northern side of the building doesn’t receive any kind of direct sunlight during major time of the year, therefore planting taller tree does not have any effect on the shading efficiency of the facade.

• 8m heighted trees works best for this direction .

• Air movement plays a vital role for cooling purpose than shading.

• Shrubs of height 1.5 - 3m should be used to cool the lower floors of the building as well as to keep the perimeter cooler.

• Passive cooling in the north side can be gained by foreground cooling .

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Passive cooling through plants

5.1: Larger trees placed on north side - having no effect in further cooling

5.2: Small shrubs placed on north side cooling effect through air movement and evapotranspiration.

5.2.2. South • Large heighted trees of 15m at a distance of 5m from the centerline of the facade, should be placed.

5.3 : SHADING EFFICIENCY - 87% INTERNAL TEMPERATURE - 22 °C

• Round shaped trees with large spreading crown to be used. Palm trees (umbrella shaped) works best for south shading.

5.4 : Round top for shading

5.5 : Palm trees top for shading

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Passive cooling through plants

• Centre to centre distances to be maintained for multiple shading , with respect to a height of the tree.

- 15m heighted tree - 16m c/c - 10m heighted tree - 10m c/c - 8m heighted tree - 6m c/c • A minimum 15m stretch of the ground cover to be used in front of the south facade.

Ground covers such as grass, hedges, moss, creepers etc provides an absorbent quality to a particular stretch of the ground which helps control heat radiation by absorbing and radiating them.

5.6 : 15 m Green ground cover stretch

• Planting shrubs or short heighted trees on south side does not have much effect on shading efficiency. Small shrub should be combined with a large tree for best shading.

5.7 : SHADING EFFICIENCY - 10% INTERNAL TEMPERATURE - 28 °C

• Deciduous trees such Terminalia arjuna (arjuna), Sal tree, gulmohar, neem, should be planted on this side. Deciduous trees shed their leaves during winters , providing shade in summers and scattered sunlight in winters.

5.8 : Deciduous trees for winter sunlight

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Passive cooling through plants

5.2.3. EAST / WEST • Lower heighted trees heighted 10m - 12m at a distance more than 4m from the centerline of the east / west facade, should be used. A lower heighted tree or a tree where the crown is closer to the ground to be used.

5.9 : SHADING EFFICIENCY - 50% INTERNAL TEMPERATURE - 24 °C

• Oval or columnar shaped trees with large crown to be used.

5.10 :Columnar shape crown for east / west sides

• Centre to centre distances to be maintained for multiple shading , with respect to a height of the tree.

- 18m heighted tree - 10m c/c - 12m heighted tree - 8m c/c - 8m heighted tree - 8m c/c - 5m heighted shrub - 5m c/c • Large round shaped trees or trees with crown at a large height are not precise to be planted in east / west directions, as this would not help to stop the straight and incident sunlight.

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Passive cooling through plants

5.11 :Large and tall trees should not be used in east / west directions for shading purpose.

• Shrubs of height 5m or a low ground foliage can be planted for cooling the lower ground floors.

5.12 : SHADING EFFICIENCY - 15% INTERNAL TEMPERATURE - 28 °C

• Shorter trees with round shaped crowns should be planted with shrubs in addition to climbers for best shading option.

5.13 :Combination of shrubs and round trees for shading.

• A minimum stretch of 6m ground cover to be used which also act as a heat sink .East / west side does not have slanting rays like south.

The late afternoon sun rays are straight and can travel to an infinite distance. Therefore a ground cover of minimum 6m would be sufficient considering the angle of the sun rays.

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Passive cooling through plants

5.14 :6 m Green ground cover stretch.

• Evergreen trees should be used on east / west sides of the building as this side of the building gets a constant heat gain throughout the year. Trees such as shesham,Chikoo, Sapodilla plum, peepal (semi-evergreen),babool,etc to be used.

5.15 :Evergreen trees on east / west sides.

5.2.3. Generic considerations- (Application based) Density • Density to be considered and calculated for a large scale area ex. Site planning or campus planning • Minimum built up to plantation ratio should be 1:1 i.e 50% • 50% of density insures approximately 50% less latent load.

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Passive cooling through plants

BUILT UP : PLANTATION - 1:1 LATENT LOAD - 55%

5.16 : Site plan with 1:1 density ratio

Dark colored leaves • Dark colored leaves act as good light absorber. Dark colored leaves should be used where less heat radiation a required.

Courtyards • Deciduous trees should be used.

• Trees with leaves of small size and which are in a large numbers should be used.

• Trees with small sized leaves have a good capacity to perform evapotranspiration, eventually humidifying the surrounding and providing better cooling.

5.17 : Wind gathering or flowing through the courtyard

5.18 : Warm air converted to cooler air due to evapotranspiration of trees.

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Passive cooling through plants

Trees as wind breakers Building adjacent to a wide open space should be covered and protected with one or two rows of large trees, for screening from the warm and hot winds of summers and cold winds of winters.

5.19 : Trees as wind screens or wind breakers.

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BIBLIOGRAPHY Books: • Rakuten Kobo, PLEA Conference, Bermuda, 1982 Passive and Low Energy Alternatives • John van Lengen, 2008, The Barefoot Architect, A Handbook for Green Building,Shelter Publications Bolinas,California,USA.

Articles and Research Papers: • Alamana Minshi, The effect of surrounding vegetation on thermal performance of building.

• Srikonda Ramesh, International Journal of Engineering and Technology, Vol. 8, No. 5, October 2016, Energy Efficient Landscape for Thermal Comfort in Buildings and Built-up Areas.

• International Journal of Scientific and Research Publications, Volume 3, Issue 8, August 2013, Prevalence of Landscaping as a Means of Passive Cooling in Hot Climates: a Case Study.

• Department of Energy (DOE) by the National Renewable Energy Laboratory (NREL), a DOE national laboratory, 1995, Landscaping for Energy Efficiency.

• Alamah Misni, 2016, Faculty of Architecture, Planning and Surveying, Strategically Designed of Landscaping around Houses Produce an Extensive Cooling Effect.

Magazines and Publication: • http://www.earthscapes.in/publications.html • https://www.landscapeindia.net/publications/columns-and-media#projectsfrom-the-studio-in-1995 • https://www.landscapeindia.net/publications/columns-and-media#a-journal-ofarchitecture-urban-design-and-planning • https://www.ravindrabhan.com/articles-interview

Web References: • • • • • •

https://nzeb.in/case-studies/nalanda-university/ https://igbc.in/igbc/redirectHtml.htm?redVal=showgreencapmusnosign https://www.landscapeindia.net/projects https://igbc.in/igbc/ https://www.grihaindia.org/case-study https://manipal.edu/mu.html

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GLOSSARY OF TERMS Passive cooling: Passive cooling is a building design approach that focuses on heat

gain control and heat dissipation in a building in order to improve the indoor thermal comfort with low or no energy consumption.

Latent Load: Latent cooling load is a measure of the amount of energy that is

necessary for cooling the interior air in a building, for example, regardless of the outdoor humidity.

Solstice: Either of the two times of the year at which the sun reaches its highest or

lowest point in the sky at midday, marked by the longest and shortest days. Where the temperatures are no their peak.

Evapotranspiration: The process by which water is transferred from the land to the

atmosphere by evaporation from the soil and other surfaces and by transpiration from plants.

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