Integrated Architectural Water Systems by Jacob Russo

Integrated Architectural Water Systems A 3D printed and textile hybrid water capture, transport, and storage strategy for urban building envelopes

Jacob Russo Term / Year: Summer Term / 2018 Tutors: Dylan Wood, Tiffany Cheng Integrative Technologies and Architectural Design Research Master Thesis Course Number: 80970 Examination Number: 809701 Examiner Number: 02442 Matriculation Number: 3214408

Acknowledgements

I wish to express my appreciation to Professor Achim Menges (ICD) and Professor Dr.-Ing. Jan Knippers (ITKE) for making the ITECH program possible and promoting innovative, interdisciplinary study. I owe a special debt of gratitude to my thesis advisors, Dylan Wood and Tiffany Cheng, who provided amazing guidance and countless insights throughout this research process. They pushed me to think more critically and work more rigorously at every step of the way and for that I canâ&#x20AC;&#x2122;t thank them enough. Thank you to all my family and friends who supported me with valuable feedback and encouragement. I was fortunate to be able to collaborate with several consulting parties: Essedea GmbH & Co. KG, A&F Engineering, Arne Gruppe, Alex Faust. Thank you all for helping me turn my ideas into reality throughout my prototype development. Finally, I want to thank my parents, Marilyn and Joe Russo, who inspire me every day to pursue my passion for design and remind me to always stay humble and open-minded in my endeavors. I dedicate this work to you.

Abstract

Increasing environmental, technological, and social pressures on urban water systems in recent years have undermined water supply and security in many cities, creating a growing need for new ways of managing water as well as supplemental sources of water, which can be harnessed locally and managed on site in a decentralized way. The main argument put forth in this thesis is that building envelopes should play a leading role in the effort to capture and use local atmospheric water sources where climatic conditions are conducive. The research aim is to develop a building envelope design that combines multiple functions related to in-situ water management to establish an integrated and resilient approach for urban architectural water systems. This is done through a hybridized approach combining an existing state of the art 3D woven water capture textile with multifunctional, small-scale DLP 3D printed structures.

Contents Chapter 01: Relevance: A Need for New Ways of Managing Water

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Chapter 02: Scope & Context: Rethinking Urban Water Systems In San Francisco

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Chapter 03: State of the Art: Designs, Systems, & Technology for Water and Resource Management In Architecture

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Chapter 04: Methods: Design Framework & Computational and Fabrication Workflows for Water Systems Integration

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Chapter 05: Design Development: Integrated Architectural Water Systems

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Chapter 06: Discussion: Project Summary, Contributions, & Limitations

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Chapter 07: Outlook: The Future of Urban Water Systems

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References

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Chapter 01 Relevance:

A Need for New Ways of Managing Water

CHAPTER 01

Fig. 1: Research motivations: water demand and water scarcity issues threatening global water security. (Source: Russo 2018)

RELEVANCE:

A Need for New Ways of Managing Water Increasing environmental, technological, and social pressures on urban water systems in recent years have created significant issues, which are undermining water security in many places around the world. Some of these issues are disturbances, like drought or contamination, while others are shifts in resource management, such as urban agriculture. However, in each instance, the need for new ways of managing water are fundamental. Part of the problem stems from our existing centralized water infrastructures. Due to the fact that centralized water sources can be vulnerable to disruption, there is a strong argument for considering additional sources of waterâ&#x20AC;&#x201C;mainly atmospheric waterâ&#x20AC;&#x201C;which can be harnessed locally and managed on site in a

decentralized way. In addition, the rising demand for local food, in conjunction with increasing urbanization, will require the development of new systems for local water as well. The main argument put forth in this thesis is that building envelopes should play a leading role in the effort to harness and use local atmospheric water sources, specifically fog. The research aim is to develop a building envelope design that combines multiple water management functions to establish an integrated and decentralized approach for urban architectural water systems. This is done through a hybridized approach combining an existing state of the art 3D woven water capture textile with multifunctional, small-scale DLP 3D printed structures.

CHAPTER 01

SCENARIO

City Issue

CLIMATE/ENV

San Fran, CA Drought

New York City Hurricanes

POLLUTION

Flint, MI Pittsburgh, PA Contamination Contamination

SOC/CUL/ECO

San Fran, CA Urban Ag

Austin, TX Urban Ag

Supplemental water management strategies needed to mitigate threats to centralized water supplies

Fig. 2: Scenarios affecting U.S. cities related to water management. (Source: Russo 2018)

Some key questions that arise as a result of this research are: why does water need to be captured and used on site? Why should a building envelope be concerned with bringing atmospheric water sources into the built environment? And, why is it important to combine multiple functions into one solution in a truly integrated way? Regarding the question of capturing and using water on site, we can examine a few scenarios affecting some U.S. cities in terms of water. The first scenario considers climate and environmental issues, the second relates to issues of pollution (or contamination), and the third is shaped largely by social, cultural, and economic circumstances. All of these scenarios in major U.S. cities have a common denominator: water management.

A few of the scenarios highlighted in Figure 2 are drought conditions in San Francisco, California, water contamination in Flint, Michigan, and the push toward local food systems with urban agriculture endeavors sprouting up in many major cities across the U.S., including San Francisco, Austin, Chicago, New York City, and many more. In the case of New York City, the predominant liability related to water is stormwater management, especially with the recent increase in storm events like Hurricane Sandy. Resiliency efforts to capture and use water on site can also be an asset for stormwater management by slowing down runoff entering major waterways. It is ever more clear now that water demand and water security are challenges that will require major paradigm shifts in innovation and design in the near future.

Chapter 02

Scope & Context:

Rethinking Urban Water Systems In San Francisco

CHAPTER 02

SCENARIO

City Issue

CLIMATE/ENV

San Fran, CA Drought

POLLUTION

New York City Hurricanes

Flint, MI Pittsburgh, PA Contamination Contamination

SOC/CUL/ECO

San Fran, CA Urban Ag

Austin, TX Urban Ag

Distributed Fog Capture Need for local water systems due to drought, low rainfall, and local water demands

Fig. 3: Scope and site: San Francisco as a case study for distributed fog capture and urban building integration. (Source: Russo 2018)

SCOPE & CONTEXT:

Rethinking Urban Water Systems In San Francisco Scope With regard to the current water challenges facing U.S. cities, this thesis examines San Francisco, California, in more detail as a case study for design development [Fig. 3]. San Francisco was chosen due to the nexus of water issues it is dealing with: primarily drought and low rainfall. In addition, there is an increasing potential for the impact of supplementary local water systems to meet new demands for local food in various areas throughout the city, as well as to supplement domestic water needs. These issues, in conjunction with the fact that fog is prevalent in the San Francisco Bay Area, make San Francisco a prime location for a distributed fog capture and urban building integration proposal.

The scope of this research ranges from the urban scale to the meso material scale of the designed system [Fig. 4]. The conceptual framework of the project is developed at the urban residential community scale. This is not an urban planning proposal or a design intended for megacity implementation at this stage. The goal is to look at an area within San Francisco, which demonstrates the potential for design integration based on specific site criteria. This will be discussed further in later sections. The architectural concept of this project is developed at the building scale. The technical development, with regards to computational and fabrication workflows for functional prototyping, occurs at the component and meso material scales. In terms of smaller scales, while certain small scale biological principles were analyzed for design inspiration, the research does not attempt to take on nanoscale material development.

CHAPTER 02

MEGACITY SCALE

COMMUNITY SCALE Framework

BUILDING SCALE Architectural Concept

COMPONENT SCALE Prototyping

MESO MATERIAL SCALE Prototyping

NANO SCALE

Fig. 4: Scope and scale: four focus areas of the research scope from urban community scale to meso material scale. (Source: Russo 2018)

The four focus areas of the thesis scope provide a range of scales with which to explore–both technically and conceptually–the various challenges related to integrated architectural water systems. When it comes to the second question, posed in the previous chapter, of why building envelopes should take part in the effort to harness and use local atmospheric water sources, it is important to look at where there is high water demand in cities. Two examples–domestic and food production–are examined in this thesis. With an increase in urban agriculture in major cities around the U.S. and the world and heightened concerns over domestic water use and waste, as well as potable water safety, it will be important to build resiliency and redundancy into our future urban water systems.

One way to do this, is to design our buildings accordingly. By implementing new strategies for building envelopes to capture and manage atmospheric water, such as fog and rain, we can supplement, or support, centralized water supply systems or access water when it would otherwise be lacking. In addition, it will allow cities to develop more localized resource loops related to water, food, and even energy. By designing and redesigning our urban buildings to be able to actively facilitate critical resource management, we can establish a more integrated and ecologically-attuned nexus approach to city building and infrastructure design.

CHAPTER 02

SUPPLY

DEMAND

Fog Prevalent in SF Freshwater Low energy Low cost

Rainwater Scarce Unpredictable Roof substances

Greywater/Wastewater Filtration/treatment Energy intensive Expensive

Building Envelope System Existing infrastructure as interface to harness supplemental water sources

Domestic Household fixture water use

Urban Ag Trend toward more local food systems

Desalination Expensive Energy intensive Harmful by-products

Fig. 5: Scope and context: using existing building envelopes to harness fog. (Source: Russo 2018)

Context This thesis looks specifically at water systems integration within the context of existing buildings, principally residential building envelopes in San Francisco [Fig. 5]. Existing facades can be an important asset in acting as the interface to harness supplemental water sources since they are already constructed, as opposed to building completely new infrastructure from scratch, which can be costly and time consuming. It is important to reiterate that fog capture is the main atmospheric water source being investigated due to the fact that it is a prevalent atmospheric source of freshwater in San Francisco, where rain is scarce and unpredictable. Capturing fog is also a relatively low energy and low cost endeavor in comparison to other alternative water supply methods such as greywater or wastewater reuse and desalination, which require

higher energy inputs and capital investments (Smith 2012; Fried 2009). With regards to supplying water for local domestic demands such as indoor fixtures in residential homes (i.e. toilet, shower, faucets) as well as local food production, fog can provide a effective means to supplement water supply close to home and utilize passive strategies for water collection and transport. The research also falls within the context of four key topics [Fig. 6a]. These topics underpin the methodologies developed in this thesis and position the research within the broader discourse of architecture, design, and technology to establish a relationship with current state of the art projects in an attempt to develop new ideas and design possibilities with reference to an existing body of related and relevant work.

CHAPTER 02

(a)

INTEGRATED ARCHITECTURAL WATER CAPTURE & MANAGEMENT LOCAL & DECENTRALIZED URBAN SYSTEMS TECHNOLOGY FOR WATER CAPTURE & MANAGEMENT FABRICATION METHODS FOR FUNCTIONAL WATER INTEGRATION

(b)

Centralized Water Supply - Relies on central grid, vulnerable to disturbance: climate change, pollution, decay - Significant energy input to pump/move water - Systems separate from architecture, need to build/maintain separate infrastructure

VS.

Decentralized Water Supply - Supplement the grid when necessary - Passive water movement across shorter distances → reduce energy inputs - Systems can be architecturally integrated into existing building surfaces → faster & cheaper to build/maintain/repair - Local resource loops: resiliency through redundancy

Fig. 6: Research context topics and comparison of centralized vs. decentralized water supply. (Source: Russo 2018)

By situating the research contextually in this way, the thesis can begin to address the third question posed in the first chapter: why is it important to combine multiple functions into one solution in a truly integrated way? One main reason is to contribute to the effort of designing more resilient infrastructure. By combining functions of water capture, transport, and storage, as well as other performance criteria, into one building envelope system, rather than relying on various disparate parts to create a whole, there is a real opportunity to develop more seamless and harmonious systems approaches to our infrastructure. This, in turn, will help to build resiliency into those systems. In addition, capturing and using local atmospheric water sources can be an asset in the effort toward urban resource decentralization. This could have benefits

over centralized water systems [Fig. 6b]. There may not be a need to completely decouple from centralized grids, but having more redundant–or backup–systems in place would support the resiliency and long term sustainability of our urban water systems and promote water security. Furthermore, while centralized systems tend to rely heavily on pumps to move water up into buildings, by harvesting atmospheric water sources as they precipitate, in-situ facade water systems can take advantage of gravity to transport water. In addition, utilizing existing vertical faces of buildings (not just horizontal roofs) will naturally increase the surface area available to collect water and provide an existing backbone for retrofits rather than relying solely on new construction.

