Desert Bastion: a Self-Sustaining Space to Live, Grow, and Play

NEW LISTING - SELLING FAST, BUY WHILE YOU CAN!

1600 square-foot, 2 bedroom/1 bathroom fully modernized apartment located in the sandy dunes of the Sahara Desert. Comes equipped with a fully modernized kitchen, workout area, bathroom, two fully furnished bedrooms, and more. This pilot project also means the habitat is equipped with a sophisticated water-purification and collection system, solar array system, and integrated vertical garden. This habitat is fully self-sustaining, providing all the necessities for inhabitants to live in the arid and harsh conditions of the desert. Make sure to purchase your property while supplies last!

Call +1 800 111 1234 or email saharaconstructions@desert.com for more details or to book a guided viewing of the property.

For legal reasons (maybe?), this listing is not for an actual existing property, but was rather used solely as a interesting way to introduce the modelled habitat that this instructable will be covering. Alright, time for the actual introduction...

Hello, my name is Nicholas Nguyen and as of the time of writing I am in Grade 12 currently attending Bayview Secondary School in Richmond Hill, Canada. In a rapidly changing would, both in an economic and climate sense, it is important for humans to develop and utilize advancing technologies to make the environments in which we reside more enjoyable and sustainable. When the world around an individual does not allow one to thrive, it is it the responsibility of the habitat that the individual lives in to not only provide them with the means of basic survival, but to allow for the maintenance and growth of ones livelihood as well. One of the major problems that the world faces today is land degradation, specifically land desertification. Not only does approximately 49 million square kilometers (~19 million square miles) of the Earth's total land area consist of desert, about 4 million square kilometers of additional land area is being degraded annually, with about 120,000 square kilometers of that degraded land turning into desert (The World Counts, 2024). A third of the world's land surface is threatened by the ever growing issue of desertification, making it one of the most prominent effects of climate change that we as a human race must overcome. If it is not possible for us to change the environment that we live in, then we must adapt, and construct habitat's or living spaces that can properly accommodate the ever-evolving harsh conditions that mother nature throws at us.

Furthermore, a lot of regions in the world that are not considered deserts in the traditional sense still possess many of the problems that desert environments hold. Namely the lack of adequate water, whether it is for agriculture, for appliances, or for consumption, is becoming increasingly rare in certain areas due to a multitude of causes. Some examples is the water curtailment in Idaho, which is expected to affect around 500,000 acres of farmland, or the water main break in Calgary, AB which is currently causing a water shortage for the city at the time of my writing. Although the main environment that this habitat will be focused on is the desert, it will be applicable to almost any region in the world, as many of them face similar problems that life in the desert does. With that, I introduce you to what I call the Desert Bastion, the name coming from both the environment that this habitat will embrace, but also the fact that this habitat will be a bastion for a better way of life despite the harsh conditions that will inevitably be faced in the desert environment.

side note: I hope you guys enjoy the renders (especially of the interior of the habitat), my cpu became hot enough to fry an egg and probably would've melted my PC if I didn't have a cooling fan. The export onto this website did appear to drop the resolution of the renderings quite a bit though.

• Autodesk Fusion360 Software
• I would have opted to use 3DS Max instead, but due to the constraints of my laptops available SSD storage, GPU, and personal knowledge of myself, I decided to go with Fusion360 for the purpose of this habitat creation. If you have knowledge in 3DS Max, you can definitely get some more realistic interior modelling done using that software.
• In terms of rendering, you can use Blender as well and import your models from Fusion360, but again, I did not do this due to the constraints on my laptop CPU/GPU.

The desert environment is filled with a multitude of challenges that oppose the traditional way of human life, so it comes as no surprise that desert regions are sparsely populated, especially given the relatively low population density in those regions. However, despite this, desert regions make up a large portion of the Earth's total land area, so it is vital to be able to inhabit these lands, which will become more important as humanities population continues to grow. Thus, it must be considered the specific features of the desert environment that will influence both the design and materials used for the construction of this habitat. These obstacles that must be overcome in the desert are namely the;

• Lack of arable land
• Limited water and rainfall
• Large variations in temperature (High during the day and low during the night)
• Sandstorms / Strong winds
• Occasional flooding during periods of strong rainfall
• Soft/loose building foundation

All of the aforementioned barriers to life in the desert will affect the way in which the necessities of life are sustained in this habitat, whether it is the cultivation of agriculture to the procurement of water, innovative designs must be incorporated into the design of this habitat in order to ensure that the these needs are not simply met, but can be provided for in a viable and efficient manner given the scarcity of resources in the desert. Hence, these issues will need to be solved in their own unique ways. Once the solutions for these issues have been formulated, with the habitat being fully self-sustaining while providing for the basic human needs, it can then be further considered how the habitat can provide a space for its inhabitants to grow, work, and play. I will first be outlining each challenge and their solutions prior to showing the steps for the CAD modelling for all of the solutions and the final habitat itself.

However, before moving on, some benefits of the desert that can be taken advantage of are the abundance of solar energy and heat energy, which can be exploited using rather simple principles of physics which i will be outlining later on.

