Evapora've cooling in Natural History Museum of Pales'ne Testing the performance of the evaporative cooling screen for Palestine museum of natural history
2018–19 Zeynab Bozorg
University of Westminster, Faculty of Architecture and Environmental Design Department of Architecture MSc Architecture and Environmental Design 2018/19 Sem 3 Thesis project Collaboration with NGArchitects
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ABSTRACT With the growing concern of climate change, environmental design has been in a high demand for design approaches in contemporary architecture (Jankovic, 2012) . Overheating is one of the major concerns in hot arid climate setting, of Bethlehem, Palestine. People in this region develop many strategies to cope up the heat issue. Passive system has been a great potential for energy reduction and improving the environment. Passive cooling technique as an innovative technology , helps the building to achieve comfort condition in a natural way. Using traditional techniques have a great potential in reducing energy demand and providing better environment. This ancient cooling technique has been rediscovered in the recent decades an as effective and environmentally friendly alternative to Air conditioners which is successfully implementing in design industry. The study analyses the performances of the evaporative cooling screen on a Selected room from Palestine museum of natural history.
This paper, is demonstraIng the capability of the porous ceramics in cooling the space with water absorbance In different arrangements and its effect on the temperature ,humidity and water consumpIon. In order to achieve this the paper is divided in 2 chapters; AnalyIcal work and experiment. Hence the experiment in conducted to test the different ceramic arrangements and their effects on the temperature reducIon. Findings presented in this paper suggest, arrangement of the ceramics plays an important role in opImizing the performance of evaporaIve cooling. The result should be taken into consideraIon for the applicaIon of the evaporaIve cooling system of the perforated wall in hot climates. Hence, passive evaporaIve cooling using porous ceramic components can achieve comfort condiIons inside buildings in hotdry climates
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CONTENT Acknowledgement Abstract Chapter 1 1. Introduc9on 1.1 General background 1.2 Thesis project 1.3 Project aim. 1.4 Research ques9on 1.5 Hypothesis 1.6 Methodology 1.7 Result 1.8 Structure 1.9 limita9ons
Chapter 4 6 6 7 7 8 8 9 10 11 11
Chapter 2 2. Literature review 2.1 Architecture of the city/city culture. 2.2 Local materials 2.3 Evapora9ve cooling
12 13 17 18
4. Experiment 4.1 Evaporative cooling experiment 46 4.2 First scenario 4.3 Second scenario 4.4 Third scenario 4.5 Data comparison 4.6 Water consumption 4.7 Conclusion
45 49 53 56 59 60 61
Chapter 5 5.1 Design Proposal 5.2 Scenario comparison 5.3 Lab wind pattern 66 5.4 Rooms specification 5.5 Renders 5.6 Site plan
63 64 67 68 73
Chapter 3 3. Site Studies 3.1 Site loca9on 3.2 Site topography 3.3 Area specifica9on 3.4 Climate 3.5 Sun path study 3.6 Sun hours 3.7 Sun analysis 3.8 Solar radia9on 3.9 Wind flow analysis 3.10 Court yard study 3.11 Laboratory
25 26 27 28 30 33 35 36 37 39 40 41 3
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ACKNOWLEDGEMENT
I would like to express my infinite thanks to my personal tutor and project leader Nasser Golzari and NGArchitects for giving me this opportunity to join and share interests on this project. My deepest gratitude goes to my family for the unceasing encouragement, support and attention. I am also grateful to my partner who supported me through this venture. My appreciation goes to Juan Vallejo for assisting me with his valuable knowledge and Kartikeya Rajput for beneficial comments and criticism. I am also grateful to Neil Kiernan for providing me the information I required for my research. I take this opportunity to express gratitude to all the tutors that I have had during this incredible year. Finally, I am grateful to Dr Rosa Schiano-Phan for introducing me to new concepts which allowed me to explore more areas this year.
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CHAPTER 1
01
INTRODUCTION
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1. I N T R O D U C T I O N 1.1 GENERAL BACKGROUND
Architects today integrate principles of sustainable design as a crucial matter. It’s a challenge to control the climatic functionality of a building naturally. Over the last few years, developing countries have witness a severe energy crisis specially in summer season due to the cooling load requirement of the buildings (Arif Kamal, 2012). Building energy demand constantly is raising and according to Boukhanouf et al., (2015) 70% of building energy consumption is accounted for cooling system signify 30% of total prime energy globaly. It is challenging task to keep the buildings running system low cost and sustainable in a hot and dry climate countries. Bethlehem, Palestine has very high temperature and high amount of sun hours in a typical day of summer, overheating in summer periods, could be considered as a climatic issue in this region.
On the other hand, because of political issues that Palestine and Israel are involved with, resources of commercial energy, significantly Oil and electricity are almost dependent on imported energy supplies. Specifically, in west bank, where the majority of people are living and most of the economic activities are happening, also has insufficient primary energy resources. (Energy Sector Review, 2007). Hence, it is beneficial to keep the building running system low cost and almost zero energy consumption, and maximize the usage of natural ventilation and cooling in order to promote a sustainable ecosystem in the region. As a solution to that, in hot and dry climate specially in certain conservative regions where the socio-cultural consideration has implemented the use of the skin. The idea of perforated skin is used globally, however in countries like Palestine it is concentrated more and one could see the examples of using traditional architecture in today’s era and combining it with contemporary trend. According to Fathy, (1986), perforated skin for the buildings has many purposes; controlling the direct daylight, hence shading, balancing the natural air flow, cooling naturally with the help of wet ceramics and helping with the level of privacy which is essential in the conservative Islamic communities .
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1.2 THESIS PROJECT The Pales4ne Museum of Natural History (PMNH) was established in 2014 with provided land from University of Bethlehem and large amount of dona4ons and volunteer efforts. The aim of this development is to educate and research about natural world, heritage and culture, Also to make an interac4on between humans and environment. The Architectural approach of the new proposed scheme has been influenced by the dominant landscape of PMNH and the available land. In this scheme , 2 exis4ng stone buildings , sister building to the North and the Admin block to the south west , are going to be remodelled and used. The no4ceable hill site topography includes areas with threatened and endangered plants like four species of orchid and star of Bethlehem. The value of PMNH reflects to a sensible proposal that blends architecture and environment into the landscape by using a green design and locally sourced materials.
1.3 PROJECT AIM This thesis is inspired by the collaboration between university of Westminster and NG Architects leading by Nasser Golzari. The topic developed in the thesis departed from an Open source project of “Construction of a new museum in Bethlehem, Palestine”. The museums first phase consists of the exhibition rooms and laboratory room due to the fact that it is on the process of constructing, and it a is a part of interest, is selected to test the proposed design for the cooling system and come up with a design optimization. Evaporative cooling screens which are built from wet ceramics and water pipes need to be tested in terms of cooling effects and modified for the lab room which has similar features with the exhibition rooms. The study of this paper will be done by the author and some data collected from the project leader.