CHAPTER 02

Finally, rather than employing traditional top-down approaches to building design, where mechanical systems such as plumbing and water pipes are typically considered as separate from the architectural features, a decentralized strategy could, inversely, lend itself to more of a bottom-up model. In this sense, water capture and transport systems within the framework of building envelope design could become more architecturally integrated and, through increased expression and visibility, play a larger spatial, experiential, and educational role as well as a performative one.

CHAPTER 02

Golden Gate Heights aerial view. (Source: Robinson 2017)

Chapter 03

State of the Art: Designs, Systems, & Technology for Water and Resource Management In Architecture

CHAPTER 03

Fog harvesting polyester mesh (2D)

Warka Water Arturo Vittori

Dew condensing collector Material geometry + properties

Centralized tank

Large storage tank

Passive (gravity)

Fig. 7: Warka Water. (Source: Hobson 2016)

Woven textile

Fog harvesting 3D structure polyester mesh (3D)

CloudFisher Aqualonis

Flexible trough collector Material geometry + properties + fabrication

Centralized tank

Small storage tank

Passive (gravity)

Fig. 8: CloudFisher. (Source: Aqualonis 2018)

STATE OF THE ART:

Designs, Systems, & Technology for Water and Resource Management In Architecture

canopy shades the lower sections of the tower to prevent the collected water from evaporatingâ&#x20AC;? (Hobson 2016).

In order to position this research in the context described in the previous chapter, it is important to examine the current state of the art. This chapter presents various projects, which address certain aspects of the research focus in one way or another and demonstrate where there is new potential for interpretation and innovation.

The goal of the system is to provide clean drinking water for rural communities in the developing world. The project demonstrates a simple, cost effective, and locally attuned strategy well suited for remote regions.

Within the framework of in-situ water capture, Warka Water by Arturo Vittori is a good example of a multifunctional system that collects and stores water and uses gravity for water movement [Fig. 7]. The structure consists of a bamboo frame, which supports a polyester mesh material inside. â&#x20AC;&#x153;Rain, fog and dew condenses against the mesh and trickles down a funnel into a reservoir at the base of the structure. A fabric

Similarly, the CloudFisher project by Aqualonis is another example of a kit-of-parts system for rural applications, which also takes advantage of a textile strategy for water capture [Fig. 8]. The benefit of using textile meshes, such as polyester, include low cost and ease of achieving large surface area with lightweight components. The development of a 3D woven mesh for the CloudFisher further increases the surface area for water capture.

CHAPTER 03

Common ice plant

Rain Bellows Rachael Meyer, Alexandra Ramsden, Jennifer Barnes & Michele Richmond Relies on mechanical system

Decentralized (large scale)

Cells respond to water flux

Closed facade module

Cells expand to store water

Open facade module

Condensation capture surface

Bumpy surface structure

Swellable facade fin

Multi-material 3D printed fin (absorbent polymers)

Mechanical

Fig. 9: Rain Bellows. (Source: Eleven 2017)

Namib Desert beetle

Rheotile Myrna Ayoub

Material Decentralized geometry + (temporary) properties + fabrication

Passive (gravity, capillary action)

Fig. 10: Rheotile. (Source: Ayoub 2015)

This research considers the benefits of textiles for water capture, but attempts to overcome some of its key limitations, such as unidirectional water transport and the need for a separate structural system to support the textiles. The Rain Bellows project envisions urban building envelopes as potential large scale water storage sites [Fig. 9]. Drawing inspiration from the common ice plant’s epidermal bladder cells, the proposal features two-story water storage “bellows”–or containers–that expand and contract based on water intake. The goal is to clean and store stormwater for reuse. Rheotile by Myrna Ayoub is also a building envelope system design that deals with biomimetic water management [Fig. 10]. It is an excellent example of a meso scale multifunctional and multimaterial strategy,

which leverages hydrophobic and hydrophilic properties to capture and move water in order to actuate facade shading and privacy components. The Rheotile uses 3D printing to take advantage of multiple materials that can absorb water and trigger the desired response and component functionality. These two projects influence this research in terms of their biomimetic approach to building envelope water systems. Rheotile is novel with regard to its component and material scale treatments, and employing the benefits of multimaterial 3D printing to achieve precise functionality and cohesive integration with other system elements. However, while both projects grapple with decentralized water storage, the scale of the manifestations are too large (Rain Bellows) or too small (Rheotile) to synthesize the scale of water capture and distributed storage strategies aimed for in this project.

CHAPTER 03

Transparent 3D printed facade component

Fluid Morphology TUM

Macro Spatial adaptability

Meso Natural ventilation, sun-shading

Micro Acoustic deflection

Integrated airflow channels

Fig. 11: Fluid Morphology. (Source: Mungenast 2017)

Close up of 3D printed structure

Spong3D TU Delft + TU Eindhoven

Two reversed pumps are integrated into the external layers of the facade panels

Bioinspiration: fluid carrying of blood vessels; leaf veins

Fig. 12: Spong3D. (Source: David 2017)

The next two projects exemplify truly innovative multifunctional building envelope integration. Of particular appeal is the extent to which 3D printing is used for the following benefits: fusing multiple functions into one system through geometric variation; leveraging geometric differentiation to achieve heterogenous directionality of flow through the systems; creating a self-supporting component. Fluid Morphology by TU Munich illustrates this well through its consideration of a range of scales at which the various system functions are designed [Fig. 11]. From macro to micro, the transparent 3D printed facade component is able to integrate a variety of performance criteria, while maintaining an architecturally and structurally viable module proposal. Specifically, the integrated airflow channels, featured in the meso scale layer of the component, can be fine tuned in terms of

diameter, distance, and directionality to meet the needs of the facade. 3D printing as a fabrication method is highly beneficial for this type of design methodology due to the fact that the channels need to be internal and precisely tailored to regulate flow. Spong3D, a collaboration between TU Delft and TU Eindhoven, also shows how a facade system can be 3D printed with a complex structure, in this case to enable the optimization of a building’s thermal performance [Fig. 12]. “Central air cavities of various sizes provide the necessary insulation, while a moveable liquid flows through a series of channels around the outer edges, storing heat when needed” (David 2017). This is an excellent precedent due to its incorporation of functionality related to water transport. The channels, based on natural fluid-carrying configurations like blood vessels or the veins of leaves, are made significantly

CHAPTER 03

Water Tower House integrates water storage

WATERshed LOHA

A system of interventions at multiple scales, combining living, public space and water-based infrastructure into a new hybrid patchwork

Sponge House is composed of a sponge filtration system embedded in the houseâ&#x20AC;&#x2122;s envelope

Fig. 13: WATERshed. (Source: LOHA 2015)

Customizable electricity production

Solar Roof Tesla

Solar Roof integrates with the Powerwall home battery to collect and store solar energy whenever you choose, providing reliable off-grid electricity

Store excess energy, minimizing reliance on utilities

Fig. 14: Tesla Solar Roof. (Source: Tesla 2015)

easier to fabricate and integrate into the overall geometrically diverse component via 3D printing. Here, again, the intent is for the panel to be self-supporting as to not require an external structural system in order to be integrated into a building. Similarly, this thesis aims to employ strategies of multifunctional integration through geometric variation and meso material manipulation, but places a greater emphasis on the specific functions of water capture, transport, and storage, with the additional criteria of airflow regulation and self-supporting characteristics. These two state of the art examples present a solid foundation upon which to expand and innovate. The final pair of projects are positioned at the scale of the interwoven urban fabric and have interesting implications for urban resource management.

The first, WATERshed, by LOHA, envisions a series of interventions at multiple urban scales in Los Angeles, fusing living and public space with water infrastructure [Fig. 13]. The Water Tower House integrates water storage on the roof of homes. The Sponge House incorporates an absorptive filtration system within the building envelope. The result is a new distributed, hybrid patchwork of water systems for the city. The last example is the Tesla Solar Roof, which is included here because it alludes to a real paradigm shift in resource management, in this case energy systems [Fig. 14]. However, the shift toward decentralized, off-grid utilities could have significant implications for water systems as well. While this thesis proposes a more radical retrofit to existing homes, the concept of in-situ resource loops is being validated in mainstream architectural design by the Tesla home model.

CHAPTER 03

(a)

A HYBRID APPROACH

Textiles

Advantages Large, continuous surface area Extremely lightweight Cost effective Disadvantages Single function: water capture Limited, vertical transport Not self-supporting Extra components needed for integrated applications (architectural)

Architectural Implementation

3D Printing

Multifunctional Water Management -

Advantages Integrate multiple functions Tailor for multidirectional water transport Self-supporting structures Customize parameters for architectural integration Supplement water capture Disadvantages Not as efficient for water capture as textile Cost

Fig. 15: Case for a hybrid approach: leveraging advantages of textiles and 3D printing. (Source: Russo 2018)

Having undergone this research phase of relevant state of the art precedent projects, it was clear that in terms of water management, both textile systems as well as 3D printed systems have advantages and disadvantages. A summary of these pros and cons are highlighted above in Figure 15a. Many of the advantages of textile systems–their ability to easily achieve large surface areas, their lightweight characteristics, their cost effectiveness–were assets that were particularly beneficial in their standard applications and could also be leveraged in a building integration application. However, with regard to devising an architectural implementation scheme, which brings multifunctionality and actual systems integration to the table, the current manifestation of textile fog capture systems lacks some key features. Most notably, while textiles, such as the 3D woven system used in the

CloudFisher project, are increasingly optimized for water capture efficiency, they are fairly limited to this primary function. Water transport is accomplished, but simply in one direction–vertically downward–uniformly across the entire system. One of the other significant disadvantages of textile systems is that they are not self-supporting. A separate frame is required to hold the system and, typically, this support structure also only performs this singular function, but does not otherwise benefit the system. An integrated architectural water systems approach could, therefore, benefit significantly from some of the critical advantageous exemplified by 3D printing, especially with regards to water management. The integration of multiple functions cannot be overstated. While 3D printing technologies have not yet achieved the same efficiency as textiles in terms of water

CHAPTER 03

(b)

capture, the ability to enhance water capture through additional geometries for increased surface area could supplement textile water capture strategies. In addition, 3D printing could be leveraged to tailor systems for multidirectional water transport. In contrast to typical textile configurations, the ability to move water in multiple planes and transport it back into a building envelope system would be essential for architectural integration. Finally, the potential for creating selfsupporting structures with 3D printing, would enable a more integrated approach to linking water management functions to a building envelope design. A 3D printed structural system could also be customized hierarchically to perform multiple functionsâ&#x20AC;&#x201C;not only acting as a structural support but achieving various design criteria related to the intended water functions.

Hence, this thesis aims to propose a hybrid approach to integrated architectural water systems, whereby 3D printing is used to both enhance textile water capture systems as well as add new, innovative systems integration potentials and symbiotic, multifunctional design opportunities [Fig. 15b].

Chapter 04

Methods:

Design Framework & Computational and Fabrication Workflows for Water Systems Integration

CHAPTER 04

Fig. 16: Research methodology. (Source: Russo 2018)

METHODS:

Design Framework & Computational and Fabrication Workflows for Water Systems Integration The challenge of developing an integrated building envelope design that combines multiple functions related to in-situ urban water management requires the establishment of a research methodology well-suited to the design process. Figure 16 shows an overview of the approach taken in this thesis. The research methods are broken into two main areas: technical development and conceptual development. The technical development portion focuses on integrating the multiple functions, outlined in the scope, into the building envelope design. These, again, are water capture, water transport, water storage, regulating airflow, and a self-supporting structural system.