Image Source: https://globalplantcouncil.org/lessons-from-the-desert/

The next few steps will talk about the solutions that this habitat will use in order to overcome the aforementioned problems stated in the previous step.

It should come as no surprise that the desert makes for a less than ideal area for farming and traditional agricultural practices. Firstly, desert regions have a lack of natural rainfall, requiring intense irrigation methods in order to sustain agriculture. Furthermore, there is also a lack of fertile lands for agricultural practices due to a low content of nitrogen and a high content of calcium carbonate and phosphate in the sandy soil. The high concentrations of calcium carbonate in the soil results in a increase in acidity (and thus pH) of the soil, resulting in a decrease in available nutrients available for plants to uptake and absorb.

More than 95% of farming practices necessary to sustain the world's population with food is conducted on the uppermost layer of soil. However, over the last 150 years, nearly half of the most productive and fertile soil has disappeared across the world, threatening crop yields and creating dead zones (Guardian, 2019). California can be used as one of the most effective examples for the prevalence of this issue, California's largely desertified climate paired with the growing lack of available water is threatening agricultural farming practices. This comes as a concern as California is one of the largest suppliers of crops in the United States, accounting for 8% of food supply in the US despite it only containing 1% of the available farmland. Furthermore, both farming and living in California is predicted to be impossible by 2040, as experts have deduced that California's water supply has the potential of being stripped by that year if usage levels remain at its current state. Most of the water usage comes from traditional cultivation practices, as it accounts for approximately 70% of water usage worldwide, which is only aiding in the lack of water caused by droughts in countries around the world such as the United States and Chile (OECD). This necessitates the need to for the use of more innovative farming techniques.

Due to my previous experience in the realm of hydroponics, this inevitably eventually led me to the discovery of vertical farming. Vertical farming has an abundance of advantages over traditional outdoor farming practices, the fact that vertical farming is predominantly carried out indoors also allows for greater control over the surrounding environment and the use of smart technologies to increase crop yield. Vertical farms are generally used in areas where traditional farming is just not practical, and the desert makes one of the perfect environments to utilize the technologies that vertical farming has to offer. Nonetheless, it is still important to keep in mind that traditional farming practices are still vital for the long-term sustainability of the world's food supply chains, but in this case, it will be more beneficial and viable to utilize vertical farming methods. Vertical farming has two main advantages over traditional farming, being the reduced land footprint required for the same amount of yield, and the reduced water consumption which has been estimated to be 80%-99% less than traditional farms which is essential in an environment that does not offer much water in the first place. Thus, for the above reasons and advantages, vertical farming will be utilized in this habitat.

The lack of water supply, mainly due to the lack of rainfall that desert regions receive, is a great inhibitor of life in the region, in terms of both animals and plantation. However, despite the lack of life in these arid regions, there are still organisms that manage to find a way to survive through ways of adaptation and evolution. Likewise, we can use biomimicry in order to create effective solutions for this problem. Biomimicry is a type of innovation where scientists and engineers look for solutions to the challenges that face human beings by using the patterns that we observe to occur in nature. Nature has creations that are both accurate and time tested, being subjected to various conditions and millions of years of evolution. In engineering, biomimicry applies because nature inspires designs such as aircraft and navigation vessels among other things. One good example is the similarity in the shape of the B-2 stealth aircraft to an eagle, as shown in one of the pictures above. Similar to how engineers and designers have used the structure of birds to help with the design of fixed wing aircraft, it can also be used in this case to solve the problem of the lack of water in the desert.

With this in mind, it can now be introduced .... the camel and the cactus. These are two examples of organisms that have adapted to not succumb to the water restrictions presented in the desert, but rather to embrace it and find methods to overcome this issue. The desert is known for the lack of vegetation/foliage due to the absence of enough rainfall to support plant and animal life. However, the cactus and camel have both adapted to these harsh conditions by storing a water or fat in their stems or humps respectively. The abundance of stored water within the cactus collected during periods of rain allows it to survive the dry periods in the desert. The camel also stores fat within its hump, which when consumed through metabolic process's can release both water and energy necessary for the camel to survive. Similarly, the habitat can collect rainwater from both the gutters on the roof as well as the ground, which can then be transported to a reservoir in which the stored water can be accessed whenever needed. At my house, I currently have two barrels that collect water from the gutters whenever it rains, which allows for the storage and future use of that water for tasks such as watering the garden, essentially eliminating the need to use water from my hose.

Another feature of the camel is its ability to hold onto and absorb water from its exhaled air. When a camel is dehydrated, the surfaces of its nasal cavity become hygroscopic which allows it to retain and absorb water vapor from the air it exhales, allowing for it to better conserve precious water that the desert severely lacks. This habitat will also utilize similar principles in order to collect water from the air. Many of you may have notices water condensing on your window or the grass outside during the morning, this is due to the fact that colder air is less able to water vapor, resulting in that water vapor condensing out of the air and onto surfaces. In order to understand the reason behind this occurrence, some chemistry knowledge will be needed. Below shows the equilibrium chemical equation between liquid and gaseous water.