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1.4 RESEARCH QUESTION
The project for the second phase will be in the construction process shortly while the design process is almost at final stage. Environmental strategies for this phase need to be analyses and improved, In case of any alteration. This thesis aims to recommend and redesign the proposed evaporative cooling screen based on the outcome of analysis in order to implement improved strategies. The research aims to determine the below objectives: 1.4.1 Testing the performance of the proposed design for the evaporative cooling screens (skin) in terms of effectiveness in cooling and ventilation. 1.4.2 Analysing different arrangement of wet ceramics screen terms of better cooling effect 1.4.3 Checking the sufficiency of the screen in terms of ventilation of the lab with no other stack. 1.4.4 Using CFD to analyse the air flow in the site, specially courtyard to check the wind flow and speed near the lab room.
1.5 HYPOTHESIS
Designers increasingly look at the past as a point of reference to aid with today’s energy efficiency matter. Undoubtedly, wet ceramics, as sued in traditional cooling method, help in reducing the temperature and it is a device for shading and also to intercept the direct solar radiation as well as reducing uncomfortable glare. In addition to the, the device is an archetypical element to offer more privacy compare to a typical window particularly which is a main factor in Arab-Islamic culture. However, considering the current condition of the site, which is very exposed, overheating is a main factor in monitored months and lack of surrounding context would result in high solar radiation and evaporative cooling rate of wet ceramics during summer. Therefore, functionality of the device could potentially decrease. 8
1.6 METHODOLOGY AND RESEARCH METHOD The methodology for this research is mainly: 1.6.1 Primary data collecDon EvaporaDve cooling experiment The study has its origin from a live project in Bethlehem to test the proposed method for cooling system. Using a physical model in 1:1 scale is the best way to test the effecDveness of porous ceramic. Due to the limitaDon in soOware’s accuracy, this method of collaDng data was chosen. The experiment was completed with Lab tools in the university of Westminster. RealisDc dimensions of the ceramics were used for a closer result to the reality. 1.6.2 Secondary data collecDon Desk research Using exisDng data and comparing the informaDon from different sources of arDcles, books, Journals and etc, in order to understand the environmental performance of the chosen part of the site based on the climaDc changes in the region and beVer look of the architectural trend used in the region in order to adapt with the climaDc variaDons.
Related literature reviews were studied about the evaporaDve cooling system and cultural point of view. Some primary data collected from the collaboraDve team. since fieldwork was not possible due to poliDcal issues. The data is studied with the informaDon obtained from neighbouring weather staDon, Jerusalem, Israel. - Computer based simulaDons The collected data is used to process the built environment with the help of digital soOware like Grasshopper ,ladybug plugins and ComputaDonal Fluid Dynamics (CFD).
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1.7 RESULT The purpose of this project is to test the performance of the evaporative cooling screens which is built from porous ceramics and water pipes, for in particular Laboratory room of Palestine Natural History Museum. This study will recommend new design strategy for cooling system to the architects in order to optimize the proposed design. As this thesis focused on one room, with similar layout to other exhibition rooms, all the analysis and experiment are based on the dimension and data of this room (Laboratory). The main outcome of this thesis suggests, due to the high solar radiation which lead to high rate of evaporation in the ceramics, the cooling system would not have significant reduction of indoor temperature, unless the amount of ceramics per wall, are increased. Moreover, water consumption is significantly high, considering that Palestine is an arid region, supplying high amount of water would be expensive and laborious, As a solutions to that the study recommends;
placing two layers of ceramic screens in front of each other in order to compact the mitigated air temperature in between two screens and lower temperature air flows in the second screen. As a result, the temperature will be reduced twice and the second layer would water consumption would be much less due to the fact that first layer is causing shading. Since the device is used for the shading purposes as well, the study suggest a combination of porous ceramic screens with wall integrated system , where the porous ceramic layer is integrated in a cavity wall , hence, air contacts the wet ceramics via the controllable opening located on the top level of the wall and gets cooler and heavier and exit the wall, to the indoor space , from the smaller opening on the bottom of the wall. Wall integrated system has a better cooling performance in this condition ,since sunlight does not affect evaporation, Therefore the study recommend a combination of both strategies to display the cultural blend of wet ceramic as well as placing all integrated system in some parts of the museum to achieve comfort indoor temperature. 10
1.8 STRUCTURE The thesis is divided into 4 main chapters.
1.8.1 THEORITICAL BACKGROUND
The first chapter covers the introduction of the topic, research questions, Methodology and hypothesis with a brief overview of the project outcome. 1.9 LIMITATION 1.8.2 ANALYTICAL STUDIES OF THE SITE In this chapter the context has been analysed. Climate analysis plays an important role in this project since a good understanding of the climate changes in different season is essential in finding a better solution for the cooling system. 1.8.3
EVAPORATIVE COOLING EXPERIMENT
The physical experiment process is introduced, and 3 different scenarios are tested and analysed. 1.8.4.
The evaporative cooling experiment has its limitation resulting from the ability of the air to absorb moisture. The experiment was completed in the university lab therefore keeping the outdoor air wet bulb temperature, low, was out of control . To have an accurate result the experiment must have been completed in a same climatic condition as Bethlehem, however with the help of second heather the outdoor temperature was reduced slightly.
DESIGN PROJECT
This chapter is the explanation of the research outcome, based on the analytical studies and evaporative cooling experiment . a new design solution is proposed in particular for the lab and extends to the all part of the museum.
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CHAPTER 2
02
LITRETURE REVIEW
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2.1 ARCHITECTURE OF THE CITY/ CITY CULTURE
Many years ago, where energy was not accessible, builders had to test and develop passive ingenious system that improve indoor thermal comfort and responds to climatic conditions through local sources. Fernandes, Dabaieh , Mateus, Bragança, (2014) believed; Vernacular architecture was developed to respect the climatic factor and environment as well as valuing the culture and traditional construction. The design of the museum could be said that is an inspiration from courtyard housing in Palestine, where it is considered as a effective feature in providing calm and airy internal environment during the long hot dry weather, which is also mixed with the social concept implanted within the community at those times in past (Amjed ,2010). Bianca,(200) in her study believe: ”The symmetrical and totally balanced order of the courtyard can be interpreted as the timeless centre of gravity of the house, while the periphery responds to the given circumstances and pressures of the earthly environment” The courtyard in the centre of all the proposed exhibition rooms and labs, could help the control of the thermal performance as well as helping with more daylight through the spaces with less or no opening to the exterior.
Figure1: A basic courtyard house in the Casbah in Algiers (Golvin 1988)
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Construc)on technology in Pales)ne lacks a3en)on to clima)c changes and people mostly build houses without seeking engineering consultancy. Addi)onally, architects and designers do not consider clima)c changes as a main design criteria. Most of the belongings do not provide desirable environment for occupants in the building. This comfort could be achieved by orienta)ng the rooms and openings on a right way with selec)ng suitable materials, in order to respect and use the best of the clima)c condi)on of that region. In the tradi)onal Pales)nian houses with hot arid climates, air ow and ven)la)ons act as a main feature, arrangement in the opening of the courtyard helps the be3er cross ven)la)on between outside and inside. Furthermore, adding shaded area helps a steady ow of air which a case of ven)la)on occurs when hot air rises from the ground and drags the cool air from the courtyard across shaded area.
