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Camel’s nose strategy: New innovative architectural application for desert buildings
Solar Energy 176 (2018) 725–741
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Camel’s nose strategy: New innovative architectural application for desert buildings
T
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Merhan M. Shahda , Mostafa M. Abd Elhafeez, Ashraf A. El Mokadem Architecture and Urban Planning Department, Faculty of Engineering, Port-Said University, Port Said, Egypt
A R T I C LE I N FO
A B S T R A C T
Keywords: Biomimicry Architectural application Desert buildings Camel nose system
As desert areas represent the most of the Arab countries lands, hence, these areas suffer from scarcity in the sources of water in addition to high temperatures. Furthermore, these areas encounter an increased demand for non-renewable energy resources, in order to achieve thermal comfort for individuals. Accordingly, this paper focuses on how Biomimicry science could be employed in designing and innovating an architectural product compatible with the desert environment to be a part of the desert ecosystem. Hence, this paper is devoted to explore the camel as the best-adapted animal in the desert environment, through focusing on camel nose technique. Thus, this paper attempts to prove the hypothesis that: Buildings can be designed in compatible with the desert environment, by simulating the adaptation method of the camel nose technique. Moreover, this paper raises some questions and seeks to answer them through a practical model. to design a system for buildings to obtain water from the air? • IsIs itit possible to design a system for buildings to help in reducing high temperature? • Howpossible • can increasing the exposed surface of the vaporization assists in increasing the rate of cooling?
A new architectural application has been suggested in this paper to simulate “Camel Nose System” where scientific experiments have been conducted to test the efficiency of this model, starting with the designing stage, manufacturing and the implementation of the applied model. Consequently, after the stage of analysis and results, the paper has reached through scientific experiment many results including, (1) calcium chloride as a moisture-absorbing material can absorb 1.3 L of water depending on the special conditions in the Egyptian desert atmosphere, (2) the reduction of temperature to 5° and the humidity has increased to 20%. This new architectural application has been utilized to improve desert buildings.
1. Introduction As a matter of fact, nature is the source of inspiration for architects as it is for scientists. However, there are not sufficient studies that conclude and devise solutions from nature to all areas of science and architecture. Humans whom God has distinguished by a lot of abilities which differentiate them from other organisms, where their bodies are provided by a lot of environmental control means which enable them to adapt to several changeable circumstances around them. However, the human's ability to adapt to the surrounding environment is almost limited compared to organisms, but God granted the human mind to think, analyze and understand, how organisms can adapt to the environment and then apply this in the science fields, including architecture (see Fig. 1).
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Therefore, scientists investigated nature trying to use a variety of achievements and attempt to assimilate them. Accordingly, a branch of knowledge appeared called “Biomimicry” which means (Nature Simulation) is an innovation method that seeks sustainable solutions by emulating nature's time-tested patterns. Biomimicry can become a mean for the integration of architecture product with the environment and become a part of the ecosystem of the environment “Closed circle”. Desert lands represent most of the area of the Arab countries. Consequently, these areas suffer from scarcity in the sources of water, high temperature and increased demand for non-renewable energies, to achieve thermal comfort for individuals, without paying attention to trying to apply Biomimicry. Therefore, this paper problem lies on how can Biomimicry science be employed in designing and innovating architectural product compatible with the desert environment to be a part of the desert ecosystem, as the desert organisms coexisted, without
Corresponding author. E-mail address: [email protected] (M.M. Shahda).
https://doi.org/10.1016/j.solener.2018.10.072 Received 22 August 2018; Received in revised form 14 October 2018; Accepted 26 October 2018 0038-092X/ © 2018 Elsevier Ltd. All rights reserved.
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Fig. 1. Comparison between human and organism through the adaptation methods and possession of the mind. Source: Drawn by the author. Fig. 2. The Nile Valley and Nile Delta covers 5.5% of the total area of Egypt, Where the concentration of population. Source: Drawn by the author.
damaging the ecosystem. Accordingly, this paper focuses on the most important animals in the Arabian desert and the most adapted ones to the desert environment.
temperatures and humidity, daily, in Egypt. By analyzing and studying the Egyptian desert areas: Sinai, Eastern Desert, Western Desert (Shahda, 2015), it is obvious that the most serious difficulties in desert areas are (1) Humidity: low during the day, high at night, (2) Temperatures: high during the day, low at night. (3) Water scarcity. Here were appeared some questions: What organism is able to adapt to these difficulties?; What is the adaptation method of this organism?
2. Background: Why the desert; Why Camels? This part of study intends to answer some questions; Why the desert; Why Camels? Moreover, aims to analyze the natural characteristics of the desert environment, to prevail over the most crucial difficulties in the desert environment. 2.1. Why the desert?
2.3. Why Camels? Approximately 1/3 of Earth's land surface is a desert. A desert is a barren region that receives very little precipitation - less than 250 mm per year (about ten inches) (Meigs, 1953, 1957). Thus, living conditions are hostile for plant and animal life. The search cares about warm desert areas which include most of the Arab regions, including the (Arab Republic of Egypt) spatial scale of the search. The desert environment is characterized in this region by the following: lack of rain, prevails drought, extreme poverty in plants and the scarcity of the animals (The World's Largest Deserts, 2018; Desert, 2018). There are basic factors, which exist in arid desert torrid areas which force organisms to adapt to its cruel climatic and environmental conditions (Naseer, 2005; Laity, 2009). Hence, the following are the characteristics of hot deserts:
It is beyond doubt that all beings reflect the endless power and knowledge of their Creator. This is expressed in numerous verses in the Qur'an where it is pointed out that everything created by Allah is actually a sign; The 17th verse of the Surah Al-Ghashiya tells us about “camel”. “Will they not regard the camels, how they are created? (17)” (Holy Quran, Surah Al-Ghashiya), the fact that has to be carefully examined and thought of. In this part, this animal on which the Qur'an invites us to ponder by the expression, “Do they not look at the Camels, how they are created?” will be tackled in this study. The characteristic feature of the camel is its body structure, which is not affected even by the most severe conditions. Many characteristics of the camel prove that this animal is created particularly for dry climate conditions (Schmidt-Nielsen, 1964). The Arabian camels are found in the very hot deserts of North Africa and the Middle East (Nelson et al., 2015). For many characteristics of the camel can be referred to Shmida et al. (1986), Johnson (2011), Langman et al. (1978), Roberts (1986), Hill et al. (2004), Rastogi (1971).
• Daily thermal extent is long. • High values of solar radiation. • High temperature. • Shortage of water resources, dryness and low relative humidity. • The scarcity of food sources. • Openness and extension of the surface of the earth.
2.4. The camel's adaptation in the desert environment and how can this adaptation be exploited in architecture?
2.2. The natural characteristics of desert environment in Egypt Camels have countless adaptation techniques that allow them to live substantially in desert conditions, for many methods to the camels' adaptation in the desert environment can be referred to Shahda (2015), Schmidt-Nielsen (1972, 1956), Nasal Surfaces Remove Water Vapor, Rundel and Gibson (2005), Halpern (1999), Harun (1999), Yagil (1985). Therefore, at this stage of the search, the research tries to prove this hypothesis:
Egypt is predominantly desert. The desert environment land in Egypt is 95% of the total area of Egypt. The Nile Valley and Nile Delta are the most important regions, despite covering only about 5.5% of the total area of Egypt which is cultivated and permanently settled and supporting about 99% of the population (David and David, 2002) (see Fig. 2). There is the desert environment in the three regions of Western Sahara and the Eastern Desert and the Sinai Peninsula (Geography of Egypt, 2018). This study is intended to compatibility with conditions and characteristics in the Egyptian desert, to propose an architectural model under such conditions. To determine the climatic conditions of the case study, the maximum and minimum temperatures average and relative humidity were analyzed for some cities which fall within the scope of the desert lands in Egypt. Fig. 3 shows the average
Since camels can survive in a desert biome because of its physical features, thus, desert buildings can be adapted with the desert biome by mimicking the adaptive methods of the camel. Moreover, how to analyze the organism “camel”, to approach a new scientific hypothesis that can be formulated architecturally. Accordingly, the study focuses on one of
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Fig. 3. The average temperatures and humidity, daily, Egypt. Source: (Beautiful weather Graphs and Maps, 2018).
temperature. When it is exhaled, it is cooled even further by passing over the same nasal membranes, this time by a process of dehumidifying instead of humidifying, the nasal membranes are coated with a special water-absorbing substance that extracts the moisture from the air like the cooling coils of a dehumidifier. A net savings of 68 per cent in the water usually lost through respiration occurs just between the cooling and drying phases of the breathing cycle (Croome, 2013; Clements-Croome and Croome, 2013). The mechanism responsible for the cooling of the exhaled air is a simple heat exchange between the respiratory air and the surfaces of the nasal passageways. On inhalation, these surfaces are cooled by the air passing over them, and on exhalation heat from the exhaled air is given off to these cooler surfaces. In camels, the arterial blood in the carotid rete is cooled by the cold venous blood before entering the brain. The blood cooled in the nasal cavity by evaporative heat loss is diverted to the brain sinuses via the nasal and angular veins (see Fig. 4). This leads to a significant cooling of the brain tissue. Thus, the camel has the brain cooling system gives it the ability to withstand intensely high body temperatures without damaging it's brain due to this cooling system. The brain cooling system not only provides protection for the brain in extreme temperatures, but it also allows the camel to have a wider range of tolerance for hot conditions (Elkhawad, 1992). The camel is able to survive in temperatures that would normally be lethal to the other creature's brain. Fig. 5 shows the size of the large disparity between the temperatures through the camel's head, which is exposed to high temperatures in the desert that up to above than 45 °C, the temperature of the nose appears between 40 and 35 °C. The temperature drops in the turbinates area of 25–20 °C, and it appears a significant reduction in the brain
the properties of camels' adaptation: Camel's Nose, as it will be demonstrated in the context of this study.
