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LANDSCAPING AND PASSIVE COOLING IN HOT-HUMID CLIMATES THE ROLE OF SOFT LANDSCAPE ELEMENTS IN PASS IVE COOLING OF BUILDINGS IN HOT HUMID CLIMATE

Dissertation submitted by Gayathry Mohan 113701032 Bachelor of Architecture, VII Semester ‘B’

Faculty Of Architecture Manipal Institute of Technology Manipal University November 2014

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FACULTY OF ARCHITECTURE MANIPAL UNIVERSITY CERTIFICATE We certify that the Dissertation entitled “ THE ROLE OF SOFT LANDSCAPE ELEMENTS IN PASSIVE COOLING OF BUILDINGS IN WARM HUMID CLIMATE”, that is being submitted by Gayathry Mohan, 113701032, in the VII semester of B.Architecture undergraduate programme, Faculty of Architecture, Manipal University, Manipal is a record of bonafide work, to the best of our knowledge.

-----------------------------Faculty in charge

----------------------Director 2

ACKNOWLEDGEMENT I would like to express my gratitude to my dissertation guide, Ms Richa Mahesh Kandpal, without whose sincere guidance, valuable suggestions and positive outlook I could not have completed this dissertation successfully.

I would also like to thank Mr K.S. Sherigar and Ms Mahima Thussu, my jury panel for their insightful comments and suggestions. Special thanks to Mrs Nandineni Ramadevi for her guidance and support.

Sincere thanks to Ms Nisha Karla Vaz of Stonewater Ecoresort, Goa and Mr Sumanth of Wild Woods Spa and Resort, Udupi for allowing me to do a case study of their resort premises and facilitating the obtaining of all the information I required for my dissertation.

Lastly I would like to express my heartfelt gratitude to my parents and friends for their constant encouragement and support.

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ABSTRACT Background: Achievement of thermal comfort is one of the most important facets of building design in any climatic condition. Depending on the location and season, emphasis is given to either cooling or heating of indoor and outdoor spaces by controlling the air temperature, humidity, air velocity and light intensity. In tropical climates thermal control is of paramount significance due to the disparity between the magnitudes of sources of overheating versus the availability of natural sources of cooling. Hot and humid climates present the additional challenge of regulating the humidity level in addition to thermal control to achieve thermal comfort within built environments. Mechanical systems such as air conditioning are accountable for almost half of the energy costs of a building. In recent years, such activities have been identified as the main contributors towards global climate change through emission of carbon di oxide and other greenhouse gases into the atmosphere. This has led to the increasing trend of using passive cooling systems which help in temperature management and subsequent reduction in the cooling load of buildings.

Historically too, builders had always recognized the usefulness of plants as structural materials and as landscape elements that offered shelter from the vagaries of nature such as sun, snow, wind and rain. Builders often used the natural vegetation to modify and improve the microclimate of the site.

Aim: This study aims to look into the various methods by which landscape features, besides serving merely aesthetic purposes, can be used for passive cooling of the built spaces.

Methods to conduct the study: The study mainly involves analyses of existing literature on the basic principles of passive cooling, role of landform, vegetation and water on thermal control and dissipation of humidity. It also studies how select soft landscape features such as green roofs, vines, vegetated facades and ponds, and roof ponds and can help in passive cooling, by looking into experiments conducted by other 4

researchers. Case studies of buildings with plenty of landscaping is conducted and thermal comfort surveys are carried out using questionnaires among a select user group of 15 people and analysed in context of the landscaping.

Inferences: This study shows us the various ways in which landscaping and passive cooling are closely linked to each other and gives knowledge on correct landscape practices can help in passive cooling of the built spaces and reduce the cooling load of buildings.

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TABLE OF CONTENTS CHAPTER 1 -Introduction 1.1 Background…………………………………………………………8 1.2 Relevance of the study…………………………………………….8 1.3 Aim……………………………………………………………………9 1.4 Objectives……………………………………………………………9 1.5 Research statements……………………………………………….9 1.6 Scope and Limitations…………………………………………..9-10 1.7 Methodology…………………………………………………….10-11 1.8 Outcome of the research………………………………………….11 CHAPTER 2 – Passive cooling 2.1 Introduction………………………………………………………….12 2.2 Passive cooling strategies……………………………………..12-14 CHAPTER 3 – Cooling Effect of Water 3.1 Introduction……………………………………………………...15-16 3.2 Landscape pond-secondary experimental study…………….16-17 CHAPTER 4 – Cooling Effect of Vegetation 4.0 Introduction………………………………………………………18-19 4.1 Wind control……………………………………………………..19-21 4.2 Solar Radiation control………………………………………...21-24 4.3 Cooling through evapotranspiration…………………………..25-26 CHAPTER 5 – Cooling effect of landforms 5.0 Introduction…………………………………………………………..27 5.1 Control of wind……………………………………………………….27 5.2 Control of Radiation…………………………………………………28 5.3 Control of Temperature…………………………………………….28 5.4 Improvement of other landscape features………………………..29

CHAPTER 6– Secondary study of experiments conducted on select landscape features 6

6.1 Vegetated facades……………………………………………..........30-31 6.2 Vegetated roofs……………………………………………………….32-33 6.3 Vines……………………………………………………………………33-35 CHAPTER 7 – Case study 1 7.1 Location…………………………………………………………………...36 7.2 Climate………………………………………………………………...36-37 7.3 Landscape features and their cooling effect………………….......37-38 7.4 Questionnaire and survey results…………………………………..40-41 7.5 Analysis and Conclusion…………………………………………………41 CHAPTER 8 – Case study 2 8.1 Location…………………………………………………………………...42 8.2 Climate…………………………………………………………………….42 8.3 Landscape features and their cooling effect………………………43-44 8.4 Questionnaire and survey results…………………………………..44-45 8.5 Analysis and Conclusion……………………………………………..45-46 CHAPTER 9 – Findings and Conclusion 9.1 Findings………………………………………………………………..46-47 9.2 Conclusion……………………………………………………………......47 BIBLIOGRAPHY……………………………………………………………...48 LIST OF FIGURES………………………………………………………..49-51 APPENDIX 1……………………………………………………………….52-53

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INTRODUCTION: 1.1.

BACKGROUND:

Due to its proximity to the equator, the hot-humid climate regions generally experience averagely a uniform temperature, high humidity, high intensity of solar radiation and low wind velocity all year round. Hot humid climates are sultry and slow changing. They are characterized by heavy, moisture-laden air that resists wide daily fluctuations in temperature. (Moffat & Schiler, 1981) There are two aspects to passive cooling in such climatic conditions. The first is temperature management through minimizing heat gain, heat storage, promoting heat dissipation. The second is the dissipation of humidity by promoting ventilation. Passive cooling covers all natural processes and techniques of heat dissipation and modulation without the use of energy.