Figure 2 , two-storey house with central courtyard h"p://www.womeninthebible.net/biblearchaeology/ancient_houses/ 14
Example of courtyard houses in Palestine
Figure3, Nada al Shu’aibi Courtyard House
Figure4 architectural plan of the courtyard house
Figure5 architectural section of the courtyard house
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Figure6, Typical courtyard house in Pales7ne
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2.2 LOCAL MATERIALS
Since Mediterranean vernacular architecture is valued as an sustainable and energy efficiency model for nowadays architecture, and that is believed to be an outcome of consuming local constrains and local sources (Cardinale, Rospi and Stefanizzi, 2013).Moreover, several studies have discovered good building performance of vernacular architecture by emphasising on benefits of local materials , it is beneficial to depend on local sourced materials, natural elements, such as stone, bricks, concrete. In this way, the construction cost is also reduced and materials have better thermal conductivity. In addition to that, not requiring technical equipment, makes it suitable for contemporary Fernandes et al. , (2014); evaluated the passive buildings (Weber et al., 2014). However, importance of vernacular architecture that some studies have criticized such techniques for must be reviewed in order to build sustainably. contemporary buildings because of the limitations In relation to that; Weber and Yannas, 2014 of changes In weather condition and valuable also emphasised on good thermal resources (Foruzanmehr and Vellinga, 2011). performance of the local materials in vernacular architecture in the Mediterranean climate. Tawaha et Al.,(2019) ,states; buildings today, are dependent on fossil fuel energy and main work load is on mechanical equipment in particular heating and cooling to control the indoor comfort .while, studies show that , cooling passive strategies used in Mediterranean vernacular architecture were practical solution for energy efficient buildings. “The strongest point of vernacular architecture is the harmony between environment and buildings.� (Tawayha, Braganca and Mateus, 2019: 896). in Mediterranean vernacular architecture, local connect, culture and traditions are blended. Tawaha et Al., (2019) believes; in today’s era, vernacular architecture is considered as sustainable strategies in construction. With the built of modern building in particular in developing countries like Palestine, it is more difficult to see the cultural identities saved been maintained in order to achieve a sustainable built environment.
Figure7, Properties of some vernacular and conventional building materials 17
2.3. EVAPORATIVE COOLING Passive evaporative cooling method uses the evaporative of water to cool the air. Usage of porous ceramics in this method comes from vernacular architecture of hot and dry regions (Schiano-Phan, 2004).(Figure8) Buildings in Mediterranean climate must benefit from high hours of sun; however, some technologies need to be used in order to reduce usage of air conditioning by provide cooling naturally in order to have a healthy environment. Hence, it is beneficial to consider evaporative cooling technique. using ceramics as main porous to produce evaporation, links back to the ancient middle east 10,000BC where, where the first mud bricks, hardened with sun-drying (Campbell and Pryce, 2003). Porous ceramics evaporator is incorporated in contemporary architecture as faรงade screens and they are an evolution of ventilated faรงade with providing shading and filtered light. Usage of evaporative cooling screens couples with a cross or stack ventilation to stimulate evaporation.
In relaWon with that , Englart, (2017),in his study states the soluWon of avoiding a direct contact of air with the water to prevent passageway of bacteria such as Legionella from water to air. In regards with that, Johnson, Yavuzturk and Pruis (2003); have proposed a porous barrier between water and the air in order to create a kind of semi-direct evaporaWon cooling. Vallejo (201X) , in His research demonstrate a large scale wall of cooling system with porous ceramic which was designed for 2012 solar decathlon Europe even in Madrid , Spain, where, the project was inspired by tradiWonal central courtyard to cool the air through porous ceramics we^ed by irrigaWon system evaporaWon in central paWo, integrated by cavity wall (Figure9)
However, several studies had revealed disadvantage of direct contact of porous ceramics with water. Schiano-Phan ( 2004) , in her study, mentions the risk of microbiological contaminations and chance of growing harmful bacteria as a direct contact with water.
Figure8 , process of evaporaWve cooling
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Figure9 ,Wall application evaporative cooling system for Solar Decathlon Europe event
Figure10 , Interior and exterior view of pa6o ,Madrid ,September 2012. (Vallejo , 2018)
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As an outcome , indoor environment benefit from radiant cooling as the cooled air driven through the room with the help of small fans placed at the bottom of the walls. Reports show that cavity air temperature remained between 5-10 °C lower than ambient air since occupied air temperature reduced 1-3°C. Although, the indoor achievement is small, the project success in showing the flexibility of the porous ceramics to integrate evaporative cooling method in buildings (Gomes and Herrero, 2018) .The most influencing and inspiring large-scale usage of ceramic screens system in Expo Zaragoza 2008, designed by Francisco Mangado, discussed in their studies. The project used large vertical ceramic columns and misting system to keep the porous surface wet (Figure11) to create a cooler environment around the building. This system reduced the air temperature about 4-7°C with aid of fandriven air flowing downwards in the inner ceramic surface to deliver the air at ground level.
Monitored data proves that surface temperature of the ceramics ranged from 25.2°C -32.5°C when the relaTve humidity was 33.6% and ambient temperature 34.9 °C. This system posiTvely obtained improvement in comfort condiTons during summer season for the visitors and set a precedent for future references.
Figure11, Porous ceramic columns in Expo Zaragoza 2008 and pillar section ,(Vallejo ,2018) 20
Figure12 , Expo Zaragoza ,2008,Spanish pavilion
Figure13, ceramic sections h"ps://www.google.com/search?rlz=1C5CHFA_enIR810IR810&biw= 821&bih=671&tbm=isch&sa=1&ei=6HleXb1j8sGuBNWVqvgM&q=Ex po+Zaragoza+2008+spanish+pavilio&oq=Expo+Zaragoza+2008+spa nish+pavilio&gs_l=img.3...49671.52240..52515...0.0..0.94.1129.16.. ....0....1..gws-wizimg.......0i30j0i5i30.lRiaVV_LPcM&ved=0ahUKEwi995G9rZbkAhXyoI sKHdWKCs8Q4dUDCAY&uact=5#imgdii=6Bg9OpWTJLxlDM:&imgrc= pXh5v61T_AqMnM:
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Referring to an Israeli firm , in 2010 a new ceramic screen cooling system called “Ecooler” inspired from traditional “Mashrabiya” was introduced to the market by StudioKahn . The screen consists of hollow ceramic tiles filled with water and linked to each other with a horizontal and vertical surface (Figure14) The designers stated each sample contained about 550 ml of water and half of this was emptied per day as an average. The data suggested that the system would consume approximately 2.4 litres/m2 .Despite the fact that this system consumes low amount of water, functionality of it has not yet been tested and only the manufacturer has provided the indications on the cooling capacity.
Figure14, Ecooler concept and screen application in indoor spaces ( Juan Vallejo 2018.)