3. A new innovative idea, inspired by the Camel's nose How does Camel's nose work? In 1979 Schmidt-Nielsen linked up with Zoologist Amiram Shkolnik and discovered that the real secret of the camel's remarkable ability for desert survival is found in its ingeniously designed nose and discovered the secret of the camels aircooling ability. The camel makes use of two principles of physics: cooler air holds less moisture; and the greater the surface area, the faster the rate of evaporation or condensation. Evaporation results in cooling (Warren, 1982). K. Schmidt-Nielsen, R. C. Schroter, A. Shkolnik found an intricate labyrinth of narrow highly scrolled air passageways in the camel nose, which greatly increases its surface area available for heat and moisture transfer. Typically, a human nose has only about 160 cm2 of an interior surface area, while the camel has about 1000 cm2 of mucous membrane on the nasal interior. This intricate labyrinth named “Turbinates”, are spongy nasal bones, and the camel turbinates are highly scrolled, providing narrow air passageways and a large surface area for water and heat exchange (Schmidt-Nielsen, 1981a, 1981b). Camels can reduce the water loss due to evaporation from the respiratory tract in two ways: (1) by decreasing the temperature of the exhaled air (2) by removal of water vapor from this air. Camel's nose acts as both of humidifier and dehumidifier with every breathing cycle. The hot, dry air that is inhaled passes over the large area of the moist membrane. This air is immediately humidified by picking up moisture from the nose and is cooled in the process. This cooler air passes to the lungs and remains at approximately body
Fig. 4. The cooling system for the head and brain of a camel. Source: (Elkhawad, 1992). 727
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4. Proposed architectural model using “Camel's nose” system To prove the hypothesis research in a practical way, Camel's Nose technique must be analyzed through the physical and engineering sciences (see Fig. 8). The techniques are “1-The dew point. 2-Humidity. 3Increase the exposed surface for cooling or evaporation. 4- Condensation and vaporization. 5- Absorbent materials to moisture. 6- Solar energy as an energy source”. – These techniques can be reviewed in more depth by reference to Horstmeyer (2006), Chaker et al. (2002), McNaught and McNaught (1997), Solar Energy Perspectives (2011), Abdou (2000). – Even, we can get the foundations and criteria for drafting an architectural model and we can take advantage of these technologies in the proposed model.
Fig. 5. Camel thermoregulation. Source: http://www.worldofwarmth.com.
4.1. The idea of the proposed model After studying and analyzing all the foundations and criteria, which the hypothesis is based upon of architectural application which are inspired by the Camel Nose System, and the spatial determinants. At this phase of the study, a suggestion of the perception of the proposed model. Fig. 9 shows the design idea of the model, where it can be summarized in the following steps:
Step 1 The model needs to provide water for use in cooling the building, with the scarcity of water in the desert, as well as the opportunity to increase humidity in the desert atmosphere at night, water can be provided by pulling air humidity at night. The fact that could be achieved by using a moisture-absorbing material
Fig. 6. A brief analysis of the Camel's Nose idea. Source: drawn by the author.
temperature up to 11 °C.
Step 2 After pulling a large amount of moisture by the absorbent material, how can the water be taken from it? The design must succeed in evaporating this moisture to become water vapor, through the exploitation of large solar energy in the desert, by exposing the moisture-absorbing material to sunlight in a closed vacuum to cause evaporation of water vapor
3.1. A brief analysis of the Camel's nose idea Fig. 6 summarizes the idea of the camel's nose, where the temperature of the inhaled air is elevated up to 45 °C. Hot air is exposed to moist surfaces which it is called turbinates, the air becomes humid. Relatively cold air enters the camel body. Exhaled air is saturated with water vapor, exposed to the wet and cold turbinates, water vapor condenses on these surfaces. So the camel does not lose water when exhaling process. The result is very low temperatures inside the body and the brain of the camel in a remarkable way. Moreover, camel provides a portion of the water needs through the process of breathing.
Step 3 Water vapor that evaporated in moisture-absorbent material, must condense on the surface which is relatively colder than the ambient temperature. As in the nasal turbinates surfaces in the camel's nose, this is achieved by designing the shaded surface from the heat-insulating material. It is preferred in the design to achieve an increase in the surface exposed to condensation Step 4 The technique of collecting condensed water on the surface is very important. This could be achieved by designing the path to collect water from the surface, and the connection with a tube, where the water is going to get into the burlap. It is important to design the tank to collect the water, to facilitate its use to the extent required in the ventilation and humidification
• The camel's nose acts as both of humidifier and dehumidifier with every breathing cycle. • The camel uses another principle of physics: the increase the surface area is, the faster the rate of evaporation or condensation. • The camel has a brain cooling system. • Camel can meet part of its needs for water, by condensing the water
Step 5 The dry hot air that prevails in the desert weather, is pulled into the building by ventilation fan air installed on the ventilation hole of the building. A group of burlap slices is placed before the ventilation fan. Materials such as straw and burlap are considered as materials which work to increase the area allocated for evaporating
vapor which comes out with the exhaled air.
Step 6 The water that has been collected in the tank is being used by spraying burlap which was placed in front of suction in the ventilation slot, when the dry hot air passes on wet burlap. The water would gain a part of the heat of the air, and then a part of the water evaporates. During that, a drop-in temperature occurs inside the building and the air is saturated with an amount of water and becomes moist air
In the framework of trying to prove this hypothesis, the study tackles questions and tries to answer them through practical model for the vacuum architectural (see Fig. 7).
• Is it possible to design a system for buildings to obtain water from the air? • Is it possible to design a system for buildings to help in reducing the temperature of the interior spaces? • How can increasing the exposed surface of the vaporization or
4.2. Proposed models The study suggests nine models, taking into consideration that each model is being developed through the following model and so on. Where the models were designed one after another. The design of the model has been modified based on any problem appeared in the previous model, to get the final version, which is expected to be extremely
condensation to increase the rate of cooling?
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Fig. 7. Summary Analysis about camel's nose (water recycling system). Source: Drawn by the author.
Fig. 8. The foundations and criteria for drafting an architectural model. Source: Drawn by the author.
Fig. 9. The idea of design. Source: Drawn by the author. 729
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To make the calculation and Measurement easier
Fig. 10. The idea of proposed models, Final version V 9. Source: Drawn by the author.
1 cubic meter Fig. 11. Converting the theoretical model to practical model. Source: Designed and drawn by the author.
on the southern facade of the building, where it is exposed to the sun for a long time. It consists of a glass box with a door at its bottom that opened at night and closed during the day. The top of the glass box surface is sloped. There are two tanks to collect the condensed water. There is a slot for ventilation on the wall of the room, the ventilation hole consists of a layer of burlap, where there is a ventilation fan behind this slot. The operation system of the proposed model: The door of the glass-box is opened at night. Absorbent material is exposed to
positive. For more details, the diligent reader can refer to Shahda (2015). Accordingly, the nine versions of architectural applications can be applied to southern facade for desert buildings, where the southern facade is more exposed to sunlight for long periods during the day in Egypt. The model is presented through the following points: “Proposed design; Design description; The operating system of the proposed model; Evaluation of the design”. Fig. 10 shows the design idea of the proposed models, Final version V 9. Design Description: The design is a treatment that can be located 730
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A glass lid of the glass prism
Tightly closed glass prism The steel drawer colored Black
A Fig. 12. A change in the design of the glass prism and steel base. Source: Designed and drawn by the author.
Fig. 13. A change in the design of the water storage technique in the tank. Source: Designed and drawn by the author.
Separated model
An integrated model Fig. 14. Separate the solar collector from the model facade. Source: Designed and drawn by the author.
atmospheric humidity, which is great during the period of dawn. In this study, the ability of calcium chloride has been tested as an absorbent material to absorb moisture (water vapor) from the air (Shahda, 2015). The result of the experiment has been proven:
phase 5: results phase 4: analysis
1. The high capacity of calcium chloride to absorb moisture from the air. 2. Dawn has been selected as the time where the percentage of humidity is at the highest level. 3. The sunlight must be focused on the container to occur the condensation. 4. The inner surface of the container must be painted black, to absorbs the largest amount of sunlight. 5. The container must be isolated from the floor below to prevent heat loss. 6. It is preferred to think of how to increase the exploitation of solar energy, to get the best results.
phase 3: implementation phase 2: fabrication
Phases of the proposed experimental model
phase 1: design
Fig. 15. Phases of the proposed experimental model. Source: Drawn by the author.
For more details, the diligent reader can refer to Shahda (2015). In the early morning, the door is closed, the glass-box is exposed to 731
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Fig. 16. The proposed design with solar collector, Perspective. Source: Designed and drawn by the author.
Fig. 17. The proposed design, section. Source: Designed and drawn by the author.
temperature. Evaluation of design: By comparing this proposal with the previous versions (Shahda, 2015). This model is superior in the following:
sunlight during the day. The heat of the sun evaporates moisture which is collected in the moisture-absorbent material, water vapor heads to the surface and condenses on it. The condensed water is collected in a tank, then the water pipes splash the water over the burlap. The fan pulls the hot air. Hot air passes over burlap dampened with water. Thus, cool wet air enters the room with a remarkable decrease in
1. Tightly closed glass-box means that the opportunity of condensation would be great, this increases the chance of condensation of water 732
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Fig. 21. Stage 4: Calcium Chloride absorbs the moisture from the air. Source: Designed and drawn by the author. Fig. 18. Stage 1: Design and implementation of the model. Source: Designed and drawn by the author.
Fig. 22. Stage 5: In the morning the lid is closed. Source: Designed and drawn by the author.
Fig. 19. Stage 2: At night, the lid is opened, Calcium Chloride is placed. Source: Designed and drawn by the author.
Fig. 23. Stage 6: Calcium Chloride is exposed to sunlight in the closed prism. Source: Designed and drawn by the author.
Fig. 20. Stage 3: Calcium Chloride is exposed to humidity. Source: Designed and drawn by the author.
and thus it increases the water that will be used to cool and humidify the air. 2. Compilation of the water in the tank and then the water cools during the night and used during the day. As well as the use of another tank to collect the condensed water during the day will help to increase the efficiency of cooling and humidification of air.
5. Experimental model (converting the theoretical model to practical model)
Fig. 24. Stage 7: Moisture (water vapor) evaporates from calcium chloride. Source: Designed and drawn by the author.
Before testing the proposed model, the theoretical model must be converted to practical model by: 733
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Fig. 25. Stage 8: Water vapor condenses on the surface. Source: Designed and drawn by the author. Fig. 28. Stage 11: The burlap is sprayed with water, which has been stored in the second tank. Source: Designed and drawn by the author.
Fig. 26. Stage 9: Condensate water accumulates in the path. Source: Designed and drawn by the author.
Fig. 29. Stage 12: Hot dry air passes on the wet burlap, comes out cool moist air. Source: Designed and drawn by the author.
Fig. 27. Stage 10: The water will be stored in the first tank. Source: Designed and drawn by the author. Fig. 30. Stage 13: The remaining water is stored in the third tank. Source: Designed and drawn by the author.