In this paper we analyse the role of soft landscape elements namely landforms, vegetation and water on heat gain preventative techniques as well as modulation and heat dissipation techniques. The study focuses on the effect of vertical landscape features like vines, vegetated walls, green roofs and water features like landscape ponds on thermal control.

The impact of all the landscape features on passive cooling is studied with regard to the four main parameters of thermal comfort namely temperature, humidity, air-movement and radiation.

1.2.RELEVANCE:

Rising concerns over global environmental phenomena such as global warming and greenhouse effect coupled with fuel shortages have forced us to look for ways of reducing energy consumption and emissions. Mechanical systems of cooling like air conditioning are coming under a lot of flak as they contribute greatly towards emission of harmful gases into the atmosphere.

Since landscaping provides the interconnection between the outdoor environment and the indoor built space, it has the potential to incorporate the landscape features into the passive cooling of the indoor environment and thus reduce the cooling load of the building.

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1.3.AIM: Assessment of the role of landscape elements in passive cooling strategies of buildings in hot-humid climate.

1.4.OBJECTIVES OF THE STUDY: 1. To analyse the impact of the following soft landscape features on Solar Radiation, Wind Control and the climatic aspects of Temperature and Relative Humidity within the building: i) Landforms ii) Vegetation iii) Water 2. Secondary study of experimental results on selected landscape features namely: i) Vegetated walls ii) Vines iii) Vegetated roofs 1.5.RESEARCH STATEMENTS: To analyse: -The role of soft landscape elements in passive cooling strategies.

-The effect of soft landscape elements on the various parameters of thermal comfort-temperature, humidity, air movement (wind), radiation.

1.6.SCOPE AND LIMITATIONS OF THE STUDY: 1. The study does not include the aesthetic aspects and construction techniques and economic savings of the landscape features and focuses mainly on the thermal impact of the same.

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2. The comparative analysis will be mainly literature-based due to nonavailability of many live examples.

3. Primary Surveys of users of buildings with passive cooling techniques will be very limited and the focus will be more on secondary data collection.

4. The performance characteristics of landscaping features will be analysed for the hot and humid climate context only and not for other climate typologies.

5. Primary conduction of field and laboratory tests will not be explored and more focus given to detailed study and analysis of secondary study of experiments.

1.7.METHODOLOGY

The study involves review and analysis of existing literature on principles of passive cooling, application of the principles of passive cooling by soft landscape features like green roofs, roof ponds, vines and landscaped ponds.

Thermal comfort surveys are conducted among a user group of 50 people to assess the correlation between thermal comfort and landscaping. Study of

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experimental results of laboratory and on field experiments conducted by other researchers.

1.8.OUTCOME OF THE RESEARCH: The research emphasizes on the effects of various soft landscaping elements on passive cooling and studies the ways in which the two can be integrated to achieve thermal comfort in building design for hot humid climate.

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2.PASSIVE COOLING 2.1.INTRODUCTION: The term passive cooling covers all naturally occurring processes and techniques of heat dissipation and modulation, as well as overheat protection and related building design techniques. This means without any other form of energy input than renewable energy sources or the use of other major mechanical systems. (Asimakopoulous, 1996) Passive Cooling strategies can be categorized into the following: -prevention of heat gains -modulation of heat gains -Rejection of heat to natural heat sinks from interior spaces 2.2. PASSIVE COOLING STRATEGIES: 2.2.1 Prevention of Heat Gains: Prevention of heat gains in the interior of a building includes two types of heat gains: i) External heat gains which originate from the association of the building with the outdoor environment. The main sources are: a) Solar Radiation: which is directly transmitted indoors through glazing or is absorbed by the opaque elements and consequently conducted indoors. b) Ambient temperature: which is conducted through the building fabric and convected by ventilation and air infiltration. ii) Internal heat gains: The main sources are metabolic heat( heat produced by the occupants), artificial lighting, appliances and activities like cooking and bathing.

Solar control is the primary design measure for heat gain protection. The use of various shading devices in reducing the incident solar radiation can greatly reduce the cooling load. External shading of opaque walls with natural 12

vegetation, external or internal shading and high thermal mass glazing can result in comfortable thermal environments.

The built form and internal space layout determines the exposure of interior spaces to incident solar radiation and wind. The building shape affects both heat lost and heat gained, by reducing or increasing area of exposure.

The building envelope determines the physical processes taking place between the outdoor environment and indoor spaces. The goal is to reduce heat gains due to high outdoor air temperatures and incident solar radiation.

Thermal insulation can reduce the heat conducted through the building materials.

Behavioural and occupancy patterns in a building can be properly evolved in order to achieve thermal comfort .

Lastly, the control of internal heat gains can be achieved by careful planning of the design and operation of internal heat sources such as artificial lighting, equipment and occupants.

2.2.2 Modulation of heat gains: Modulation of heat gains can be achieved by the use of materials with high thermal storage( or thermal mass) in the building’s structure. This procedure provides an attenuation of peaks in internal temperatures, by delaying the discharge of heat until a later time when outdoor ambient temperatures are lower. At the same time it reduces the heat flow reaching the interior of the building as part of the stored heat in the envelope is reradiated and convected back to the external environment during the evening hours. (Asimakopoulous, 1996) 2.2.3. Heat Rejection: The design of the building should ensure means to reject the heat build-up in the interior of the building. The main techniques of natural cooling are: a) cooling with ventilation b) radiative cooling 13

c) evaporative cooling d) earth cooling a) Natural ventilation: It is caused by pressure difference at the inlets and outlets of a building envelope as a result of wind velocity and stack effects. To enhance its effectiveness the wind can be properly channelled and moved through the building. (Asimakopoulous, 1996) b) Radiative Cooling: Radiative cooling is based on the fundamental principle that any warm body emits thermal energy in the form of electromagnetic radiation to the facing colder ones. In direct radiative cooling the roof acts as the radiator since it is the element of the building that absorbs the biggest part of the solar radiation during summer. Use of high thermal storage materials can increase the radiative potential of a building. c) Evaporative cooling: Evaporation is the phase change of water from liquid to vapour accompanied by the release of high amounts of heat from the air that comes in contact with the wet surface or from the surface where evaporation takes place. In direct evaporative cooling the ventilated air passes over a wet surface and is cooled

by evaporation. In indirect evaporative cooling, the

evaporation takes place on a surface which is cooled during this process. The air that comes in contact with the cool surface is subsequently cooled without increasing its moisture content. d) Earth cooling: The earth can serve as a cooling source due to its high thermal capacity which keeps the soil temperatures considerably lower than the ambient air temperatures during summer. In direct earth cooling the cooling capacity of the earth is directly exploited by fully integrating the building within the earth or by partially earth integrating the building’s envelope.

