Design 4: Studio Report by Andrew Chew

Department of Architecture National University of Singapore 2021/22_YEAR 2_Semester 2 AR2102 Design 4 : CLIMATE | ENVIRONMENT | ENVELOPE Unit 2 : Adapt | Adapting | Adaptation | Adapted Figures Design Report ANDREW CHEW WEN JING & THEON AW KAI JUN PRAIRIE - SHROOMS WAY

CONTENT

Task 01 (Create) - Individual Work (Weeks 01 to 03)

Task 02A, 02B (Evaluate, Analyse) - Prototype - Pair Work (Weeks 03 to 08) 26 Emerging Condition and Prototype Development 36 Prototype Testing and Experimentation 40 Site Studies - Climatic/Environmental Study and Typological Study

Prototype Design 60 Task 03 (Apply) - Final Prototype and Collective Model - Pair Work (Weeks 09 to 12)

Critical Evaluation of Project 92

The cumulative work is the result of integrating both passive and active strategies of wind. The passive strategy - relying on the work of existing winds - are being channelled through the shophouse while also attempting to create its internal air flow provided by differences in air pressure. The active strategy - in attempting to create air flow by temperature gradient - is through the angled funnels to trap heat and warm the surrounding air. In attempting to bring airflow through the shophouse through the strategy of the wind corridor, much of the existing shophouse has to be reworked to spatially configure with the introduction of the funnel forms.

Task 01 (Create) - Individual Work (Weeks 01 to 03)

ANDREW CHEW WEN JING | A0235051U Dots indicate temperature distribution in ground Diagonal lines indicate darkness level Air pressure regions is indicated by dots in a streamline

Section of a Prairie Dog Burrow System - chambers and tunnel networks

Andrew Chew: Prairie Dog - Research The Prairie Dog is a rodent species found in the cool temperate countries of USA, Mexico in the Northern Hemisphere. Living in spacious, windy plains, these subterranean creatures are the keystone species within the habitats they reside in. Often temperatures poses unfavourable climatic extremes - extreme heat in the summer and shivering cold in the winter. In burrowing underground, these dogs carve their dwellings as deep as 5m. Most burrows have two entrances which has two mounds. Understandbly, natural ventilation does not occur in subterranean spaces and the dogs risk asphyxiation. Hence by making one mound higher than the other, the burrow system capitalises on the Bernoulli’s principle by having its geometry modified. Prairie Dogs are an adeptive species which utilises the underground to their favour. Burrow Plugging might be used against invasive subterranean species such as burrowing owls and rattlesnakes, that also utilises the network of tunnels for their residence. When encountering surface predators such as coyotes and eagles, watchdogs will warn their kin in united resistance.Yet when the predators are away, competition among kin is at play. Prairie Dogs battle out between cotories - differing family groups of Prairie Dogs - for competition of food, building resources, and mating. 7

Black - Tailed Prairie Dogs

Dimensions & Physical Attributes

Master of Ventilation in the underworld (Cynomys ludovicianus)

15 - 18.5 cm

31 - 41 cm

Location of Prairie dog species in North America (in lighter grey)

A pair of Prairie dogs sitting at a dome mound.

Design Hypothesis

Prairie Dogs are subterranean creatures that dig burrows as their habitat. Found commonly in the west in large windy plains, they take advantage of winds in ventilating their burrows. Understandably, natural ventilation does not occur naturally in subterranean spaces, and diffusion is not enough in replacing used air in burrows that are as deep as 5m and as wide as 10m. Yet intriguingly the prairie dog burrows are known to be breezy and liveable spaces as a result of scientific principles that work in the favour of prairie dogs. With mounds at their burrow entrances, they vary in height and shape specialised to draw high velocity air into the tunnel. Crater mounds, which are higher mounds with sharp edges, deflects windward wind down into the tunnels due to the Coanda effect. At the same time, used air within the tunnels are forced out of the crater mound as a result of differences in air pressure. The fluid dynamics of air falls in line with the Bernoulli’s principle, maintaining the pressure, kinetic and potential energies along the air streamlines. The diameter of the tunnels that expands out to the streamline of air assist to enhance efficacy of ventilation performance, thereby preventing the dogs succumbing to asphyxiation.

Habitat LENGTH: 5 - 10m

Diet

- Mainly herbivore, with grasses and leafy vegetation as the main diet. - Occasionally eat grasshoppers, cutworms, bugs, beetles. - Plants also provide hydration for the dogs thus they don’t need to drink water.

DEPTH: 2.5 - 5m

Climatic Hierarchies

- Reaches sexual maturity by two years of age. - Breeds once a year, though the timing ranges from January to March. - These dogs find their mates in the summer. The females are hiberanting undergound, while the males chase after and defend their burrows. - Often takes place underground, and gestation lasts around 30 days. - Infancticide is common. New pups are highly dependent on their mothers until they are mature enough to go to the surface.

Ventilation through the tunnels of the burrows helps to keep these colonies cool in the summer, and warm in the winter. This is essential in thermoregulating the bodies of Prairie Dogs in surviving harsh weather conditions.

Food Web - Reaches sexual maturity by two years of age. - Breeds once a year, though the timing ranges from January to March. - Often takes place underground, and gestation lasts around 30 days. - Infancticide is common. New pups are highly dependent on their mothers until they are mature enough to go to the surface.