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Water supply system for evapora/ve cooling applica/ons could be high depends on the weather condi/on of the day ,the arrangement of the ceramics and the scale of the applica/on .however that could be a crucial issue in countries struggling with water suppliers. Generally, the water is supplied by mis/ng, dripping or water pipes which enter the porous ceramic and spready through the surface. - A study of cooling system in a residen/al building in Europe designed by students from the university of No?ngham for the 2010 Solar Decathlon even in Madrid, states a water consump/on if 4o litre for five hours of opera/on during a hot day.
This double height two storey building included eight micronisers in misting system and cooled the air drawn through the roof (Figure16) This allowed the system to reduce the ambient air by 12-14 °C, however the relative humidity increased to 4065% from 15% during operating hour. Another monitored data from a greenhouse in Almeria, Spain ,presented temperature reduction of 8°C, with average water consumption 146.3 l/m2 for eight hours of operation per day. (Franco, Valera and Peña, 2014).
Figure15
Figure16, House section showing the summer daytime airflow path and external and internal dry- bulb temperatures monitored during 22nd-24th June 2010 (Ford et al., 2012, pp. 293, 297)
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PROJECT BY ARCHEA ASSOCIATI FIRENZE, ITALY
FIGURE17,NEMBRO PUBLIC LIBRARY AND AUDITORIUM Nembro, Italy 2005-2007
Figure18
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CHAPTER 3
03
SITE STUDIES
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3.1 S I T E L O C A T I O N
Figure19, world map
Latitude 31.705791 Longitude 35.200657
The site is located in Bethlehem, located in central West bank, Pales5ne, About 6 miles south of Jerusalem. The site is located on a hill surface of 8 meter, there are no building with in 100 metres of it. The museum includes exhibi5on rooms, courtyard, the living bridge as phase 1 and the nucleus-cocoon block as phase 2 which is in the process of construc5on.
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3.2 S I T E T O P O G R A P H Y
Bethlehem map
The site has located on hill surface of about 8 meter . As shown in the figure, there are no adjacent building to the site, what would make the area exposed to daylight and prevailing wind .
Figure20, site map
8m
Figure21 , site topography
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3.3 A R E A S P E C I F I C A T I O N 3.3.1 EXHIBITION ROOMS
The proposed scheme consists of several exhibition rooms and offices, emerging with the landscape, the topography of the land itself plays an important role, it accommodates exhibitions rooms by carving into it and let them be a part of the landscape. These rooms are sensitive to the temperature and light since it offers a new way of displaying, the design challenges the large, all-purpose warehouse type of exhibitions rooms, to, small, domestic type of living nests. This space would exhibit plants, bird hall, fish hall, rock hall and etc, also introducing laboratories for the educational Figure22 purposes. 3.3.2 COURTYARD
The proposed courtyard is a key space for gatherings and events organized by the museum, which is inspired from the Palestinian cultural landscape that, courtyards are known for place of activities. interestingly, the existing topography’s steepness created this great opportunity to integrate seating within the landscape, hence, the courtyard becomes desirable for outdoor auditorium/theatre. 3.3.3 THE LIVING BRIDGE Figure23
Adding a suspended bridge provides a strategic connection to the existing building, to make the bridge environmentally comfortable, somewhere for visitors to stand by and observe the building and also to view the courtyard from above. In addition to that, vegetation and shading would be added over and under the bridge for visitors more comfort. 28
The shading strategy uses local vegeta2on to avoid the direct sun penetra2on and overhea2ng, which also benefits the bridge to have a connec2on with the landscape too. The both indoor and outdoor of the museum are connected together, in a case of exhibi2on, small intangible cultural heritage would be displayed indoor and larger items viewed in the courtyard.
3.3.4 NUCLEAUS COCOON BLOCK
The Cocoon is influenced by the tradi2onal rural Architecture in Pales2ne that a no2ceable structure drives visitor to the main room at the entrance. hence, the new building float in the site supported by structural columns and joint with a suspended bridge which is also shaded with the plants and vegeta2ons con2nuing from the sisters building. Interes2ng part of the Nucleus is the environmentally responsive skin around the cocoon. Hence, in order to apply the strategies on the skin, clay 2les, which make the skin, act as a passive cooling system to the cocoon. The Nucleus block comprise the lecture room and ancillary rooms host admin offices that creates a playful scenario. Consequently, the proposed design represents the modern approach to the museum while respec2ng the local condi2ons and cultural features. The proposed architectural design allows addi2onal space for exhibi2ng new pieces, arranging events and separate places for laboratories and educa2onal services. In addi2on to that, all the new forms have a strong connec2on with the local context and tradi2onal landscape. This study focuses on the Laboratory room as shown in (figure). This room has a similar layout as the exhibi2on room and theatre, also, it is the main room of the museum since valuable species are been treated the experiments take place there.
Figure24
Figure25
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3.4 C L I M A T E
Figure26, koppen-Geiger climate classification,
The climate plays an important role in determining the architecture of a city. In accordance with koppen-Geiger climate classification, Palestine has Mediterranean climate type of BSH, hot dry summers and cool winters with slight precipitation.
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3.4 C L I M A T E Monthly Average Climate Data 35.00 DBT mean max
30.00 25.00
DBT mean min
20.00 15.00
Global Horizontal Radiation
10.00
Wind Velocity
o
C
kW/m2
m/s
Warmest months July / Aug 33°
5.00
Coldest months Jan / Feb / Dec 3°
DBT mean average
0.00 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Monthly Average Relative and Absolute Humidity 100.00 90.00
Highest humidity Feb / Jan / Dec 90%
80.00
%
70.00
Lowest humidity May – Sep 20%
60.00
RH mean max/min (%)
50.00
AH mean max/min (g/kg)
40.00
RH mean average (%)
30.00
AH mean average (g/kg)
20.00 10.00 0.00 Jan Feb Mar Apr May Jun
Jul
Aug Sep Oct Nov Dec
Least rainfall May 12mm
50 45 40 35 30 25 20 15 10 5 0
30 27 24 21 18 15 12 9 6 3 0
days
Most rainfall Feb 46mm
mm
Cumulative Rainfall
Rainfall Days
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Most overcast sky Jan
Most sunny sky Jun
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3.4.1 TEMPERATURE
The informa5on presented on the graph is collected based on weather sta5s5cs from metronome meteorological data base 19902001.the graph is showing average maximum temperature of 33°C for August and average minimum temperature could fall as low as 3°C from December to February. It is beneficial to analyse the climate to see the warmest months in order to operate cooling system. Future climate data is not available for selected region , however, based on online sources the temperature is expected to increase and the region would suffer from water resources since the rainfall is expected to decrease.
Palestine is considered as one of the world’s most water-scare region, rainfall is excepted to decrease and the temperature increase. Studies show that this climate change , puts the agricultural industry in risk since half of the water extracted from groundwater wells are being consumed for agriculture.