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3.

COOLING EFFECT OF WATER

3.1. Introduction: Water surfaces modify the microclimate of the surrounding area by reducing the ambient air temperature either through evaporation(latent heat) or by contact of the hot air with the water surface which is cooler, owing to its high thermal mass. Fountains, ponds, streams and waterfalls or mist sprays may be used as cooling sources in order to lower the air temperature of outdoor spaces and of the air entering a building.

Water bodies of all types modify climate and reduce its extremes. Because a large percentage of the radiation striking the water surface is stored by the water, a small percentage of the solar radiation is radiated off the water surface. (Fig.1) Since all water bodies radiate a smaller percentage of solar radiation than does a landmass they act as a moderating influence on abrupt temperature changes on land near the water body. (Robinette, 1983) The leeward side of the water body will always be cooler since the wind is cooled as it moves across the surface of the water body. Therefore areas or activity spaces which need to be naturally cooler should be located on the leeward side of water bodies.(Fig.2) Water also affects the psychological perception of heat through the sound of falling or running water and by the reduction of glare.

As water surfaces increase the air humidity their existence can be problematic in very humid climates and thus circulation of the air should be promoted.

A design that endorses ponds, pools, or fountains into the landscape should follow certain guidelines to minimize the potential rise in humidity. The body of water should not be placed upwind from the enclosed space. Do not completely enclose fountains or pools with trellises or walls as they discourage breezes and contain the humid air. (Moffat & Schiler, 1981) A pond must be very large or employ spray features in order to have a significant effect on air temperatures in an outdoor space, however. (Givoni, 1994). Ponds can also be integrated with indoor spaces to provide cooling 15

using air or water as a heat sink to reject heat. The amount of cooling available from a landscape pond would be limited by the size of the pond and the degree to which the pond surface is shaded from direct sunlight. Other features that could enhance the cooling ability of the pond include; the proximity of the pond to the building, the depth of the water, strategies to increase airspeed at the water surface, fountain sprays to increase the rate of evaporation, exposure of the water surface to radiant loss to the sky. A heat transfer system must be used to transfer the cooling energy from the pond to an interior space. Both water and air can be used as transfer mediums.

(Sandifer, 2009)

Fig.1: Absorption of radiation by land and water

Fig.2: Cooling of air when it passes over water

3.2. LANDSCAPE POND: SECONDARY EXPERIMENTAL STUDY:

From the results of the experiments conducted by, S.A. Sandifer on landscape ponds(Fig.3) it was concluded that water shaded by aquatic plants has temperature patterns and levels similar to water that is covered by artificial shade structures. The amount of cooling produced by the plant shaded ponds 16

was also sufficient to indicate potential use for passive cooling system applications.

The deep pond experiments showed that deeper ponds or ponds with deep chambers may offer better performance than shallow (18 inches or less) plant shaded ponds.

The results obtained to date for the pond cooled test cell indicate that such a system could provide cooling for an interior space. The tests using an artificial shade (plywood) also show that either air or water could be used as a transfer medium.

Based on the results of these tests, it appears that a pond with both air and water heat exchange could provide better performance than a pond with either one or the other. The use of the air exchange system at night could improve the performance of the pond, since night time air temperature minimums usually fall below that of the pond water. Additionally, an air exchange system could provide cool air instantly while the high mass ceiling exchanger needs to operate for at least one day before the effects could be seen.

Fig.3: Diagram of a landscape pond cooling system

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4. COOLING EFFECT OF VEGETATION 4.0. Introduction: Vegetation includes trees, bushes, and vines which regulates the temperature and humidity by controlling solar radiation, direction of wind, precipitation and through evapotranspiration. It controls solar radiation by filtration of the sun’s rays, control of the amount of heat radiated by ground surfaces, and through total or major obstruction of the solar radiation itself. (Fig.4) It controls wind through obstruction of hot winds, filtration, guidance and reflection.(Fig.5)

Fig.4 Effect of plants on solar radiation control

Besides this vegetation also plays an important role as a natural evaporative cooling device, through the process known as Evapotranspiration. Trees and other plants transpire moisture in order to reject their sensible heat. The heat transferred by evapotranspiration is close to 2320 kJ per kg of evaporated water. (Asimakopoulous, 1996)

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Fig.5 Effect of plants in wind control

4.1. WIND CONTROL One of the ways in which vegetation affects the micro climate and hence the thermal comfort of man is through its control of the flow of wind. (Robinette, 1983). Air movement or the lack of it controls human comfort to a large degree especially in hot-humid climates where the air is usually muggy and moisture laden. The most significant effect of wind is due to the increasing of evaporative and convective cooling.

Planting can materially affect the movement of air through and about buildings; dependant on the way it is used, planting may either augment or reduce the natural airflow through the building; planting may cause actual change of direction of air flow within the building; planting on the lee side of buildings has little or no effect on the movement of air through the building unless it is such that it obstructs the outlet openings. (Robinette, 1983) There are various methods of control of winds flow, from complete blockage, to filtering, redirecting, channelizing, deflection or interception. (Robinette, 1983) The degree of control desired in a particular situation will decide to a large extent the precise height, density, and spacing of the wind control devices.

Channelling of breezes: 19

Trees and bushes can be positioned in such a way as to improve ventilation conditions inside the building by guiding more of the cooling breezes into the building or even by preventing the wind from spilling around the sides of a building. (Fig.6 & 8) If bushes are used, they should be positioned at a distance from the building in order not to deflect the evening breezes above the building.(Fig.7) (Asimakopoulous, 1996).

Fig.6 Shrub close to tree in order to promote ventilation

Fig.8 Shrub positioned to create negative pressure and draw air from inside the building

Fig.7 The location of the shrub should not deflect the wind over the building

Fig.9 trees and shrubs positioned to direct breezes toward windows.