Environmental Territories In abandoned burrows, other animals such as rattlesnakes and burrowing owls are known to occupy these constructs. In the lookout of prey, prairie dogs alter the landscape around their burrows in eating and clipping vegetation. This do benefit grazing animals such as bison, bighorn sheep and pronghorn by contributing to new plant growth that provides higher nutritional quality. The burrowing action contributes to enhance nitrogen uptake in plants.

Enveloping Boundaries By adapting the burrow conical shape, these mounds are to reduce rainwater infiltration into the tunnels and chambers of the Prairie Dog. These tunnels also channel rainwater into the water table to prevent runoff and erosion. Burrowing action alters the soil composition in the region by reversing soil compaction that result of cattle grazing.

Sleep & Hibernation

- Primarily crepuscular (active at dusk and dawn) during warmer months. - Most dogs are active in the summer. - In cool or overcast weather, the dogs can remain above ground all day. - They go into periods of dormancy or “torpor” during the coldest periods of the year. - Activity and appetite during winter is minimised. Can sleep for many days straight.

Process

15 - 20 cm

- Weighs about 1kg - Tan with whitish or buff - white belly. - Tips of tails sparsely covered with black hair - Short ears with relatively large black eyes. They have dichromatic vision, a type of colour blindness which only two out of three primary colours are recognised. - Excellent hearing for predator detection.

Reproduction & Development

Food web system of the Prairie dog Ecosystem.

1.Wind – induced ventilation of the burrows occurs due to the shape and height of the mount entrance causing differences in the pressure creating a continuous air – circulation. 2.Plugged emergency exit that provides as an air pocket while also serve as a quick escape route close to the surface. 3.Sentry chamber for the dogs to listen closely for predators. 4.Tunnels can be blocked off / plugged to isolate the space from the daylight in the event of a predator attack. 5.The pressure difference also regulates the temperature within the burrow, as cold air is high pressured and warm air is low pressured, helping prairie dogs to thermoregulate. 6.Additional tunnel for ventilation or for quick escape from enemies that infiltrated the tunnels (e.g Badgers / subterranean animals) 7. Rainwater chambers to help divert rainwater and prevent internal flooding.

Source: Kristin johnson

The plains next to the Rocky Mountain Ranges in USA.

Web system showcasing the role of Prairie Dogs in the ecosystem and interactions with other species. Source: Humane society of the United States

Coyote pup looks inside a burrow in hopes of snatching a prairie dog as its prey. Source: NPS / Wind Cave National Park

ANDREW CHEW WEN JING A0235051U UNIT 2 | VICTOR LEE STUDIO

Speculation of Forms

Analogue Model Shaded Airwell, Accessible Corridor SCALE 1: 100

of Mound and Tunnel

Higher Mound height

Opening without Mound

Reverse Funnel

Widened tunnel opening

The higher the height of the burrow mound, the efficacy of ventilation in the burrows is increased.

Even an opening without mound can induce ventilation provided that a mound with a higher height is nearby.

With a funnel into the ground, this will increase air pressure, and also helping to direct rainwater into the burrow.

Facing the windward side, this helps in increasing efficacy of air. Also helps to make tips sharper thereby improving efficacy.

Dome Mound

Reverse - Dome Mound

Funnel & Crater

Funnel Hybrid

Found near the leeward side, air gets sucked into the vent, provided that air pressure in the mound is low.

Similar to the funnel, it cuts into the ground with a dome - shaped. Can collect more rainwater.

Wind can only pass over the mound at one side only.

Differing elevation levels can create a higher region of air pressure, while preventing flooding.

PLAN

RIGHT ELEVATION

SHADED AIRWELL

FRONT SECTION ISO

Vertical Opening

Oblique Opening

Reverse - Crater Mound

The higher the funnel of the burrow mound, the efficacy of ventilation in the burrows is increased.

Might be effective in facing winds to intake direct flow of air.

Might assist in collecting more ventilation with a bigger opening.

Oblique Funnel Hybrid

When opening is at the base, likely only unidirectional wind will flow through the tunnel.

RIGHT SECTION PLAN Horizontal Tunnel

Venturi - Tube

Variation in height

Normal transportation tunnel for prairie dogs. When unused, it helps with the flow of air.

When forced through a constriction, velocity increases and air pressure decreases, in turn drawing more air.

Wind flow is deflected in the tunnel, and probably causes vortices.

INACCESSIBLE CORRIDOR

3 FRONT ELEVATION

Research on Scientific Principles enabling the

ISO

Factors Factorsenhancing enhancingefficacy efficacyof of Wind induced ventilation of burrows Wind - induced ventilation of burrows

Wind - Induced Ventilation of the Burrow of the Prairie Dog, Cynomys ludovicianus Wind - Induced Ventilation of the Burrow of the Prairie Dog, Cynomys ludovicianus

Height of Burrow Height of Burrow

The higher the height of the Burrow on the s The higher the height of the Burrow on the e or essure or windward side of the plains, the more likely it is to windward side of the plains, the more likely it is to nd tial and tap on higher velocity winds for natural ventilation. tap on higher velocity winds for natural ventilation. give will give Air velocity flowsflows higher above ground thanthan nearnear Air velocity higher above ground to thetoground. the ground. in f a of a out Crater mounds are recorded to be as 1m. Crater mounds are recorded to as be high as high as 1m.

