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public space for the extreme: evaporation

Category: ⚐ EN+architecture+city+networkedurbanism+research+sustainability

Fog Assembly, Olafur Eliasson, Versailles 2016. Image courtesy of Olafur Eliasson, Anders Sune Berg

Fog Assembly, Olafur Eliasson, Versailles 2016. Image courtesy of Olafur Eliasson, Anders Sune Berg

Evap·o·rate, to pass off in vapor or in minute particles.

All evaporative cooling rely on the energy required for the evaporation of water to absorb heat from the air and lower the temperature. This is due to the very high enthalpy of vaporization of water, the phase transition between the liquid and the gaseous state requires in fact a large amount of energy (which is more properly called enthalpy) that is taken from the air in the form of sensible heat (which is the temperature, something we feel with our skin and determines our comfort) and it is converted into latent heat (which is an energy “hidden” in the vapor component of the air). The result of this adiabatic process is a drop in the temperature of air and an increase in its humidity, therefore it’s clear that this cooling system is particularly effective in dry and hot climate zones where the higher humidity and the lower temperature can be both seen as advantages. Clearly the evaporating process is a key also for some convective cooling processes (that we treated here) but they rely also on the reduced buoyancy of cooler and more humid air to obtain the final effect while evaporative cooling techniques only rely on the evaporation of water.

Blur Building, by Diller+Scofidio, Swiss EXPO 2002. Image taken from https://vimeo.com/122910558

Blur Building, by Diller+Scofidio, Swiss EXPO 2002. Image courtesy of david huang

Although primitive evaporative techniques were used in ancient times (in combination with convective and ventilation devices like windcatchers and qanats in iran) and porous water jars are still used in many hot areas in combination with Mashrabiya other ventilation apertures to naturally cool down the interior of buildings the use of evaporation to cool down outdoor spaces is very recent. Evaporative cooling depends largely on how effective we are able to evaporate water, and a basic physical variable plays a big role in this case: surface-area-to-volume ratio, the more surface area we are able to expose the more energy we are able to exchange.  There are basically  two ways to proceed nowadays to maximize the surface area, evaporative pads and misting. Evaporative pads are generally used in evaporative cooling machines oriented to indoor cooling, these pads are cheap and effective but they are relatively fragile, require continuous maintenance and are most effective in controlled environments where the airflow can be adjusted and controlled, the “wetpads” are made of porous materials that have to be maintained wet while air passes through. The peculiar structure of these materials offers the largest possible surface area to the passing air which is then humidified and pushed into the building or the room. This technique can’t be used for outdoor cooling clearly because of the required control to the ariflow that is necessary.

Misting is instead widely used nowadays to lower temperatures both in buildings and open spaces. The use of water mist to generate passive cooling in closed buildings is strictly related to passive (or mechanical) evaporation towers and therefore to what we have been explaining in the convective technique post in open spaces the use of water jets and mist is instead very efficient (of course depending on specific climate conditions) and cost effective.

Although it is not strictly designed to be a bioclimatic public space, the Miroir d’eau designed by Michel Corajoud in 2006 in Bordeaux is one of the most successful examples of water evaporation usage in public space design. In this case a large square, just in front of the famouse Place de la Bourse, is designed to be a large water mirror where hundreds of water nozzles spray water from the floor either in the form of a fountain or of a mist cloud. In the first case, where tall gushes are produced, water evaporation is limited and the playful atmosphere dominates the large plaza, but when short mist clouds are produced the evaporation rate of the water is greatly increased and a cooling effect is produced, although in Bordeaux climate conditions are quite mild, and hot days are limited to few occasions during summer the square is very popular.