Breezes may be managed by designing the landscape to channel breezes into a building or an outdoor space. Here the Venturi Effect can be used to advantage. (Fig.9) A narrowing wind scoop that funnels air towards the building can accelerate and increase the cooling impact of a light breeze that would otherwise be ineffective. (Moffat & Schiler, 1981) Windbreaks and Shelter Belts: An isolated tree or stand of trees acts almost like a solid barrier to the wind forcing the wind over or around. Thus wind speed can be increased at the edges of tree or stand. (Robinette, 1983)

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Trees and bushes can act as windbreaks to the hot winds if they are located to block the wind reaching the building. Especially in mechanically ventilated buildings this arrangement can reduce the cooling load of the buildings as a dense screen can reduce wind pressure and velocity by 75-85% which results in a lower cooling load due to reduced heat gains by convection and air infiltration from the developed pressure. (Montgomery, 1981). The vegetative windbreaks on the windward side should be positioned at a distance not more than 1-1.5 times the height of the building. A cluster of canopy trees, shrubs, or trees creates a dead air space around it, which decreases the air velocity for about five times its height on the windward side and about 25 times its height on the leeward side. (Montgomery, 1981) The degree of protection and wind reduction depends upon the height, width and penetrability of the plants used.

4.2.SOLAR RADIATION CONTROL Rational planting of vegetation around the building can offer significant shade.

This can be in the form of trees, bushes, pergolas, trellis, etc. The shade offered by vegetation is better than any artificial shading device as vegetation also modifies the thermal properties of the surrounding air and improves the microclimate around the building. (Asimakopoulous, 1996). Vegetation helps in the control of excess or unwanted solar radiation through Absorption, Reflection, Radiation and Transmission. (Fig.10, 11, 12, 13, 14, 15, 17) DIRECT RADIATION CONTROL

Fig.10 Single layer canopy

Fig.11 Multiple layer canopy

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Fig.12 Perforated Canopy

Absorption: All types of plants and trees depend upon solar radiation for their existence. The forest absorbs 60 to 90 percent of the total solar energy received. The amount of radiation absorbed depends on the density and development of the foliage. (Robinette, 1983)

REFLECTED RADIATION CONTROL

Fig.13 Shaded Wall

Fig.14 Shaded Wall & Reflecting Surface

Fig.15 Vegetative control of radiation reflection off water

Fig.16 Tree Form Shadow Patterns

Reflection: Trees and plants also reflect back into the atmosphere a certain percentage of the solar radiation. If a dense forest cover absorbs 75-85% of solar radiation and transmits about 5%, it reflects 15-20%. (Geiger, 1957)

Fig.17 Filtration

Fig.18 Radiated Heat

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Fig.19 Obstruction

Fig.20 Reflected Radiation

The challenge in hot humid areas lies in choosing plants that provide adequate shade but at the same time they should be limited in number because of the undesirable effects of extra humidity produced by heavy plantings. Overly dense plantings obstruct the cooling breezes and trap the humidity in a pocket of dead air. (Moffat & Schiler, 1981) (Fig.21) Tall plants with light foliage are recommended as they do not block the air and permit less disturbed air movement through the foliage.

Fig.21 Ventilating breezes pass unobstructed under canopy

Horizontal overhangs, like pergolas are preferable at the south orientation, while trees should be preferred on the east-southeast and west-southwest orientations. Bushes can also be used to shade east and west facing windows, while vertical trellises covered with climbing plants are effective on east and

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west facades. (Fig.22) Creepers are also useful in shading the envelope of the building. (Asimakopoulous, 1996) Shrubs can effectively block early-morning and late-afternoon sunlight on eastern and western exposures, respectively. Small-leafed, open-branched shrubs provide shade without unduly restricting air movement for passive cooling. Vegetation close to the residence also lowers the air temperature near the home, reducing the heat conducted through the walls. Espaliered shrubs, (shrubs trained to grow horizontally against a wall), can block a great deal of sunlight before it strikes and heats up the wall. (Meerow & Black, 1993)(Fig.23)

Fig.22 Vine Covered Trellis shading southern exposure

Fig.23 Espaliered shrubs can insulate a wall from heat build-up.

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4.3.COOLING TROUGH EVAPO-TRANSPIRATION Plants release water through pores in their leaves. The evaporative loss of this water is called transpiration. As hot air passes over the surface of the leaves, the moisture absorbs some of the heat and evaporates. The air surrounding the leaf surface is thus cooled by the process. This interaction is called evaporative cooling, which can lower air temperatures surrounding vegetation by as much as 9째F (5째C). (Meerow & Black, 1993) The greater the leaf area in the landscape, the greater the cooling effects of transpiration. The use of plants for shade and wind control instead of structural features such as fences and arbours thus provides an additional benefit toward maintaining thermal comfort. To maximize the effects of evaporative cooling, increase the amount of plant cover around the building. Use turf grasses and ground covers to their fullest potential in the landscape as alternatives to paved surfaces such as asphalt or concrete. (Meerow & Black, 1993) Although trees absorb most of the solar radiation falling on their leaves-up to 90%-they reradiate back a small portion of it. (Fig. 24 & 25) The absorbed solar radiation is mainly consumed for evaporation of water from the leaves.

This process cools down the leaves and consequently the air in contact with them and release vapour, increasing the air humidity. The remaining small portion of the solar radiation is used for photosynthesis.

Fig.24 summer performance of a tree

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Fig.25 winter performance of a tree

Leaves with open pores release about 50 to 70% of the amount of water vapour that would be released from the same water area, under the same climatic conditions, effectively releasing a quantity of water about five times that of the leaves’ weight. (Evmorfopoulou, 1988) Trees can transpire upto 378.54 litre of water in one day and the corresponding cooling effect on a hot dry summer day can be equivalent to five air conditioning units running for 20 hours. (Akbari, Davis, Dorsano, Huang, & Winnett) The cooling effect of plants, due to the combined effect of evapotranspiration and the shade they offer can result in heavily landscaped areas in an ambient temperature drop in the immediate surroundings by 5.5 to 8.5 degree Celsius in hot climates. (Setti, 1981) A shaded area with spread tree canopy, is about 22.2 degree Celsius cooler than an unshaded area owing to evapotranspiration. (Bowen, 1980)

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5.COOLING EFFECT OF LANDFORMS 5.0.Inroduction: A small scale landform is any, which may, to some degree, be altered by the site designer. They exist within the framework of large scale landforms, and their basic effects differ only in scale, but are to some extent controllable.

(Robinette, 1983). Small scale landforms can be either concave or convex with respect to the horizontal surface of the earth. It may be possible to position buildings to make use of the existing small scale landforms or create new ones to modify the microclimates. Almost always the landforms are used in combination with vegetation.