Shape ShapeofofBurrow Burrow

Tunnel TunnelDiameter Diameter

Similarly - sized burrows, but with differing opening Similarly - sized burrows, but with differing opening styles, influence efficacy of wind ventilation. styles, influence efficacy of wind ventilation.

According to Vogel (1973), “expansion of the According to Vogel (1973), “expansion of the diameter of the burrow as it meets the free stream diameter of the burrow as it meets the free stream improves its performance” improves its performance”

Crater mounds, with its sharp edges, increases Crater mounds, with its sharp edges, increases efficacy on on thethe windward side in in ejecting efficacy windward side ejecting expended airair from thethe burrows. expended from burrows.

The Theburrow burrowtunnels tunnelscan canbe be visualised visualised as as aa conical conical form, form,the thewider widerend endexpanding expanding with with the the narrower narrower end deeper inside the tunnnel. end deeper inside the tunnnel. This Thismight mighthave haveconnections connections to to the the Venturi Venturi Effect Effect Phenomenon. Phenomenon.

Wind Velocity (Magnitude by Arrow) Wind Velocity (Magnitude by Arrow)

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Area ofArea HighofPressure High Pressure

Area of LowofPressure Area Low Pressure

MoundsMounds of similar shape shape but differing height,height, invitesinvites high high of similar but differing velocityvelocity winds to ventilate the tunnels. The higher the height winds to ventilate the tunnels. The higher the height of the mound, the the lower air pressure the mound. of the mound, the lower air the pressure inside inside the mound. This accounts for the coanda effect as wind is deflected This accounts for the coanda effect as wind is deflected over over the higher in the process, extracting air within the higher moundmound and in and the process, extracting air within the mound. the mound.

Two Two distinct typestypes of Burrow Openings. BothBoth provide elevated distinct of Burrow Openings. provide elevated access into into the tunnels, essential for the dogs to sentry for for access the tunnels, essential for the dogs to sentry predators, and and preventing rainwater flooding in the tunnels. predators, preventing rainwater flooding in the tunnels. a - The - Shaped opening. These are are commonly found a - Dome The Dome - Shaped opening. These commonly found near near the windward end end of tunnels. TheyThey have a mound sizesize of of the windward of tunnels. have a mound 2 - 32m- 3inmdiameter andand are are no higher thanthan 0.20.2 - 0.3m. in diameter no higher - 0.3m. b - Crater Mound. AlsoAlso known as the rim rim crater. They areare the the b - Crater Mound. known as the crater. They conspicuous entrances for burrows. have a smaller mostmost conspicuous entrances for burrows. TheyThey have a smaller diameter of -1m m and go high as high as 1m. basebase diameter of 1m 1.5- 1.5 m and cancan go as as 1m.

The Thediameter diameterofofthe thetunnels tunnelsisissure suretotocause causeair airparticles particles to to be be forced forcedtogether. together.ByBymanipulating manipulatingthe thesize sizeofofthe thetunnels, tunnels, the the dogs dogs can cancreate createa aconstriction constrictionfor forair airtotoblow blowatathigher higher velocity. velocity.

Source: on Mound Architecture of the Black - Tailed Source: NoteNote on Mound Architecture of the Black - Tailed Prairie Cincotta Prairie Dog,Dog, Cincotta

Viscous Sucking/ /Entranment Entranment Viscous Sucking Viscosity of air the - air - refers to the internal stickyness of the Viscosity of the refers to the internal stickyness of the air particles sticking together be defined air particles sticking together (also(also cancan be defined as as resistance to shear forces). higher viscosity, resistance to shear forces). The The higher the the viscosity, the the greater the velocity of current. the current. greater the velocity of the

Scientific Principles

Fluid Dynamics and impact on nature study

Bernoulli’s Principle

mechanism is found more in other organic tubular ntilation mechanism is found more in other organic tubular on of theof the This This systems as sea sponges in facilitating movement al phenomenon systems suchsuch as sea sponges in facilitating movement henomenon through the sea. enouli’s Bernouli’s through the sea.

ure difference fference s a smaller cross maller cross through. This ugh. This r kinetic energy etic energy

An increase in the speed of the fluid occurs simultaneously with a decrease in static pressure or potential energy. The sum of kinetic, potential and pressure energy on any point in a flowline will give a constant.