HEAT + H2O (l) ⇌ H2O (g) 

The "double half-arrows" in the above reaction depicts that both the forward and backwards (leftwards) reactions are possible, instead of solely the forward reaction being possible as commonly depicted by a single forwards pointing arrow. This means that at equilibrium, the rate at which liquid water is vaporizing into gaseous water and the rate at which gaseous water is condensing into liquid water are equal. Furthermore, the HEAT term on the left side of the equation shows that this reaction is endothermic (absorbs heat energy from surrounding environment) in the forward direction, and is exothermic (releases heat energy) in the backwards direction. Le Chatelier's principle also states if the conditions of a system in dynamic equilibrium is changed, the equilibrium of that system will shift to counteract the change. In this case, if the temperature of the surrounding environment was lowered, the equilibrium of the system will shift to the left in an attempt to release more heat to counteract the drop in temperature. In the process of the equilibrium shifting left (where the backwards reaction is favored), liquid water is also produced along with the heat, which explains why water condenses out of warmer air when it is cooled. However, the air must be cooled to its dew point (which is usually from 0C - 11C in the desert), which is the temperature at which condensation can actually be observed.

Thus, we can now apply this theory into extracting water from the surrounding air. In fact, this is already seen in most air-conditioning systems, where the condensed water is drained out through a drain tube. Except in this system, the water will be collected for use. In addition, the habitat will also use a fan or a pump running throughout the day to draw air from the outside environment into either a heat exchanger which will manually cool the air until condensation forms, or to transport the air underground, where the lower temperatures below the surface level can naturally cool the air until the water in it condenses. This will allow for a constant generation of water that is not limited to when the air-conditioning system is running. The condensed water can then be collected and transported to the water reservoirs for future usage as well.

In addition to water collection, water recycling is another means of reducing the pressures on what is already a very restricted water supply. In fact, a type of water recycling was already covered in the previous step. Water collection from sources such as rain water and runoff stormwater are both considered a type of water recycling. However, what I specifically mean by 'water recycling' in this step is the recycling of greywater (water from bathroom sinks, laundry, showers), and wastewater/blackwater (water from toilets, kitchen sinks, dishwashers). Many urban developments in the modern society lack the means of effective water recycling, causing them to draw from high quality potable water supply, which is a problem even in well-developed areas.

An important aspect of water recycling is also the effective use of water itself. F. Naji and T. Lustig suggest that increasing the control people have over their lives is the key to increasing social sustainability. Their logic is that if people have more control over their lives, they are able to use resources more effectively. If this concept is then applied to water recycling, it means that users should have more control over their own water recycling systems. However, this is not enough, as they also need to feel that these recycling systems are reliable and not prone to failure. A way to increase people's control over their water recycling system is to ensure that it is decentralized, but also have a centralized monitoring system to ensure that these systems are all operating efficiently and to the correct safety standards. Similarly, each habitat will be equipped with its own water recycling system, but in addition to a centralized monitoring system, each habitat will have it's own mini-monitoring data panel which will feed live data back to the inhabitants about water quality measurements (pH, TDS, hardness, suspended sediment), and amount of water available for use. The first image/figure depicts the elements of the water cycle is modelled by BASIX, which can be used to determine the efficiencies and viability of water recycling methods.

The second image shows some data regarding different methods of water recycling (or lack thereof) using the BASIX simulation/model. The main columns of focus are the Mains Water Savings %, 20 y $ costs, and 20 y $ savings. As you can see, recycling methods 2, 4 and 5 include some of the highest percentage reduction in water usage from water mains, indicating that those methods are the most effective at reducing external water consumption needs. However, it can see that the costs of options 4 and 5 far outweigh the savings over a 20 year period. This makes sense, as water treatment is generally a lengthy process that takes time and chemicals to fully disinfect and treat the water, especially if it meant to be potable. However, later on in this instructable, I outline a filtration process that should greatly reduce the costs associated with proper water filtration for both potable and general use. Furthermore, option 3 outlines the use of greywater for the irrigation of agriculture, which I have also implemented into this habitat. The savings come much closer to the costs of the system, as minimal processing is needed for the water. However, option 1 outlines the importance of integrating water efficient systems into the habitat, as it is the only water reduction/recycling method that has a positive net savings over the 20 year period. Thus, it will generally be the goal of this habitat to utilize water efficient appliances. Appliances such as washing machines, dish washers, toilets, and showers are a few that may come to mind. Depending on which appliance/fixture the water is being collected from, different filtration methods would also need to be used depending on whether the fixture produces black or greywater.

Many households and facilities around the world rely on energy intensive methods such as air-conditioning systems to cool down the interior during hot days. Another technology that can be utilized is the passive daytime radiative cooling, which is the process of moving heat from the Earth's surface to outer space. In order to move this heat from the Earth's surface to space, the atmospheric window can be used, which is the region of electromagnetic spectrum that can pass through the Earth's atmosphere. The optical, infrared, and radio windows make up the 3 main atmospheric windows. Thermal/heat radiation can essentially be thought of as infrared radiation (think of how thermal imaging camera's detect infrared radiation), showing how use of the atmospheric window can result in heat transfer from the Earth to space. The atmospheric window is between 8-13 μm, as can be seen in Image 2 in the selective emission section. Furthermore, during daytime, the incident solar irradiance is dominated by solar irradiation at short wavelengths of 0.3-2.5 μm. This can be seen in the selective absorption section of Image 2. The solar irradiation heat flux, meaning the rate at which heat is transferred to a material, is in the order of 1000 W/m², and it has been demonstrated that just 10% of solar absorption in the 0.3-2.5 μm region can completely nullify the radiative cooling effect of a certain material. Therefore, as shown in Image 1, a good radiative cooling material must also be a strong reflector of radiation in the wavelengths of 0.3-2.5 μm.