Miroir d’eau, Michel Corajoud, 2006, Bordeaux, France. Image courtesy of Tony Hisgett CC-BY-NC

Miroir d’eau, Michel Corajoud, 2006, Bordeaux, France. Image courtesy of Tony Hisgett CC BY 2.0

Vaporizing water coming from the floor is a quite common and effective mean to condition large open spaces, the effect that everybody has noticed of a slight refreshment when passing by a fountain in a square or, even more, while staying close to a waterfall is due to the very same thermodynamic principle, the small drops of water that the are created when water breaks while falling to the ground or splashing into more water dramatically increase the surface-area-to-volume ratio favoring a faster evaporation, the nebulized microscopic drops evaporate instantly causing a sudden temperature drop that can be magnified by the wind or other design inventions. In the Sevilla 1992 EXPO this effect was widely used, large fountains and water basins were placed all around the EXPO along all the main paths and squares to increment climatic comfort, in some areas even vertical walls of water were designed to expose the visitors to an even more effective cooling device, but the most common strategy was the use of conventional fountains and mist nozzles integrated in the many green shading roofs.

Calle Torricelli, EXPO 1992, Sevilla. Image Courtesy of Mapio

Calle Torricelli, EXPO 1992, Sevilla. Image Courtesy of Mapio

The design of these spaces has to be developed with special care, the effectiveness of the strategies used in Seville for example varied much depending on the surrounding conditions, evaporative cooling could be very effective if combined with the right design of protective and shading elements, with a correct sun and wind exposure and material use but could be also nullified simply by not considering the wind variation. Even if water vaporization is widely used in many terraces, bars, public venues, etc. because of its low cost, obtaining an effective bioclimatic effect is harder to achieve. Ecosistema Urbano employs evaporative cooling in one of their seminal project, in the Vallecas ecoboulevard, the Ludic and the Media Tree are not equipped with evaporative towers but with water spraying nozzles that are oriented towards the circular public space beneath them.

Media Tree, Ecobulevar, Ecosistema Urbano, Vallecas 2004. Image courtesy of Ecosistema Urbano

Media Tree, Ecobulevar, Ecosistema Urbano, Vallecas 2004. Image courtesy of Ecosistema Urbano

The main innovation in the use of evaporation in this case is due to the form of the designed public space, because, as we already said, there is not much to innovate about the nozzles technology itself. Actually the most important issue is the control of the water flow and pressure as it has to be correctly regulated depending on the actual dry-bulb and wet-bulb temperature, relative humidity etc. in the case that those variables are considered, evaporation should be instantaneous without any dripping nor condensation. In the case of the Media Tree temperature and humidity sensors regulate the flow and the pressure of the water flowing to the spraying nozzles constantly adapting it to the weather conditions. In this case the design is particularly effective not only because of the cooling technology but mostly because of the shadow provided by the “trees” themselves and the protective design of the ground section that allow the cooled air to linger in the “inhabited” space and not being immediately dispersed.

Blur Building, Diller+Scofidio, 2002 EXPO, Switzerland. Image courtesy of theredilist.

Blur Building, Diller+Scofidio, 2002 EXPO, Switzerland. Image courtesy of theredilist.

But misting has a close bound with atmosphere and space, being one of the few atmospheric phenomena that we can directly observe fog and mist have been used also to define spaces, these new approaches, even though not directly related with bioclimatic architecture, open the door for future developments. In one of their most famous, and paradoxically iconic, works Diller+Scofidio designed a “formless, massless, colorless, weightless, odorless, scaleless, featureless, meaningless” that was basically made of mist and nothing else. Their explication for the work was open-ended, blur-building was not only the name they gave to it but also a factual assertion: the definition of it was also blurry. This event contributed to redefine, or to destroy, the meaning of building and the separation between what is a building and what is environment, up to even questioning what is architecture, for the first time the space was not defined by walls or windows or any stable solid material but was only an undefined mutating cloud made of vaporized water.
But this wasn’t in fact the first building that used mist water to blur its edges (although that they are all curiously related to universal expositions, more about expos here), the Pepsi pavilion in Osaka was the result of the fructuous cooperation between engineers and artists within the Experiments in Art and Technology  group and it was constantly covered with a thick layer of fog that partially hid it. In this case the building was still present and firm, a concrete entity with an interior and exterior form and a “conventional” space inside but the fog sculpture, designed by the japanese artist Fujiko Nakaya who spent her life working with fog, contributed to the creation of a memorable innovative pavilion.