Mechanism examples that can induce ventilation flow into the Mechanism examples thatPrairie can induce Dog’s ventilation burrows. flow into the Prairie Dog’s burrows. 1. Any tubular structure or opening facing the current of the 1. Any tubular structure the current of the wind or willopening receive facing cross - ventilation. wind will receive crossopening - ventilation. 2. A tubular structure whose is perpendicular to the 2. A tubular whose openingsignificantly is perpendicular to airflow. the windstructure current will experience reduced wind current will experience significantly reduced 3. Demonstration of Bernoulli’s principle in a airflow. burrow. Note that air movesoffrom a region of higher pressureNote to a region 3. Demonstration Bernoulli’s principle in air a burrow. of low air pressure. that air moves from a region of higher air pressure to a region 4. Thanks to of fluid viscosity, when a tube in that orientation low air pressure. experiences a wind when current, internal air flow in the tube 4. Thanks to fluid viscosity, a tube in that orientation moves towards the end of the tube with a greater experiences a wind current, internal air exposed flow in the tube air velocity. moves towards the end of the tube exposed with a greater 5. Similar setup but tube is placed against a surface, or airthe velocity. substrate. blows the surface, velocityoris lower 5. Similar setupAs butairthe tubeacross is placed against athesurface, nearer towards substrate. Internalthe airvelocity flow in isthelower tube will substrate. As air blows the across the surface, move towards the end Internal with greater velocity to will suction. nearer towards the substrate. air flow in thedue tube move towards the end with greater velocity due to suction. Source: Animal Physiology, Fourth Edition, Sinauer Associates, Source: Animal Physiology, Fourth 2016 Edition, Sinauer Associates,

constriction striction wer the cross he At cross point 3 as oint as ave 3decreased decreasedis enomenon is defies eenon amount ount defies is ion, pressure pressure is this In practice, actice,devices. this venturi ri devices.

This is the principle that accounts for the lift in airplanes, and the spilling motion of fluids out of a container. This experiment carried out, showcases a setup with a flat plate, two differing mounds of

Area of Low Air Pressure

Assuming there is friction between air particles (viscosity), the area below the moving particles stream gets dragged along due to the friction, reducing pressure at that area. This force provides the suction to draw air out of borrows, and in turn provide natural ventilation.

Expended Air In burrow Area of Low Air Pressure

Factors enhancing efficacy2 2of Viscous Wind - induced ventilation of burrows

Coanda effect is the reason behind the spillage of Viscosity of the drink when poured out of a cup. air particles sti Wind - Induced Ventilation of the Burrow of the Prairie Dog, Cynomys ludovicianus

The higher the height of the Burrow on the windward side of the plains, the more likely it is to tap on higher velocity winds for natural ventilation. 3 Air velocity flows higher above ground than near to the ground. Crater mounds are recorded to be as high as 1m. Wind Velocity (Magnitude by Arrow)

Coanda Effect It is the phenomenon in which moving air particles react to curved surfaces.

As compared to the pressure of the moving air particles which is higher, the net difference causes a change in direction of the wind current. Coanda effect is the reason behind the spillage of drink when poured out of a cup.

Venturi Effect

Shape of Burrow Venturi Effect

Height of Burrow

As wind blows over the crater mound, it creates an area of low air pressure below the mound. This is so as air below the streamline of wind gets dragged along (due to viscosity), hence an area of low air pressure. This forces air inside the burrow to replace it. This phenomenon causes air to be deflected over curves.

Source: https://www.youtube.com/watch?v=HrkqWL9Q9l4 At point 1, Pressure, P1 is 10kPa more than P2 And Cross - sectional area A P1 = 5 A P2 Hence Velocity V2 = 5 V1 In short, Area of High Pressure Area of Low Pressure Wind (Particle) velocity is dependent on the cross - sectional area difference between the constriction and non - constriction areas. Mounds of similar shape but differing height, invites high velocity winds to ventilate the tunnels. The higher the height I speculate that the structure of Prairie dog tunnels can be modified of the mound, the lower the air pressure inside the mound. in cross - sectional width to increase wind speeds, thereby This accounts for the coanda effect as wind is deflected over increased rate of exchange of air. the higher mound and in the process, extracting air within the mound.

Similarly - sized burrows, but with differing opening The venturi effect is accountable for the ventilation of the styles, influence efficacy of wind ventilation. dog’s burrows. The venturi effect is a special phenomenon that can be explained scientifically the Bernouli’s Crater mounds, with its sharp edges, with increases Principle. efficacy on the windward side in ejecting expended air from the burrows. This hypothetical scenario shows the pressure difference between point 1 and 2. At point 2, there is a smaller cross - sectional area, which particles are forced through. This creates pressure, that is converted to higher kinetic energy of the particles.

At point 2, particles flow faster through this constriction and has LOWER pressure. In theory the lower the cross - sectional area, the HIGHER the pressure. At point 3 as the pipe opens up, the receiving end will have decreased Two distinct types of Burrow Openings. Both provide elevated access into the tunnels, essentialpressure. for the dogs to This sentry for flow rate, and increased phenomenon is predators, and preventing rainwater flooding in the tunnels. knowna -as Effect. (As the pressure amount defies The the Dome Venturi - Shaped opening. These are commonly found near the windward end of tunnels. They have a mound size of known principles). However at the constriction, pressure is 2 - 3 m in diameter and are no higher than 0.2 - 0.3m. b Crater Mound. Also known as the rim crater. They are the increased to suck water / secondary fluid. In practice, this most conspicuous entrances for burrows. They have a smaller allows base for diameter the even through of 1m -mixing 1.5 m and of can gas go as high as 1m. venturi devices. Source: Note on Mound Architecture of the Black - Tailed Prairie Dog, Cincotta

ANDREW CHEW WEN JING ViscousA0235051U Sucking / Entranment Viscosity of the air - refers to the internal stickyness of the UNIT 2(also | VICTOR air particles sticking together can be defined asLEE STUDIO resistance to shear forces). The higher the viscosity, the greater the velocity of the current.