• Using the basic derived principles • Choosing the appropriate spaces and sizes. • Changing in the model to facilitate its implementation. 5.1. Using the basic derived principles
• • •
•
Concentrating of sunlight: The design of the condensation box of water vapor that is evaporated from the moisture-absorbent material depends on the concentration of light and heat from the sun on a small area. Converting light to heat: Designing the bottom of the water vapor condensation box with a black surface and low reflection improves the effectiveness of turning light into heat and substantially improves the effectiveness of the evaporation. Trapping heat: The air inside the box must be isolated from the
•
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outside air. The glass cover locks up the hot air inside the box. This makes it possible to reach to high temperatures in it. The condensation increases by increasing the surface that exposed to condensation: It is preferred in the design to achieve an increase in the surface exposed to condensation. The evaporation increases when there is more exposed surface: when the dry hot air passes on wet burlap, the water would gain a portion of the heat from the air, and then part of the water evaporates, and thus temperature goes down.
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closed.
• The solar collector has been proposed to increase the chance of solar • • •
Fig. 31. Stage 14: Hot air comes out of the ventilation hole at the top of the vacuum. Source: Designed and drawn by the author.
•
5.2. Choosing the appropriate spaces and sizes Designing of one cubic meter vacuum to calculate the amount of absorbent material easily, which will be used, as well as to calculate the required amount of water to reduce the temperature inside the vacuum (see Fig. 11).
•
5.3. Changes in the model to facilitate its implementation To facilitate the implementation of the model in blacksmith's workshop and glass workshop, some changes have been made:
6.1.1. The idea of operational stages of the proposed model This part deals with the proposed stages. These stages are considered the introduction to the practical experiment, to activate the proposed model as follows (see Figs. 18–31).
• The way of opening the lid of the glass prism, which is a glass lid • •
reflectance and increase solar energy, the prism with the steel base is placed inside the solar collector (see Figs. 16 and 17). On the south facade of the box, a slot has been designed for ventilation where a ventilation fan is installed on it to pull warm air into the vacuum. In front of the ventilation fan, a place is designed to put a burlap, above the burlap there is a perforated pipe, to spray the burlap by the pipe. In the design, there are two tanks to collect the condensed water from the glass prism, in the first tank water will be collected from the moisture condensation, which was present in the absorbent material, inside the base of the glass prism. At night, water in the first tank is emptied in the second tank which will be isolated from the atmosphere, to use water during the day in cooling and moisturizing the vacuum. At the same time, the first tank is filled from the condensed water, to facilitate the vacuum cooling continuously, without waiting until water cools inside the tank. Thus, the cycle of improving the environmental conditions inside the vacuum is a closed cycle.
opens at night to enter moisture, which was changed to be a drawer, that goes on the steel base of the prism and the rest of the glass surface is well soldered by silicone material (see Fig. 12). Changing the design of the tank, which includes two tanks. In the implementation stage, it becomes one tank, as it was difficult to implement the idea (see Fig. 13). Changing in the installation method of the prism and the solar collector on the model facade, by separating the solar collector and the glass prism from the model, in order to facilitate the implementation (see Fig. 14).
6.2. Phase 2: Manufacturing the proposed experimental model
• Display the design to blacksmith's workshop, with an explanation of each part in detail. • Implementation of the adjustable steel structure, to facilitate the transfer to the place of experiment. • Installation of wood panels on the steel frame and make a slot, to install the ventilation fan, with diameter 20 cm • Implementation of the base of the glass prism which is made of steel,
6. Phases of the proposed experimental model
•
There are five phases of the practical experiment for the proposed model: (phase 1: design; phase 2: fabrication; phase 3: implementation; phase 4: analysis; phase 5: results) (see Fig. 15).
•
6.1. Phase 1: The proposed design
• •
• The
proposed model consists of a cube-shaped box, nominally 1 m × 1 m × 1 m, a prism installed on it where its base is made from steel, the base is painted in black matte and its glass lid is tightly
Fig. 32. The solar collector is covered by shiny aluminum foil sheets. Source: The photo was taken by the author during the experiment. 735
the condensed water pipe is installed in the base. the base which is painted in matte black, with dimensions 30 × 90 cm Manufacture of a steel frame to install a ventilation fan and a mesh to lay the burlap inside it, along with manufacturing a steel pipe with holes which will be located over the burlap mesh. Manufacturing the glass prism in the cutting and welding glass workshop, welding the prism by Silicon, and making sure that the glass prism is tightly closed. Manufacturing the solar collector in the blacksmith workshop. Purchasing the rest of the experiment requirements which are a thermal insulation sheets of glass wool, a water tank that has a faucet and calcium chloride moisture-absorbent material.
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Fig. 33. The burlap is cut and placed inside the metal mesh. Source: The photo was taken by the author during the experiment.
Fig. 36. The model after insulation. Source: The photo was taken by the author during the experiment.
Fig. 34. The model before installing thermal insulation. Source: The photo was taken by the author during the experiment.
6.3. Phase 3: Implementation The implementation phases are divided into: 1. The phases of the preparation. 2. Applying the experiment phases. 6.3.1. The phases of the preparation.
• Transferring the model to the location of the experiment. • The empty steel box is weighed before putting calcium chloride, and
Fig. 37. Spraying the water on the burlap. Source: The photo was taken by the author during the experiment.
then the box is weighed once more after putting calcium chloride to determine the weight of calcium chloride, before its exposure to atmospheric humidity. Finally, the box is weighed after the exposure of calcium chloride to moisture during the night.
Fig. 35. Using glass wool for insulation. Source: The photo was taken by the author during the experiment. 736
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Table 1 Measurement of solar radiation. Measurement of solar radiation and rate of condensation
Measurement of solar radiation
Hour
Temperature (°C)
solar radiation (W/m2)
9:30 am 10:30 am 11:00 am 12:30 pm 1:00 pm 1:30 pm 2:0.30 pm 3:0.30 pm
30.1 33.3 34.4 34.6 34.9 35.2 35 34.5
777 804 889 969 950 1007 982 896
•
Image
Figs. 34–36). During Installation of the steel pipe, a problem appears, that there was too much water falling. So water hose is installed instead, which has holes above the metal mesh, that mesh contains the burlap (see Fig. 37).
6.3.2. Applying the experiment phases Part I of the experiment: the moisture inside the glass prism was absorbed by Calcium Chloride during the night before where the lid in the morning was closed. Secondly, the solar collector was directed in the south direction, where the sun's rays exists for as long time as possible. Thirdly, solar radiation was measured, which is measured by watts per square meter, every half- an hour, from half past nine o'clock am to half past three o'clock pm, with observing the rate of condensation on the glass surface of the glass prism (see Table 1 and Fig. 38). Fig. 39 illustrates the condensation of humidity. To follow the stages of the moisture condensation on the glass and the amount of water, which is accumulated in the water path refer to appendix 1 in Shahda (2015). Part II of the experiment: Using condensed water in the process of reducing the vacuum temperature and humidity of the air, water will be placed inside the tank after cooling, at a temperature of 20 °C, where the air temperature in the desert at night is between 15 and 20 °C (see Fig. 40). Then, the tank is insulated by glass wool, then a hose is insulated to connect water to burlap, and the ventilation fan is connected by a power supply, accordingly, the temperature and humidity inside and outside the vacuum is noticed.
• Firstly,
Fig. 38. (Solar radiation) reading. Source: The photo was taken by the author during the experiment.
• •
Fig. 39. rate of condensation, after 150 min. Source: The photo was taken by the author during the experiment.
• • •
During temperature and humidity observation, readings were as follows: (see Table 2).
– The weight of the empty box is 3.5 kg. – The weight of the box that contains the dry calcium chloride is 7.6 kg. – The weight of the box that contains the calcium chloride after exposure to moisture is 11.3 kg. – It can be concluded by measuring the box weight, that the weight of Calcium Chloride when it is dry, equals (7.6–3.5 = 4.1 kg) – It can be deduced by measuring the amount of moisture that has been absorbed by Calcium Chloride, equals (11.3–7.6 = 3.7 kg). The model is installed at the roof of the Faculty of Engineering in Port Said. The solar collector is covered by shiny aluminum foil sheets to reflect the rays of the sun on the glass prism (see Fig. 32). The burlap is cut and placed inside the metal mesh in front of a ventilation fan, see (see Fig. 33). The model is covered by heat insulator (glass wool) (see
6.4. Phase 4: Analysis 6.4.1. Analysis of the experiment readings After the completion of practical experiment, and notation the readings, as it has been reviewed in the previous stage. Readings must be analyzed to reach the experiment results. Fig. 41 shows the graphic diagram for the solar radiation readings during the experiment. It is clear that the highest solar radiation was at 1:30 pm. At that time, condensation reached its peak degrees. Fig. 42 illustrates the graphic diagram of the comparison between temperatures (Temperature under sunlight -Outdoor; Temperature in the shade-Outdoor; Temperature-In door). At the beginning of the experiment, the temperature in the shade 737
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Fig. 40. Model after water tank insulation and startup of operation. Source: The photo was taken by the author during the experiment. Table 2 The readings of temperature and humidity. The readings of temperature and humidity Time
11:15 am 12:00 pm 12:45 pm 1:30 pm 2:15 pm
Outdoor
In door
Temperature Under sunlight
Temperature in the shade
Humidity
Temperature
Humidity
37.3 °C 38 °C 39.1 °C 39.5 °C 38 °C
34.4 °C 34.7 °C 34.9 °C 35.2 °C 34.5 °C
51% 58% 56% 54% 57%
34 °C 31.8 °C 31.4 °C 30 °C 29.9 °C
52% 67% 67% 72% 72%
Fig. 42. Comparison between temperatures, graphic diagram. Source: Drawn by the author, source of data from experiment readings.
Fig. 41. Solar radiation readings. Source: Drawn by the author, source of data from experiment readings.
Fig. 43. Comparison between outdoor and indoor humidity, graphic diagram. Source: Drawn by the author, source of data from experiment readings.
(outside the model) approached the temperature inside the model. After 3 h of starting the experiment, the temperature dropped [34–29.9 °C = 4.1° C], the temperature decreased about 4 °C compared to the temperature inside the model at the beginning of the experiment. Moreover, the temperature dropped from 34.5 °C to 29.9 °C = 4.6 °C. The temperature decreased about 4.6 °C compared to the temperature outside the model at the same time.