3.4.4. SKY
The city experience 25 sunny days as an average in June and less than 8 sunny days in Jan. less than 20% cloud cover are considered as sunny, 20-80% cloud cover as partly cloudy and more than 80% as overcast.
3.4.2 HUMIDITY
Rela5ve humidity reaches 90% at night from December to February while it drops to about 20% in day5me from May to August . The absolute humidity ranges from 4g/kg in winter to 11 g/kg .
3.4.3 CUMULATIVE RAIN FALL
Pales5ne experience substan5al seasonal varia5on through a year. January and February experience the highest number of rainy days and maximum cumula5ve rainfall is about 46mm, whereas, in June to September, there are no evidence of rainy days. Under 3 mml is considered as dry in this climate and over 150 mm mostly wet.
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3.5 S U N P A T H S T U D Y
The sun path was developed with the help of weather file generated from Meteonorm. The file was graphically demonstrated and analysed by grasshopper plugin in Rhino. Studying the sun path is important in order to use the sun in a beneficial way. The sun rays access the site from mainly south , and south east . The sun study shows different movement of the sun in Summer, winter and equinox . As shown in sun path diagram, almost 50% of the days from May to August have temperature around 24°C.to 27C.
21st May – 21st Aug
21st December From sunrise 6am unFl 3pm
Equinox- 21st March Almost no morning sun, Sun from 11-7pm
21st July No morning sun, Sun from 1-7pm (sunset)
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3.5. S U N P A T H S T U D Y
Summer Solstice Equinox Winter Solstice
S.V.F
Figure27, Sun Penetra0on in courtyard- lab at 3:00 PM for Summer sols0ce, Equinox and Winter Sols0ce
21st December 12pm
21st June 12pm
21st June 12pm
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3.6. S U N H O U R S
The penetration of sun was observed through the sun hour analysis . The figures represent the exact areas receive direct sun in ‘hours’ per ‘selected time frame of the day The site benefits from high number of sun hours. Average 6 hours of sun is evident for June, average 4 hours of sun for march and average of 1.6 hours of sun for December figures show movement of sun in different seasons and hours .
Average sunlight hour 1st June31st June 6h
Average sunlight hour 1st March31st March 4h
Average sunlight hour 1st December-31st December 1.60 h
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3.7 S U N A N A L Y S I S In the summer 21st June, the day is long about 14 hours. As the sun rises at 3:35 am at angle of 61° from South East-East and sets 17:48 at South West-West . it is clear that the south elevaFon will have the highest solar radiaFon. The solar radiaFon analysis show amount of heat energy and sun light have been transferred to earth. PalesFne has maximum average global solar radiaFon of 800 W/m2 in June and the lowest average solar radiaFon of 300 W/m2 in December and January.
As shown in radiaFon diagrams, in summer , west and east are mostly affected while in Winter south direcFon is mostly affected by high radiaFon.
Daily Average Horizontal Radiation
Highest horizontal radiation in June
9.00 8.00 7.00
kW/m2
6.00 5.00
Global
4.00
Diffuse
3.00 2.00
Lowest horizontal radiation in Jan
1.00 0.00 Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
36
3.8. S O L A R R A D I A T I O N
The solar radiation analysis is used to have better understanding of energy amount falls on the different facades over the year, that is direct result of building orientation overshadowing by surrounding buildings and latitude. Average radiation rate in the site Is as high as 5.9 kWh/m2 in June , due to the fact that they are no surrounding buildings and the site is very exposed. The radiation is conducted for three seasonal different months : January ,June ,March due to the reason that, the most distinctive sun angle happening in this period. The average radiation in January is 3.34 kWh/m2, It is clearly increased to 4.4 kWh/m2.in March. The analysis show that the ground surface is mainly affected in summer season. The greatest amount of irradiation is occurring around the building, the centre of the building where the courtyard is , slightly has lower radiation.
37
3.8 S O L A R R A D I A T I O N
Through cooler days, solar heat gains are welcome however, the analysis show there could be a need for shading ,to protect the rooms from overheaAng.
1st March Facing South-west 6 am to 6 pm The lower angle of the winter sun , leads to radiation dominating on South and south east , 1st January Facing South 6am to 6pm
1st June Facing South-west 6 am to 6 pm
1st December Facing south 6 am to 6 pm
38
3.9 W I N D F L O W A N A L Y S I S To visualize the wind flow generated on the site and across the building, wind simulations were analysed by using CFD (Computational Fluid Dynamics). The wind experiences variable speed at different location highly depended on the local topography and other factors. Average wind speed in the windiest part of the year, that, lasts for 3.7 months , is more than 3.13 m/s .while the city experience 8.3 calm months with average wind speed of 2.9m/s. As shown in wind diagram , in summer , wind is less stronger and it mostly hit the city from west and northwest , while
In winter stronger prevailing wind blows from East and West. In mid-season, wins dries from west and north west. As a consequence, it would be better to consider west and north west as the main direction for natural ventilation. The low height of the rooms and the hill surface , creates a favourable wind pattern . The result of the wind speed in further used to UTCI to measure the outdoor comfort.
Dynamic CFD simula.on, site sec.on , prevailing wind East
39
3.10 C O U R T Y A R D C O M F O R T
The Universal Thermal Climate Index (UTCI) was analysed in order to see how comfortable is the courtyard ,since the lab entrance is from the courtyard and si<ng spaces are located there . The analysis are provided for the 2 criAcal months January and July in three different hours ,morning 9:00 am ,noon 12:00 pm and aHernoon 15:00 pm by lady bug tool, with he same Epw weather file.
32° 35% 4.5m/s
The result show , in winter there is no thermal stress (UTCI less than 26°C but more than 10°C) in the courtyard from 9 :00 am to 12:00 pm , however, slight heath stress in the aHernoon.
1st July9am
1st Jan 9 am
1st July12pm
1st Jan 12 pm
1st July15pm
1st Jan 15 pm
In summer there is moderate heat stress (between (between 28°C and 32°C) in the morning and strong heath stress (above than 32°C) observed in the aHernoon.
12° 66% 3.1m/s
40
3.11 L A B R O T A R Y
Figure28, site plan
LAB SPECIFICATION Figure28 shows the layout of the chosen room in the building, The middle lab is a single-story room with 50 m2 area, in the earth and just at the hill surface. The proposed design for this Lab is a single ventilated opening, with 3.5m height and 6m width, consist of a layer of ceramics with 20 strips of clay accompanied by water pipe through it.
41
3.11 L A B R A T O R Y 3.11.1 LAB VENTILATION In order to provide sufficient fresh air according to CIBSE , 10 l/s per person, is it important to naturally cool down the building in day@me, with help of natural ven@la@on strategy. As men@oned, the lab’s ven@la@on is designed as a single inlet-outlet. As shown in the ven@la@on analysis ,using Op@vent tool, it had this ability to demonstrate the efficiency of the openings. based on the dimension of the room , dimensions of the inlet-outlet , 50% aperture set to the programme and the propor@ons of it, fresh air in not sufficient and there is requirement for cooling, Moreover to that, the room Is not within comfort band also. The inlet is not a fixed window to measure the aperture, however, since half of the inlet in covered with ceramics, the aperture is es@mated to be 50%. As shown in psychometric chart states the comfort band for the region to be between 23°C-27°C. The analysis of the Psychometric Chart with the help of Ladybug Tools, showed that the passive design strategies need to improve the cooling during day @me .