There are 2 main types of radiators that underly the working principles of passive radiative daytime coolers (PDRCs). These 2 types are photonic radiators which are cooled by relying on proper periodic structuring (such as a patterned surface), and nanoparticle-based radiators which rely on the optical properties of the nanoparticles. However, standard PDRC's made from thin HfO₂, SiO₂, Al₂O₃, and TiO₂ metal oxide layers, although effectively cooling 7 degrees Celsius under direct sunlight, are extremely difficult and expensive to produce due to its complex manufacturing process. However, there has been some research done on electrospun microfibers that are doped with the same Al₂O₃ metal oxides. This process if much cheaper and accessible since it is already used for items such as wearable textiles and devices. The distribution of Al₂O₃ throughout the nanofiber can be observed in Image 3 with the presence of white "specks" throughout the fiber. Furthermore, as seen in Image 4, a higher percentage composition by weight of the metal oxide within the fiber increases its percentage reflectivity. It is interesting to note that the reflectivity for the 9.09 wt% is slightly lower than 4.7 wt%, suggesting that the 4.7 wt% for the metal oxide doping is the most effective. Lastly, nanofibers doped Al₂O₃ result in the highest reflectivity values between all the previously mentioned metal oxides which is evidenced in Image 5. Note that these reflectivity values or for a double layered sheet with a aluminum foil substrate. The aluminum foil increases the reflectivity values of the radiative coolers significantly.

Furthermore, the peak absorptivity of the various samples as shown in Image 6 within the atmospheric window of 8-13 μm (the outlined red section) suggests that SiO₂ and TiO₂ doped nanofibers exhibit spectral selectivity. Since emissivity is equal to absorptance at thermal equilibrium, this implies that the emissivity of the sample is also high within the 8-13 μm range, whereas reflectivity is high at all other wavelengths, both important criteria needed for passive radiative daytime cooling. Also, combinations of two different metal oxides yielded the best results, with SiO₂ and Al₂O₃ yielding the strongest absorptance in the atmospheric window. Thus, the radiative cooler's installed on the exterior of this habitat will be a combination of nanofibers doped with both SiO₂ and Al₂O₃.

As briefly mentioned in my introductory steps, some other problems that will be posed in the desert regions include, sandstorms or strong winds, occasional flooding, and the lack of solid foundations on which structures can be built.

As shown in the tables above outlining the average and maximum wind speeds in the Coachella Valley desert (picked due to the availability of data), the maximum and average maximum wind speeds can be quite high resulting in a classification between the ranges of high winds to strong gales, peaking during the Summer months. This will need to be kept in mind during the design phase of the habitat, to ensure that the structural elements of the design can withstand the forces acting on it caused by the wind. As a result, I will be conducting tests in CFD as well as Fusion360's simulation space in order to ensure that the structural designs of the habitat can withstand the strong wind conditions effectively.

Another problem that the desert poses is the risk of flooding, generally caused by periods of heavy rains and storms. I did find it surprising that desert regions can still see floods occurring, especially given my previous thought of deserts being extremely dry all year long. Here are a few videos showing an example of a flood in the Sahara Desert, giving an idea of how despite the dryness of the desert, flooding can sometimes be quite drastic and severe. In fact, the extreme dryness of the desert's soil/sand and the lack of vegetation works to exaggerate the effects of flooding, as excess water is not able to be effectively absorbed into the ground or by plants.

https://www.youtube.com/watch?v=fw0o6jv5Rec&ab_channel=shuvs

https://www.youtube.com/watch?v=-EiICzIk6CM&ab_channel=NatureNews

More recent events in Dubai have also showed the drastic effects of flooding caused by abnormal rainfall in places that traditionally have little rainfall year-round. In order to prepare the habitat for this issue, the living areas will be elevated on columns/pillars which will allow for the flood waters to simply flow underneath the habitat to ensure that there is minimal to no damage to the actual living space itself caused by the flooding. The pillars used to support the habitat will also be utilized for the vertical farms as well as the elevator system to allow inhabitants access to and from the habitat, allowing for a more efficient use of space. Furthermore, due to the lack of a solid foundation in these desert areas due to the top layer being mostly sand, the pillars will have to be deep enough to reach the solid bedrock below the sand to ensure that the shifting and loose sand above does not disrupt the foundation of the habitat.

The next few steps will talk about how the habitat will be able to exploit the advantages that the desert environment brings.