It is obvious that the highest temperature was at 1:30 pm and the significant difference in temperatures was at 1:30 pm. The outdoor temperature in the shade [35.2 °C]- indoor temperature [30 °C] = [5.2 °C]. The temperature decreased about five degrees Celsius compared to the temperature outside the model at the same time. 738
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6.4.2. The amount of required water and calcium chloride in the experiment The following mathematical formula has been used to calculate the amount of water that must be used to spray burlap and to reduce the temperature from 40 °C to 28 °C, depending on the special conditions in the desert atmosphere: Mathematical formula: Calculations in m3 can refer to appendix 2 in Shahda (2015).
ṁ a (h2 − h1) = ṁ w Cpw (t w3 - t w4) + ṁ a (ω2 − ω1 )Cpw t w4 ta1 = 40 °C Q = 20% ta2 = 28 °C Q = 50% tw3 = 20 °C tw4 = 28 °C
(h2 − h1) = ṁ w/ṁ a Cpw (t w3 - t w4) + (ω2 − ω1 )Cpw t w4 ṁ a /ṁ w = 5.7, about 6 kg air, refer to appendix 2 in Shahda (2015). Where: ṁ a → of air ṁ w → of water So 1 m3 air needs 1∕6 L water Fig. 44 shows the equilibrium water vapor pressure of various forms of calcium chloride at various temperatures. The rate at which moisture is absorbed by a given quantity of calcium chloride depends on applying-specific variables. While it was difficult to estimate the rate of moisture absorption, it is not difficult to determine the maximum water amount that can be absorbed per kg of calcium chloride at the given humidity and temperature by the following formula (Calcium Chloride A Guide to Physical Properties):
Fig. 44. Vapor Pressure of CaCl2. Source: (Calcium Chloride A Guide to Physical Properties).
Fig. 43 shows the graphic diagram for comparison between indoor humidity and outdoor humidity. It is clear that the difference between indoor humidity and outdoor humidity at the beginning of the experiment, after 3 h of starting the experiment is [72–52% = 20%], and the difference between humidity outdoor, after 3 h of starting the experiment and indoor humidity, after 3 h of starting the experiment is [72–57% = 15%].
Water absorbed = (Start%/End%) − 1 Consequently, the amount of water according to the special conditions of the desert atmosphere: 1 kg Calcium Chloride absorbs 1.13 L water. For calculations, refer to appendix 2 in Shahda (2015).
Fig. 45. Model: Apartment building, section. Source: Designed and drawn by the author. 739
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Fig. 46. Model: Apartment building, plan. Source: Designed and drawn by the author.
7. A model to use the proposed architectural application in desert buildings
energy to enhance the natural stack ventilation in the building by using passive solar energy. 7.2. The most important reasons for the preference of the Camel's nose system
The study proposes four architectural models, for utilizing the proposed architectural application in desert buildings, by designing: air movement through the plans; air movement through the sections (Shahda, 2015). subsequently, the models were analyzed by environmental simulation program (Ansys). This paper suggests one of them. For other models, please refer to Shahda (2015).
• This system aids to provide water needed for humidification and •
7.1. Model: Apartment building The model is an apartment building, each floor consists of two apartments. The exterior walls of the building have been designed from double walls, between the walls, there are thermal insulation materials. The idea of the model is to include an internal vacuum consisting of a windcatcher and a chimney. Windcatcher works to supply the building with air after being cooled and moistened by camel's nose system. The chimney works to pull the hot air out of the building. Figs. 45 and 46 show the cooling phases of the building, as follows:
• • •
A. Moisture is being pulled from the air by using absorbent material; Vaporization of the water vapor then the condensation of water vapor on the prism glass surface; Collecting the condensed water in the tank Accordingly, water passes through pipes to spray the burlap. B. Pulling the hot air and passing it on the wet burlap thus warm and dry air is cooled by evaporating. C. Cold air passes from the vertical corridor, which is considered a windcatcher to horizontal corridors. D. Through the cool air corridor, cold moist air passes in the horizontal passages in the floor, then the air comes out of the cold air outlet. E. When air heats up, its density is reduced, and moved in the direction of low-density. Air rises and goes out of the hot air outlet. F. Across the chimney: Air moves from high-pressure areas to the low pressure and high-temperature areas. The solar chimney uses solar
cooling from the available moisture in the desert environment at night. Subsequently, the system works to provide the water as a scarce resource in the desert. This architectural application works to provide humidification and cooling for each building spaces and acts as an integrated system, not as a separate device that is installed in each room of the building. The remaining water from this system can be used to cultivate the roof, and myriad of other activities. This system does not depend on non-renewable energies to provide air movement inside the building, but it serves to move the air inside the spaces by creating low-pressure areas to pull air. Buildings in which this system will be used will save money than buildings that use air conditioners or air desert conditioners.
8. Conclusions Through the practical approach to transform Camel's Nose technique to design idea, the following results have been reached:
• The •
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paper considers the analysis of Camel's Nose Technique, through Physics and Engineering sciences and employ these techniques in the field of architecture. Through analyzing the techniques of Camel's Nose System, some principles have been reached, which were applied to the proposed model: (Concentrating sunlight; Converting light to heat; Trapping heat; The condensation increases by increasing the surface that exposed to condensation; The evaporation increases when there is more exposed surface).
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By analyzing the practical experiment, the following results have been reached:
David, A.R., David, R., 2002. The Pyramid Builders of Ancient Egypt: A Modern Investigation of Pharaoh's Workforce. Routledge. Desert, Wikipedia, the free encyclopedia, Retrieved March, 2018 from the world wide web, http://en.wikipedia.org/wiki/Desert. Elkhawad, A.O., 1992. Selective brain cooling in desert animals: The Camel (Camelus dromedarius). Comp. Biochem. Physiol. A Compar. Physiol. 101, 195–202. Geography of Egypt, Wikipedia, the free encyclopedia. Retrieved March, 2018 from the world wide web. http://en.wikipedia.org/wiki/Geography_of_Egypt. Halpern, E. Anette, 1999. “Camel”. In Mares; Michael A. Deserts. University of Oklahoma Press, pp. 96–97. Harun, Y., 1999. For Men of Understanding, Part I: “The Four Animals Emphasised In The Qur’an”/The Camel, Ta-Ha. Publishers Ltd. Hill, R.W., Wyse, G.A., Anderson, M., Anderson, M., 2004. Animal physiology (Vol. 2). ^ eMassachusetts. Sinauer Associates, Massachusetts. Holy Quran, Surah Al-Ghashiya (17). Horstmeyer, S., 2006. Relative Humidity.... Relative to What?. The Dew Point Temperature… a better approach.[online] Retrieved March, 2017 from the world wide web. http://www. shorstmeyer.com/wxfaqs/humidity/humidity. Johnson, A.T., 2011. Biology for Engineers. CRC Press. Laity, J.J., 2009. Deserts and Desert Environments. John Wiley & Sons. Langman, V.A., Maloiy, G.M.O., Schmidt-Nielsen, K., Schroter, R.C., 1978. Respiratory water and heat loss in camels subjected to dehydration. J. Physiol. Dis. Nigerian Veterinary Journal 36 (4), 1299–1317. McNaught, A.D., McNaught, A.D., 1997. Compendium of Chemical Terminology, vol. 1669 Blackwell Science, Oxford. Meigs, P., 1953. World distribution of arid and semi-arid homoclimates. Review of Research on Arid Zone Hydrology. Arid Zone Programme 1. UNESCO, Paris, pp. 203–10. Meigs, P., 1957. Arid and semiarid climate types of the world. In: Proceedings, International Geographical Union, 17th Congress, 8th General Assembly. International Geographical Union, Washington DC, pp. 135–138. Nasal Surfaces Remove Water Vapor: Camel, AskNature, Retrieved March, 2018 from the world wide web, https://asknature.org/strategy/nasal-surfaces-remove-watervapor/#.W9R2hWgzbIU. Naseer, R., 2005. analytical comparison between the principles of environmental control applied in the architecture of the desert areas and their counterparts in all of living nature and technology industry. Al-Azhar Univ. Eng. J., AUEJ 8 (6), 6. Nelson, K.S., Bwala, D.A., Nuhu, E.J., 2015. The dromedary camel; a review on the aspects of history, physical description, adaptations, behavior/lifecycle, diet, reproduction, uses, genetics and diseases. Niger. Vet. J. 36 (4), 1299–1317. Rastogi, S.C., 1971. Essentials of Animal Physiology. New Age International, pp. 180–181. Roberts, M.B.V., 1986. Biology: A Functional Approach. Nelson Thornes. Rundel, P.W., Gibson, A.C., 2005. Ecological communities and processes in a Mojave Desert ecosystem. Cambridge University Press. Schmidt-Nielsen, K., 1964. Desert animals. Physiological problems of heat and water. Desert animals. Physiological problems of heat and water. Schmidt-Nielsen, K., 1972. How Animals Work. Cambridge University Press. Schmidt-Nielsen, K., Crawford, E.C., Hammel, H.T., 1981a. Respiratory water loss in camels. Proc. Roy. Soc. Lond. B 211 (1184), 291–303. Schmidt-Nielsen, K., Schmidt-Nielsen, B., Jarnum, S.A., Houpt, T.R., 1956. Body temperature of the camel and its relation to water economy. Am. J. Physiol.-Legacy Content 188 (1), 103–112. Schmidt-Nielsen, K., Schroter, R.C., Shkolnik, A., 1981b. Desaturation of exhaled air in camels. Proc. Roy. Soc. Lond. B 211 (1184), 305–319. Shahda M., 2015. Biomimicry: an Approach for Designing Desert Buildings, PHD, Port Said University. Shmida, A., Evenari, M., Noy-Meir, I., 1986. Hot desert ecosystems: an integrated view. Ecosyst. World 12, 379–387. Solar Energy Perspectives, 2011. International Energy Agency. (PDF). Archived from the original. Retrieved March, 2018 from the world wide web. https://www.iea.org/ publications/freepublications/publication/Solar_Energy_Perspectives2011.pdf. The World's Largest Deserts, Desert map, Geology.com, Retrieved March, 2018 from the world wide web. http://geology.com/records/largest-desert.shtml. Warren, H. Johns, 1982. The camel's amazing nose, A Magazine for Clergy/Volume 55/ Number 8. Retrieved March, 2016 from the world wide web, https://gcmin-rnr.s3. amazonaws.com/cdn/ministrymagazine.org/issues/1982/issues/MIN1982-08.pdf. World of Warmth, Life is all about thermoregulation, Retrieved March, 2016 from the world wide web. http://www.worldofwarmth.com. Yagil, R., 1985. The desert camel. Comparative physiological adaptation. Karger.