42
LABRATORY 3.11.2. LAB VENTILATION Based on CFD results, as shown in Figure30 , the air movement enters from the bottom of the room ,drives to the top part and exit from there. The temperature is less by the ceramic screens and more by the edges of the room, as seen in the figure, Air is not circulation correctly through the depth of the room . There will ceiling stack introduced in the next chapter to help with the air circulation. Figure29, room wind ďŹ&#x201A;ow
Figure30, room wind flow
Figure31, shows the site section ventilation for single sided ventilation
43
LABRATORY 3.11.3 LAB ELEVATION
Figure32, East facing Section , showing ventilation pattern
Figure33, shows an elevation of the proposed ceramic screens.
44
CHAPTER 4
04
EXPERIMENT
45
4.1 E V A P O R A T I V E C O O L I N G E X P E R I M E N T
4.1.2 EXPERIMENT AIM This experiment seeks to observe the performance of the ceramics screen evaporative cooling system in three different ceramic arrangements, more exposed to the wind, less exposed to wind and mixture of both arrangement. The impact of the different ceramic orientation has been tested in this experiment and the outcome of the different scenarios are compared and analysed.
4.1.3 OBJECTIVES TO FOCOUS CLIMATE CONTROL
To represent the climatic condition of Palestine, the relative humidly and dry bulb temperature need to be maintained as â&#x20AC;&#x153;Temperate dry climateâ&#x20AC;?
WATER EVAPORATED
Keep track of the ceramic weighs when fully saturated and measure after the experiment id done to see how much water evaporated in different arrangement. HYPOTHESIS
In the Evaporation process, water converts to vapor by using the energy from surrounding heat, hence, outcome is reduction of the temperature. Hence; -Drop in dry bulb temperature and increase in relative humidity. -Similar temperature reduction for both scenarios. -Lower surface temperature in the ceramic compare to nearby.
SURFACE TEMPERATURE
Understand the variation in surface temperature of the ceramics in different arrangement TEMPERATURE
Checking the temperature difference near the ceramics between different arrangement and compare to the no ceramic scenario.
46
4.1 4 EQUIPMENT
Ceramics 200mm x 10 mm Wooden column Fan heather Ducting pipe to transfer hot air from the fan to the chamber 150 mm diameter Insulated steel trolley test cell 1240 mm x 755 mm x 810 mm Digital weighting scale trey Anemometer Thermal camera Data logger Thermometer 4.1.5 PROCEDURE
In this experiment the ceramics are made in the lab with the provided clay. Create a wooden mould in the required measurements. Press and roll the clay in the mould until it is uniform. Leave it for a week to dry Leave it for firing in the kiln for half a day. Measure the ceramics weight, while being dry. Put the ceramics in measured amount of water until it saturates (the colour of the ceramics gets darker) Weight the ceramics after saturation. Keep track of the saturation time. Note down the surface temperature of the ceramics. Connect the heater with the pipe to the chamber for the hot air to pass through inlet. Take measurements of the temperate and humidity of the room Figure33, experiment recorded photos
47
Switch on the fan and try to keep the temperature of the inlet close to the desirable condi6on. A9ach the ceramics with the wooden column and place it according to the chosen arrangement. Take measurement of the humidity, temperature, wind speed near the inlet and the ceramics. Tale surface temperature of the ceramics and surrounding the chamber Keep repea6ng the process for at least 30 minutes. Make sure the inlet temperature stays the same or switch it oďŹ&#x20AC; In case of high temperature. Check the surface temperature and record the values. Remove the ceramics from the column and take it out of the chamber. Weight the trey in case of any collected water. Measure weight of ceramic, and calculate the amount of water evaporated. Calculate the rate of evapora6on Repeat the same procedure with the other two arrangement. Make sure you leave some6me for the chamber to cool down and reach the ini6al temperature.
4.1.6 LIMMITATION
The experiment is done in the basic standard in the university lab to result in some suggestion for the cooling system better performance, Findings could be not accurate due to the reason that flexible pipe does not attach to the chamber tightly and that increases the chance of heat loss and infiltration. The opening of the chamber in wide and exposed to the lab environment, that could affect the result of the temperature measurement near the ceramics. Achieving desirable climatic condition in the lab is limited since you are not able control the room temperature , the result could be not accurate due to this issue.
48
4.2 F I R S T S C E N A R I O In the first scenario , three ceramics with the arrangement shown in Figure34 , are located inside the chamber with 10cm distance from each other. The data is recorded with two data loggers, one located inside the chamber where the heating source is blowing , and the other one is located externally, near the ceramics as shown in Figure35. Thermometer and anemometer are also placed externally, near the ceramics (Figure36,37) to measure the temperature and the velocity .
Figure35
Figure36
Figure37
X3 20 cm
10 cm
10 cm Figure34
Water pipe
Depth of the chamber 49
Hea1ng source Figure38
4.2.1 O B S E R V A T I O N
Recorded temperature of the room with thermometer
44.6% 23.8C
The lab temperature and humidity is recorded as 23.8 ° and 44.6%. The temperature near the ceramic is remaining stable on 25°C ,after 30 minutes .. All the outcome temperatures will be compared with chamber temperature(inlet) as base case temperature. Weight of the ceramics before and after saturation are recorded as seen in Figure40. After switching the fan on , the temperature inside the chamber started rising until it reached 36°38°,the wind velocity near the fan is recorded as 1.1 m/s and 0.1 near the ceramics. Figure39 shows porosity of the ceramics based on the formula provided . The observation for the first scenario took almost 30 minutes. Surface temperature dropped considerable at the first 10 minutes to 21° -22 °(Figure40 ). Weight of
( wet ceramic – Dry ceramic ) X 100 ( wet ceramic – water )
Porosity calcula<on for ceramics
1.1 m/s
0.1 m/s Near ceramics
Inside chamber
25°C
Objects
27°C
Weight in Porosity Kg
Weight of Ceramic 1 0.461 g dry Ceramic 2 0.400 g ceramic Ceramic 3 0.425 g Weight of water added
1) 12.5% 2) 18.6%
0.5 L
Weight of Ceramic 1 0.520 g wet Ceramic 2 0.480 g ceramic Ceramic 3 0.490 g
3) 14.7%
Figure39
Saturation time : 7 mins Waters used: 0.5 litre No water collected from the tray
Surface temperature
Dry
Wet
After 5 min
After 10 Min
Ceramic 1
26°
26°
23°
23.8°
Ceramic 2
26°
25°
22°
23°
Ceramic 3
26°
25°
23°
23.2°
Figure40
50
Data logger 2 ( Inlet )
4.2.2 D A T A O U T C O M E CONTINIUES MONITORING
Data logger two, shows the temperature and humidity near the ceramics . As shown, the temperature started decreasing from 27°C to 25.02°C. The data is collected every 5 minutes in duration of 30 minutes. Data loggers one (Figure42), inside the chamber , shows the temperature reduction when the fan is switched on, and how it decreases by switching off the fan . however, humidity , stays high in both cases. Ceramics have helped the temperature to decrease by 1.8°C. Weight of ceramic 1 after evaporation in this case: 0.491
OUTSIDE CHAMBER 1st Scenario 27.500 °C
48.0 %RH
27.000 °C
47.0 %RH 46.0 %RH
26.500 °C
45.0 %RH
26.000 °C
44.0 %RH
25.500 °C
43.0 %RH
25.000 °C
42.0 %RH
24.500 °C
41.0 %RH
24.000 °C
40.0 %RH 1
2
3
4
5
Temperature
Figure41
6
7
8
Humidity
Data logger 1 (outlet)
INSIDE CHAMBER 1st Scenario 30.500 °C
40.0 %RH
30.000 °C
35.0 %RH
29.500 °C
30.0 %RH
29.000 °C
25.0 %RH
28.500 °C
20.0 %RH
28.000 °C
15.0 %RH
27.500 °C 27.000 °C
10.0 %RH
26.500 °C
5.0 %RH
26.000 °C
0.0 %RH 1
2
3
Temperature
4
5
Humidity
Figure42
25.02°
27°
47%
38.5 %
2
1 Figure43
51
Thermal camera
4.2.3 R E S U L T The surface temperature has been monitored with a thermal camera for 20 minutes and the readings show that there is a uniform heat distribution , the temperature is reduced in range of 1-2 degree less than wet bulb temperature.