As mentioned briefly in the introduction section of this instructable, despite the multitude of downsides that must be overcome in order to live in the desert, there are also a few benefits that can be taken advantage of to increase the ease of living. Two examples of this are namely the abundance of both naturally available solar and heat energy, which can both be used to generate electricity to power the daily functions of the habitat. In order to make use of heat energy to convert it into electrical energy, I made use of the thermoelectric effect, specifically the Seebeck effect. In order to make use of this effect, a thermal couple must be used, which is essentially a pair of semiconductors connected together as shown in the diagram above. One of the semiconductors is an n-type semiconductor which has an excess of electrons, and the other semiconductor is a p-type which will have the ability to accept electrons (note that any pair of semiconductors in which there is an imbalance of charge will work too). When a heat source is applied to one the bottom side of the thermocouple, electrons will flow from the n-type semiconductor to the p-type semiconductor which results in an electrical current being generated (Seebeck effect). It is also important to be noted that the voltage of the current does not scale with the temperature of the heat source itself, but with the temperature difference between both of the ends of the thermocouple. Voltages generated by a single thermocouple are also quite small as well, so it is common practice for multiple thermocouples to be connected together to create usable power levels.

My plan is for the thermocouples to be integrated directly into the walls of the habitat, where the difference between the inside and outside temperatures (outside being hot, and inside being cool) will be able to generate sufficient electrical current to power the majority of appliances within the habitat, greatly reducing the need for the generation/transportation of electricity by other means. The table above shows the average high temperatures in the desert (in Fahrenheit), resulting in a large temperature differential between the indoor and outdoor environments which will make the wall-integrated thermocouples a viable source of electricity generation .

In my last step I talked about the use of thermocouples, however, outdoor temperatures in the desert tend to be significantly cooler during the night, which will cause the electrical energy generated by the thermocouples to likely decrease the unusable levels. Thus, solar panels can be used to generate and and transport electricity throughout the day to batteries which can store energy to be used during the night, where the temperature differential between the outside and inside of the habitat is low. This will allow for the continuous electricity supply throughout the entirety of the day, with the need for minimal use of alternative power generation methods, resulting in the habitat being more self-sufficient. Solar panels work by utilizing a silicon or other semiconductor material to absorb photons from sunlight, releasing electrons during the process which in turn generate an electrical direct current which is then converted to alternating current for regular use. In a way somewhat similar to how a thermocouple works, solar panels also use p- and n-type semiconductors to facilitate the flow of electrons.

There are also 3 types of solar panels, polycrystalline, monocrystalline, and thin-film. As shown in the first graph above (labelled Fig.3), monocrystalline generally has the highest performance-ratio during the cooler months which is most noticeable during the months of November to February. However, thin-film generally has a higher performance ratio value during the hotter summer months of May to August. This shows that thin-film has a lower performance drop during the summer in comparison to other types of cells, which is mainly due to its ability to maintain a low temperature by letting off more excess heat due to its thinness. The performance ratio is the ratio between the theoretical and actual energy output given a value for the total solar energy incident on the photovoltaic cells, meaning that monocrystalline panels generally perform better during colder temperatures while thin-film performs better during hotter temperatures.

This first led me to believe that thin-film might be the obvious choice for the desert, since the temperature in those regions is relatively high all year-round. However, if we look at the second graph, thin-film has a significantly lower daily system efficiency (percentage of solar energy converted to usable electrical power) in comparison to the other solar panel types, resulting in a larger surface area needed to generate the same amount of solar energy as mono- and poly- crystalline PV cells. This fact can also be more clearly seen in the third graph (Fig. 7) as the power generated per m² for the thin-film panels is significantly lower than other panel types. In contrast, the power generated per m² for the monocrystalline panel is the highest out of all the different types, making it a viable option when the constraint of the available roof area that the habitat can provide for solar panels is taken into consideration.

Thus, monocrystalline PV cells will be used to construct the solar panels, as they provide a good electrical power generation per area and provide relatively stable performance during higher temperatures. The solar panels will also likely be mounted facing the Southward direction, as that provides a higher energy output than the Eastward/Westward facing counterparts as also shown on the bar graph. I am also thinking about the idea of having solar panels that can adjust to the position of the Sun in the sky, but I am currently unsure of how much more energy output that will result in, making the justification for a potentially unnecessarily added complexity difficult.

Source of graphs: ScienceDirect

An off-the-grid house or habitat is one that does not rely on the public servicing for one or more of the utilities such as gas, electricity, and water. As of the current design, the habitat has the potential ability to be self-sufficient in terms of providing for adequate water and electricity/power generation.

Power and Electricity Generation:

As mentioned in my previous steps, the use of both thermocouples and solar panels will be used to meet the electricity requirements of the habitat. The average household electricity usage per year is about 10,203 kWh, and with the monocrystalline solar panel generating about 267.2 kWh of electricity per m², that makes out to approximately 38.09 m² of solar panel area needed to provide enough energy for the habitat all year long. The average house size, even on the lower end will be around 484 square footage, and with the roof size being about 1.5 times the square footage of the house, this will leave approximately 556 square footage available for solar panel installation. This translates to about 52 m², which is more than enough space for the required solar panel footprint to sustain the power requirements of the habitat. The PDRC materials integrated into the exterior walls of the habitat will also allow for a lesser amount of electricity required to run the cooling systems such as air conditioning systems for the habitat. Lastly, the thermocouples integrated into the walls will most likely allow for any energy needs that are unmet by the solar panels alone to be fulfilled.