• The proposed model which mimics the Camel's Nose System suc• •
ceeded in reducing the temperature 4 °C, compared with the temperature inside the model at the beginning of the experiment, and 5 °C compared to the temperature outside the model at the same time. The model succeeded in increasing the relative humidity, 20% between indoor humidity and indoor humidity at the beginning of the experiment, and 15% difference between humidity outdoor after 3 h of starting the experiment and indoor humidity after 3 h of starting the experiment. The results of using the mathematical formula which had been used to calculate the amount of water that must be used to spray the burlap, to lower the temperature from 40 °C to 28 °C, depending on the special conditions in the desert atmosphere. 1 m3 air needs about 1∕6 L water 1 kg Calcium Chloride Absorbs about 1.13 L water
The study succeeded in proving the hypothesis “whereas Camels can survive in a desert biome because of their physical features. Desert Buildings can be designed to be adapted in a desert biome by mimicking the adaptation characteristics of the camel”. Overall, the information presented in the paper configures a comprehensive framework for the understanding Camel's Nose System, and an initial assessment to employ this system in the field of architecture. Nonetheless, more information is needed to apply the system in many architectural applications in the desert environment. Furthermore, studies should analyze the adaptation methods of organism's habitats with the surrounding environment for application in architecture. Acknowledgments The authors would like to thank the reviewers for their insightful comments for the improvement of the manuscript. References Abdou, O., 2000. “Green Architecture: A Holistic Approach” Ecological Approaches to Architecture, medina, Cairo. Beautiful weather Graphs and Maps, weatherspark, Retrieved October, 2018 from the world wide web, https://weatherspark.com/#!dashboard;a=Egypt. Calcium Chloride A Guide to Physical Properties from Occidental Chemical Corporation (OxyChem). Retrieved March, 2018 from the world wide web. https://www.oxy. com/OurBusinesses/Chemicals/Products/Documents/CalciumChloride/173-01791. pdf. Chaker, M., Meher-Homji, C.B., Mee, T., 2002, January. Inlet fogging of gas turbine engines: Part A—fog droplet thermodynamics, heat transfer and practical considerations. In: ASME Turbo Expo 2002: Power for Land, Sea, and Air. American Society of Mechanical Engineers, pp. 413–428. Clements-Croome, D., Croome, D.J., 2013. The book Intelligent Buildings: Design, Management and Operation, 2nd ed. Telford ICE. Croome, C. Derek, 2013. The Camel’s Nose, Natural Ventilation News, ISSUE 08, Retrieved October, 2018 from the world wide web. https://www.cibse.org/ getmedia/3dbfdb4f-6aa4-4dbd-b3b3-4f3721aabd40/CIBSE-Natural-VentilationGroup-Newsletter-Issue-8-(2013).pdf.aspx.
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Camel’s nose strategy: New innovative architectural application for desert buildings
T
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Merhan M. Shahda , Mostafa M. Abd Elhafeez, Ashraf A. El Mokadem Architecture and Urban Planning Department, Faculty of Engineering, Port-Said University, Port Said, Egypt
A R T I C LE I N FO
A B S T R A C T
Keywords: Biomimicry Architectural application Desert buildings Camel nose system
As desert areas represent the most of the Arab countries lands, hence, these areas suffer from scarcity in the sources of water in addition to high temperatures. Furthermore, these areas encounter an increased demand for non-renewable energy resources, in order to achieve thermal comfort for individuals. Accordingly, this paper focuses on how Biomimicry science could be employed in designing and innovating an architectural product compatible with the desert environment to be a part of the desert ecosystem. Hence, this paper is devoted to explore the camel as the best-adapted animal in the desert environment, through focusing on camel nose technique. Thus, this paper attempts to prove the hypothesis that: Buildings can be designed in compatible with the desert environment, by simulating the adaptation method of the camel nose technique. Moreover, this paper raises some questions and seeks to answer them through a practical model. to design a system for buildings to obtain water from the air? • IsIs itit possible to design a system for buildings to help in reducing high temperature? • Howpossible • can increasing the exposed surface of the vaporization assists in increasing the rate of cooling?
A new architectural application has been suggested in this paper to simulate “Camel Nose System” where scientific experiments have been conducted to test the efficiency of this model, starting with the designing stage, manufacturing and the implementation of the applied model. Consequently, after the stage of analysis and results, the paper has reached through scientific experiment many results including, (1) calcium chloride as a moisture-absorbing material can absorb 1.3 L of water depending on the special conditions in the Egyptian desert atmosphere, (2) the reduction of temperature to 5° and the humidity has increased to 20%. This new architectural application has been utilized to improve desert buildings.
1. Introduction As a matter of fact, nature is the source of inspiration for architects as it is for scientists. However, there are not sufficient studies that conclude and devise solutions from nature to all areas of science and architecture. Humans whom God has distinguished by a lot of abilities which differentiate them from other organisms, where their bodies are provided by a lot of environmental control means which enable them to adapt to several changeable circumstances around them. However, the human's ability to adapt to the surrounding environment is almost limited compared to organisms, but God granted the human mind to think, analyze and understand, how organisms can adapt to the environment and then apply this in the science fields, including architecture (see Fig. 1).
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Therefore, scientists investigated nature trying to use a variety of achievements and attempt to assimilate them. Accordingly, a branch of knowledge appeared called “Biomimicry” which means (Nature Simulation) is an innovation method that seeks sustainable solutions by emulating nature's time-tested patterns. Biomimicry can become a mean for the integration of architecture product with the environment and become a part of the ecosystem of the environment “Closed circle”. Desert lands represent most of the area of the Arab countries. Consequently, these areas suffer from scarcity in the sources of water, high temperature and increased demand for non-renewable energies, to achieve thermal comfort for individuals, without paying attention to trying to apply Biomimicry. Therefore, this paper problem lies on how can Biomimicry science be employed in designing and innovating architectural product compatible with the desert environment to be a part of the desert ecosystem, as the desert organisms coexisted, without
Corresponding author. E-mail address: [email protected] (M.M. Shahda).
https://doi.org/10.1016/j.solener.2018.10.072 Received 22 August 2018; Received in revised form 14 October 2018; Accepted 26 October 2018 0038-092X/ © 2018 Elsevier Ltd. All rights reserved.
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Fig. 1. Comparison between human and organism through the adaptation methods and possession of the mind. Source: Drawn by the author. Fig. 2. The Nile Valley and Nile Delta covers 5.5% of the total area of Egypt, Where the concentration of population. Source: Drawn by the author.
damaging the ecosystem. Accordingly, this paper focuses on the most important animals in the Arabian desert and the most adapted ones to the desert environment.
temperatures and humidity, daily, in Egypt. By analyzing and studying the Egyptian desert areas: Sinai, Eastern Desert, Western Desert (Shahda, 2015), it is obvious that the most serious difficulties in desert areas are (1) Humidity: low during the day, high at night, (2) Temperatures: high during the day, low at night. (3) Water scarcity. Here were appeared some questions: What organism is able to adapt to these difficulties?; What is the adaptation method of this organism?
2. Background: Why the desert; Why Camels? This part of study intends to answer some questions; Why the desert; Why Camels? Moreover, aims to analyze the natural characteristics of the desert environment, to prevail over the most crucial difficulties in the desert environment. 2.1. Why the desert?
2.3. Why Camels? Approximately 1/3 of Earth's land surface is a desert. A desert is a barren region that receives very little precipitation - less than 250 mm per year (about ten inches) (Meigs, 1953, 1957). Thus, living conditions are hostile for plant and animal life. The search cares about warm desert areas which include most of the Arab regions, including the (Arab Republic of Egypt) spatial scale of the search. The desert environment is characterized in this region by the following: lack of rain, prevails drought, extreme poverty in plants and the scarcity of the animals (The World's Largest Deserts, 2018; Desert, 2018). There are basic factors, which exist in arid desert torrid areas which force organisms to adapt to its cruel climatic and environmental conditions (Naseer, 2005; Laity, 2009). Hence, the following are the characteristics of hot deserts:
It is beyond doubt that all beings reflect the endless power and knowledge of their Creator. This is expressed in numerous verses in the Qur'an where it is pointed out that everything created by Allah is actually a sign; The 17th verse of the Surah Al-Ghashiya tells us about “camel”. “Will they not regard the camels, how they are created? (17)” (Holy Quran, Surah Al-Ghashiya), the fact that has to be carefully examined and thought of. In this part, this animal on which the Qur'an invites us to ponder by the expression, “Do they not look at the Camels, how they are created?” will be tackled in this study. The characteristic feature of the camel is its body structure, which is not affected even by the most severe conditions. Many characteristics of the camel prove that this animal is created particularly for dry climate conditions (Schmidt-Nielsen, 1964). The Arabian camels are found in the very hot deserts of North Africa and the Middle East (Nelson et al., 2015). For many characteristics of the camel can be referred to Shmida et al. (1986), Johnson (2011), Langman et al. (1978), Roberts (1986), Hill et al. (2004), Rastogi (1971).
• Daily thermal extent is long. • High values of solar radiation. • High temperature. • Shortage of water resources, dryness and low relative humidity. • The scarcity of food sources. • Openness and extension of the surface of the earth.