Figure48
Wind circula=on
Figure44
Starting point
Figure45
DBT(°C)
WBT(°C)
ST(°C)
25
13.3
23.2
Figure52
Based on the CFD results, this arrangement of the ceramics, which is less exposed to the air, Have 0.4 m/s wind speed only by 0.55 meter away from the panel ( Figure46). This could mean that only people near by the ceramic by 0.5 meter can feel cooler. Compare to people sitting at the bottom of the room . Figure47 , shows how the air flows near the ceramic in this case of arrangement. As demonstrated in Figure50,51, illuminance of the lab is reduced by 30 % after applying the ceramic panels. The shading effect of this arrangement works well.
Figure49
After 20 minutes
Illuminance ,Ceramic panels applied
Wind flow
Figure46
Figure50
Figure47 Figure51
Illuminance , ceramic panels not applied
52
4.3 S E C O N D S C E N A R I O INSTALATION To test the second arrangement we need to cool down the chamber for at least 30 minutes in order to obtain more realistic results. In this case, three ceramic are arranged in a way that is more exposed to the flowing wind. Figure54.
Inside Chamber
Close to ceramics
After 10 min
Surface Temperatur e
26.7째
22.3째
22.4째
Wind velocity
1.1 m/s
0.1 m/s
0.1 m/s
Figure53
Surface temperature has dropped to 22.3 째C and remained low for a longer time compare to the surface temperature of the first scenario. This means that the previous arrangement, evaporated more water since it had less area exposed to wind. Wet ceramic weight 0.550 Weight after evaporation 0.535
Figure54
Figure55
X3
Figure56 53
Data logger 1( Inlet )
4.3.2. D A T A O U T C O M E The result of data loggers show that the temperature near the ceramics have reduced by 2 degree, from 26.4° to 24.4°. Data logger 1 , also shows temperature has decreased from 27.3 to 26.4, since it cools down after the fan switched off..
INSIDE CHAMBER 2nd Scenario 27.400 °C
40.0 %RH
27.200 °C
35.0 %RH
27.000 °C
30.0 %RH
26.800 °C
25.0 %RH
26.600 °C
20.0 %RH
26.400 °C
15.0 %RH
26.200 °C
10.0 %RH
26.000 °C
5.0 %RH
25.800 °C
0.0 %RH 1
2
3
4
Temperature
5
Humidity
Figure57
Data logger 2 (outlet)
OUTSSIDE CHAMBER 2nd Scenario 27.000 °C
47.5 %RH
26.500 °C
47.0 %RH
26.000 °C
46.5 %RH
25.500 °C
46.0 %RH
25.000 °C
45.5 %RH
24.500 °C
45.0 %RH
24.000 °C
44.5 %RH
23.500 °C
44.0 %RH
23.000 °C
43.5 %RH 1
2
3 Temperature
Figure58
24.4°C 46.6 %
2
4
5
6
Humidity
26.4°C 36.6%
1
Figure59
54
4.3.3 R E S U L T
A;er providing the same environment and repea?ng the experiment this ?me for the second ceramic arrangement, it can be Cleary seen from the CFD results Figure64, that ;the air circula?on is improved and it goes through almost half of the lab , people would feel cooler if siHng by 2 meter from the panel.
Thermal camera
Figure64 Figure60
Starting point
Wind circulation
Figure65
Figure61
A;er 20 minutes Surface temperature captured from thermal camera, is less than the first case, that means the water was evapora?ng more in the first case, since the air blockage ra?o was higher. However, this ceramic arrangement does not provide enough shading , and it works weaker than the first scenario. (Figure66 )
Figure66
Illuminance ,Ceramic panels applied
Wind flow
Figure62
Figure63
DBT(°C)
WBT(°C)
ST(°C)
25°C
23.4°C
22.5°C
Figure67 55
4.4 T H I R D
SCENARIO
INSTALATION This case produced after finalizing this arrangement works better for cooling the air and less water evaporates in this arrangement, compare to the first scenario . Due to the fact that previous arrangement only reduced the temperature by almost 1.8 °C to 2 °C , this scenario aims to test the temperature after duplicating the layer, means increasing the number of ceramics , and placing the same layer behind it.
Figure68
Objects Weight of dry ceramic
Weight in Kg Ceramic 1,4
0.461 g
Ceramic 2,5
0.400 g
Ceramic 3,6
0.425 g
Figure69
X8
Figure70 56
Data logger 1 (Inlet ) INSIDE CHAMBER 3rd Scenario
4.4.1 D A T A O U T C O M E Data loggers in this case, have shown a high drop of temperature compare to the other 2 cases. The temperature near the ceramics , remained constant at 23.1°C. (data logger 2) . Recorded data , demonstrate high rise of humidity which is 56% at the 7th point with is 35 minutes of the running time. The temperature started remaining constant from 6th point . Figure73 shows the wind flow from the ceramics
28.000 °C
45.0 %RH
27.800 °C
40.0 %RH
27.600 °C
35.0 %RH
27.400 °C
30.0 %RH
27.200 °C
25.0 %RH
27.000 °C
20.0 %RH
26.800 °C
15.0 %RH
26.600 °C 26.400 °C
10.0 %RH
26.200 °C
5.0 %RH
26.000 °C
0.0 %RH 1
2
Figure71
3 Temperature
4
5
Humidity
Data logger 2 (outlet) OUTSIDE CHAMBER 3rd Scneario 27.000 °C
60.0 %RH
26.000 °C
50.0 %RH
25.000 °C
40.0 %RH
24.000 °C
30.0 %RH
23.000 °C
20.0 %RH
22.000 °C
10.0 %RH
21.000 °C
0.0 %RH 1
2
3
4
Temperature
5
6
7
Humidity
Figure72
24.02°
26.7°
56%
38.5 % .