The research into the building envelope functions are further specified through the type of development in the thesis [Fig. 17]. Water capture, water transport, and structural support are addressed through a design and fabrication hybrid strategy to enhance the functionality of an existing water capture textile system. Regulating airflow is undertaken via a textile manipulation strategy to increase the surface area of the textile system. Finally, water storage is examined on the conceptual level through the development of a water resource decentralization strategy to bolster urban resiliency. By beginning with a focus on function, the stage is set for a bottom-up approach with the aim to fulfill the functional requirements of the system rather than putting the main emphasis on what the design should look like, as in a top-down method. This portion of the research looks closely at the key performance criteriaâ&#x20AC;&#x201C;

CHAPTER 04

Fig. 17: Methodological scope of functional investigations. (Source: Russo 2018)

both on the material level and the building level– necessary to implement an integrated, multifunctional strategy for building envelope water systems. The criteria are honed through a process of rapid prototyping, supplemented by in depth research into biological systems. By going about the process in this way, an important design space can be tapped into, which examines how some of the explored functions have been achieved by organisms in nature. This project takes a look at a few of the system functions–mainly water capture and transport–through a biological lens, to learn important lessons from organisms who perform those functions incredibly well. In addition to biological strategies, the integration of the system functions was underpinned by various performance criteria related to the implementation of a fog capture system on a building facade–mainly the

need to leverage airflow directionality and expand water transport directionality. All of the functional criteria set up the basis for the system logics, which were translated into a computational and fabrication workflow. From rapid prototyping with FDM 3D printing and a 3D printing pen, the final fabrication method of DLP and SLA 3D printing was eventually chosen for functional prototyping. The conceptual portion of the research methodology focuses on site selection and implementation of a building envelope design in San Francisco. The main design criteria examined are fog supply, water demand, and urban scale. By understanding the parameters that would lead to an appropriate design deployment proposal, a specific location within the city was determined for a case study.

CHAPTER 04

(a)

(b)

Fig. 18: Water flow on existing 3D woven textile system. (Source: Russo 2018)

In order to create a hybrid system, which could leverage the benefits of both textile and 3D printing strategies, it was important to start with the existing material system that was to be employed in the design. In this thesis, the 3D woven fog capture textile by Essedea (and seen in the CloudFisher project by Aqualonis) was the baseline water capture strategy. The goal was to use this system differently from how has been typically implemented in real world applications–in a building integration proposal, rather than just in an isolated use case–and further enhance its functionality as well as introduce new functions to the overall system integration. Therefore, the current functionality of the textile was analyzed in terms of a typical vertical setup. Figure 18 takes a closer look at the structure of the textile and its mechanisms for water capture and transport. Figure 18a shows a closeup photograph of the textile in elevation, highlighting the hexagonal geometry of the textile’s outer edges and the

main path of water travel along these edges. As fog comes into contact with the system [Fig. 18b], water droplets condense on the outer edges as well as the interior 3D woven filament structure. Water travels quickly down the outer edges. Droplets that condense inside the filament “web” travel down and along the filaments toward the edges. The textile is 15mm thick and has a fog separation degree of 75-85% (Stegmaier 2017). The average daily water harvest ranges from 4-14L/sqm depending on the region and time of year (Aqualonis 2018). With these principles of the textile in mind, the next step was to begin to introduce strategies for functional enhancement in terms of both water capture and water transport, in addition to self-supporting characteristics. At this stage, the biological investigation became integral for gaining insight into efficient water capture

CHAPTER 04

FUNCTION

CAPTURE + MOVE WATER

Movement

Joint

Condensation

Spindle-knot

Cribellate orb weaver spider (Uloborus walckenaerius)

Rainwater and fog capture; directional water transport

Silk web spindle-knots and joints

ORGANISM

STRATEGY

MECHANISM

Fig. 19: Biological investigation into cribellate orb weaver spider silk principles. (Source: Zheng et al. 2010)

and transport strategies that could potentially supplement and enhance the principles already integrated into the textile design. The silk web of the cribellate orb weaver spider, Uloborus walckenaerius, demonstrates an amazing synthesis of fog and rainwater capture and transport functions [Fig. 19]. This ability is the result of a unique fiber structure that forms after wetting. “When dry spider silk is placed in fog, its structure changes as water starts to condense and form drops that move along the silk fibre” (Zheng et al. 2010). As water condensation continues, periodic spindle-knots form. The fibers are characterized by these “periodic spindle-knots made of random nanofibrils and separated by joints made of aligned nanofibrils.” Through a combination of surface energy gradients and Laplace pressure, continuous condensation and directional collection of water drops

around spindle-knots is achieved. These characteristics are very appealing for a building envelope system to direct water from the water capture interface to the water storage system and use areas. This research into the strategies of the orb weaver spider were very promising because they alluded to the potential of filament-like water capture and transport methods, such as those found in the 3D woven textile. They also hinted at the opportunity to increase and add functionality such as continuous condensation and possibly multidirectional water transport.

CHAPTER 04

TESTING PRINCIPLES

3D printed model

Airflow direction Humidifier (fog simulator)

Focus Questions: - How does water condense on 3D printed structures? - Can 3D printed structures perform as directional water transport mechanisms?

Water supply

Plexi humidity chamber

Experiment setup for physical tests

Fig. 20: Experiment setup for rapid prototyping phase. (Source: Russo 2018)

Since the research in this thesis was not aimed at redesigning the textile or inventing new textile systems, and it was determined in the state of the art analysis that 3D printing strategies could provide multiple advantages in a hybrid material approach, it became clear that the technical development would focus primarily on determining the most appropriate 3D printing integration and hybridization strategies with the textile system. In order to start testing the ability for 3D printing technologies to perform the intended functions and further be applied in a hybrid system with the textile, a rapid prototyping process was employed using a 3D pen. An experimental setup [Fig. 20], consisting of a Plexiglas humidity chamber containing a humidifier in the main compartment and an interior shelf compartment for the 3D printed model to stand, was built to simulate fog and analyze condensation and water movement on

the prototypes. Two key focus questions were important for the initial qualitative analysis of these early rapid prototypes to begin to evaluate their feasibility for systems integration. The first question was: how does water condense on 3D printed structures? The second: can 3D printed structures perform as directional water transport mechanisms? Figure 21 highlights some of the early 3D pen prototypes, their demonstrated condensation (photographs) and water movement (diagrams), as well as some key takeaways related to the primary prototyping functions of water capture, water transport, and integrating structural support. It became clear through this process that water would condense on thin, 3D printed filamentlike struts and sagging elements, along the lengths of the structures. This was promising from the point of view of enhancing the water capture functionality of the

CHAPTER 04

Fig. 21: Results and takeaways from rapid prototyping phase. (Source: Russo 2018)

3D woven textile. However, moving forward, it would be important to determine an appropriate material and fabrication strategy that would be capable of producing a thin, yet durable, end-product. This would be critical not only for enhanced water capture functionality, but for the ability of the 3D printed system to actually be able to interface with the textile system at a similar scale to the 3D woven filaments in order to facilitate water movement across materials. Since creating a seamless material gradient was not in the scope of this research, using geometric strategies to bridge the gap between the two materials would be key. In this sense, scale was an essential factor in achieving a functional material interface. In terms of directional water transport, the early prototypes were observed to enable water to move in multiple directions, essentially adhering to and flowing in the direction of the struts. This was exciting because it hinted at the opportunity

to utilize these types of structures to transport water in future functional prototypes as well. One key takeaway was that it would be important to maintain a continuous path for water to travel and not have areas where water would come to a “dead end” and stop moving, such as in some of the tests with sagging elements that were not linked by a continuous strut. As these tests demonstrated the ability for 3D printed structures to move water not only vertically downward, as in the textile system (the typical direction for common fog capture systems), but also back into space, multidirectionality became a clear potential for future water transport investigations. Moving forward, it would also be a major parameter for the system to move water from a larger number of water capture locations–or condensation zones–to fewer, localized points where water would enter the building envelope system and then be stored or used.

CHAPTER 04

BUILDING CONSTRAINTS

Typical standalone fog capture systems are deployed in unobstructed locations and only transport water directly downward into water storage containers

Building envelope integration should consider how fog flows around buildings as well as water transport not only downward but also into the building for water storage and use

Fig. 22: Building constraints for architecturally integrated system implementation. (Source: Russo 2018)

Finally, through this initial rapid prototyping phase, the process of creating 3D printed structures to enhance water functionality further evinced the advantage of 3D printing to create self-supporting systems. From the point of view of integrating structural support into the design, it was apparent that combining structural performance with the water functionality using the same fabrication process would be ideal for multifunctional integration. Once some of these system integration potentials were discovered, the next step was to introduce some important constraints related to design implementation on a building envelope. Figure 22 illustrates some of the criteria considered. As seen in the state of the art research, most typical standalone fog capture systems are deployed in unobstructed locations and only transport water directly downward into water storage

containers. As this thesis seeks to position itself in contrast to these systems to present an architecturally integrated design, there were some essential building parameters to factor in. For example, building envelope integration would have to consider how fog flows around buildings. In addition, it would need to take into account water transport not only downward but also into the building for water storage and use. Some of these issues started to emerge in the early prototyping stage, but further investigation was necessary to establish the overarching system logics.

CHAPTER 04

AIRFLOW CONSTRAINTS (a)

(b) General wind direction

Air moves up

Suction at roof + sides

Air is almost still Air moves down

Area of reverse flow at back

In the front of the building, air moves up and down from where wind initially hits the vertical face in section

In plan, air moves out and around the sides of the building

Fig. 22: Airflow constraints for architecturally integrated system implementation. (Source: Russo 2018)

Another key set of parameters to take into consideration were various airflow constraintsâ&#x20AC;&#x201C;or how air and fog flow around buildings. While standalone fog capture systems rely on free, unobstructed airflow through their systems to guarantee optimal fog capture, a system integrated into a building facade would inherently face the challenge of the facade as liability to unobstructed airflow through the water capture textile. Therefore, a strategy, based on a few fundamental principles of airflow around buildings, was employed to overcome this issue. Figure 22 shows the basic airflow principles and areas of interest for this project related to the building envelope. In Figure 22a, the sectional diagram shows airflow coming into contact with the building face on the left. From where the air, or wind, initially hits the vertical face (air is almost still at this point), air flows up and down along the face (Schueller 1977). As fog flows in the same general direction of prevailing airflow and

wind, the primary, unobstructed fog path should change as well, from parallel to the ground to predominantly vertical along the building facade, regardless of the height of the building. While airflow starts to exhibit different behavior at other locations around the building and could have interesting design criteria implications for the proposed system, the development of the system logics in this research and design development project are limited in scope to the front face of the building. However, the airflow along the front face are considered in plan as well as section [Fig. 22b]. As air hits the facade, it flows outward toward the corners of the building in plan (Hunt 2005). This behavior, in conjunction with the vertical manifestations in section, are key drivers in the establishment of the integrated, hybrid system logics.