Pepsi Pavillion, A.E.T. Osaka EXPO 1970, Osaka.

Pepsi Pavillion, A.E.T. Osaka EXPO 1970, Osaka. Image courtesy of A.E.T.

At the Seville EXPO in 1992 the so called “bioclimatic sphere” was also one of the main attractions of the whole exhibition and surely one of the most iconic ones. A tubular sphere was placed in the middle of one of the most important boulevards of the exhibition rounded by fountains and water basins as a part of the bioclimatic design of the open space of the exhibition. Although being highly symbolic and recognizable this sphere as reported in the follow-up publications about the Expo was not really contributing to any bioclimatic effect on the square or the boulevard, this depended basically on the fact that the device was placed in an open space and the diffusion of mist was not controlled in any way (a very interesting publication about the follow up of the climate conditioning in the EXPO 92 has been published by the same engineers that contributed to the design of the project and a short extract can be found here).

Esféra Bioclimática, EXPO Sevilla 1992.

Esféra Bioclimática, EXPO Sevilla 1992.

In 2016 also the famous artist Olafur Eliasson started working with fog and misting, naturally he is not concerned with the bioclimatic function of fog but more about the terms of landscape and vision and interaction between the user and the fog itself. Placed in the Versailles garden, “fog assembly”, is a ring emitting a swirling mist that involves the objects around and changes appearance depending on the site conditions. The user is invited to interact with the installation, crossing it and begin part of the fog it is producing, in this sense, this artwork can be easily assimilated to a public space generating a connection with the theme of this research.

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Public Space for the Extreme: Convection

Category: ⚐ EN+architecture+city+networkedurbanism+research+sustainability+Uncategorized

Digestible Gulf Stream, Philippe Rahm, Venice Biennale 2008. Image courtesy of Philippe Rahm.

Digestible Gulf Stream, Philippe Rahm, Venice Biennale 2008. Image courtesy of Philippe Rahm.

Con·vec·tion. Convection results from the tendency of most fluids to expand when heated.

The use of convective air flows with the purpose of cooling traditional houses was not alien to traditional Persian and middle eastern architecture. Joining the “simple” badgir ventilation system with more refined and complex cooling technologies was one of the most advanced points reached by Persian/Iranian building knowledge. Passive cooling systems in the Yazd desert were so advanced that iced formed (and accumulated) during the cold winters could be conserved frozen until the height of the long, hot, desertic summer.
In addition to sensible cooling, the cooling caused by a change of air temperature but not its humidity, badgir combined with a savvy use of water can provide also evaporative cooling which is generally more effective than sensible cooling alone.

Water deposit cooled with badgirs in the Yazd desert, in Iran

Water deposit cooled with badgirs in the Yazd desert, in Iran. Image courtesy of Flickr user dynamosquito, CC BY-SA

In order to do so, windcatchers have to work together with a water source that supplies water which is then evaporated cooling down the flowing air, this can be achieved in many ways. The first one is taking advantage of the of the basement damp walls of the windcacher itself, if there is enough humidity in the underground the basement walls will be constantly wet and when the wind tower is working as an air intake the evaporation of the thin superficial layer of water will cool down the downward incoming stream of air. The second solution is to put a water source, if available, right under the shaft of the tower, a fountain or a small pool is used in this case, sensibly and evaporatively cooling down the entering wind. A great example, found in Yazd, combines and refines even more these two methods placing the tower further than usual from the house (50 m) and then using an underground tunnel to connect the tower with the house. The tunnel, being underground benefits both from the earth thermal inertia and from the humidity of the soil and at the end of the tunnel a fountain is placed to cool down even more the air. The third, and more advanced, passive cooling system based on windcatchers benefits from an underground water stream to cool down the water.