2
1
Figure73
57
4.4.2 R E S U L T Based on the data collected ,this case, helps with the shading a lot more as seen in Figure77. Surface temperature had variable results, the first row arrangement clearly had lower surface temperate , the row behind it had higher surface temperature, since it was closer to the heating flow.
Figure74
CFD result shows the wind distribution through the room. Double layer strategy help the air to filter twice, in a way that the warmer air touches the first layer and its temperature reduces, after it passed by the gap between two layers, hit the ceramics of the second layer and looses its wet bulb temperature temperature more.
Wind circulation
Figure75
Figure76
Wind flow
Illuminance ,Ceramic panels applied
Figure77
DBT(°C)
WBT(°C)
ST(°C)
Front layer
25°C
23.4°C
22.9°C
Back layer (closer to heating)
25°C
23.4°C
21..8°C 58 Figure78
4.5 D A T A C O M P A R I S O N First Scenario
DBT (°C)
WBT(°C)
Humidity(%)
Surface Temperature
Water evaporated(g)
Inlet
27
16.5
38.5
27
Outlet
25.02
13.3
47
23.2
0.029
Water evaporated(g)
Figure79
Second Scenario DBT (°C)
WBT(°C)
Humidity(%)
Surface Temperature
Inlet
26.4
17.1
36.6
26
Outlet
24.4
14
46.6
22.5
0.015
Water evaporated(g)
Figure80
Third Scenario DBT (°C)
WBT(°C)
Humidity(%)
Surface Temperature
Inlet
26.7
18
38.5
27
Outlet (Front row)
23.1
15.8
56.5
21.8
0.011
Outlet(back row)
23.1
15.8
56.5
22.9
0.015
Figure81
59
4.6. W A T E R C O N S U M P T I O N Based on the tool designed by Juan Vallejo , data shows that during the operation months and hours, which are expected to be May-September 12- 18, the amount of water consumption for 1 ceramic panel is expected to be 32 liters per day. However, as mentioned in previous page, water consumption can vary depends on the orientation of the ceramics. In first scenario more water in used compare to the second scenario, since ceramics are less exposed to wind and that position blocks the wind from entering to the room. Based on the calculations, each room would need 32 liters , in the best performance, and the cocoon consist of 56 ceramic screens would use 1792 liters if all of the panels are supposed to be wet. However, this number will be increased due to the high rate of evaporation in the site since the radiation is extremely high .
Monthly Average Climate Data 35.00
m/s
30.00 25.00
kW/m2
20.00 15.00
o
C
10.00 5.00
Figure82, water consumption, tool analysis
0.00 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
60
4.7 C O N C L U S I O N
Since single sided ventilation, was not sufficient, ceiling stack was introduced to circulate the air through the depth of the room and improve the cooling system performance. Effect of evaporative cooling method is significant, particularly for hot and high dry bulb temperature. It is clear that the effect of this method will be more substantial in a larger scale. In regards with the ceramic material, shape , orientation and the porosity of the object effects the evaporation and performance of the system. With the correct application , the system will achieve effective performance. Nevertheless, the physical properties of evaporator and its material , would have an effect of the cooling process .. In the first 2 scenarios , the temperature dropped only by maximum2°C,however by increasing the number of the ceramics and locating them behind the first row, the temperature dropped by about 4°C. water consumption is less in the second scenario due to the position of the ceramics .
61
CHAPTER 5
05
Design project
62
5.1 D E S I G N P R O P O S A L
The results of the experiment in the first and second scenario , have proved that the ceramic screens cool down the space almost by 1-2°C and the CFD results suggest that people nearby the ceramics can benefit from reduced temperature.
Since the design combines traditional Arab architecture with modern integration, using the ceramics in the museum, make the visitors realizes, vernacular architecture is still usable in modern architecture.
However, the 3rd scenario , evident that, the more number of ceramics and arrangement of the layers can reduce the temperature more than 2-3°C. This temperature reduction is potentially for the ceramics with double layer and behind each other. This arrangement lets the air to cool down twice, due to the fact that it compacts in between the layers and pass through two ceramic screens.
Due to the high evaporation and water crisis of the area, it is decided to combine two cooling strategies ,in order to optimize the design performance .
Apart from the cooling strategy of the ceramic panels, shading is also an important role of this system.
Figure83, Wall integration ceramics
Each wall is a mixture of ceramic screens and wall integrated ceramics. It is beneficial to cover the ceramics and create shading for them to minimize the evaporation On the walls, a gap for hot air to enter the cavity , and a gap for cool air to enter the room is considered. The position of the wall is chosen according to the wind flow.
Figure84,Site overheating issue will not effect 63
5.2 S C E N A R I O C O M P A R I S O N
Figure85, East facing section of the Lab showing 1 layer screen
27 °- 28 °
30 °
Outside temperature
Figure86
Inside temperature 64
SCENARIO COMPARISON
Figure87, East facing section of the Lab , showing 2 layer screens
28째
30 째
Outside temperature
25 째-26째
Inside temperature
65
5.3 L A B W I N D P A T T E R N
Figure88 , East facing section of the Lab CFD, showing wind pattern and temperature difference. Provided stacks , helping the air circulation in room , resulting in better performance of the cooling screens.
66
5.4 R O O M S S P E C I F I C A T I O N
Entrance Exhibition room 1 Office 1 17.5 m2 35 m2
Figure89 Figure93
Laboratory 50 m2
Office 2 16 m2
Figure90 Figure94
Exhibition room 2 Ground floor 110 m2
Office 3 14 m2
Figure91 Figure95
Exhibition room 2 First floor 40 m2 Figure92
67
5.5 R E N D E R S
Figure96, Offices view, showing the wind flow through the wall integrated ceramics and the ceramic screens. 21st July 12:00 pm
68
RENDERS
Figure97, Lab elevation , East facing 21st July 3:00 pm
69
RENDERS
Figure98, East facing , demonstrating combination of wall integrated system and ceramic panels. 21st July 11:00 am
70
RENDERS
Figure99, Render of the biggest size office , 21st July 3:00 pm
71
RENDERS
Figure100, Interior render of the Lab room
72
5.6 S I T E P L A N
Figure101, Ground floor plan of the cocoon
Figure102, Top floor plan of the cocoon
73
SITE PLAN
Figure103, Top floor plan of the cocoon, showing offices layout
74
EP
TP
SITE PLAN
n ptio rece
office
wc
EP
office
EP
EP
Admin block
Figure104, Floor plan for lab and exhibition rooms, showing rooms layout
courtyard -entrance level
75
Bozorg
Zeynab
W1 5 5 2 3 04 02
09
2019
10,208
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