2.4. The camel's adaptation in the desert environment and how can this adaptation be exploited in architecture?
2.2. The natural characteristics of desert environment in Egypt Camels have countless adaptation techniques that allow them to live substantially in desert conditions, for many methods to the camels' adaptation in the desert environment can be referred to Shahda (2015), Schmidt-Nielsen (1972, 1956), Nasal Surfaces Remove Water Vapor, Rundel and Gibson (2005), Halpern (1999), Harun (1999), Yagil (1985). Therefore, at this stage of the search, the research tries to prove this hypothesis:
Egypt is predominantly desert. The desert environment land in Egypt is 95% of the total area of Egypt. The Nile Valley and Nile Delta are the most important regions, despite covering only about 5.5% of the total area of Egypt which is cultivated and permanently settled and supporting about 99% of the population (David and David, 2002) (see Fig. 2). There is the desert environment in the three regions of Western Sahara and the Eastern Desert and the Sinai Peninsula (Geography of Egypt, 2018). This study is intended to compatibility with conditions and characteristics in the Egyptian desert, to propose an architectural model under such conditions. To determine the climatic conditions of the case study, the maximum and minimum temperatures average and relative humidity were analyzed for some cities which fall within the scope of the desert lands in Egypt. Fig. 3 shows the average
Since camels can survive in a desert biome because of its physical features, thus, desert buildings can be adapted with the desert biome by mimicking the adaptive methods of the camel. Moreover, how to analyze the organism “camel”, to approach a new scientific hypothesis that can be formulated architecturally. Accordingly, the study focuses on one of
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Fig. 3. The average temperatures and humidity, daily, Egypt. Source: (Beautiful weather Graphs and Maps, 2018).
temperature. When it is exhaled, it is cooled even further by passing over the same nasal membranes, this time by a process of dehumidifying instead of humidifying, the nasal membranes are coated with a special water-absorbing substance that extracts the moisture from the air like the cooling coils of a dehumidifier. A net savings of 68 per cent in the water usually lost through respiration occurs just between the cooling and drying phases of the breathing cycle (Croome, 2013; Clements-Croome and Croome, 2013). The mechanism responsible for the cooling of the exhaled air is a simple heat exchange between the respiratory air and the surfaces of the nasal passageways. On inhalation, these surfaces are cooled by the air passing over them, and on exhalation heat from the exhaled air is given off to these cooler surfaces. In camels, the arterial blood in the carotid rete is cooled by the cold venous blood before entering the brain. The blood cooled in the nasal cavity by evaporative heat loss is diverted to the brain sinuses via the nasal and angular veins (see Fig. 4). This leads to a significant cooling of the brain tissue. Thus, the camel has the brain cooling system gives it the ability to withstand intensely high body temperatures without damaging it's brain due to this cooling system. The brain cooling system not only provides protection for the brain in extreme temperatures, but it also allows the camel to have a wider range of tolerance for hot conditions (Elkhawad, 1992). The camel is able to survive in temperatures that would normally be lethal to the other creature's brain. Fig. 5 shows the size of the large disparity between the temperatures through the camel's head, which is exposed to high temperatures in the desert that up to above than 45 °C, the temperature of the nose appears between 40 and 35 °C. The temperature drops in the turbinates area of 25–20 °C, and it appears a significant reduction in the brain
the properties of camels' adaptation: Camel's Nose, as it will be demonstrated in the context of this study.
3. A new innovative idea, inspired by the Camel's nose How does Camel's nose work? In 1979 Schmidt-Nielsen linked up with Zoologist Amiram Shkolnik and discovered that the real secret of the camel's remarkable ability for desert survival is found in its ingeniously designed nose and discovered the secret of the camels aircooling ability. The camel makes use of two principles of physics: cooler air holds less moisture; and the greater the surface area, the faster the rate of evaporation or condensation. Evaporation results in cooling (Warren, 1982). K. Schmidt-Nielsen, R. C. Schroter, A. Shkolnik found an intricate labyrinth of narrow highly scrolled air passageways in the camel nose, which greatly increases its surface area available for heat and moisture transfer. Typically, a human nose has only about 160 cm2 of an interior surface area, while the camel has about 1000 cm2 of mucous membrane on the nasal interior. This intricate labyrinth named “Turbinates”, are spongy nasal bones, and the camel turbinates are highly scrolled, providing narrow air passageways and a large surface area for water and heat exchange (Schmidt-Nielsen, 1981a, 1981b). Camels can reduce the water loss due to evaporation from the respiratory tract in two ways: (1) by decreasing the temperature of the exhaled air (2) by removal of water vapor from this air. Camel's nose acts as both of humidifier and dehumidifier with every breathing cycle. The hot, dry air that is inhaled passes over the large area of the moist membrane. This air is immediately humidified by picking up moisture from the nose and is cooled in the process. This cooler air passes to the lungs and remains at approximately body
Fig. 4. The cooling system for the head and brain of a camel. Source: (Elkhawad, 1992). 727
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4. Proposed architectural model using “Camel's nose” system To prove the hypothesis research in a practical way, Camel's Nose technique must be analyzed through the physical and engineering sciences (see Fig. 8). The techniques are “1-The dew point. 2-Humidity. 3Increase the exposed surface for cooling or evaporation. 4- Condensation and vaporization. 5- Absorbent materials to moisture. 6- Solar energy as an energy source”. – These techniques can be reviewed in more depth by reference to Horstmeyer (2006), Chaker et al. (2002), McNaught and McNaught (1997), Solar Energy Perspectives (2011), Abdou (2000). – Even, we can get the foundations and criteria for drafting an architectural model and we can take advantage of these technologies in the proposed model.
Fig. 5. Camel thermoregulation. Source: http://www.worldofwarmth.com.
4.1. The idea of the proposed model After studying and analyzing all the foundations and criteria, which the hypothesis is based upon of architectural application which are inspired by the Camel Nose System, and the spatial determinants. At this phase of the study, a suggestion of the perception of the proposed model. Fig. 9 shows the design idea of the model, where it can be summarized in the following steps:
Step 1 The model needs to provide water for use in cooling the building, with the scarcity of water in the desert, as well as the opportunity to increase humidity in the desert atmosphere at night, water can be provided by pulling air humidity at night. The fact that could be achieved by using a moisture-absorbing material
Fig. 6. A brief analysis of the Camel's Nose idea. Source: drawn by the author.
temperature up to 11 °C.
Step 2 After pulling a large amount of moisture by the absorbent material, how can the water be taken from it? The design must succeed in evaporating this moisture to become water vapor, through the exploitation of large solar energy in the desert, by exposing the moisture-absorbing material to sunlight in a closed vacuum to cause evaporation of water vapor
3.1. A brief analysis of the Camel's nose idea Fig. 6 summarizes the idea of the camel's nose, where the temperature of the inhaled air is elevated up to 45 °C. Hot air is exposed to moist surfaces which it is called turbinates, the air becomes humid. Relatively cold air enters the camel body. Exhaled air is saturated with water vapor, exposed to the wet and cold turbinates, water vapor condenses on these surfaces. So the camel does not lose water when exhaling process. The result is very low temperatures inside the body and the brain of the camel in a remarkable way. Moreover, camel provides a portion of the water needs through the process of breathing.
Step 3 Water vapor that evaporated in moisture-absorbent material, must condense on the surface which is relatively colder than the ambient temperature. As in the nasal turbinates surfaces in the camel's nose, this is achieved by designing the shaded surface from the heat-insulating material. It is preferred in the design to achieve an increase in the surface exposed to condensation Step 4 The technique of collecting condensed water on the surface is very important. This could be achieved by designing the path to collect water from the surface, and the connection with a tube, where the water is going to get into the burlap. It is important to design the tank to collect the water, to facilitate its use to the extent required in the ventilation and humidification
• The camel's nose acts as both of humidifier and dehumidifier with every breathing cycle. • The camel uses another principle of physics: the increase the surface area is, the faster the rate of evaporation or condensation. • The camel has a brain cooling system. • Camel can meet part of its needs for water, by condensing the water
Step 5 The dry hot air that prevails in the desert weather, is pulled into the building by ventilation fan air installed on the ventilation hole of the building. A group of burlap slices is placed before the ventilation fan. Materials such as straw and burlap are considered as materials which work to increase the area allocated for evaporating
vapor which comes out with the exhaled air.
Step 6 The water that has been collected in the tank is being used by spraying burlap which was placed in front of suction in the ventilation slot, when the dry hot air passes on wet burlap. The water would gain a part of the heat of the air, and then a part of the water evaporates. During that, a drop-in temperature occurs inside the building and the air is saturated with an amount of water and becomes moist air
In the framework of trying to prove this hypothesis, the study tackles questions and tries to answer them through practical model for the vacuum architectural (see Fig. 7).
• Is it possible to design a system for buildings to obtain water from the air? • Is it possible to design a system for buildings to help in reducing the temperature of the interior spaces? • How can increasing the exposed surface of the vaporization or
4.2. Proposed models The study suggests nine models, taking into consideration that each model is being developed through the following model and so on. Where the models were designed one after another. The design of the model has been modified based on any problem appeared in the previous model, to get the final version, which is expected to be extremely
condensation to increase the rate of cooling?
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Fig. 7. Summary Analysis about camel's nose (water recycling system). Source: Drawn by the author.
Fig. 8. The foundations and criteria for drafting an architectural model. Source: Drawn by the author.
Fig. 9. The idea of design. Source: Drawn by the author. 729
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To make the calculation and Measurement easier
Fig. 10. The idea of proposed models, Final version V 9. Source: Drawn by the author.
1 cubic meter Fig. 11. Converting the theoretical model to practical model. Source: Designed and drawn by the author.
on the southern facade of the building, where it is exposed to the sun for a long time. It consists of a glass box with a door at its bottom that opened at night and closed during the day. The top of the glass box surface is sloped. There are two tanks to collect the condensed water. There is a slot for ventilation on the wall of the room, the ventilation hole consists of a layer of burlap, where there is a ventilation fan behind this slot. The operation system of the proposed model: The door of the glass-box is opened at night. Absorbent material is exposed to
positive. For more details, the diligent reader can refer to Shahda (2015). Accordingly, the nine versions of architectural applications can be applied to southern facade for desert buildings, where the southern facade is more exposed to sunlight for long periods during the day in Egypt. The model is presented through the following points: “Proposed design; Design description; The operating system of the proposed model; Evaluation of the design”. Fig. 10 shows the design idea of the proposed models, Final version V 9. Design Description: The design is a treatment that can be located 730
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A glass lid of the glass prism
Tightly closed glass prism The steel drawer colored Black
A Fig. 12. A change in the design of the glass prism and steel base. Source: Designed and drawn by the author.
Fig. 13. A change in the design of the water storage technique in the tank. Source: Designed and drawn by the author.
Separated model
An integrated model Fig. 14. Separate the solar collector from the model facade. Source: Designed and drawn by the author.
atmospheric humidity, which is great during the period of dawn. In this study, the ability of calcium chloride has been tested as an absorbent material to absorb moisture (water vapor) from the air (Shahda, 2015). The result of the experiment has been proven:
phase 5: results phase 4: analysis
1. The high capacity of calcium chloride to absorb moisture from the air. 2. Dawn has been selected as the time where the percentage of humidity is at the highest level. 3. The sunlight must be focused on the container to occur the condensation. 4. The inner surface of the container must be painted black, to absorbs the largest amount of sunlight. 5. The container must be isolated from the floor below to prevent heat loss. 6. It is preferred to think of how to increase the exploitation of solar energy, to get the best results.
phase 3: implementation phase 2: fabrication
Phases of the proposed experimental model
phase 1: design
Fig. 15. Phases of the proposed experimental model. Source: Drawn by the author.