Water Collection:

As aforementioned, the habitat will have the ability to both collect rainwater and condensed water from the air. On average, a household uses 230 cubic meters of water per year. Despite the various methods of water collection and condensation methods I have previously outlined, I believe that this habitat will unfortunately not be able to be fully self-sustaining in a water sense. Even systems such as the ISS with extremely advanced water generation and recycling methods still relies heavily on water deliveries from Earth for crew members. However, the water collection/generation systems used in the habitat and the lower water requirements of the habitat's vertical farm will limit its reliance on external water sources and/or deliveries. Furthermore, as stated in previous steps, the habitat will be able to collect and recycle water from appliances throughout the habitat. This will decrease the water requirements of the habitat, making the habitat more self-sustaining.

Agriculture/Farming:

The habitat was planned to have a vertical garden as previously stated, and with the low water requirements of vertical farming, this should allow the habitat to provide adequate water for the crops to grow. Vertical farms will be placed on the exterior wall of the habitat, which will allow for adequate space for the plants to grow, as well as an added cooling/shading effect for the habitat. Nevertheless, the problem of raising livestock still exists, and it is likely that meat will have to be imported from other sources. Raising livestock is generally very resource intensive in terms of both food/water and land required. However, smaller livestock such as chickens can be housed in the vicinity of the habitat which can reduce the reliance on external sources for meat food sources.

For the purposes of this design challenge, I wanted to actually create a detailed model of the interior of the habitat's. After all, that's where individuals will actually be living everyday, and is one of the most important parts which will really make this habitat complete. Every piece of furniture that you see in this design was individually modelled, with human factors and ergonomics taken into account. Even things that would not be visible to the eye, such as framing and piping were also modelled, although to a less detailed extent. Essentially, all of these models of furniture were made by creating a sketch of the required dimensions, followed by a lot (and I mean a lot) of various extrusions and fillets/chamfers. Image 7 shows a general floorplan of the interior space.

Kitchen:

The layout/floorplan for the kitchen can be seen in Image 1. The kitchen includes a stove with an integrated oven as well as a vent fan, cupboards and drawers, a bar-style dining area, a fridge, sink, as well as various other kitchen appliances that people living in this space will need.

Lounge/Living Area:

The lounge area is the section right beside the kitchen. It is pretty basic and includes a L-shaped couch with a movable leg rest, as well as a drawer for storage and a flatscreen TV above it. The couch can also double up as a bed as it is a fold up sofa bed, creating an extra bed to sleep on if need be. The kitchen as well as the lounge area make up the communal area of the habitat/living space.

Bedrooms:

This habitat includes two bedrooms. The bedroom closest to the entrance contains a working desk, as well as a drawer with a flatscreen TV above it. Both beds also include a slidable storage drawer underneath the bed to give the living area additional storage space, without adding to the total footprint that the furniture take up in the habitat. The other bedroom is quite similar as well, but includes a L-shaped cabinet/storage space.

Bathroom:

The bathroom contains a standard sink as well as a bathtub, and a toilet (of course). The sink is separated from the bathtub area, which leaves access to the sink available even when another individual is using the toilet or bathtub. All of the fixtures in the bathroom will also be connected to the water filtration and collection system. Water coming from the sink and the shower will be treated as greywater, while the toilet water will be treated as blackwater, which will need more intensive processing if it is meant for consumption.

Main Closet/Wardrobe:

Pretty self-explanatory, a place where the occupants can store their various clothing items. It is placed beside the entrance door for maximum convenience (used for directly storing jackets and shoes for when occupants enter and exit the habitat, for example).

Exercise/Workout Room:

In order to the occupants in this habitat to fully thrive, there needs to be a way to maintain their overall health. In terms of physical health, the workout room will allow occupants to get physical exercise without the need to be exposed to the harsh environment of the desert. The gym will also be able to serve a secondary purpose of generating electricity. The main source of electricity generation will be from the stationary bike, which will be equipped with an inverter to create usable electricity for the habitat. For example, at the gym I am able to sustain around 150-250 Watts of power consistently.

Parts of the habitat that are exposed to the external elements of the desert are the ones that were taken into the most consideration in terms of their material makeup. The exterior walls of the habitat will be made of concrete. The many properties such as it's high thermal mass, fire resistance, wind resistance, and general durability make it ideal for handling the harsh temperatures and other conditions found in the desert. Furthermore, the concrete exterior wall will also be reinforced with steel rebar in order to increase its durability to temperature changes and thermal expansion/contraction. However, since concrete isn't the best insulator, foam insulator will be used between the interior drywall and the exterior concrete wall in order to provide adequate insulating properties for the habitat. The fences and deck area will also be predominantly made up of fiberglass, as it is also resistant to high temperatures (and temperature changes), while also being relatively lightweight.

Details that you will find in most modern living spaces were also included as well, trims where the walls and the floors meet were included (sketching process shown in Image 1), with trim designs on one of the hallways of the habitat which gives it more style and life, so to speak.

The next steps will be about modelling and integrating the individual components that allow the habitat to function as it is, as mentioned in previous steps, this will include the water collection/generation system, solar panels, thermocouples, vertical gardens, and wind turbines.