5.1.Control of wind: Small scale landforms may be used to obstruct, block, redirect or create eddies on the leeward side of a particular landform. Careful planning of small scale landforms can be used to direct wind flow towards specific areas which require cooling.

Landforms are usually soft and rolling and have a tendency to pitch the wind up or down. Friction with the ground results in higher speeds near the top of the mountain or the hill on the windward side and less turbulence on the leeward slope. (Asimakopoulous, 1996). During the day, the air next to the land heats up faster than free air at the same height and thus warm air moves up along the slopes. During the night, the slope surface cools down by radiation faster than the free air, thereby forming cold breezes that slide down the slopes. (Fig.26)

Fig.26 Air pattern in a valley throughout the day

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5.2.Control of radiation: The creation of positive or negative (concave or convex) landforms within the larger land area can help in providing a better orientation for obstruction of solar radiation. (Fig.27) The amount of radiation received on a surface depends on the inclination and orientation of the site. In the Northern hemisphere, south facing slopes receive more direct sunlight than those facing north. The amount of solar radiation incident on slopes also varies according to the season. As an inclined surface receives more solar radiation during winter and less during summer compared to a flat surface, sites located on slopes receive less radiation during overheated periods. (Asimakopoulous, 1996)

Fig.27 Effect of slopes on radiation

5.3.Control of Temperature: The ground radiates heat absorbed during the day in the night. Since cool air is heavier than warm air, a cold-air layer is formed near the ground surface.

Cold islands are created near the lowest point. This effect is more pronounced due to the flow of cool air down the valley slopes. However the higher grounds of the slope will be warm as the cold air circulation from the ground mixes with the surrounding warm air. (Fig.28)

Fig.28 Temperature stratification on a slope

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5.4.Improvement of other landscaping features: Small scale landforms may be modified or created to provide assistance to vegetation used for climate control. (Fig.29 &30) This may be the use of landforms to improve the location or total height of the vegetation for better obstruction of solar radiation or hot winds.

Fig.29 Landform to improve the interception of solar radiation by the pergola

Fig.30 Landform to improve the height of vegetation

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6. SECONDARY EXPERIMENTAL STUDIES: 6.1.VEGETATED FACADES: 6.1.1. EXPERIMENTAL SETUP:

Four experimental buildings of dimensions 2.5 meters long by 2.5 meters wide by 3.5 meters high were constructed using standard practices and placed on a concrete pad.

The buildings consisted of 4-sided square-hip 4/12-pitch roof .The interior walls and ceiling were covered with 1.6 cm thick gypsum drywall. The buildings had no windows and a single door was installed on the wall opposite the instrumented wall. The buildings were neither artificially cooled nor heated during any part of the experiment. The buildings were small enough to be rotated 90 degrees with a large forklift periodically so that the one instrumented wall faced either south or west. (Fig.31 & 32) Two of the buildings received the green faรงade treatment while the other two served as controls and received no green facades. One wall of each building was instrumented with a set of thermistors (temperature), a pyranometer (solar irradiance) and an anemometer (wind speed). (Tilley, Price, Matt, & Marrow, 2012)

Fig.31 Experimental buildings were typical wood construction

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Fig.32 Cross Section diagram of the thermistor locations across the instrumented wall.

Based on experiments conducted by David Tilley, Jeff Price, Serena Matt and Brodie Marrow, vegetated façade were shown to help in passive cooling of spaces through the following methods: a) Reduced indoor air temperature: The cooling effect was typically most pronounced during the late afternoon between 3:00 to 9:00 pm when the mean temperature reduction was 4oC (7oF). b) Exterior Wall Temperature: The green facades reduced the temperature of the exterior walls. The maximum reduction was observed when the green facade buildings were 14oC (25oF) cooler than the bare wall buildings.

c) Ambient Air Temperatures: The green facades were able to reduce the urban heat island effect by reducing the temperature of the surrounding air. d) Heat Flux: The green facades clearly reduced heat flux into the building’s exterior walls and interior space. Less heat flux into the exterior walls resulted in the temperatures of the exterior walls being lowered. Ultimately, exterior wall temperature represented the heat that can flow into the buildings to raise the indoor temperature. (Tilley, Price, Matt, & Marrow, 2012)

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6.2.VEGETATED ROOFS:

6.2.1 EXPERIMENTAL SETUP: Two sample sod roof modules were constructed and temperatures beneath the sample sod roof installations were measured along with temperatures beneath standard roofing materials of two colors; brown and white. Two different planting configurations were tested; one module was planted with gray fescue grass and a second module planted with a combination of California coastal sage scrub plants. (Fig.33) The temperature of the runoff water from one of the planted modules was also monitored.

Fig.33 Vegetated roof test module diagram.

A vegetated roof shades the entire roof during the day. Through shading and transpiration, the vegetation can dissipate heat that would otherwise be absorbed at the roof surface and the vegetated surface is exposed to the night sky. (Sandifer, 2009)Unlike tree shading, vegetated roof strategies can eliminate/reduce solar radiation on the entire roof, throughout the day.

Vegetated roofs can take advantage of night time radiant loss due to the exposure of the vegetated surface to the night sky. The potential cooling of the system can be transferred directly or indirectly into the structure below.

Vegetated consists of not only the foliage, but the entire plant and the soil substrate that the plant grows in: the root system and the soil column. A vegetated roof is a complex system and the effects reflect the combination of the mass of the soil interacting with irrigation water in addition to the effects of the shading/ cooling from the foliage above the soil. (Sandifer, 2009) 32

6.2.2 CONCLUSIONS: The results show that vegetated roofs can serve as exceptional passive cooling elements. In one test that compared temperatures beneath a sod roof module and two standard roof assemblies (one dark and the other painted white), the fescue grass roof reduced temperatures at the roof membrane by 44 degrees compared to the dark asphalt roof surface and by 25 degrees compared to the white painted surface. Temperatures beneath the module with Fescue grass had daytime average temperatures 5 degrees C below the outdoor daytime average. Timing and method of irrigation can be used to improve the cooling potential of vegetated roof systems. (Sandifer, 2009)

6.3.VINES Vines are most commonly used in the form of pergolas. A pergola-grown vine has the advantage of being able to shade glazed surfaces such as windows as well as opaque building surfaces such as a roof. The vine-covered pergola also creates a shaded outdoor space adjacent to the building, increasing outdoor thermal comfort on hot days and lowering the cooling load on the building envelope.