For more details, the diligent reader can refer to Shahda (2015). In the early morning, the door is closed, the glass-box is exposed to 731
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Fig. 16. The proposed design with solar collector, Perspective. Source: Designed and drawn by the author.
Fig. 17. The proposed design, section. Source: Designed and drawn by the author.
temperature. Evaluation of design: By comparing this proposal with the previous versions (Shahda, 2015). This model is superior in the following:
sunlight during the day. The heat of the sun evaporates moisture which is collected in the moisture-absorbent material, water vapor heads to the surface and condenses on it. The condensed water is collected in a tank, then the water pipes splash the water over the burlap. The fan pulls the hot air. Hot air passes over burlap dampened with water. Thus, cool wet air enters the room with a remarkable decrease in
1. Tightly closed glass-box means that the opportunity of condensation would be great, this increases the chance of condensation of water 732
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Fig. 21. Stage 4: Calcium Chloride absorbs the moisture from the air. Source: Designed and drawn by the author. Fig. 18. Stage 1: Design and implementation of the model. Source: Designed and drawn by the author.
Fig. 22. Stage 5: In the morning the lid is closed. Source: Designed and drawn by the author.
Fig. 19. Stage 2: At night, the lid is opened, Calcium Chloride is placed. Source: Designed and drawn by the author.
Fig. 23. Stage 6: Calcium Chloride is exposed to sunlight in the closed prism. Source: Designed and drawn by the author.
Fig. 20. Stage 3: Calcium Chloride is exposed to humidity. Source: Designed and drawn by the author.
and thus it increases the water that will be used to cool and humidify the air. 2. Compilation of the water in the tank and then the water cools during the night and used during the day. As well as the use of another tank to collect the condensed water during the day will help to increase the efficiency of cooling and humidification of air.
5. Experimental model (converting the theoretical model to practical model)
Fig. 24. Stage 7: Moisture (water vapor) evaporates from calcium chloride. Source: Designed and drawn by the author.
Before testing the proposed model, the theoretical model must be converted to practical model by: 733
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Fig. 25. Stage 8: Water vapor condenses on the surface. Source: Designed and drawn by the author. Fig. 28. Stage 11: The burlap is sprayed with water, which has been stored in the second tank. Source: Designed and drawn by the author.
Fig. 26. Stage 9: Condensate water accumulates in the path. Source: Designed and drawn by the author.
Fig. 29. Stage 12: Hot dry air passes on the wet burlap, comes out cool moist air. Source: Designed and drawn by the author.
Fig. 27. Stage 10: The water will be stored in the first tank. Source: Designed and drawn by the author. Fig. 30. Stage 13: The remaining water is stored in the third tank. Source: Designed and drawn by the author.
• Using the basic derived principles • Choosing the appropriate spaces and sizes. • Changing in the model to facilitate its implementation. 5.1. Using the basic derived principles
• • •
•
Concentrating of sunlight: The design of the condensation box of water vapor that is evaporated from the moisture-absorbent material depends on the concentration of light and heat from the sun on a small area. Converting light to heat: Designing the bottom of the water vapor condensation box with a black surface and low reflection improves the effectiveness of turning light into heat and substantially improves the effectiveness of the evaporation. Trapping heat: The air inside the box must be isolated from the
•
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outside air. The glass cover locks up the hot air inside the box. This makes it possible to reach to high temperatures in it. The condensation increases by increasing the surface that exposed to condensation: It is preferred in the design to achieve an increase in the surface exposed to condensation. The evaporation increases when there is more exposed surface: when the dry hot air passes on wet burlap, the water would gain a portion of the heat from the air, and then part of the water evaporates, and thus temperature goes down.
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closed.
• The solar collector has been proposed to increase the chance of solar • • •
Fig. 31. Stage 14: Hot air comes out of the ventilation hole at the top of the vacuum. Source: Designed and drawn by the author.
•
5.2. Choosing the appropriate spaces and sizes Designing of one cubic meter vacuum to calculate the amount of absorbent material easily, which will be used, as well as to calculate the required amount of water to reduce the temperature inside the vacuum (see Fig. 11).
•
5.3. Changes in the model to facilitate its implementation To facilitate the implementation of the model in blacksmith's workshop and glass workshop, some changes have been made:
6.1.1. The idea of operational stages of the proposed model This part deals with the proposed stages. These stages are considered the introduction to the practical experiment, to activate the proposed model as follows (see Figs. 18–31).
• The way of opening the lid of the glass prism, which is a glass lid • •
reflectance and increase solar energy, the prism with the steel base is placed inside the solar collector (see Figs. 16 and 17). On the south facade of the box, a slot has been designed for ventilation where a ventilation fan is installed on it to pull warm air into the vacuum. In front of the ventilation fan, a place is designed to put a burlap, above the burlap there is a perforated pipe, to spray the burlap by the pipe. In the design, there are two tanks to collect the condensed water from the glass prism, in the first tank water will be collected from the moisture condensation, which was present in the absorbent material, inside the base of the glass prism. At night, water in the first tank is emptied in the second tank which will be isolated from the atmosphere, to use water during the day in cooling and moisturizing the vacuum. At the same time, the first tank is filled from the condensed water, to facilitate the vacuum cooling continuously, without waiting until water cools inside the tank. Thus, the cycle of improving the environmental conditions inside the vacuum is a closed cycle.
opens at night to enter moisture, which was changed to be a drawer, that goes on the steel base of the prism and the rest of the glass surface is well soldered by silicone material (see Fig. 12). Changing the design of the tank, which includes two tanks. In the implementation stage, it becomes one tank, as it was difficult to implement the idea (see Fig. 13). Changing in the installation method of the prism and the solar collector on the model facade, by separating the solar collector and the glass prism from the model, in order to facilitate the implementation (see Fig. 14).
6.2. Phase 2: Manufacturing the proposed experimental model
• Display the design to blacksmith's workshop, with an explanation of each part in detail. • Implementation of the adjustable steel structure, to facilitate the transfer to the place of experiment. • Installation of wood panels on the steel frame and make a slot, to install the ventilation fan, with diameter 20 cm • Implementation of the base of the glass prism which is made of steel,
6. Phases of the proposed experimental model
•
There are five phases of the practical experiment for the proposed model: (phase 1: design; phase 2: fabrication; phase 3: implementation; phase 4: analysis; phase 5: results) (see Fig. 15).
•
6.1. Phase 1: The proposed design
• •
• The
proposed model consists of a cube-shaped box, nominally 1 m × 1 m × 1 m, a prism installed on it where its base is made from steel, the base is painted in black matte and its glass lid is tightly
Fig. 32. The solar collector is covered by shiny aluminum foil sheets. Source: The photo was taken by the author during the experiment. 735
the condensed water pipe is installed in the base. the base which is painted in matte black, with dimensions 30 × 90 cm Manufacture of a steel frame to install a ventilation fan and a mesh to lay the burlap inside it, along with manufacturing a steel pipe with holes which will be located over the burlap mesh. Manufacturing the glass prism in the cutting and welding glass workshop, welding the prism by Silicon, and making sure that the glass prism is tightly closed. Manufacturing the solar collector in the blacksmith workshop. Purchasing the rest of the experiment requirements which are a thermal insulation sheets of glass wool, a water tank that has a faucet and calcium chloride moisture-absorbent material.
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Fig. 33. The burlap is cut and placed inside the metal mesh. Source: The photo was taken by the author during the experiment.
Fig. 36. The model after insulation. Source: The photo was taken by the author during the experiment.
Fig. 34. The model before installing thermal insulation. Source: The photo was taken by the author during the experiment.
6.3. Phase 3: Implementation The implementation phases are divided into: 1. The phases of the preparation. 2. Applying the experiment phases. 6.3.1. The phases of the preparation.
• Transferring the model to the location of the experiment. • The empty steel box is weighed before putting calcium chloride, and
Fig. 37. Spraying the water on the burlap. Source: The photo was taken by the author during the experiment.
then the box is weighed once more after putting calcium chloride to determine the weight of calcium chloride, before its exposure to atmospheric humidity. Finally, the box is weighed after the exposure of calcium chloride to moisture during the night.
Fig. 35. Using glass wool for insulation. Source: The photo was taken by the author during the experiment. 736
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Table 1 Measurement of solar radiation. Measurement of solar radiation and rate of condensation
Measurement of solar radiation
Hour
Temperature (°C)
solar radiation (W/m2)
9:30 am 10:30 am 11:00 am 12:30 pm 1:00 pm 1:30 pm 2:0.30 pm 3:0.30 pm
30.1 33.3 34.4 34.6 34.9 35.2 35 34.5
777 804 889 969 950 1007 982 896
•
Image
Figs. 34–36). During Installation of the steel pipe, a problem appears, that there was too much water falling. So water hose is installed instead, which has holes above the metal mesh, that mesh contains the burlap (see Fig. 37).
6.3.2. Applying the experiment phases Part I of the experiment: the moisture inside the glass prism was absorbed by Calcium Chloride during the night before where the lid in the morning was closed. Secondly, the solar collector was directed in the south direction, where the sun's rays exists for as long time as possible. Thirdly, solar radiation was measured, which is measured by watts per square meter, every half- an hour, from half past nine o'clock am to half past three o'clock pm, with observing the rate of condensation on the glass surface of the glass prism (see Table 1 and Fig. 38). Fig. 39 illustrates the condensation of humidity. To follow the stages of the moisture condensation on the glass and the amount of water, which is accumulated in the water path refer to appendix 1 in Shahda (2015). Part II of the experiment: Using condensed water in the process of reducing the vacuum temperature and humidity of the air, water will be placed inside the tank after cooling, at a temperature of 20 °C, where the air temperature in the desert at night is between 15 and 20 °C (see Fig. 40). Then, the tank is insulated by glass wool, then a hose is insulated to connect water to burlap, and the ventilation fan is connected by a power supply, accordingly, the temperature and humidity inside and outside the vacuum is noticed.
• Firstly,
Fig. 38. (Solar radiation) reading. Source: The photo was taken by the author during the experiment.
• •
Fig. 39. rate of condensation, after 150 min. Source: The photo was taken by the author during the experiment.
• • •
During temperature and humidity observation, readings were as follows: (see Table 2).