CHAPTER 04

SYSTEM LOGICS

Typical fog capture textile orientation in a vertical setup

Horizontal orientation hinders water transport

Angled orientation allows for fog capture from various directions; still exploits hexagonal geometry to move water toward the building

Fig. 23: System logics: textile orientation. (Source: Russo 2018)

The system logics presented here are what were determined to be some of the most important design and fabrication criteria for the development of the final design. They are a synthesis of the initial prototyping studies and research into the various building integration parameters, which would influence the successful implementation of the building envelope system. These logics were subsequently developed into a pseudocode that served as a template for the computational and fabrication workflow of the design development and functional prototyping phases. Figure 23 illustrates the devised logics related to the orientation of the existing 3D woven textile employed within the integrated, hybrid system. As previously discussed, fog capture textiles are typically oriented verticallyâ&#x20AC;&#x201C;where fog moves primarily parallel to the groundâ&#x20AC;&#x201C;and use gravity to move water down. The optimal orientation of the textile is understood to be perpendicular to the airflow or fog

vector. Since fog will begin to demonstrate a different path of travel along a vertical building envelope (up and down along the face from the initial point of contact), it becomes integral to adapt the textile orientation accordingly, to maximize water capture potential based on the shifted fog vectors. If the textile were oriented completely horizontal, this would satisfy the criteria for an orientation perpendicular to the new fog vectors. However, as previously discussed, the textile is specifically designed to move water quickly along its edges via vertically oriented hexagonal filament arrays. Thus, implementing the textile in a perfectly horizontal configuration would not take advantage of the ability of textile outer edge geometry to transport water via gravity. In fact, it would hinder water transport within the system, potentially leading to water loss through evaporation as fog droplets would not be directed away from their initial condensation points.

CHAPTER 04

SYSTEM LOGICS

Increased surface area through continuous undulating layers

Additional water collection zones created by undulations

Parameterization for optimal scalability and system requirements

Fig. 24: System logics: textile undulations. (Source: Russo 2018)

Consequently, an angled orientation was determined to be the most suitable adaptation for deployment of the textile system in the integrated building application. This would allow for water to be captured from fog moving through the textile at various airflow vectors along the vertical building face. It would also still take advantage of the textile edge geometry to leverage gravity and passively move water toward the building. The question then arose: how can the system take advantage of the angled textile orientation while still maintaining another key asset of textiles as fog capture mechanismsâ&#x20AC;&#x201C;their ability to achieve large surface areas as lightweight systems? Figure 24 demonstrates the system logics developed to answer this question and attempt to increase the potential performance of the system. The concept entails introducing an undulating textile language. Creating a curved textile geometry can increase the amount of layers for water

capture by increasing surface area while still notably maintaining a continuous surface along the full length of the building envelope. This would help to ensure optimal system fluidity in terms of visual appearance but also water capture and transport continuity. In addition to increasing the water capture surface areas through continuous undulations, the curved surface introduces depth to the system, which provides opportunities for even more fog collection potential within the negative space regions. This will be discussed as a prominent asset with the introduction of the supporting branch system. The textile undulations can be controlled in terms of height, length, and angle to optimize the system for different fog directions, wind speeds, and building scales.

CHAPTER 04

SYSTEM LOGICS

Branch network integrated to enhance water capture, transport water, and support the system

Maximize branch contact points with textile to increase continuous condensation and directional transport

Optimize branch locations and angles to leverage passive water transport via gravity

Fig. 25: System logics: branch network. (Source: Russo 2018)

In order to actually achieve the curved, undulating textile geometry, it became clear that a supporting structure had to be integrated [Fig. 25]. At this point, the advantages of 3D printing started to play an integral role. This was the ideal opportunity to integrate the findings and criteria from the early prototyping and building constraint research phases. Through this synthesis, it was determined that the structural system to be integrated to create a self-supporting hybrid strategy could, in fact, also have a prominent function in managing water in the system. As previously mentioned, the system would need to interface with the textile at multiple points and hierarchically make its way back toward the building envelope to fewer, localized points. This attribute would not only be an asset in terms of structural stability but also for capturing and moving water away from the system. As discovered in the biological research phase, an important characteristic for increased water capture

of cribellate orb weaver spider silk is the cycle of continuous condensation and directional water transport. If the system could start to integrate these principles through increasing the contact points of the textile support structure with the textile itself, this could provide another method to enhance water capture functionality. These logics led to the conceptualization and design of a multifunctional, 3D printed branch network. Again, the function of the branches is to act as both a structural support system for the textile, facilitate the transport of water away from the textile and into the system, as well as to supplement water collection in the spatial regions created by the textile undulations. Similar to the consideration of maintaining gravity-fed water transport on the textile, leveraging gravity to move water along the branch network was a desirable trait for creating a

CHAPTER 04

SYSTEM LOGICS

In plan, the vertical setup is also limited in leveraging various fog directions

Undulations in plan increase surface area and wider regions at house edges maximize flow through textile

Branch lengths and spans vary based on textile undulations and required contact points

Fig. 26: System logics: plan adaptations. (Source: Russo 2018)

passive system. The system logics and subsequent fabrication constraints embedded in the computational workflow reflect this through a verification process whereby no branches, which interface with the textile, could impede gravity-based water flow, and no branches could direct water toward the exterior of the system (away from the building envelope) if they were not connected to other branches that redirected it back toward the interior. One apparent result of these logics in the current manifestation of the design is that the branch network culminates at the intersection with a main branch element (which transports the water back into the envelope pipe system) and no branches bifurcate from the main branch from below. This scheme would need to be assessed at a larger scale to determine if its effect on structural stability and maintaining the textile undulation geometry are significant enough to warrant redesign.

The system logics also address design criteria influential to the system performance in plan [Fig. 26]. In a building integration application, typical vertical fog capture systems would also be limited in their ability to harness the various fog directions that result when fog hits the building face and moves outward toward the corners. Textile undulations are, thus, also introduced in plan to increase surface area for fog capture. Since airflow seems to shift outward and around building corners even at an offset distance from the building face, deeper undulation regions–or “flare zones”–at building corners are incorporated to maximize fog flow through the textile. The lengths and spans of supporting branches vary accordingly, based on textile undulations and required contact points.

CHAPTER 04

3D woven textile for water capture Water transport midrib

Structural branches; water transport veins

Hex attachment node

Previous studies

Testing principles with textile + 3DP hybrid

Hybrid test for directional water transport

Fig. 27: Rapid prototyping: synthesis of studies into hybrid framework. (Source: Russo 2018)

The ruleset devised in the system logics phase provided the foundation for the development of a computational and fabrication workflow for the hybrid design approach. In conjunction with another round of rapid prototyping with the textile and 3D printed (pen) structures to explore the hybrid principles through physical testing [Fig. 27], the key findings from this phase were synthesized for implementation into the final system design and functional prototypes. Figure 28 highlights the key takeaways. With regard to enhancing water capture functionality, the primary criteria are to: ensure airflow through the textile for optimal capture efficiency of wind blown fog droplets; optimize the textile orientation to maximize fog interception; and integrate a tight-knit network of thin elements to interface with the textile (and also physically attach to it).

For multidirectional water transport, it is essential to: expand water transport directionality to multiple spatial planes; maintain directionality of the textile hexagonal edge geometry for surface water transport; and incorporate a method for transitioning water from outside to inside the system. Finally, relating to the integration of self-supporting features, the most important takeaways from the previous research and development were to: interface with the textile at the meso material scale to support the geometric variation of the undulating surface; connect to an existing building envelope system and interior water usage applications; and introduce a hierarchy of elements to create a gradient of water-structure functionality.

CHAPTER 04

KEY TAKEAWAYS/CRITERIA

Enhance water capture

Multidirectional water transport

Integrate structural support

Ensure airflow through the textile for optimal capture efficiency of wind blown fog droplets

Expand transport directionality to multiple spatial planes

Interface with textile at meso material scale to support geometric variation

Optimize textile orientation to maximize fog interception Tight-knit network of thin elements to interface with the textile (also to attach)

Maintain directionality of textile hex geometry for surface water transport Method for transitioning water from outside to inside the system

Connect to existing building envelope system and interior water usage Hierarchy of elements to create a gradient of water-structure functionality

Fig. 28: Key design criteria for functional prototyping. (Source: Russo 2018)

The system logics development phase culminated in the creation a Grasshopper script, which integrated the multiple design criteria, investigated in the technical portion of the research methodology, with the ability to explore and control parameters related to the textile and branch geometries. Fabrication constraints for functional prototyping were also taken into account in the parameterization processes and overall computational workflow. These include textile undulation parameters, branch direction for efficient water flow, branch length and diameter, branch spread and textile contact areas, branch junctions, and building envelope water transport and structural integration.

The following pseudocode [Fig. 29] provides an overview of some of the computational and fabrication constraints built into the workflow based on the system logics.

CHAPTER 04

BRANCH NETWORK PSEUDOCODE

Textile surface edge curve

Divide inner edge curve

Select point close to bottom of undluation

Evaluate surface to map hex grid to textile

Hex points on surface

Explode tree to get specific point groups

Solve intersection points for region and trimmed branch curves

Find closest points between intersection points and textile point group

Closest points on textile surface based on max distance for fabrication

Textile surface

2D hexagonal cell grid

Fig. 29: Computational workflow pseudocode for textile and branch hybrid system. (Source: Russo 2018)

CHAPTER 04

LSystem source string

Move point to establish main branch line

Point groups at textile inner undulations

Deconstruct intersection points and closest points to find Z values

Divide main branch line and cull end points for branch seed points

Turtle geometric solver for branch bundles

Branches pre-trim

Offset textile inner edge curve for region

Create closed Brep region to trim branches

Trimmed branches. Trim offset from textile to create top branch network transition layer

Individual point group to work on branching

Calculate if closest point Z values are larger than intersection point Z values

Logic based on passive water transport using gravity. From the closest points on the textile, or points on the perimter of the graph above, water can only travel down.

If true, dispatch closest points with larger Z value into separate list

Connect points with lines. All connected branches follow water transport logic

Final striated branching network. Top layer is most tightly packed and branch scale is similar to textile filaments to exhance water capture and directionally transport water down into lower layers. Lower layer branches increase in scale down to main branch to aid in structural stability and transport more water around external branch surfaces.

Chapter 05

Design Development: Integrated Architectural Water Systems

CHAPTER 05

Fig. 30: Site selection design criteria. (Source: Russo 2018)

DESIGN DEVELOPMENT:

Integrated Architectural Water Systems The conceptual portion of the research methodology is expanded upon in the design development phase of the thesis. This portion starts with a zoomed out view of San Francisco and through the consideration of various design criteria related to site selection, a specific location within the cityâ&#x20AC;&#x201C;Golden Gate Heightsâ&#x20AC;&#x201C;is chosen as the main focus area for conceptual design implementation. The site selection design criteria that are emphasized in this research are: fog prevalence (or supply), water demand, and urban scale and topography [Fig. 30]. Fog prevalence is investigated with the goal of finding the best possible locations within the city of San Francisco to deploy a fog harvesting system based on where there

is the most consistent and maximal presence of fog. The water demand criterium has to do with trying to understand which areas of the city need supplemental water sources based on existing infrastructure service and new demands for local resources. Finally, the urban scale and topography inquiry looks more closely at the scale of the urban intervention in terms of building and neighborhood typology as well as the topographical features of the urban site to leverage increased fog capture potential and neighborhood layout in order to propose new decentralized programmatic zones and resource sharing opportunities.

CHAPTER 05

22% increase in water demand from 2010 to 2035 If droughts persist and rain is scarce, fog capture may be an advantageous strategy to supplement the region's water needs--SF has an average of 108 foggy days per year

Over 66% of water supply imported from outside the region

San Francisco Bay Area California, U.S.A.

28% increase in population by 2040

Fig. 31: Key factors impacting San Francisco Bay Area water management. (Source: Russo 2018)

Before going further into the site selection design criteria investigation, it is important to spotlight a few important statistics related to the San Francisco Bay Area, which will have a significant impact on the future of water in the region. Figure 31 highlights these points. According to the SPUR report, “Future-Proof Water: Where the Bay Area Should Get Its Water in the 21st Century,” there will be a 22% increase in water demand in the area from 2010 to 2035 (SPUR 2013). This is a concern because about two thirds of the of the Bay Area’s water supply comes from outside the region. Couple this with a 28% population increase by 2040, which is a major factor in increasing water demand and will most likely have significant implications for domestic water use, and the situation begins to look dire. Not to mention the challenges of climate change,

which continue to exacerbate drought conditions in the region (Graff 2018). If droughts persist and rain is scarce, fog capture may be an advantageous strategy to supplement the region’s water needs. San Francisco has an average of 108 foggy days per year and the supply is very consistent (Current Results 2018).