Relevant principles affecting airflow This mechanism isfactors found more inpossibly other organic tubular The venturi scientific effect is accountable for the ventilationand of the geometric 3

Area of High

Mounds of simi velocity winds to of the mound, th This accounts for the higher moun

Bernoulli’s Principle

Air Breeze

Wind Velocit

As compared to the pressure of the moving air particles which is higher, the net difference causes a change in direction of the wind current.

Fluid Dynamics and impact on nature study

Formulae for the Bernoulli’s principle, which obeys the principle of conservation of energy in physics.

Crater mounds are

Coanda Effect

Scientific Principles

This is the principle that accounts for the lift in airplanes, and the spilling motion of fluids out of a container.

Air velocity flows to the ground.

This experiment carried out, showcases a setup with flat plate, two wind differing mounds of similar height, and the burrow with a flowmeter. The aarrow indicates direction as the similar height, burrow a tunnel. flowmeter. The arrow direction as the set and up isthe placed in awith wind The height of theindicates mounds wind are 1.6cm. Formulae for the Bernoulli’s principle, which obeys the principle set upofis placed in a wind tunnel. The height of the mounds are 1.6cm. conservation of energy in physics. The table below shows the flow rates of air with different mounds. Clearly when there is heightbelow difference the wind is greatly amplified, evenwhen if the there heightis Theatable showspresented, the flow rates of airvelocity with different mounds. Clearly is 1.6 cm. a height difference presented, the difference wind velocity is greatly amplified, even if the height difference is 1.6 cm. Air Breeze Wind Induced Ventilation of the of the Prairie Dog, It is - the phenomenon inBurrow which moving air Vogel particles ExpendedSource: Air In burrow Source: Wind - Induced Ventilation of the Burrow of the Prairie Dog, Vogel react to curved surfaces.

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Abstract Drawing of the environmental and social relationships faced by the Prairie Dog.

Diagram illustrating the dispersal of spores with the asymmetrical shape of the mushroom

THEON AW: Mushroom - Research The adeptive qualities of the mushroom, allows for the dispersal of spores in environments where there is limited airflow. In the dense undergrowth of the forst floor, air pressure is limited, thereby the mushrooms are unable to passively rely on wind currents for spore dispersal. As such, these fungi employ a number of adeptations that enables the organism to creative convective airflow to aid in the dispersal of spores. The enlargewd pileus increases the surface area for rapid evaporation which cools the surrounding air. On the underside of the mushroom, the gills not only increase the surface area for more efficient spore dispersal, but also traps air and moisture, creating a humid environment underneath. Coupled with the cool evaporated air, a climatic hierarchy is created whereby the difference in density of the air between the cooler and warmer air creates a convective airflow to assist the efficient dispersal of spores.

Mushroom Spore Rain

Research Summary on the Mushrooms

Abstract Drawing on the environmental relationship of mushrrooms.

no. 9: ANDREW CHEW no. 10: THEON AW

1 : 20 SHADED / UNSHADED AIRWELL SECTION 17

ANDREW CHEW Probe B - A3

SECTION A - A

1 : 20 ACCESSIBLE / INACCESSIBLE CORRIDOR 19

ANDREW CHEW Probe B - C5

THEON AW Probe B - B3

THEON AW Probe B - D5

Task 02A, 02B (Evaluate, Analyse) - Prototype Pair Work (Weeks 03 to 08)

Both of our nature studies deal with the usage of wind, through different methods. The Prairie Dog burrow system utilises existing winds and redirects it through living spaces by the manipulation of geometry to influence air pressure zones. The mushroom relies on an asymmewtrical form that influences the temperature gradient. This helps to further complement the strategy of natural ventilation in Singapore’s context. Airflow in the built environment is often stale air with high temperatures. Wind occurs naturally due to differences in temperature gradient - which inevitably influences the air pressure gradient. While temperature is one way to manipulate the air pressure gradient, geometry is another way.

Initial Pairing Evaluations There was much back and forth in the process in polishing up earlier work, while also researching to proceed the project forward. At the same time, there was a concerted need in merging both of our nature strategies in envisioning a possibility to benefit a space typology. The first interim was largely based on speculation of what we think works. In figuring out the initial design, we had trouble understanding the workings of each others’ strategies. There was also the issue of the usage of operative forms. We ironed out that funnels was the best way forward in directing wind, speeding up wind, and altering its direction. In the week after the first interim, we had personal logistical challenges that affected our workflow. Nevertheless we continued to speculate on our prototype the week after interim.

Initial Prototype - Interim Review 01 The mushroom and Prairie Dog both manipulates wind in their own right. Hence it rightfully complements in terms of strategy in our intervention. However what was lacking was clarifying our intentions (both passive and active) to accumulate into our forms for the prototype. A corridor is usually seen as a transitory space, while a balcony is a dead - end space; often connected to an existing space. A balcony is usually a very well - defined cantilever structure of a building, offering its viewers vistas. A corridor, on the other, is scalable and can allow for the quality of both shaded and unshaded. However our assigned qualities for both balcony and corridor, presents some challenges with the integration of our nature studies together. Due to the coming of these components together, we have to reimagine what we typically think of what defines a balcony and corridor separately, as well as examine such possibilities within Tiong Bahru. The most promising, is the the alleyway inbetween blk 55 & blk 56, to which we developed our first prototype.