Climatic Tree in the Vallecas Ecoboulevard, Madrid 2004. Image courtesy of Ecosistema Urbano.

Climatic Tree in the Vallecas Ecoboulevard, Madrid 2004. Image courtesy of Ecosistema Urbano.

The use of convection with the purpose of cooling public space is mostly centered on evaporative towers, in a normal evaporative (cooling) tower hot water is distributed in the upper part of the tower, the sprayed hot water release heat in the atmosphere condensing and flowing down to the bottom of the tower where it is collected and recirculated if it’s the case. In evaporative towers designed to cool the surrounding space the process is inverted, cool water is sprayed with nozzles at the top of the tower and rapidly evaporating absorbs energy from the air coming in from the top of the tower, the cooler and more humid air being denser descends to the bottom and causing the area above it to cool down. The design of an evaporative tower able to work properly is challenging, a single design flaw or dysfunction can cause the sprayed water to condensate an drip.

During the 1992 Seville Expo the white towers of the Avenida de Europa were originally designed just to be architectural objects landscaping one of the main avenues of the exhibition but considering a wider plan to improve public space comfort in the whole exhibition area, technically developed with the help of the “termotecnica” group of the university of Seville, were converted into evaporative towers to improve the environmental conditions in the area.

The design, obviously not conceived thinking about the cooling effectiveness, had to be converted a posteriori into a cooling machine. Two main modifications were made: a wind collecting cap was added to the top of the tower and nozzles were installed inside it. For six months the exhibition remained open and the engineers responsible for the bioclimatic design of the event collected data about the functioning and the performances of the design (the report can be found in this book). The added wind-collecting cap proved to be too small for the purpose it was installed and was not sufficient to “catch” enough wind during an average summer day. The second flaw was caused by the structural design of the tower itself, the internal part of the chimney wasn’t smooth and wasn’t totally free either, the secondary steel structure that stiffened the tower was in fact a lattice continuously crossing the chimney section, water nozzles were installed in circles on the inner perimeter of the membrane and functioned properly but the vaporized water copiously condensed on the lattice structure causing continuous dripping under the tower itself. This was obviously a major flaw and the towers functioned only partially, also due to the difficult maintenance of the water nozzles.

In 2004 Ecosistema Urbano realized one of its most iconic designs, the eco bulevard in Vallecas, Madrid. Each one of the three trees has different characteristics and each one is focused on a different aspect of public space, but in this case the most interesting is the northernmost one that was designed as a rack of twelve evaporative cooling towers grouped to form a semi-enclosed public space shaded and cooled by the bioclimatic tree. Each one of the cylinders is made of two textile tubes, the exterior and reflexive one creates a protective layer for the inner cooling mechanism, the interior tube is the evaporative tower itself. A cap, provided with three openings to collect winds from all directions, is placed on the top of the inner cylinder, right under the cap there is a fan that starts spinning when temperatures rise above 28ºC to increment the existing breeze or to move the air if there is no breeze at all. About at the height of the fan water is sprayed creating a fine mist and its evaporation greatly increases the cooling effect on the air descending in the inner tube and then exiting in the semi-enclosed public space, delimited by the crown of the cooling towers.

Ecobulevar- Arbol de Aire, Ecosistema Urbano, 2004, Ensanche de Vallecas, Madrid.

Ecobulevar- Arbol de Aire, Ecosistema Urbano, 2004, Ensanche de Vallecas, Madrid.