CHAPTER 05

2 SF yearly wind direction distribution (%): W + WSW prevailing

Fog Prevalence San Francisco gets an average of approx. 10 hours of fog per day in the summer

San Francisco Fog Zone Map Fog zones 1 and 2 (fog belt) get the most consistent fog over the course of a single day and a whole year

Fig. 32: Average summertime hours of fog and low clouds per day in the SF Bay Area. (Source: Torregrosa et al. 2016) Fig. 33: San Francisco fog zone map. (Source: Google My Maps 2016)

In terms of fog prevalence, research was conducted to understand how much fog San Francisco receives and which areas and neighborhoods within the city receive more than others. Figure 32 shows a map of the region, highlighting the average summertime hours of fog and low clouds per day. San Francisco is called out with a dashed circle. From the map, it is apparent that the Bay Area receives approximately 7 to 14 hours of fog and low clouds per day in the summer months. This is promising because it is during these months that arid conditions and drought can be heightened. Having a local supply of supplemental freshwater would be advantageous for mitigating these conditions. From the map, it can be observed that certain areas of the city seem to get more hours of fog than others. This would be an important distinguishing characteristic to clarify in order to make a more informed site selection decision. Figure 33 zooms in a bit further into the city and presents

a fog zone map breakdown of areas and their respective fog prevalence. It is clear that the zones on the Western side of the city–in direct proximity to the Pacific Coast–get the most consistent fog coverage. Zones 1 and 2, considered to be the “fog belt” area, demonstrate high potential for fog harvesting design deployment. The advection fog coming off of the Pacific Ocean (Torregrosa et al. 2016) and transitioning onto the mainland by means of the prevailing Western and Southwestern winds, could be a real asset in the effort to introduce locally available and distributed water sources to the area. In addition to being a potential benefit for local mitigation of water scarcity, the fog prevalence presents an opportunity to supplement the centralized water grid, which is not immune to the risk of disturbance. Figure 34 illustrates the water supply network for the San Francisco Bay Area and surrounding region. San Francisco is called out with a

CHAPTER 05

Water Supply Major water-importing infrastructure in the Bay Area brings in water from outside of the region

Urban Ag in the Fog Belt Increasing demand for local food systems, which could benefit from local water sources

Fig. 34: Bay Area water importing infrastructure map. (Source: SPUR 2012) Fig. 35: Interactive map of current public urban agriculture sites in SF, with fog belt filter. (Source: SF Rec & Park 2018)

dashed circle. It is evident that the major water-importing infrastructure in the area brings in water from outside the region. This is problematic not only because of the energy input to pump water in centralized systems and the huge costs associated with maintenance related to pipe leaks (Lam et al. 2016; Salzman 2012), but there are some location specific challenges as well. For one, some of the infrastructure crosses major fault lines (ABAG 2014) and could be vulnerable to damage if a major earthquake were to hit. In addition, a 2015 article in Hoodline news entitled “Is San Francisco Part Of California’s Water Crisis?” called attention to the fact that “snowpack in the Sierras, which feeds California’s surface water for the remainder of the year, was this April at an all-time low in recorded history, lower even than the faltering snowpack concurrent with the 1977 drought in California” (Avery 2015). If the effects of climate change continue to threaten the region’s main

water supplies, it may be crucial to start to adopt a more locally-attuned, decentralized approach. The advantages of this type of approach could not only provide a supplemental solution for challenges related to climate change, but could be an asset in the shifting trend toward other local resources–mainly food. Figure 35 shows a map of public urban agriculture sites in the fog belt area of San Francisco. These sites are just a few among the total number of projects throughout the city. The ones is the fog belt are of specific interest to this research since they allude to an overlap of local water demand and supplementary water supply from the prevalent fog in the area. Increasing demand for local food systems could benefit from local water sources that are harnessed and used on site and take advantage of passive strategies for water capture and transport.

CHAPTER 05

vs Urban Scale Low rise neighborhoods may contribute more to impact of decentralization

Topography Altitude is an asset for fog accumulation here (upslope fog)

Hill Districts Potential for increased fog capture and optimal design implementation on hillside residences

Golden Gate Heights Nexus of water demand, fog prevalence, and urban scale

Fig. 36: Urban scale analysis of SF Hill Districts for fog capture and system implementation. (Source: Russo 2018) Fig. 37: Chosen case study site: Golden Gate Heights, SF. (Source: Google Earth Pro 2018)

In terms of urban scale and topography, the hill districts within the fog belt demonstrate excellent potential for design implementation [Fig. 36]. Along with being positioned strategically from the perspective of fog prevalence and the growing trend of local food production sites, the low to mid rise urban building typology of the homes in the hill districts could contribute to a more impactful deployment strategy within the decentralized systems framework. While a highrise application would benefit from large surface areas for fog capture on vertical building surfaces, the impacted radius of distributed water resources within the urban context would remain relatively centralized in early stages of implementation. On the other hand, integrating local water capture systems in neighborhoods with smaller building types could contribute to a more successful decentralized network of systems, which would at first likely be individual (homes, apartments) but could

provide the foundation for a scalable shared web of distributed, resilient urban utilities. In addition, the topographical conditions of the area– notably the hills–provide yet another advantage for fog harvesting. Altitude is a key factor for upslope fog, which forms “when air flows upwards over rising terrain and is adiabatically cooled to its saturation temperature” (WMO 2018). The neighborhood layout has also been affected by the topography through the offsetting of houses on the slopes. Figure 37 shows an aerial view of a portion of the Golden Gate Heights neighborhood. On the hillside, rows of houses at different altitudes on the slope are separated by open space. Some of this space is taken up by backyard and garden spaces. However, there seems to be a fair amount of underutilized terrain. Within the framework of decentralized resource management, these spaces

CHAPTER 05

Golden Gate Heights homes are typically wood frame construction

Fig. 38: Typical wood frame construction of residential houses in Golden Gate Heights. (Source: Russo 2018) Fig. 39: System implementation as a retrofit construction proposal. (Source: Russo 2018)

are prime locations for the introduction of new programmatic zones, which could include communal urban agriculture plots and areas for combined water storage and reuse on site. Through this conceptual development phase of the research methodology, pertaining to site specific design criteria, it was therefore determined that the Golden Gate Heights neighborhood would be an ideal location for a the conceptual implementation of the architecturally integrated hybrid water system. The population of the neighborhood is about 14,649, with approximately 69% homeowners. The median household income ranges from $116,845-$134,898 and the median home value is around $1,051,656 (City-Data 2018). These demographics are also important for the consideration of design implementation because while the proposed design seeks to incorporate cost effective systems for

water management, compared to the other high capital investment strategies discussed previously, the novel approach to material integration of this work would likely require some higher initial capital investment to become more of a mainstream solution. Therefore, this neighborhood would be ideal in the sense that the intended early adopters could also theoretically afford to take on some risk in the process of helping to develop new beneficial strategies to rethink water management in the region. The design proposal aims to address the system integration as a retrofit solution [Fig. 39]. This is not to say that a new construction proposal would not be viable within this framework. However, this is outside the scope of the research. In the context of the home retrofit model, the construction type and materiality of the typical existing home in Golden Gate Heights were considered. Most of the homes are wood frame construction with a stucco finish [Fig. 38].

CHAPTER 05

Undulating textile Undulating textile leverages fog flow along building leverages fog face flow along building face

Supporting branch Supporting branch system transports water via gravity system transports water via gravity

Building Integr

Fig. 40: Building integration sectional perspective rendering. (Source: Russo 2018)

ration

CHAPTER 05

Distributed, Distributed, gravity-based water storage gravity-based water storage

Indoor passive Indoor passive hydroponic wick system hydroponic wick system

CHAPTER 05

House site plan

SF yearly wind direction distribution (%): W + WSW prevailing

Airflow through system Textile undulations Branch module Face of existing wall Textile flare zone

Partial facade plan at flare zones Branch variations are used to manipulate textile undulations to flare out in plan for increased fog capture

Neighborhood plan Curved block layouts & building adjacencies direct prevailing winds across multiple facades

Fig. 41: System development in plan: flare zones. (Source: Russo 2018)

This construction type would actually allow for a fair amount of flexibility in how the system was attached to the building envelope but it would be advantageous for the attachment and penetration of water systems through the wall system to remain relatively minimal as to not overly disturb the existing structure or cause major concern for water infiltration. Figure 40 on the previous page presents the design for the architecturally integrated hybrid system. In the rendering, all of the major features of the system design can be seen. The undulating textile on the building facade can cover any portion of the envelope surface (where there are no windows or doors), depending on the scale of the retrofit desired, to maximize uninterrupted fog capture and transport through the system. The undulations can be pre-designed to leverage optimal fog flow along the building face, and the textile precut

to conform to the connecting branch system. The supporting branch network transports water from the textile through the system and to storage and use areas via gravity. There is also a distributed, gravitybased water storage system to serve indoor household water demands such as water fixtures and indoor food production. Passive food growing systems can be linked to harness the collected water as well. The illustration shows one example of a hydroponic wick system connected to the envelope design through the wall penetration. The system is design so that the branches only need to penetrate through the wall at points where water is directly stored for use on the interior, i.e. hydroponic setup, shower, toilet, etc. Hence, the distributed water storage strategy. Smaller water storage containers are dispersed in the ceiling close to the exterior envelope where water passes through the wall system. The water is stored for

CHAPTER 05

House site plan

SF yearly wind direction distribution (%): W + WSW prevailing

Airflow through system Face of existing wall Corner branch module Textile corner wrap-around condition Alleyway between houses

Partial facade plan at corner Wrap-around conditions at corners facilitate fog capture continuity on multiple house faces

Neighborhood plan Envelopes are not physically linked across multiple houses, but small alleyways in between homes provide additional surface area for capture

Fig. 42: System development in plan: corner wrap-around condition. (Source: Russo 2018)

on-demand use or for extended periods of water scarcity. Besides being able to leverage passive water transport by positioning the water storage containers as close to their end use locations as possible, and strategically above them, dispersing the storage among multiple tanks fosters resiliency through redundancy. If one source where to get disturbed from damage or contamination, other tanks could take over the demand without resulting in a full system interruption. Any water that is not collected in the system will drop down to the bottom where a trough, incorporated simply to ensure as little water loss as possible, will distribute it for exterior on-site use. Figures 41 and 42 show the system in plan as it relates to the overall neighborhood block scheme as well as the building envelope design. The curved block layouts, on some of the Golden Gate Heights hillsides, in conjunction with the close building adjacencies, direct prevailing winds across multiple

facades. The partial facade plan [Fig. 41] illustrates how the textile undulations are designed to create â&#x20AC;&#x153;flare zonesâ&#x20AC;? in plan to take advantage of the shifting fog directions resulting from the curved house chains and the fog flow across the single as well as multiple facades. In these zones, branch variations are used to manipulate the textile undulations to flare out in plan for increased fog capture. In addition, branches can be staggered in plan at alternating heights to ensure that the branch spreads cover the full textile surface and capture the maximum amount of water as it drips down through the system layers. Building envelopes are not physically linked across multiple houses, but the small alleyways in between homes could provide additional surface area for fog capture. At house corners, wraparound undulation conditions of the textile also facilitate fog capture continuity on multiple house faces [Fig. 42].