Research, Early Experiments for the proof of concept.v

1 : 50 SECTION A - A

BALCONY

CORRIDOR B

BALCONY

1 : 50 TYPICAL PLAN 31

1 : 50 AXONOMETRIC PROJECTION

1 : 50 OBLIQUE PROJECTION

1 : 20 PART SECTION B - B PORCHE DRAWING

This arrangement of balcony X corridor highlights a specific typology found in the Tiong Bahru estate. For this instance, the balconies are covered with miniature one - way funnels that only stimulates one way airflow. A temperature gradient is created to induce airflow by creating a tall funnel that heats up the volume of air within. The low air pressure left behind forces air through the constrictions of the mini funnels in replacing it. The balcony is shaped as a funnel on plan with the mini - funnels surrounding the roof. This helps the air to remain cool in the day in maintaining a region of high air pressure.

Emerging Condition and Prototype Development With the development of COVID - 19, people attitudes has shifted from “zero - COVID” tolerance and paranoia, to accilimatising to live with both the symptoms presented by the virus, as well as it’s disruptive impacts on society and the way of life. One way to look at this is the development of the Omnicron varient that has been largely widespread, but the least lethal varient, as compared to earlier varients such as Delta. Recognising this, the government has shifted away from constantly changing social gathering rules, to boosting herd immunity against the Omnicron varient. Many Singaporeans in their social circles are steadily reporting the rise of COVID infections and their self isolation away in their homes. The home has become the space not only for recovery from the virus, but also a means for the infected to continue working from home with digitalised tools. This has been very different from the early days of the circuit breaker period of the COVID - 19 virus where an infection grants one to immediate stay in dedicated COVID facilities. Until the day comes where COVID is as common as the common flu, perhaps is there a way to better design our residences to support self - isolation, yet allow some degree of distanced social interaction? The knowledge gained from our nature studies prompt a thought between us. COVID spread can be made worse with cross - ventilation in our homes without any physical protection. Earlier studies on the spread of COVID particles showed that these particles are dispersed air - borne from a person’s respiration, and the direction of travel depended on the inlet and outlet of air. An article by Mckinsey prompted that vertical laminar airflow can effectively prevent the airborne transmission of coronavirus particles. Although understandbly referring to mechanised ventilation sysytems, there is potential to redirect natural ventilation in a vertical one - way direction in reducing spread. Hence the concern remains of whether natural ventilation is capable of inducing one - way airflow, replenishing the room with fresh air, while safely redirecting used, contaminated air away from the residence.

Scientific CFD study of COVID particles simulation

Sketch on the possible conclusion of the emerging condition

Prototype Testing and Experimentation It was clear that two areas of interest needs to be tested - the passive strategy of the Prairie Dog, and the active strategy of the mushroom. Due to a research paper conducted on the study of Prairie Dog’s ventilation, it is thought that airflow can be enhanced through these factors: Height of Mound, shape of burrow, and tunnel diameter. These, along with a plethora of other factors, are being put to the test by designing mockups. Testing of asymmetry is another challenge. Currently there is no software in visualising both thermal gain and convective currents even if there is, learning and mastering the software would be a time - consuming process. Hence the mockup is needed to be heated up manually and placed in a chamber of smoke to observe air movement over time. Besides computer simulation - which can surprisingly yield inaccurate blunders - physical testing was also done with the construction of our own wind tunnel. Smoke was used in visualising the wind flow in identifying eddies. For certain models, it was necessary to see the direction of air movement in realising a certain objective. Autodesk Flowdesign allows for the easy digital visualisation of wind flow, however changes in the airflow over time might yield weird results. Hence it is best to cross - check with the making of scaled prototypes. In the image on the left, is a testing of a wind catcher mockup in a physical wind tunnel. When sprayed with smoke from a smoke machine, it is obvious that airflow can be funneled downwards and into deep interior spaces.

Hypothesis on Burrow and Urban Canyons

Autodesk Flowdesign Experiments

Test 1

Temperature Testing and flow diagram By varying the angle of these fins, the steepert the angle, it is observed that air moves faster through it in that particular direction. This provides us a general rule of thumb in arranging of our angled fins to suit the directionality of air.

Test 2

Diagram Sketch of the formation of Eddies For any displacement of wind over a surface edge, an eddy is formed. They indicate regions of low air pressure. Most of the time air moves in a turbulent air flow when wind strikes an object, creating swirling regions of air that moves randomly. Through continual testing in flowdesign, a repeated observation over the formation of eddies is observed. It can alter wind speed, direction and exchange of air within a model space. There are some ways to counter the formation of eddies - mound positioning, gentler curved surfaces, and narrow widths of spaces to prevent the swirling of air internally. 52

Site Studies - Climatic/Environmental Study and Typological Study Different spatial typologies presenting the Corridor and Balcony combination can be observed throughout Tiong Bahru. We had to rethink what “corridor” and “balcony” meant to us, and launched ourselves in exploring as many of these typologies as possible. These initial investigations of the spatial typology has led us to choose the alleyway configuration between Blk 64 and Blk 65. In addition to the presence of prevailing winds along Tiong Poh Road and Eng Hoon Street, this alleyway presents the most diverse types of corridor balcony typologies. The presence of spiral staircases, together with dog - leg staircases lining the banks of the alleyway, presents to us not only a makeshift balcony which residents can use for drying of their clothes, but also a ‘vertical corridor’ with ‘balconies’ connected by a series of staircases. We conducted site measurements of temperature and wind at street levels of Tiong Bahru estate. These were done between 1200 - 1300. Some relationships of these environmental factors can be deduced with the built environment. Narrow alleyways tend to have higher temperatures and stale wind. Wider Roads are larger volumetrically, which supports the faster flow of wind. It is often at these roads that axes of site prevailing winds are found.