The water filtration and collection system consists of multiple units (such as the one above) located around the habitat in order to store rainwater and condensed water from the air which can then be filtered and processed to be distributed. The images above show a unit of the water collection system, which will be used to both store water (in the large tank), and filter and distribute it to the rest of the habitat for use. This unit will be able to collect water both from the rainfall as well as the water condensed out of the air.

Another mechanism I decided to implement into this habitat is the use of distillation systems that use the power of solar energy. These distillation systems would allow for the filtration of water from contaminants such as heavy metals, dirt, salt, and microbes among other things. Distillation essentially works by heating water until it starts to produce vapor, then condensing/cooling those vapors back down to be collected, ridding it of most of the contaminants present in the original water sample. However, instead of using solar energy to be converted into electrical energy (Ex. solar panels to produce electricity to heat the water), the solar energy from the sun can be used to directly heat the water, since using the sun's energy directly is more efficient that using commercial solar panels to produce usable energy, as they only have an efficiency of around 20%. The direct thermal energy provided from the sun will be used to heat and vaporize the water, which can then be condensed back down into a separate chamber where it is collected into the aforementioned water collection systems. This results in a preliminary filtration system that requires minimal use of electricity. Referencing back to step 4, this will greatly reduce the energy requirements of the filtration system, which works to cut costs associated with water filtration. In fact, distilled water would be much better for use in car washing and laundry washing, since it lacks the impurities and minerals of regular water (refer to option 4 in image 2 of step 4). However, if this distilled water were to be used for drinking or potable purposes, it will likely have to be further treated with chemicals, as well as having additional minerals added to it (purely for taste purposes).

In terms of how the distillation system will work, refer to image 3. The distillation panel has 2 distinct layers. The clear/glass layer (blue line) will be where the water to be filtered enters, while the opaque layer (green line) below is where the distilled water will be condensed and collected. There will also be a hydrophobic layer in between the 2 panels. This hydrophobic layer (red line) will not allow liquid water to pass through but will let vaporized/gaseous water to pass through it's microporous structure similar to how breathable waterproof fabrics work, which allow sweat to perspirant out but do not let moisture in. The panels also have larger surface areas in order to ensure a maximum amount of solar energy is let in to heat the water. This distillation should be adequate enough treatment for water if it is used for general purposes such as sinks, toilets, and watering plants, as long as it is not consumed. However, as stated in a previous step water meant for consumption will have to be further treated within the storage compartments as shown in Images 1 and 2. Furthermore, distilled water is generally not suitable for plant watering as it can result in stunted growth and discoloration due to lack of essential minerals and nutrients needed for plant growth. To resolve this, the distilled water can have nutrient solution added to it prior to it being delivered to the plants in the vertical farm.

Despite the passive cooling methods described in the previous steps of this instructable, the habitat will still have an active climate control system to ensure that the habitat is most ideal for the inhabitants. Sub-surface and near-surface temperatures generally vary greatly from surface temperatures, especially in the desert. Underground temperatures tend to be significantly cooler during the day, and warmer during the night, where surface temperatures in the desert can reach as low as -4 degrees Celsius. Furthermore, temperatures underground are relatively constant as well, which is demonstrated by the Graph shown in Image 1. At depths below approx. 10 meters, temperatures are constant at around 20 degrees Celsius. Note that this graph is for Malaysia, but a similar graph will be yielded for a desert region as well.

After all this, you may think that this habitat will be situated underground to take advantage of the constant temperature, but there are a few potential problems with putting the actual habitat below the surface. One of such problems is shifting and moving sand caused by natural winds, in fact, that is how sand dunes are formed in the first place. If the habitat were to be located underground, it would need to have an exit point that is above ground (unless the occupants want to live underground forever, which is likely not the case). The shifting sand and sand dunes have the potential to slowly obstruct the entrance to this habitat, making entrance in, and more importantly entrance out of the habitat much more difficult if not impossible. One such example to demonstrate this is the shifting of Lala Lallia, which is one of the largest sand dunes in the world, is shifting Westward at a rate of approx. 1.6 ft/year due to a wind blowing from the East. This effect of shifting sand can be exaggerated during periods of higher wind speeds, which can be relatively common in the desert regions, making it paramount that the actual habitat itself is not situated below surface level.

Thus, instead of the actual habitat being located underground, above surface air will be transported through the climate control system, where it will then passed-through below ground, naturally cooling or heating it before it is then released into the habitat. During the day time, the underground temperature will be cooler than above surface temperatures, allowing for the outside air to be cooled through the climate control system before entering the habitat. During the night, below surface temperatures will generally be warmer than above surface temperatures in the desert, allowing for the outside air to be warmed before entering the habitat. Regardless of the temperature that it is outside, this will allow for the habitat to remain at a constant temperature despite being located above ground, while also saving electricity since a conventional air-conditioning unit is not being employed. This "natural" air conditioning unit consists of an external air intake system which deliver the air through the pipe system shown in Image 2. The first section of this system (the cylindrical tube), consists of an filter which will get rid of any particulate or viral matter present within the air. The second section consists of a coil, which will be located approximately 15 meters below ground level, which the air will then be delivered through in order to be naturally cooled through convection. The coil structure allows for an adequate length of tube to allow the air to fully reach the underground temperature without taking up a large footprint. As mentioned in previous steps, as the air is cooled, water will condense out of it. Thus, the final portion of this system contains a rectangular water extractor to remove the condensed air from the pipe which can then be collected into the water collection/filtration system of this habitat. In addition, this climate control unit will also circulate air from within the habitat itself which would allow for water to be condensed out of the interior air as well, making the climate control system also double up as a dehumidifier.