6.3.1. EXPERIMENTAL SETUP: The experiment involved placing of vines in front of a south facing brick wall.

Surface temperature was measured in several places in the shade of the vine and on the exposed brick surface. Thermocouples were placed in holes drilled to the centre point and the inside edge of the brick surface in order to track heat transfer through the material. (Fig.34) Another test was done on a west facing stucco wall with a vine covering 8- 16 inches thick. (Fig.36) In this test thermocouples were placed on the stucco surface in both sun exposed and vine shaded areas. At the same location a test of the thermal conditions around

a

west-facing

pergola

covered

with

a

Wisteria

vine

was

conducted.(Fig.35) (Sandifer, 2009)

33

Fig.34 Pergola section showing thermocouple locations

Fig.35 Shaded area below pergola with data collection enclosure.

Fig.36 Experimental setup

6.3.2 FINDINGS: Vines grown against a building surface at a thickness of 12-14 inches (30-35 cm) can reduce surface temperature to the level of, or slightly below, the ambient air temperature.

34

Vines growing directly on walls or on pergolas can be an effective means of reducing the problem of heat gain in the west facing wall.

A vine covered pergola as well as surface grown vines can modify surface temperature, shade glazed openings and provide more comfortable outdoor areas next to buildings.

Surface temperatures were reduced by up to 30 deg. C. Air temperatures in the foliage and below were reduced by 7-10 deg. C. (Sandifer, 2009)

35

7. CASE STUDY 1: STONEWATER ECORESORT, GOA 7.1. LOCATION: Vasco Da Gama, Goa comes under the Koppen climatic zone of hot humid.

Stonewater Eco-Resort is a beach resort, located on the shores of Santarem Beach in Vasco Da Gama on the coast of the Arabian Sea. 7.2. CLIMATE Temperature: Goa experiences a tropical climate for the most part, moderated by the Arabian Sea. Winter (September to March) temperatures range 20°C to 32°C. (Fig.38) In summer (April to May), Goa weather gets hot and humid, with daytime temperatures peaking in the high 30s. The thick and heavy atmosphere is finally relieved with the onset of the Monsoon season (June

to

August).

The

wind

and

rain

are

heaviest

in

July.

(http://www.worldweatheronline.com) Seasons: Goa comes under tropical monsoon climate under the Koppen climate classification that features a hot and humid weather for most of the year with two distinct seasons, the dry season and the monsoon season.

Monsoon season (June till September): July is the wettest month of the year with more than 995 mm of rainfall. (Fig.37) The average high stands around 30°C. During this time the city receives a reduced level of sunshine as July gets not more three hours of sunshine per day.

Dry season (October till May): More than 32°C of average high and average low of 20°C. From December till February it remains sunny with low humidity.

Moreover, night time temperatures go down into the mid teens. January with more than 320 hours of sunshine remains the sunniest month of the year.

36

Fig.37 Average Rainfall

Fig.38 Average Temperature

7.3. LANDSCAPE FEATURES Landforms: Since the resort is located on the shores of the Santarem Beach, there is cooling effect of sea breezes flowing from the sea towards the land during day. The cottages and the reception, facing the sea gets the maximum benefit. (Fig. 39 & 40)

37

Fig.39

Fig.40

The entire site is heavily contoured.

The reception and parking are located at the highest slopes while the cottages, restaurant and clubhouse are located on lower slopes at a lower height from the sea. (Fig.41) Fig. 41

The surface of the slopes get heated faster than the air at the same height, creat cold air pockets near the ground while the air near the top is relatively warmer. This causes cooling breezes to flow down the slope.

Shading from solar radiation: Pathways are shaded by trees which absorbs, obstructs and reflects the incident solar radiation and thereby reduce temperature. Bushes on both sides of the pathways also cool the air similarly.

Fig. 42

Fig.43

Fig.44

Fig.45

38

The open gathering area has no shade over it.

(Fig.46) Thermal Effect: Lack of vegetation above the gathering ground causes high temperature due to lack of shading, high incident radiation, reflection of large amounts of radiation by the paved floor.

Fig.46

Water Features: Although the swimming pool itself has no shading, the area surrounding the pool edge is well shaded by trees and bushes. (Fig.47)

Fig.47

Thermal Effect: Shading, Absorption and Reflection of solar radiation, Evaporative Cooling effect of water and cooling through evapotranspiration.

Vine covered pergolas and walls: Pergolas covered with creepers are used in the reception building(Fig.49) and also to provide shading of the seating areas around the pool( Fig.48)

Fig.48

Fig.49

Vines and creepers are grown on the ground next to the cottages(Fig.50 & 51) and allowed to grow onto the walls and in most case up till the roof.

Thermal Effect: Cooling effect due to shading and evapotranspiration.

39

Fig.50

Fig.51

7.4. QUESTIONNAIRE AND SURVEY RESULTS: The questionnare ( refer to Appendix) was distributed among a user group of 15 people including the staff and guests. All the participants of this survey were literate adults who had an educational qualification of atleast college level. The questions were regarding the thermal comfort of the users with respect to different spaces within the resort. It also looked into the season, the time of the day, the type of activity participants were engaged in prior to the survey and the type of clothing they adorned at the time of the survey.

Air quality indoors

Radiation outdoors

Stuffy/Stale Satisfactory

Temperature indoors

Too much sunlight Sufficient shading

Temperature outdoors

Too cool

Too cool

Neutral

Neutral

Too hot

Too hot

40

Temperature Area wise 7 6 5 4 3 2 1 0

Hot Neutral Cool

Humidity Area wise 7 6 5 4 3 2 1 0

High Medium Low

7.5. ANALYSIS AND CONCLUSION: From the questionnare analysis, and site observation, we can conclude that landscape features like water bodies, slopes(landforms), vine covered walls, pergolas covered with creepers and planting of trees and bushes help in passive cooling through reduction of temperature and diffusion of humidity.

Temperature in the cottages, pathways and spaces close to the sea were reported to be cool by majority of respondents due to proper landscaping techiniques such as vine covered roofs, and walls, solar shading, solar radiation control and orientation to capture unrestricted sea breeze.

Majority of respondents rexperienced a low humidity in the cottages. This is due to their proper positioning on the slope and unobstructed passage for sea breeze. Humidity levels experienced in the reception and seaside areas were slightly higher.

41

8.CASE STUDY 2: WILD WOOD SPA AND RESORT, UDUPI 8.1. LOCATION: Kundapura, Udupi, Karnataka. The climate is tropical in Udupi. In most months of the year, there is significant rainfall in Udupi. There is only a short dry season and it is not very effective. According to Köppen and Geiger climate is classified as Tropical Monsoon. The average annual temperature in Udupi is 27.2 °C.(Fig.52) The average annual rainfall is 4360 mm. (Fig.53) ( http://www.worldweatheronline.com)

8.2 CLIMATE:

Fig.