Site photos, featuring measurement of wind recorded and direction, and early typological studies

Typological study of Blk 55 Tiong Bahru and it’s alleyway.

2 - 3.0

1 - 1.9

0 - 0.9

Wind Speed (m/s)

34.5>=

33.9>=

Temperature (C)

32.5>=

31.5>=

Prototype Design Our focus on our prototype would be creating a possible wind corridor through the residences, contrary to making improvements to back alleys. Hence we consider the various rooms facing the wind corridor as ‘balconies’. Along block 64, the main roads lining the block are axes of prevailing winds. With the appropriate use of funnels, it is possible to channel airflow through the residences through appropriate tectonic gestures. Rethinking on the implementation of funnels had to also be done, through the arrangement of walls and rooms, while concurrently balancing the spatial needs. The wind corridor of the shophouse serves as a windcatcher funnel, channelling the flow of the air into living spaces. The fenestration positionings of rooms allow for the passive exchange of air along the wind corridor. In relating to the emerging condition of the need for self - isolation, the fenestration positionings should allow for the safe exchange of air without cross - contaiminating other living spaces. Additionally, rooms are staggered vertically to make for a difference in height. Airflow thus will be displaced to flow above the building and create passive ventilation as deemed similar to the Prairie Dogs’ chambers. A series of funnels are set in place along the wind corridor, taking the form of angled walls and roofs. Some of these roof placements varies in angle in attempting to create asymmetry. This is to encourage airflow movement during the day. The first storey residential unit will naturally have trouble having access to ventilation, being sandwiched by a unit above and beside. Opening more areas of the second storey floor plate to open sky, will encourage natural lighting and ventilation access. They also provide points of access which for the wind to flow. Like the unit above, its bedrooms also have fenestrations positioned to allow for the safe exchange of air.

First Iteration of prototype, with our efforts initially focused on the alleyway still.

Model Photos of our first prototype

Model Photos of our second prototype

KITCHEN

KITCHEN DINING ROOM

LIVING ROOM

DINING ROOM

COMMUNAL VENTILATED CORRIDOR FIVE FOOT WALKWAY A

DINING ROOM

LIVING ROOM

DINING ROOM

KITCHEN

FIRST STOREY PLAN UP

BALCONY

BEDROOM

BEDROOM OVERLOOKING LIVING ROOM

BEDROOM

OVERLOOKING LIVING ROOM

B ROOF OVER KITCHEN

ROOF OVER THE W/C

BALCONY

AIR VENTILATION OPENING

ROOF OVER KITCHEN

BEDROOM

OVERLOOKING LIVING ROOM

BALCONY

BEDROOM

UP UP ROOM ACCESS VIA STAIRCASE LANDING (HIGHEST)