CHAPTER 05

Layer I: Textile Layer II: Strut Network Layer III: Branch Network

Fig. 43: Hybrid system layers; elevation. (Source: Russo 2018)

Full path of travel from fog condensation and capture through branch transport system

Fig. 44: Primary path of water transport through system; section. (Source: Russo 2018)

Zooming into the details of the hybrid system, there are three main layers of functionality [Fig. 43]. The first layer is the textile itself. To reiterate, the primary function of the textile layer is water capture. Its secondary function is water transport into the other layers of the system. The second layer of the system is the top spread–or canopy–of the branch network. This layer is referred to as the “strut network”. It consists of the thinnest diameter branches to interface with the textile. The primary function of this layer is water transport via quick transfer into the system and its secondary function is to enhance water capture by providing a tight-knit web-like structure for additional condensation. The third layer of the system is the rest of the branch network, which transports water from the outer layers into the building envelope as its primary function. Its secondary, equally important function, is to act as the self-supporting structural framework of the system, providing stability to

the 3D printed and textile hybrid design. The system integrates a hierarchical structure across the layers to reconcile primary and secondary functionality with regards to both water management and structural performance. Figure 44 shows this structure and the full path of travel from the first point of fog contact with the textile through the layers of the building envelope system. Figure 45 highlights various points along the main path that water follows in the system, where significant functional characteristics and transitions manifest in the design. When fog comes into contact with the textile [Fig. 45a], water droplets condense on the outer edges and on the filaments within the 3D woven structure [Fig. 45b]. Additional condensation will occur on the strut network as well, due to the tight-knit geometry, which is designed to act as an extension of the textile [Fig. 45b].

CHAPTER 05

(e)

(a)

Fog comes into contact with system

(b)

Water moves through main branch to junction and pipes

(f)

Fog droplets condense on textile and strut network; struts pull water quickly into system to facilitate continuous condensation on textile

(c)

Water continues through pipe system to water storage & use

(g)

Water moves down branch network on outside of branches [branches: D = 0.8-4.6mm]

Full path of travel from fog condensation and capture through branch transport system

(d)

Water transitions from branch network to inside main branch [branch stems: D = 1.6-6mm]

One of the key contributions and innovations of this research is the integration of the strut network with the textile for enhanced fog capture. The struts are designed to be short and thin (0.8-1mm diameter), like the textile filaments (0.2mm diameter), to pull water quickly into the system to facilitate continuous condensation on textile. This is one of the important biomimetic aspects of the design as well, which was translated from the biological principles of continuous condensation and directional water transport studied in the cribellate orb weaver spider silk investigation.

Fig. 45: Full travel path and transitional zones of water moving through the system; elevations and sections. (Source: Russo 2018)

CHAPTER 05

(a)

Integrated branch hooks for textile attachment [hooks: D = 0.8-1mm]

(b)

Textile is applied onto branch system and linked to hooks [textile filaments: D = 0.2mm] [filament bundles: D = 0.5mm]

Fig. 46: Integrated branch hook system for textile attachment. (Source: Russo 2018)

Once water is pulled into the system from the strut network, it continues down the branch network on the outside of the branches [Fig. 45c]. The diameters of the branches range from 0.8 to 6mm to interface with the smaller diameter strut network elements at one end and the main branch, where water enters inside the system, at the other. The water then transitions from the branch network to inside the main branch at the branch endsâ&#x20AC;&#x201C;or â&#x20AC;&#x153;stemsâ&#x20AC;? (1.6-6mm diameter) [Fig. 45d]. The stems have integrated channels to direct water into the interior of the hollow main branch [Fig. 45e]. Once inside the system, water moves through the main branch to the junctions and pipes [Fig. 45f]. The junctions are the components designed to link the branch modules with the building envelope water transport pipe system, which brings water through the facade to the interior water storage and use sites. Figure 45g shows, again, the full path of travel from initial fog condensation and capture through

the branch transport system. Another innovative contribution to the technical development of the hybrid system in this thesis is the integrated method devised to attach the textile to the branch network module. For this, a hook system was designed, which stems from the top of the strut network at multiple contact points, normal to the textile curvature [Fig. 46a]. The diameter of the hook tube structures, 0.8-1mm, allows for the hooks to penetrate through the 3D woven structure of the textile and intertwine with the inner textile filaments, similar to a hook and loop (or velcro) system. Once the textile is applied on top of the hooks and the textile filaments linked, the connection is secure and ensures that the textile undulation geometry is maintained [Fig. 46b]. A method for reversing the hook to textile connection has not yet been devised.

CHAPTER 05

Connector pipe (male)

Branch module Branch junction module Stainless steel screw

Connector pipe (female)

Branch to junction connection Fig. 47: Connection strategy for branches, junctions, and pipes; exploded axon. (Source: Russo 2018)

Connector pipe Vapor barrier under stucco Exterior sheathing Wood framing Interior wall boards Water storage tank Penetration junction One-way valve

Wall section through pipe penetration & water storage Fig. 48: Wall penetration detail; section. (Source: Russo 2018)

The branch network and connecting components are designed as a modular system [Fig. 47]. The other elements include branch junction modules and connector pipes for water transport. The components connect through male-female joints and can then be simply attached to the building facade at the junctions with screws. Water travels through the pipes to various locations along the facade where penetrations are made to carry the water to adjacent storage and use sites on the building interior [Fig. 48]. A vapor barrier, in conjunction with sealant over PEF backing rods at the penetration sites ensure that the system stays weathertight. Additional moisture barriers can be utilized on the interior wall buildout, in between wallboards, to secure the inside space. A one-way (or check) valve is integrated into the end of the pipe at interior water storage tanks to make sure water does not flow back into the envelope system.

CHAPTER 05

Fig. 49: Assembly sequence and branch typology; exploded axon and sectional axons. (Source: Russo 2018)

In terms of the order of operations of construction, Figure 49 depicts the assembly sequence for the envelope system. As a retrofit design, the exterior wall framing, sheathing, and finish are existing features of the house construction. The branch junction modules and connector pipe units are combined and screwed into the exterior wall system with stainless steel screws. Then, the 3D printed branch modules are linked to the branch junctions via the male-female connections. Finally, the textile (which is prefabricated and precut offsite to the required house dimensions and opening locations) is attached to the branches via the integrated branch hook system. Besides the typical branch, described in detail above, a branch typology was envisioned to adapt branches to various unique conditions on the building facade. These include a roof branch, a window branch, and a trough

branch. The roof branch is intended to couple with the roof gutter and filter and transport some rainwater into the system to supplement fog supply. The window branch aims to introduce a small modular exterior window sill gutter that can connect to the envelope pipe system and harness rainwater and condensation running off of the window panes. Finally, the trough branch can link to the connector pipe system in a similar way as the others (male-female coupling as well) and ensure that any water that continues to drip down through the textile undulations and branch layers, but does not make it into the branch and envelope system, is still collected at the bottom and reused on site in some capacity (i.e. site irrigation, food production). By designing the system to be modular, various alternate branch types, such as the three described here, can be incorporated without having to redesign

CHAPTER 05

DESIGN TO PRODUCTION Branch System Design

Mesh repair

DLP & SLA 3D Printing

Mesh smoothing

Printers: Anycubic Photon, Peopoly Moai Volumes: 11.5x6.5x11.5cm, 13x13x18cm Material: UV curing resin Quality: 40-80μm Print time: 19-22h Cost: €40-45ea

Branch System Physical Prototype

Pack + ship

Remove supports

Gruppe (2018)

Fig. 50: Design to production process for the 3D printed branch modules. (Source: Russo 2018)

the whole system. The main benefit of the branch typology is to take into account the other atmospheric water sources that come into contact with the building facade. Fog capture is still the primary atmospheric water source harnessed in the design but, as previously emphasized, redundancy is one of the key factors in bolstering resiliency in any system. This concept is employed here with regard to harnessing all available water sources. The next significant step in the design development process was going from the digital design to the production of functional prototypes. The focus in this phase was the fabrication of the 3D printed branch modules. This process included several steps to go from design to production [Fig. 50] and was conducted with the help of some consulting parties related to the outsourcing of the 3D printed components.

On the digital side, there were two main procedures that were undertaken to prepare the designed branch meshes for 3D printing. The first was mesh repair, which was an automated process in Microsoft’s 3D Builder software. The reason for this step was that the designed branch mesh that was output from the Grasshopper computational workflow contained some small holes that rendered them not water tight and thus unprintable without mesh repair. 3D Builder seemed to process the repairs more effectively than other software mesh repair tools, such as Meshmixer’s. However, Meshmixer was deemed to be more suitable for the second mesh processing procedure–mesh smoothing. This process was undertaken primarily to smooth any knots, kinks, or odd angles where the branches bifurcated at various points in the network.

CHAPTER 05

FUNCTIONAL PROTOTYPES

Demo 1 Front Elevation

Demo 2 Perspective

Demo 2 Side Elevation

Fig. 51: Functional prototype demonstrators. (Source: Russo 2018)

In addition, smoothing the mesh faces was important to decrease any potential roughage on the branch surfaces that could inhibit uninterrupted water transport. This was accomplished with various smoothing brushes within Meshmixerâ&#x20AC;&#x2122;s sculpting toolbox. The print-ready branch meshes were printed primarily using a digital light processing (DLP) 3D printing process. A few of the prototypes were printed using a laser-based stereolithography (SLA) method. These two processes are very similar, the most notable difference being that SLA uses a laser to solidify resin and DLP uses a digital light projector. Both methods use UV curing resin as the print material. These processes were chosen for their unique ability to produce small, very intricate parts as well as detailed large prints within a liquid resin bath volume. The designed branch geometries were able to be successfully printed, but there were clear challenges

and limitations to the process. Time and cost were significant factors, with each branch (essentially taking up the entire print volume of 13x13x18cm, including support material) taking an average of about 20 hours and costing approximately â&#x201A;Ź45 a piece. Additionally, the generation of support material for printing was problematic at times due to the thin, tight-knit nature of many of the branches and strut network elements. This resulted in increased time and labor needed to troubleshoot the issues and come up with workarounds. This was an iterative process, which was undertaken by the outsourced consulting parties. Furthermore, since the print volume was limited in size, the scale of the functional prototypes was not completely 1:1. The branch lengths and spreads could potentially be scaled by a factor of 2 or 3 for full scale applications. However, the thin hook and strut network elements would remain the same scale (1:1 in completed prototypes) so that

CHAPTER 05

3D woven textile (100x20cm)

13cm

3D printed branches (DLP & SLA)

10x7cm branch spread

15cm

3D printed junction pipes (FDM) 10cm

Spray bottle (40-50μm)

Wallboard coated with hydrophobic paint (70x30cm)

9cm

13cm

8x4cm branch spread

12cm

5x3cm branch spread

Water collected by textile only Water transported by branch network Water outside of system Experiment Setup

Fig. 52: Experiment setup for functional prototypes. (Source: Russo 2018)

D = spray distance [cm] (from face of wallboard) H = spray height [cm] (from ground) P = spray position [cm] (from wallboard centerline) Θxy = spray angle [degrees] (from face of wallboard) Θz = spray nozzle angle [degrees] (from flat) Vs = total volume sprayed [L] Vt = volume from textile [L] Vb = volume from branches [L] Vo = volume outside of system [L] T = time interval from last spray to volume measurement [minutes]

H +

Benchmarked against vertical

Experiment Parameters

Θxy

Plan

Θz H

Elevation

Fig. 53: Experiment parameters for functional prototypes. (Source: Russo 2018)

the interface with the textile, and water functionalities, would be maintained. Once the parts were printed, the physical prepwork included packaging and shipping the modules in a secure manner with bubble wrap (prepared by consulting parties) and finally, upon receipt of the parts, removal of support material (left on due to time constraints and stability for safe shipment), which was done by me with precision scissors, protective eyewear, and a particle mask. For the physical prototypes of the junction modules and connector pipe sections, standard FDM 3D printing was employed with PLA filament. The 3D printed branch modules from this process were used to build 2 functional demonstrator prototypes, which were tested in the final experimentation phase of the research. Figure 51 shows a front elevation

photograph of Demo 1 and perspective and side elevation photographs of Demo 2. In order to test the functionality of the demonstrators, an experiment setup was devised. Figures 52 and 53 illustrate the experiment setup and parameters (respectively) that were considered during the testing of the prototypes. A spray bottle was used to simulate fog in the tests. (Spray bottle aerosol droplets are approximately 3050μm in diameter and fog droplets can range from 1-40μm in diameter. Karen 2018; FogQuest 2018). The experiments were set up so that fog sprayed at the system was collected separately in three different containers: one for water entering the system through the branch network (of primary interest), one for water collected solely by the textile, and one for water that drained off the supporting wallboard (and was not collected by the hybrid system).