Fig.52 Average Temperature

Fig.53 Average Rainfall

42

8.3 LANDSCAPE FEATURES: Vines and pergolas: Pergolas covered with vines and creepers are provided at the entrance to every cottage. (Fig.54, 55, 56) Thermal Effect: Provides cooling through solar shading, radiation control, reduction of glare and evapotranspiration.

Fig.54

Fig.55

Fig.56

Water Features: Landscape ponds (Fig.57 & 59) and swimming pool (Fig.58) Thermal Effect: Evaporative cooling effect due to water causes cooling of the spaces around.

Fig.57

Fig.58

Fig.59

Shading: Pathways and open areas are shaded by dense vegetation.(Fig.60, 61, 62, 63) Thermal Effect: Reduces temperature due to shading, obstruction, absorption and reflection of solar radiation, evapotranspiration.

43

Fig.60

Fig.61

Fig.62

Fig.63

8.4. QUESTIONNAIRE AND SURVEY RESULTS: The questionnare (refer to Appendix 1) was distributed among a user group of 15 people including the staff and guests. All the participants of this survey were literate adults who had an educational qualification of atleast college level. The questions were regarding the thermal comfort of the users with respect to different landscaped spaces within the resort. It also looked into the season, the time of the day, the type of activity participants were engaged in prior to the survey and the type of clothing they adorned at the time of the survey.

Air quality indoors

Radiation outdoors

Stuffy/Stale Satisfactory

Too much sunlight Sufficient shading

44

Temperature indoors

Temperature outdoors

Too cool

Too cool

Neutral

Neutral

Too hot

Too hot

Temperature Area wise 8 6 4

Hot

2

Neutral

0

Cool

Humidity Area wise 7 6 5 4 3 2 1 0

High Medium Low

8.5. ANALYSIS AND CONCLUSION: From the questionnare analysis, and on-site observation, we can conclude that landscape features like water bodies, vine covered walls, pergolas covered with creepers and planting of trees and bushes help in passive cooling through reduction of temperature and diffusion of humidity.

Temperature in the cottages were reported to be cool by majority of respondents due to proper landscaping techiniques such as vine covered pergolas and solar shading using trees. All pathways and open outdoor 45

spaces have proper shading using bushes and tall trees which helps control glare and heat gain due to incident radiation.

Majority of respondents rexperienced an overall higher than comfortable levels humidity.This is especially so near water bodies. This is due to restriction of flow of breezes due to overly dense vegetation.

9. FINDINGS AND CONCLUSION 9.1. FINDINGS

S.NO.

SOFT

POSITION ON

LANDSCAPE

METHOD OF

LANDSCAPE

THE BUILDING

FEATURE

PASSIVE COOLING

ELEMENT

Shading (solar radiation

VERTICAL VEGETATION

COMFORT PARAMETER

SURFACE/ 1

THERMAL

LANDSCAPING

Temperature

control), Reduces heat VINES

storage/increases Thermal Mass, Heat Insulation, Evapotranspiration, Glare Heat flux, evapotranspiration, Reduces heat

GREEN ROOFS

storage/increases thermal

Temperature

mass, Insulation

SITE/AROUND

PERGOLAS WITH

Shading (Solar radiation

THE BUILDING

VINES/CREEPER

control),Evapotranspiration,

Temperature

Reduction of Glare

TREES

Windbreaks (Wind direction

Temperature

control), Channelling of

&Humidity

breezes, Shading (solar radiation control: Absorption, Reflection, Obstruction), Evapotranspiration

46

2 WATER

SITE/AROUND

LANDSCAPE

Evaporative Cooling, Cooling

Temperature &

THE BUILDING

PONDS, POOLS

of breezes passing above the

Humidity

FEATURES

3

LANDFORMS

water body

SITE/AROUND

HILLS,

THE BUILDING SLOPES

Windbreaks( Wind direction

Temperature &

Control), Reduction of incident

Humidity

solar radiation.

Table 1: Relationship between soft landscape elements, passive cooling and thermal comfort parameters

9.2 CONCLUSION The study has enabled us to realise the importance of soft landscape elements in the passive cooling design of buildings within a hot-humid climatic context. It has elaborated on the relationship between the different passive cooling techniques, thermal comfort, thermal control and soft landscape elements. Based on the study, awareness can be enabled on the need to integrate landscaping into passive cooling of buildings instead of merely as aesthetic features. In hot-humid climates, the main aspects of thermal comfort are temperature and humidity. In this study we have analysed how landscape plays an important role in both these aspects. Accordingly, architects should take these effects into consideration while designing a landscape for a building located in hot humid climates.

47

BIBILIOGRAPHY Akbari, H., Davis, S., Dorsano, S., Huang, J., & Winnett, S. (n.d.). Cooling our Communities; A guidebook on Tree Planting and Light-Coloured Surfacing. 1992.

Asimakopoulous, M. S. (1996). Passive Cooling of Buildings. James & James (Science Publishers) Ltd. Bowen, A. (1980). Heating and cooling of buildings and sites through landscape planting and design, Passive Cooling Handbook. 5th National Passive Conference. Amheret: AS/ISES. Evmorfopoulou, C. (1988). Energy savings in buildings with use of plants on the roof and facades. 3rd National Conference on 'Soft Kinds of Energy'. Thessaloniki.

Geiger. (1957).

Givoni, B. (1994). Passive and Low Energy Cooling of. Van Nostrand Reinhold.

Meerow, A., & Black, R. J. (1993). Enviroscaping to Conserve Energy: a Guide to Microclimate Modification. University of Florida IFAS Extension.

Moffat, A. S., & Schiler, M. (1981). Landscape Design that saves enrgy. William Morrow & Co. Montgomery, D. (1981). Landscape for passive solar cooling. International Conference on Passive and Hybrid Cooling. Miami Beach: American Section of ISES. Robinette, G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Sandifer, S. A. (2009). Using the Landscape for Passive Cooling and Bioclimatic. PLEA2009 26th Conference on Passive and Low Energy Architecture . Quebec City, Canada.

Setti, B. (1981). Energy concious landscape design, In Situ, Vol 6, No 1. International Institute of Site Planning.

Tilley, D., Price, J., Matt, S., & Marrow, B. (2012). Vegetated Walls: Thermal and Growth Properties of Structured. Maryland: University of Maryland, College Park.