SECOND STOREY PLAN

BEDROOM

ROOM ACCESS TO BALCONY

BALCONY

BEDROOM

SCALE BAR 1:50 0

SECOND STOREY MEZZANINE PLAN

2.5

7.5

ISOMETRIC PROTOTYPE MODEL

FRONT ELEVATION

REAR ELEVATION 0

2.5

SCALE BAR 1:50 7.5

BEDROOM

BEDROOM BEDROOM

BALCONY

BEDROOM

FIVE FOOT WALKWAY

LIVING & DINING ROOM

KITCHEN

LIVING & DINING ROOM

KITCHEN

SECTION B - B

BALCONY BALCONY BALCONY BALCONY BALCONY BALCONY BALCONY BALCONY

COMMUNAL VENTILATED CORRIDOR

SCALE BAR 1:50

SECTION A - A 0

2.5

7.5

AIRWELL

SLIDING SLIDING

BEDROOM

AIRWELL

BALCONY

CORRIDOR

BALCONY

BEDROOM

LIVING ROOM

COMMUNAL VENTILATED CORRIDOR

CORRIDOR

LIVING ROOM LIVING ROOM

SECTION C - C

LIVING ROOM

COMMUNAL VENTILATED CORRIDOR

SECTION D - D SCALE BAR 1:50 0

7.5

FRONT

ENG HOON ST

SENG POH LANE

TIONG POH ROAD

2.5

BACK

SITE PLAN

SCALE 1:200

Model Photos of final prototype

Collective Projections The finalisation of the prototype work has led us to question the possibilities for application in Tiong Bahru. Transplanting the form of the prototype and its intentions and reworking it under new contexts, is as if designing another project by itself. We were hoping to transplant the tectonic of interlocking balconies into these other sites. However as you will see, the provided area does not make it possible. Just like how our prototype had to relook into the entire re - arrangement of spaces within the shophouse, we had to adept our intervention to still retain the original intentions of ventilation - even if it means taking on a new form. This figure ground showcases possible aggregation of the developed prototype. Many of the pre - war shophouses are copies of its spatial layout, hence it is possible to see numerous areas identified for 2 - storey. By increasing the floor count, we will likely to see the prototype being stacked if given the time for development. In blk 78, showcases the narrowest units since it is arced. By reworking the prototype into the small area, it provides a future possibility for it to be reworked into other 3 or 4 storey shophouse units. Dealing with the most spatially challenging unit, it might provide a glimmer to see how the future of self - isolation residential units may look like. Another projection we look into is the Tiong Bahru market. The commercial complex provides a typical layout of a wet market on the ground floor, the hawker on the second floor, and carpark levels on the above floors. In spite of a large middle courtyard, the hawker spaces are humid, stuffy, and poignant with food odours. Will our intervention of funnels encourage a uni - directional circulation of air thereby which the odours escape through funnel roof openings, and drawing in fresh air to replace?

ISOMETRIC

SCALE BAR 1:50 0

2.5

7.5

W/C

BALCONY BEDROOM

LIVING ROOM BALCONY W/C

BEDROOM

LIVING & DINING ROOM

BALCONY BEDROOM

DINING ROOM

BALCONY BEDROOM

KITCHEN

BALCONY KITCHEN

BEDROOM

TYPICAL FLOOR PLAN B

ROOF PLAN

SCALE BAR 1:50

2.5

7.5

ROOF LEVEL W/C

BLK 78 LOCATION IN TIONG BAHRU FIGURE GROUND

KITCHEN

LIVING / DINING ROOM

BEDROOM

FIFTH STOREY W/C

FOURTH STOREY UNIT FACING LIVING ROOM AND BEDROOMS

KITCHEN

LIVING / DINING ROOM

BEDROOM

FOURTH STOREY

THIRD STOREY UNIT FACING LIVING ROOM STAIRCASE TO FOURTH STOREY UNITS

BEDROOM

THIRD STOREY THIRD STOREY UNIT FACING KITCHEN

W/C

KITCHEN LIVING / DINING ROOM

STAIRCASE TO THIRD STOREY BEDROOMS COMMUNAL STAIRS

BEDROOM

COMMUNAL STAIRCASE

SECOND STOREY W/C

KITCHEN

LIVING / DINING ROOM

COMMUNAL STAIRS

EXTERIOR PERSPECTIVE

BLK 78 PROJECTION 1:100

BEDROOM

FIRST STOREY

Model Photos of collective

Block 78 deals with the most challenging spatial layout of the apartment. The entire block is curved, and so too are the units. Introducing the current form of the prototype, which would be interlocking balconies, will not fit due to insufficient space of the building’s footprint. In the second iteration of the projection, balconies and rooms are arranged to be prioritised having vistas out. This was not possible in the existing typology as bedrooms are made to face the backalley. By adding an additional floor, all units are able to have their bedrooms face external vistas. At the same time, the staggering along the main facade ensures the roofs of the balconies are made open to sky. In facilitating the emerging condition, the balconies are fitted with exhaust ducts that functions similar to the prototype with its chimneys. The roofs of the balconies are miniature funnels that seeks to capture the infected air should a resident contracts COVID. The projection can function with two ways. In normal circumstances, the units receive cross - ventilation through their bedrooms. When a resident in the unit contracts COVID, the supply of air will be from the living room and service spaces instead. The air exhaust will flow up through the duct that is one - way air flow, and to be brought out by prevailing winds.

Alternative Speculation interior shots

ALTERNATIVE EXPLORATION

Collective Projection

Variation 2

Variation 1

Board for collective projection

Exterior Renders

Interior shots of the collective for market

Critical Evaluation of Project As 13 weeks of this design studio comes to a close, the concerted grind saw the both of us producing models and design iterations at a never before jammed - pack pace. There were times we felt lost, however we exercised intuition and logical reasoning to guide us through these decisions. Feeling confused is part of the designer’s life as there are many grey areas and undefined boundaries. Still, the both of us are glad at the outcome of this collaboration, as evidenced by the quality of the work that hints the synergy between us. Winds in Singapore’s built environment are generally lacking. With the exception of monsoon winds and thunderstorms, Singapore does not have a consistent wind flow at ground levels. Even with the best intentions of designing a prototype around a Prairie - dog system, will likely not work in Singapore. Heat stacking to induce air flow is possible, and a key principle for natural ventilation in the hot tropics. Though unlikely for the prototype to be physically built, the ideas behind engineering the airflow for the purpose of self - isolation is a key takeaway from this project. In our experimentation, we are rigorous with the testing of geometry in relation to passive - induced prairie - dog ventilation, however the results are so similar that we virtually do not regard it as significant. We learnt that asymmetry controls airflow direction. To delve more into the specifics of form influencing wind speed would be to take up the mantle of being a physics student and meticulously engineer the results needed as evidence to guide the design. This, was not possible under 13 weeks of design studio. Hence we employed principles to guide our design, in what we think would alter the airflow to our advantage.

[FIN]

Design 4: Studio Report

Articles inside

Critical Evaluation of Project

Site Studies - Climatic/Environmental Study and Typological Study

Emerging Condition and Prototype Development