CHAPTER 05

Test 1

1.1

D = 50cm H = 50cm P = 0cm Θxy = 90o Θz = 0o Vs = 0.5L Vt = 0.09L Vb = 0.001L Vo = 0.1L T = 30min Vt+Vb = 0.09L Test 2

2.1

1.2

D = 50cm H = 50cm P = 25cm Θxy = 45o Θz = 0o Vs = 0.5L Vt = 0.1L Vb = 0.02L Vo = 0.08L T = 30min Vt+Vb = 0.12L 2.2

1.3

DEMO 1

D = 50cm H = 50cm P = 25cm Θxy = -45o Θz = 0o Vs = 0.5L Vt = 0.08L Vb = 0.02L Vo = 0.07L T = 30min Vt+Vb = 0.1L 2.3

D = 50cm H = 70cm P = 0cm Θxy = 90o Θz = 0o Vs = 0.5L Vt = 0.08L Vb = 0.001L Vo = 0.07L T = 30min Vt+Vb = 0.08L

D = 50cm H = 70cm P = 25cm Θxy = 45o Θz = 0o Vs = 0.5L Vt = 0.09L Vb = 0.02L Vo = 0.08L T = 30min Vt+Vb = 0.11L

D = 50cm H = 70cm P = 25cm Θxy = -45o Θz = 0o Vs = 0.5L Vt = 0.1L Vb = 0.02L Vo = 0.07L T = 30min Vt+Vb = 0.12L

Vt = 0.21L Vo = 0.06L

Vt = 0.15L Vo = 0.06L

Vt = 0.1L Vo = 0.05L

DEMO 1

Θxy

Θz H

Plan

Elevation

Vertical setup parameters parameters same same as as series series 11 in in respective respective columns columns Vertical textile test setup

Fig. 54: Functional prototype experiment results: tests 1 and 2, demo 1. (Source: Russo 2018) Test 3

3.1

D = 25cm H = 50cm P = 0cm Θxy = 90o Θz = 0o Vs = 0.5L Vt = 0.19L Vb = 0.06L Vo = 0.07L T = 30min Vt+Vb = 0.25L Test 4

4.1

3.2

D = 25cm H = 50cm P = 25cm Θxy = 45o Θz = 45o Vs = 0.5L Vt = 0.08L Vb = 0.03L Vo = 0.16L T = 30min Vt+Vb = 0.11L 4.2

3.3

DEMO 1

D = 25cm H = 50cm P = 25cm Θxy = 45o Θz = -45o Vs = 0.5L Vt = 0.14L Vb = 0.04L Vo = 0.11L T = 30min Vt+Vb = 0.18L 4.3

D = 25cm H = 50cm P = 0cm Θxy = 90o Θz = 45o Vs = 0.5L Vt = 0.15L Vb = 0.08L Vo = 0.09L T = 30min Vt+Vb = 0.17L

D = 25cm H = 70cm P = 0cm Θxy = 90o Θz = 0o Vs = 0.5L Vt = 0.13L Vb = 0.1L Vo = 0.13L T = 30min Vt+Vb = 0.23L

D = 25cm H = 90cm P = 0cm Θxy = 90o Θz = -45o Vs = 0.5L Vt = 0.14L Vb = 0.11L Vo = 0.09L T = 30min Vt+Vb = 0.25L

Vt = 0.26L Vo = 0.04L

Vt = 0.2L Vo = 0.05L

Vt = 0.21L Vo = 0.06L

DEMO 1

Θxy

Plan

Θz H

Elevation

Vertical series 33 in in respective respective columns; columns; Θz Θz == 00oo Vertical textile textile test test setup setup parameters same as series

Fig. 55: Functional prototype experiment results: tests 3 and 4, demo 1. (Source: Russo 2018)

This allowed for analysis of the system performance related to the individual parts of the system (textile and branches) as well as the combined hybrid. The performance of the hybrid undulating strategy was also compared to a typical non-hybrid vertical textile setup of the same dimensions (no undulations or branches). Some of the other key parameters that were measured were: spray distance, height, position, and angle, as well as spray nozzle angle. A time interval of 30 minutes was allotted in each test from the last spray to the time of water capture volume measurements to allow for most of the water droplets to drain into the collection containers. All tests used 0.5L of water as the total volume of water sprayed. The experiment findings are presented in Figures 54, 55, and 56. Tests 1 and 2 demonstrate that when spraying at the hybrid system from an angle of 45

degrees from the face of the wallboard (+45 and -45), there was a 20% increase in water collection into the branch network from spraying at 90 degrees. In addition, the volume of water collected solely by the textile remained relatively consistent across the varying spray angles. This was a significant performance boost in comparison to the standard vertical setup, which exhibited an average 40% decrease in water collected by the textile when changing the spray angle from 90 degrees to the 45 degree angles. These results seemed to confirm the hypothesis that the undulating hybrid system could increase water capture performance for a building integration application, where fog direction vectors would be more varied (including multiple angles) than typical unobstructed applications. Another interesting finding, which seemed to corroborate this as well, was a result of Test 4. In this test (4.3), the spray nozzle angle was rotate to -45 degrees from a flat

CHAPTER 05

Test 5

5.1

D = 50cm H = 70cm P = 0cm Θxy = 90o Θz = 0o Vs = 0.5L Vt = 0.2L Vb = 0.002L Vo = 0.08L T = 30min Vt+Vb = 0.202L

5.2

D = 25cm H = 70cm P = 25cm Θxy = -45o Θz = 45o Vs = 0.5L Vt = 0.17L Vb = 0.04L Vo = 0.11L T = 30min Vt+Vb = 0.21L

5.3

D = 5cm H = 60cm P = 25cm Θxy = 0o Θz = 0o Vs = 0.5L Vt = 0.11L Vb = 0.15L Vo = 0.08L T = 30min Vt+Vb = 0.26L

5.4

DEMO 2

D = 20cm H = 100cm P = 0cm Θxy = 45o Θz = -45o Vs = 0.5L Vt = 0.12L Vb = 0.09L Vo = 0.11L T = 30min Vt+Vb = 0.21L

Key Conclusions: - The hybrid undulating schemes were able to capture more water than the vertical when sprayed at various angles. - Branch to textile interface successfully transported water into the system. - Increasing branch spread correlated to increased water capture.

Θxy

Plan

Θz H

Elevation

Fig. 56: Functional prototype experiment results: test 5, demo 2. (Source: Russo 2018)

position. The spray distance was also decreased to 25cm from the face of the wallboard, which brought the spray radius within closer proximity to the branch network (fog sprayed in this test was directed at the top branch in the demo with the widest spread). This test yielded the highest volume of water–0.11L–collected by the branch network in Demo 1. Demo 2, which was the same height as Demo 1 but about triple the width and had two columns of branches (with 3 branches in each column) instead of one, performed more consistently well as a hybrid system (textile + branch water collection) than Demo 1. Each test resulted in a combined water capture volume, from the textile and branch system, of over 0.2L despite variation in spray distance, height, position, angle, and nozzle angle. This was very promising from the point of view of scalability and proportional performance increase for a larger scale system.

Some of the final key takeaways from the functional prototype testing phase were that the hybrid undulating schemes were, indeed, able to capture more water than the standard vertical scheme when sprayed at various angles. Additionally, the functional prototypes proved that the branch to textile interface successfully transported water into the system. Finally, increasing the branch spread correlated to an increase in water capture. For this thesis, larger branch spreads were not able to be tested due to fabrication and time constraints. However, future development would benefit greatly from further experimentation at larger scales.

CHAPTER 05

Fig. 57: Hybrid system water supply projections for indoor household water demands. (Source: Russo 2018)

CHAPTER 05

Single house

Indoor Shower Toilet Laundry Dishes growing

Fog

Shared by community Multiple houses Shared by neighbors

Shared exterior water storage Urban ag irrigation

Communal farming

Urban Integration Decentralized food-water nexus through local resource loops

Fig. 58: Neighborhood integration concept: decentralized local resource nexus. (Source: Russo 2018)

Upon conclusion of the prototype testing phase, it was important to take the results and, in conjunction with known data about the existing textile utilized in the hybrid system (from field test research), attempt to make informed projections about how much water the system could supply in an architecturally integrated application to meet existing domestic water demands. Figure 57 addresses this by looking at typical indoor household water use as well as typical residential vegetable consumption in relation to water use. According to a Water Research Foundation 2016 executive report entitled “Residential End Uses of Water, Version 2,” the top 3 water consuming indoor fixtures in average households are toilet, with 123 liters/ household/day (LPHD), or 24%, faucet, with 102 LPHD (20%), and shower, also with 102 LPHD (20%). A total of 517.6 LPHD of water is consumed (WRF 2016).

This is the primary water demand. From the supply side, the calculations performed for the system to determine the potential for meeting indoor household fixture demands, was based on a typical 3-story residential home. A typical front facade (approx. surface area of 107sqm) was considered and, based on the proportions of a vertical surface to the undulating surface in the design, the system cover of the undulating hybrid for the calculations was determined to be 210sqm. In order to calculate water supply for this full scale surface, an average water capture volume was used (based on the average results of the functional prototype tests conducted in this thesis and the low end water capture volume from published field test numbers for the textile). The resulting figure was 478L/day from a 210sqm hybrid design implementation. This number is likely a conservative estimate since it uses the low range of the textile’s performance (4L/sqm/day). However, full scale

CHAPTER 05

testing of the hybrid system would need to be undertaken to confirm the performance and benchmark it against the standard textile deployment scheme to prove if it performs better in an integrated architectural scheme. Nevertheless, with this amount of fog supply, the system could theoretically meet 92.3% of daily indoor household fixture demands. A calculation was also done to understand the potential for meeting food production water demands, if growing systems were put in place. With a focus on vegetables (a typical food source also appropriate for indoor home growing), based on the average amount of water necessary to grow 1kg of vegetablesâ&#x20AC;&#x201C;around 250L (i.e tomatoesâ&#x20AC;&#x201C;214L/kg; Guardian News 2016) and average U.S. vegetable consumption of about 0.5kg/ day (VE 2012), approximately 500L/day of water would be needed by a family of 4 to produce the amount of

food necessary to sustain typical veggie consumption. The fog capture system could provide 95.6% of this water. However, this would mean that no water would be used to supplement indoor fixture demands. If water is being used for urban agriculture (either indoor or outdoor), as the explored trends seem to indicate, either there would have to be a split between food growing water use and fixture use, or the system would have to be expanded to meet increased water needs. With regard to system expansion, zooming out to the neighborhood scale, Figure 58 addresses the potential for urban systems integration. The diagram envisions a decentralized food-water nexus through local resource loops, in which not only individual households can benefit from supplemental atmospheric water supply, but multiple houses can start to share resources on the community level as well.

CHAPTER 05

As mentioned in the section on branch typology, water that does not enter, or get utilized by, the system for interior water consumption, can still be an asset for outdoor use and on-site development. Shared exterior water storage systems could be implemented to irrigate larger in-situ urban agriculture endeavors. The areas in between houses and streets on the Golden Gate Heights hillsides offer ideal spaces for new programmatic infusion of communal farming and resource sharing efforts. The inclusion of multiple stakeholders across the neighborhood can begin to set the stage for future development of more local, decentralized resource networks throughout San Francisco.