48

LIST OF FIGURES Fig.1: Incident solar radiation on land and water; Robinette, G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.2: Cooling of air when it passes over a water body; Robinette, G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.3: Diagram of a landscape pond cooling system; Sandifer, S. A. (2009). Using the Landscape for Passive Cooling and Bioclimatic. PLEA2009 - 26th Conference on Passive and Low Energy Architecture . Quebec City, Canada.

Fig.4: Effect of plants on solar radiation control; Robinette, G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.5: Effect of plants on wind control; Robinette, G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.6: Shrub close to tree in order to promote ventilation; Asimakopoulous, M. S. (1996). Passive Cooling of Buildings. James & James (Science Publishers) Ltd Fig.7: The location of the shrub should not deflect the wind over the building; Asimakopoulous, M. S. (1996). Passive Cooling of Buildings. James & James (Science Publishers) Ltd Fig.8: Shrub positioned to create negative pressure and draw air from inside the building; Asimakopoulous, M. S. (1996). Passive Cooling of Buildings. James & James (Science Publishers) Ltd Fig.9: Trees and shrubs positioned to direct breezes toward windows; Meerow, A., & Black, R. J. (1993). Enviroscaping to Conserve Energy: a Guide to Microclimate Modification.

University of Florida IFAS Extension.

Fig.10: Single layer canopy; Robinette, G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.11: Multiple layer canopy; Robinette, G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.12: Perforated Canopy; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.13: Shaded Wall; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.14: Shaded Wall & Reflecting Surface; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.15: Vegetative control of radiation reflection off water; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

49

Fig.16: Tree Form Shadow Patterns; G. o. (1983). Landscape Planning for Energy Conservation.

Van Nostrand Reinhold Company.

Fig.17: Filtration; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.18: Radiated Heat; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.19: Obstruction; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.20: Reflected Radiation; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.21: Ventilating breezes pass unobstructed under canopy; Moffat, A. S., & Schiler, M. (1981).

Landscape Design that saves enrgy. William Morrow & Co. Fig.22: Vine Covered Trellis shading southern exposure; Moffat, A. S., & Schiler, M. (1981).

Landscape Design that saves enrgy. William Morrow & Co. Fig.23: Espaliered shrubs can insulate a wall from heat build-up; Meerow, A., & Black, R. J. (1993).

Enviroscaping to Conserve Energy: a Guide to Microclimate Modification. University of Florida IFAS Extension.

Fig.24: Summer performance of a tree; Asimakopoulous, M. S. (1996). Passive Cooling of Buildings. James & James (Science Publishers) Ltd. Fig.25: Winter performance of a tree; Asimakopoulous, M. S. (1996). Passive Cooling of Buildings.

James & James (Science Publishers) Ltd. Fig.26: Air pattern in a valley throughout the day; Asimakopoulous, M. S. (1996). Passive Cooling of Buildings. James & James (Science Publishers) Ltd. Fig.27: Effect of slopes on radiation; G. o. (1983). Landscape Planning for Energy Conservation.

Van Nostrand Reinhold Company.

Fig.28: Temperature stratification on a slope; Asimakopoulous, M. S. (1996). Passive Cooling of Buildings. James & James (Science Publishers) Ltd. Fig.29: Landform to improve the interception of solar radiation by the pergola; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.30: Landform to improve the height of vegetation; G. o. (1983). Landscape Planning for Energy Conservation. Van Nostrand Reinhold Company.

Fig.31: Experimental buildings were typical wood construction; Tilley, D., Price, J., Matt, S., & Marrow, B. (2012). Vegetated Walls: Thermal and Growth Properties of Structured.

Maryland: University of Maryland, College Park.

50

Fig.32: Cross Section diagram of the thermistor locations across the instrumented wall.; Tilley, D., Price, J., Matt, S., & Marrow, B. (2012). Vegetated Walls: Thermal and Growth Properties of Structured. Maryland: University of Maryland, College Park.

Fig.33: Vegetated roof test module diagram; Sandifer, S. A. (2009). Using the Landscape for Passive Cooling and Bioclimatic. PLEA2009 - 26th Conference on Passive and Low Energy Architecture . Quebec City, Canada.

Fig.34: Pergola section showing thermocouple; Sandifer, S. A. (2009). Using the Landscape for Passive Cooling and Bioclimatic. PLEA2009 - 26th Conference on Passive and Low Energy Architecture . Quebec City, Canada.

Fig.35: Shaded area below pergola with data collection enclosure; S. A. (2009). Using the Landscape for Passive Cooling and Bioclimatic. PLEA2009 - 26th Conference on Passive and Low Energy Architecture . Quebec City, Canada.

Fig.36: Experimental setup; S. A. (2009). Using the Landscape for Passive Cooling and Bioclimatic. PLEA2009 - 26th Conference on Passive and Low Energy Architecture .

Quebec City, Canada.

Fig.37: Average Rainfall of Goa; (http://www.worldweatheronline.com) Fig.38: Average Temperature of Goa; (http://www.worldweatheronline.com) Fig.52: Average Temperature of Udupi; (http://www.worldweatheronline.com) Fig.53: Average Rainfall of Udupi; (http://www.worldweatheronline.com)

51

APPENDIX 1 Thermal Comfort Survey Questionnaire: 1.NAME: 2.AGE: 3.SEX: 4.TIME: 5.SEASON: 6. What is your current Thermal Comfort?

-3

-2

-1

0

1

Cold

Cool

Slightly Cool

Neutral

Slightly Warm

2 Warm

3 Hot

7. If you experience thermal discomfort (temperature and humidity), which of the following best describes it? - Too much/ too little air movement  -Incoming sunlight heats up space - Heat from equipment - Hot floors and walls  -Cold floors and walls -Too much glare 8. How would you describe your activity level just prior to completing this survey?

-Seated quiet -Standing relaxed -Light activity, standing -Medium activity, standing -High activity 9.Clothing: Place a check by the articles of clothing you are wearing: a)Short Sleeve Shirt b)Long Sleeve Shirt skirt f)Jeans

c)Trousers d)Walking Shorts e)Knee length

g) Long Sleeve sweater h)T-shirt i)Sweatpants

52

10. How satisfied are you with the air quality?

-3

-2

-1

0

Very Dissatisfied

1

2

3 Very Satisfied

11. If you are dissatisfied with the air quality, is it: â Ş Stuffy/Stale â Ş Odorous 12. Are there any existing problems in the area?

Too much sunlight Too much shade 13. Would you like to see any of the following landscape features added to an existing area? a) Vine covered walls b) Green Roof c) Water fountains d) Ponds 14. If yes which part of the resort?

53