– The weight of the empty box is 3.5 kg. – The weight of the box that contains the dry calcium chloride is 7.6 kg. – The weight of the box that contains the calcium chloride after exposure to moisture is 11.3 kg. – It can be concluded by measuring the box weight, that the weight of Calcium Chloride when it is dry, equals (7.6–3.5 = 4.1 kg) – It can be deduced by measuring the amount of moisture that has been absorbed by Calcium Chloride, equals (11.3–7.6 = 3.7 kg). The model is installed at the roof of the Faculty of Engineering in Port Said. The solar collector is covered by shiny aluminum foil sheets to reflect the rays of the sun on the glass prism (see Fig. 32). The burlap is cut and placed inside the metal mesh in front of a ventilation fan, see (see Fig. 33). The model is covered by heat insulator (glass wool) (see
6.4. Phase 4: Analysis 6.4.1. Analysis of the experiment readings After the completion of practical experiment, and notation the readings, as it has been reviewed in the previous stage. Readings must be analyzed to reach the experiment results. Fig. 41 shows the graphic diagram for the solar radiation readings during the experiment. It is clear that the highest solar radiation was at 1:30 pm. At that time, condensation reached its peak degrees. Fig. 42 illustrates the graphic diagram of the comparison between temperatures (Temperature under sunlight -Outdoor; Temperature in the shade-Outdoor; Temperature-In door). At the beginning of the experiment, the temperature in the shade 737
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Fig. 40. Model after water tank insulation and startup of operation. Source: The photo was taken by the author during the experiment. Table 2 The readings of temperature and humidity. The readings of temperature and humidity Time
11:15 am 12:00 pm 12:45 pm 1:30 pm 2:15 pm
Outdoor
In door
Temperature Under sunlight
Temperature in the shade
Humidity
Temperature
Humidity
37.3 °C 38 °C 39.1 °C 39.5 °C 38 °C
34.4 °C 34.7 °C 34.9 °C 35.2 °C 34.5 °C
51% 58% 56% 54% 57%
34 °C 31.8 °C 31.4 °C 30 °C 29.9 °C
52% 67% 67% 72% 72%
Fig. 42. Comparison between temperatures, graphic diagram. Source: Drawn by the author, source of data from experiment readings.
Fig. 41. Solar radiation readings. Source: Drawn by the author, source of data from experiment readings.
Fig. 43. Comparison between outdoor and indoor humidity, graphic diagram. Source: Drawn by the author, source of data from experiment readings.
(outside the model) approached the temperature inside the model. After 3 h of starting the experiment, the temperature dropped [34–29.9 °C = 4.1° C], the temperature decreased about 4 °C compared to the temperature inside the model at the beginning of the experiment. Moreover, the temperature dropped from 34.5 °C to 29.9 °C = 4.6 °C. The temperature decreased about 4.6 °C compared to the temperature outside the model at the same time.
It is obvious that the highest temperature was at 1:30 pm and the significant difference in temperatures was at 1:30 pm. The outdoor temperature in the shade [35.2 °C]- indoor temperature [30 °C] = [5.2 °C]. The temperature decreased about five degrees Celsius compared to the temperature outside the model at the same time. 738
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6.4.2. The amount of required water and calcium chloride in the experiment The following mathematical formula has been used to calculate the amount of water that must be used to spray burlap and to reduce the temperature from 40 °C to 28 °C, depending on the special conditions in the desert atmosphere: Mathematical formula: Calculations in m3 can refer to appendix 2 in Shahda (2015).
ṁ a (h2 − h1) = ṁ w Cpw (t w3 - t w4) + ṁ a (ω2 − ω1 )Cpw t w4 ta1 = 40 °C Q = 20% ta2 = 28 °C Q = 50% tw3 = 20 °C tw4 = 28 °C
(h2 − h1) = ṁ w/ṁ a Cpw (t w3 - t w4) + (ω2 − ω1 )Cpw t w4 ṁ a /ṁ w = 5.7, about 6 kg air, refer to appendix 2 in Shahda (2015). Where: ṁ a → of air ṁ w → of water So 1 m3 air needs 1∕6 L water Fig. 44 shows the equilibrium water vapor pressure of various forms of calcium chloride at various temperatures. The rate at which moisture is absorbed by a given quantity of calcium chloride depends on applying-specific variables. While it was difficult to estimate the rate of moisture absorption, it is not difficult to determine the maximum water amount that can be absorbed per kg of calcium chloride at the given humidity and temperature by the following formula (Calcium Chloride A Guide to Physical Properties):
Fig. 44. Vapor Pressure of CaCl2. Source: (Calcium Chloride A Guide to Physical Properties).
Fig. 43 shows the graphic diagram for comparison between indoor humidity and outdoor humidity. It is clear that the difference between indoor humidity and outdoor humidity at the beginning of the experiment, after 3 h of starting the experiment is [72–52% = 20%], and the difference between humidity outdoor, after 3 h of starting the experiment and indoor humidity, after 3 h of starting the experiment is [72–57% = 15%].
Water absorbed = (Start%/End%) − 1 Consequently, the amount of water according to the special conditions of the desert atmosphere: 1 kg Calcium Chloride absorbs 1.13 L water. For calculations, refer to appendix 2 in Shahda (2015).
Fig. 45. Model: Apartment building, section. Source: Designed and drawn by the author. 739
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Fig. 46. Model: Apartment building, plan. Source: Designed and drawn by the author.
7. A model to use the proposed architectural application in desert buildings
energy to enhance the natural stack ventilation in the building by using passive solar energy. 7.2. The most important reasons for the preference of the Camel's nose system
The study proposes four architectural models, for utilizing the proposed architectural application in desert buildings, by designing: air movement through the plans; air movement through the sections (Shahda, 2015). subsequently, the models were analyzed by environmental simulation program (Ansys). This paper suggests one of them. For other models, please refer to Shahda (2015).
• This system aids to provide water needed for humidification and •
7.1. Model: Apartment building The model is an apartment building, each floor consists of two apartments. The exterior walls of the building have been designed from double walls, between the walls, there are thermal insulation materials. The idea of the model is to include an internal vacuum consisting of a windcatcher and a chimney. Windcatcher works to supply the building with air after being cooled and moistened by camel's nose system. The chimney works to pull the hot air out of the building. Figs. 45 and 46 show the cooling phases of the building, as follows:
• • •
A. Moisture is being pulled from the air by using absorbent material; Vaporization of the water vapor then the condensation of water vapor on the prism glass surface; Collecting the condensed water in the tank Accordingly, water passes through pipes to spray the burlap. B. Pulling the hot air and passing it on the wet burlap thus warm and dry air is cooled by evaporating. C. Cold air passes from the vertical corridor, which is considered a windcatcher to horizontal corridors. D. Through the cool air corridor, cold moist air passes in the horizontal passages in the floor, then the air comes out of the cold air outlet. E. When air heats up, its density is reduced, and moved in the direction of low-density. Air rises and goes out of the hot air outlet. F. Across the chimney: Air moves from high-pressure areas to the low pressure and high-temperature areas. The solar chimney uses solar
cooling from the available moisture in the desert environment at night. Subsequently, the system works to provide the water as a scarce resource in the desert. This architectural application works to provide humidification and cooling for each building spaces and acts as an integrated system, not as a separate device that is installed in each room of the building. The remaining water from this system can be used to cultivate the roof, and myriad of other activities. This system does not depend on non-renewable energies to provide air movement inside the building, but it serves to move the air inside the spaces by creating low-pressure areas to pull air. Buildings in which this system will be used will save money than buildings that use air conditioners or air desert conditioners.
8. Conclusions Through the practical approach to transform Camel's Nose technique to design idea, the following results have been reached:
• The •
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paper considers the analysis of Camel's Nose Technique, through Physics and Engineering sciences and employ these techniques in the field of architecture. Through analyzing the techniques of Camel's Nose System, some principles have been reached, which were applied to the proposed model: (Concentrating sunlight; Converting light to heat; Trapping heat; The condensation increases by increasing the surface that exposed to condensation; The evaporation increases when there is more exposed surface).
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By analyzing the practical experiment, the following results have been reached:
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• The proposed model which mimics the Camel's Nose System suc• •
ceeded in reducing the temperature 4 °C, compared with the temperature inside the model at the beginning of the experiment, and 5 °C compared to the temperature outside the model at the same time. The model succeeded in increasing the relative humidity, 20% between indoor humidity and indoor humidity at the beginning of the experiment, and 15% difference between humidity outdoor after 3 h of starting the experiment and indoor humidity after 3 h of starting the experiment. The results of using the mathematical formula which had been used to calculate the amount of water that must be used to spray the burlap, to lower the temperature from 40 °C to 28 °C, depending on the special conditions in the desert atmosphere. 1 m3 air needs about 1∕6 L water 1 kg Calcium Chloride Absorbs about 1.13 L water
The study succeeded in proving the hypothesis “whereas Camels can survive in a desert biome because of their physical features. Desert Buildings can be designed to be adapted in a desert biome by mimicking the adaptation characteristics of the camel”. Overall, the information presented in the paper configures a comprehensive framework for the understanding Camel's Nose System, and an initial assessment to employ this system in the field of architecture. Nonetheless, more information is needed to apply the system in many architectural applications in the desert environment. Furthermore, studies should analyze the adaptation methods of organism's habitats with the surrounding environment for application in architecture. Acknowledgments The authors would like to thank the reviewers for their insightful comments for the improvement of the manuscript. References Abdou, O., 2000. “Green Architecture: A Holistic Approach” Ecological Approaches to Architecture, medina, Cairo. Beautiful weather Graphs and Maps, weatherspark, Retrieved October, 2018 from the world wide web, https://weatherspark.com/#!dashboard;a=Egypt. Calcium Chloride A Guide to Physical Properties from Occidental Chemical Corporation (OxyChem). Retrieved March, 2018 from the world wide web. https://www.oxy. com/OurBusinesses/Chemicals/Products/Documents/CalciumChloride/173-01791. pdf. Chaker, M., Meher-Homji, C.B., Mee, T., 2002, January. Inlet fogging of gas turbine engines: Part A—fog droplet thermodynamics, heat transfer and practical considerations. In: ASME Turbo Expo 2002: Power for Land, Sea, and Air. American Society of Mechanical Engineers, pp. 413–428. Clements-Croome, D., Croome, D.J., 2013. The book Intelligent Buildings: Design, Management and Operation, 2nd ed. Telford ICE. Croome, C. Derek, 2013. The Camel’s Nose, Natural Ventilation News, ISSUE 08, Retrieved October, 2018 from the world wide web. https://www.cibse.org/ getmedia/3dbfdb4f-6aa4-4dbd-b3b3-4f3721aabd40/CIBSE-Natural-VentilationGroup-Newsletter-Issue-8-(2013).pdf.aspx.
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