CHAPTER 05

Golden Gate Heights street view. (Source: Kwak 2013)

Chapter 06

Discussion:

Project Summary, Contributions, & Limitations

CHAPTER 06

Summary

With the possibility for water depletion and increasing competition through water scarcity, new thinking and new ways of managing water are fundamental

Contributions

Technical: Multifunctional 3D printing + textile hybrid to harness and network water Methodological: Integrated approach to building envelope systems Conceptual: Local, decentralized systems for resilient urban resource management

Limitations

- Reconciling fabrication scale with scale of implementation - Creating seamless material gradients between water functions

Fig. 59: Overview of research summary, contributions, and limitations. (Source: Russo 2018)

DISCUSSION:

Project Summary, Contributions, & Limitations Coming full circle back to the larger picture, it is important to reiterate and emphasize that this project is motivated by the many factors challenging the way we manage our most vital global resources. From climate change to pollution, from population growth and urbanization to food production, the resources that we have taken for granted as renewable and ever-present, are proving to be extremely fragile and, perhaps, even ephemeral in todayâ&#x20AC;&#x2122;s world. This cannot be more true of one of, if not the most important resource of allâ&#x20AC;&#x201C;water. The goal of this thesis is to call attention to these issues and to be a call to action. As architects, designers, engineers, planners, scientists, politicians, regulators, businesspeople, entrepreneurs, educators, and thinkers alike, it is on us to come together and work in multidisciplinary ways to solve these great challenges of our time. With regards

to water, everyone has a stake. It is becoming more and more evident that we need new, fresh, and innovative ways to manage our water resources. This thesis aims to enter this conversation and participate actively in the process. The contributions of this thesis are divided into three categories: technical, methodological, and conceptual. The primary technical contribution of this research is the design and development of a multifunctional 3D printed and textile hybrid system to harness and network water for urban building envelopes. Specifically, this thesis was able to achieve some novel technical developments related to the 3D printing of functional water capture and transport mechanisms and the integration of 3D printed and textile systems. First, the development of the hierarchical branch network, with specific emphasis on the thin, tight-knit strut network, was successful in

CHAPTER 06

Fig. 60: Key research contribution: multifunctional 3D printed branch system for water capture and transport. (Source: Russo 2018)

bridging the gap between the water capture textile and the 3D printed structure for architectural integration. The strut network demonstrated the potential to begin incorporating biological principles of continuous condensation and directional water transport, seen in cribellate orb weaver spider silk. The hook system devised to attach the branch network modules to the textile was another key contribution. It illustrated an integrated material connection system, which has the potential to expand functionality in the future toward a more responsive, reversible material system. Regarding methodological contributions, this thesis advanced specific research into architecturally integrated building envelope water systems. The overarching methodology of the research highlighted the need to incorporate both technical requirements for the system, such as the functional performance criteria,

as well as equally essential site specific design criteria. It was critical to the research and an important guideline for future research to employ a process of rapid prototyping and iterative physical testing to benchmark and verify the feasibility of various functional principles and material investigations throughout the work. This is especially important for a process that involves such a dynamic variable as water. Physical experimentation and observation cannot be understated. In addition, the development of a computational workflow to implement key design and fabrication constraints into the system was a significant methodological contribution to the research. From the conceptual standpoint, the main contribution of the thesis is the development of a theoretical framework for local, decentralized systems as a strategy to facilitate resilient urban resource management.

CHAPTER 06

Fig. 61: Key research contribution: biologically-inspired strut and hook network to interface with the textile system. (Source: Russo 2018)

Cities of the future will need to leverage multiple resiliency strategies to mitigate the effects of various disturbances to critical resources. One way to do this is to take cues from the natural world: nature is locally attuned and responsive by using only locally available, abundant resources and building redundancy into its structures. We can begin to employ a similar paradigm to building and urban design and ensure that future cities have the tools necessary to manage shifts in resource availability and access and adapt strategically to change. The limitations of the research span all three categories covered in the contributions section as well. From a technical perspective, the limitations of the fabrication workflow created challenges for reconciling the prototyping scale with the scale of the proposed implementation. The main issues in this sense were the

available print volume, print time, cost, and physical post-production (removal of support material). In addition, the material used for 3D printing in the functional prototyping phase would not necessarily be the most appropriate material for a water systems applications. Further research is needed to determine the viability of using resin components for the explored application of both supplementing indoor household fixture use and agricultural irrigation water use. At this time, the research cannot conclude that it is safe to do so and does not suggest that any similar components using resin materials be used with or in proximity to food and/or domestic/potable water supplies. The research was limited in this sense because the only viable method for producing the designed branch structures was DLP and SLA 3D printing. It would be very appealing to integrate ecologically friendly or bio-

CHAPTER 06

Fig. 62: Key research contribution: transitional interface for water transport from outside to inside the system. (Source: Russo 2018)

based materials into this type of fabrication process or other processes capable of creating similar geometries or functional integration. Further research is needed to investigate these potentials. Other technical limitations include creating seamless material gradients between water functions and ensuring that the hexagonal geometry of the textile was consistently unencumbered by the undulation angles. Some of the methodological limitations were achieving full customization flexibility within the computational workflow as well as completely integrating the computational and fabrication workflows to scale. Finally, on the conceptual level, the research was limited in its full comprehension of the implications of water ownership issues with regard to the proposal of a decentralized framework. In addition, certain political, regulatory, and logistical factors were overlooked in the

implementation proposal, which would likely have an impact on the feasibility of the design of both individual systems and a larger urban scheme. Further research and development would be critical for a comprehensive local feasibility study on the scale of the individual home, neighborhood, and surrounding urban context in San Francisco.

Chapter 07

Outlook:

The Future of Urban Water Systems

CHAPTER 07

Fig. 63: Research outlook: kit-of-parts framework. (Source: Russo 2018)

OUTLOOK:

The Future of Urban Water Systems Envisioning some imaginative avenues for this research, this section looks at a few potential concepts and areas for future development. With regard to more in depth feasibility efforts and the development of methods to get the system to consumers as efficiently and insightfully as possible, Figure 63, presents an idea for future data integration and logistics. The idea starts from the basic principle that each individual home that will employ the hybrid fog capture system is located in a very specific environment. The first goal of the framework is to embed as much site specific data as possible into the development of a unique, locally-attuned and integrated water system. This would include gathering on site sensor data from the intended location as well as incorporating other

known location specific parameters such as weather data, wind speed and direction, temperature, relative humidity, etc. This information, in addition to house specific parameters like water demand, construction type, and dimensions, would provide a unique in-situ profile to allow for system customization. The second goal of the framework entails creating a kit-of-parts model based on the needs of each consumer. The overall design would still require the role of an architectural team, but each individual house profile would provide insights that would be used for the differentiation and adaptation of the various system components to work with the specific location parameters. The modularity of the system promotes this customizability. Each componentâ&#x20AC;&#x201C;the textile, branches, junctions, pipes, hardware, etcâ&#x20AC;&#x201C;is prefabricated off site and then aggregated for shipping to the consumer through e-commerce channels. The third goal of the framework

CHAPTER 07

Current System - Multiple materials manufactured separately and then integrated - Functional gradients and increased surface area at component and meso material scales - Water capture and transport mechanisms rely mainly on hydrophobic principles

Future Integration

- Multiple materials manufactured in one process; print at higher resolutions/densities - Functional gradients and increased surface area at micro and molecular material scales - Water function mechanisms combine hydrophobic and hydrophilic properties to optimize flows

Fig. 64: Research outlook: future material and functional development. (Source: Russo 2018)

is ease of transportation. This is enabled by the kit-ofparts model and lends itself to the logistical efficiency of a retrofit solution. The materials are lightweight and can be packaged and transported to the site with minimal labor. Once on site, the installation starts to blur the line between a retrofit and a DIY solution. In this way, the designer and the consumer are mutually engaged in the process in which further insights can be gained by both parties. Finally, the modularity and ease of assembly foster scalability and, thus, the system can be adapted for various water use cases, building scales, and personal aesthetics. This framework would be a potential route for the retrofit approach. On the other hand, a new construction project might see a completely different manifestation of the system altogether. Figure 64 compares the current system with an alternate concept for future

integration based on an even more radical bottom-up paradigm. While the current system still uses multiple materials, which are manufactured separately and then integrated, a future fabrication scenario could consider multiple materials manufactured in just one process, such as in biological systems. As 3D printing technologies develop further and the ability to print at higher resolutions and densities becomes more feasible, it may not even be that far fetched to think about an architectural system that could be manufactured via multimaterial 3D printing, where water functionalities are pre-programmed into the material properties and deposition strategies. The current design of the system incorporates functional gradients and increased surface area at the component and meso material scales.

CHAPTER 07

Resilient Infrastructure A paradigm shift in urban resource management from centralized systems to more integrated local, distributed networks

Fig. 65: Research outlook: resilient infrastructure paradigm. (Source: Russo 2018)

A future integrative design process could explore functional gradients and increased surface area at the micro and molecular material scales. This, again, would move toward a more biomimetic and efficient approach to material systems, especially with regard to water management. With increased surface area at the micro level, the system would likely not need to deploy undulations, and could become a thinner, even lighter, building envelope component. Optimized efficiency would also reduce the amount of facade surface area the system would need to occupy so that the overall visual appearance of the building could remain relatively unchanged. The Tesla paradigm comes to mind again here as an even more appropriate analogy to the future integration example. Imagine a modular solar panel-like element that could be attached to your roof or exterior house wall and could soak up and reuse water like the Tesla Solar Roof does with the sunâ&#x20AC;&#x2122;s energy. That would

truly be an amazing design! Finally, in the current design, the water capture and transport mechanisms rely mainly on hydrophobic principles. The 3D woven textile, being a polyester filament structure, tends to repel water that condenses on its surfaces. In addition, the branch network elements are hydrophobic (waterfearing) as well. Water adheres to the surface of the branches, but is not absorbed by them. This is what allows the water to travel along the branches and be transported into the system for use. However, similar to how biological systems leverage principles of mixed wettability to manage water in the most efficient ways (AskNature 2017), a future development of the design could entail water function mechanisms combining hydrophobic and hydrophilic properties to optimize water flows. While leveraging hydrophilic properties presents the large challenge of extracting the water once it is absorbed into the water-loving entity,

CHAPTER 07

Fig. 66: Resiliency in nature: spider web water capture. (Source: Prasert 2018)

organisms use membranes and capillary action, among other ingenious mechanisms to move water through various substances. Why can’t we do it too? The possibilities are extremely exciting, and with integrated design methodologies and cross-disciplinary collaboration, there is the real potential to not only change the way we manage resources, like water, but also transform how we manufacture and use the materials and components that will empower us to do so. In conclusion, it is my hope that with this research, there can continue to be an open dialogue about the future of our cities and built environment. We are in the very early stages of a paradigm shift in urban resource management from a centralized systems approach to a more resilient approach to our infrastructure of integrated local, distributed networks. This is the way

nature has done it for 3.8 billion years and it’s not for no reason. It’s time to take a step back from our business-as-usual practices and take a closer look at our environment. It has already started to tell us that something is not quite right in the way we manage our resources and needs a drastic change. It’s seems quite possible that it just might have a few answers for us too.

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Spider Web by Seymur Allahyarli 3D Printer by Will Adams items by ArtWorkLeaf Honeycomb by Artjom Korman Air by Academic Technologies FoMD from the Noun Project House by Lance Hancock Topography by glyph.faisalovers planter by Madeleine Bennett Shower by Aha-Soft Laundry by Deemak Daksina Toilet by Corey Niemann watering by Luis Prado Water Tank by Adam Zubin Community by flaticondesign.com vegetables by Ealancheliyan s

open box by Andreas Truck by abdul karim Location by Markus GPX File by Arthur Shlain customize by Becris Computational Chemistry by H Alberto Gongora Sprinkler by Aaron K. Kim Roll by Dilla Chee building by Juan Manuel Corredor 3D-printer by Giorgio Uboldi