The vertical garden for this habitat will be mounted on the external walls of the habitat. This placement will allow for the plants to receive adequate natural sunlight for growth, while also not needing an additional area for the vertical farm, which will unnecessarily increase the footprint of the habitat. Images 1 and 2 show the individual planters. The planters are made up of a cylindrical "container" with drilled holes to allow for water to flow in and out of the cylinder planter. The individual planters are organized into separate columns, with all the individual planters being linked to a continuous water delivery system, which allows for an easy and efficient method to deliver water to the plants with minimal waste. Any water flowing back out of the water delivery system can be recycled for future use for any of the water requirement needs of the habitat. The layout for the wall mounted vertical farm is shown in Image 4.

In terms of cycle schedule and duration, the goal of a hydroponics or vertical farming system is to keep the roots of the plants constantly moist, without having them be clogged with water for too long. The vertical farm setup for this habitat most closely resembles a nutrient-film technique that is used in hydroponics. Essentially, a steady flow of nutrient rich water is required to be constantly flowing over the roots to keep them moist. However, pauses of around 10-30 minutes is generally acceptable. This habitat will utilize pauses in the system to give it some time to rest to mitigate the effects of long-term continuous usage. However, the pauses in water flow will be limited to the night period when the sun has set, and will be no longer than 15 minutes in duration. This will allow for breaks for the water delivery system while ensuring that the plants do not get dried out in the desert climate.

While a standard fixed solar panel will be relatively easy to model, the solar panels I am opting for are ones that are attached to a solar tracker. Solar trackers essentially work by measuring light intensity at different angles to determine the position of the sun in the sky. This allows the solar panel to be aimed directly at the Sun's position throughout the day which will result in an increased energy output, while not consuming much energy to do so as well. The solar panels will also have an ability to fold into a storage "container" to protect it from being damaged by harsh conditions in the desert environment, such as sandstorms.

The first step was to create solar panel surface that is 3.7m in length and 1.9m in width. Afterwards, it was split into 4 equal sections as shown in Image 1. Components that would allow each section of the solar panel to pivot were also added to joints where then in between each section of the panel, which can be seen in Image 2. Image 3 shows how the solar panel can fold up for storage, showing the comparison between the folded side (right) and unfolded side (left). Image 4 shows the completed storage container for when the solar panels are folded up, with a "double-jointed" pivot point attached to the bottom of the container to control both the rotation and pivot of the solar panel using the solar tracker. Image 5 shows the comparison between when the solar panels are in storage vs. when they are operating, with a underside view of the storage container when it is unfolded and when it is folded, with corresponding color coding to help visualize how the storage container will transition from an unfolded to folded position. An easy way is to think of it like net of a 3D rectangular prism. Image 6 shows some dimensions for the storage container.

As previously stated, the solar tracker will also need sensors to measure light intensity, 4 of which can be seen in Image 7.

side note:

Another interesting this I came across while researching different methods of energy production using the sun was Dye Sensitized Solar Cells (DSSC). Essentially, it mimics the way in which plants produce energy from light. It contains a dye that when hit with photons from the sun will release electrons. The DSSC also contains an electrolyte that is constantly undergoing REDOX reactions, which ensures the dye has a continuous flow of electrons back into it as well. The combination of these two will create a flow of electrons, which creates current. Due to the highly conjugated structure of the dye, meaning it has a large network of alternating single and double bonds within its molecular structure, it can absorb a large wavelength of light. This means that DSSC's actually tend to perform better in low light conditions. While I found this quite interesting, I didn't believe it would have a place in the desert, as the desert is generally very sunny. Not to mention that high temperatures can also damage the DSSC, since it can cause the electrolyte to expand, rendering the cell inoperable.

There is probably a way to use brute force to make a spiral staircase, but I, like many of you, would probably prefer to use a more efficient method, which is what I will be covering in this step. Since the process is relatively complicated to explain in just words, a video I made is provided to guide you through this process instead (enjoy the background music as well!).

Notice that the exterior structure of the habitat is essentially a rectangular prism. The rational for this is to maximize the actual living space of this habitat. Curves and unnecessary shapes in the structure can result in dead space, and after all, form follows function. Note that all my renderings are in the introductory step, so if you want to check those out, feel free to head on back to the beginning! Renders of the interior portions are also taken with the interior moved out of the actual habitat itself to allow for better lighting and angles. The viewable model attached also has the interior removed from the habitat so viewers can actually see it. If the share link viewable file is not loading, feel free to let me know in the comment section and I'll see what I can do. The colors of some of the materials are not correct in the viewable file, the actual colors used in this habitat can be seen in the renderings.

Thank you for taking your time to read this instructable!