The ecobulevar, being a fully designed public space, can count on many other design characteristics that improve the overall functioning of the cooling towers, their efficiency and the energetic behavior. The design of the public space under the “tree” is very important, the enclosing section, creates a favorable space for artificial climate conditioning, though it is an open space the “habitable” part (the first 2m from the ground) are somehow closed by the design of the pavement itself, this design contributes to the refrigeration of the central area reducing the hot breeze influence at the ground level and avoiding the direct escape of cooled air. Solar panels contribute to the over sustainability of the artifact generating enough energy to power the fans and the pump for the water. Extensive studies on the ecobulevar, demonstrated that air temperature at the ground level can be up to 9ºC cooler than the air at the top of the tree and that the average temperature difference is around 6,5ºC.

The last two examples are practically based on the same design principle but there are huge differences concerning both the size and the technological character of the project.

The first one is the wind tower that the British architects Foster+Partners designed for the Masdar Institute in the planned city of Masdar, Abhu Dhabi (which they also planned). The Masdar institute is, as of 2016, one of the few built parts of the city, which, in turn, is facing serious development and financial problems with only the 5% of the planned area being completed. The core plaza of the institute hosts a 45m tall windtower that contributes to the climatic comfort of the plaza channeling down the breezes that often spire in the desert, it is important to notice that the tower is not the only element designed to improve the ambient conditions of the plaza but all the strategies are focused on the sustainability and the comfort of both the buildings and the public spaces, in this case the dense urban form is supposed to reproduce the one of the traditional local architecture and buildings façades are self shadowing reducing the reflected sun radiation in the square, streets are narrow, etc.

Masdar Institute Courtyard showing the wind tower. Image Copyright: Nigel Young/ Foster+Partners

Masdar Institute Courtyard showing the wind tower. Image Copyright: Nigel Young/ Foster+Partners

This tower is a hi-tech interpretation of traditional ones, its size is greatly increased (the highest windtower in Iran is 33m high) and many design details are engineered improvements of the original windwoter concepts. The 45m teflon sleek tube is naturally designed to offer the smallest possible resistance to the passage of the wind and to reduce the possibility of condensation to the nebulized water used for passive cooling. Computer controlled louvers opens and close according the direction and the speed of the incoming wind and reduces the suction caused by negative pressure on the downwind side of the tower, with this refined mechanism, and the triangular design, the tower is always exploiting the precious wind. To increase even more the cooling potential a ring of water nozzles, also computer controlled, is placed right at the top of the shaft transforming this tower in a evaporative cooling device.

A low-tech version, though very similar in the functioning is the windtower built at the Nitzana Educational Village, in the Negev desert at the border between Israel and Egypt. This design is constituted only by a vertical metal chimney topped by a fixed wind catcher oriented towards the prevailing wind. The playful design is enhanced by a clever usage of the bottom part of the tower, a perforated ceramic brickwork is used to enclose a relatively generous meeting place that can host dozens of people from the local community, to reduce solar gain on the habitable part of the tower a sun protection is installed around it permanently shadowing the ventilating part.

Nitzana Educational Eco-Village, Nitzana. Picture courtesy of the The Jewish Agency for Israel CC BY-SA 2.0 from flickr.

Nitzana Educational Eco-Village, Nitzana. Picture courtesy of the The Jewish Agency for Israel CC BY-SA 2.0 from flickr.

 

The cooling process is based on a combination of wind-catching, mechanical ventilation, and evaporative cooling. In the upper part of the shaft a large fan is installed to generate an artificial windflow (power is apparently generated by solar panels placed on the south side of the tower) and under the fan two rings of nozzles are placed to implement passive evaporative cooling. Though being quite a raw design, this cooling tower uses all the technical mechanisms to achieve a cost effective cooling for the small public it has to refrigerate. Compared to the Masdar windtower this one might have a major flaw, in both the Ecobulevar and Masdar the proper cooling shaft is always protected from the direct sunlight, in this case instead the shaft is thermally conductive and prone to overheating,

But the most advanced look at what convection means for the perception and comfort of the human body in the space has to be find in Rahm’s “Digestible Gulf Stream”. In this project, two white sleek metal boards are placed at different heights in a room, one of the boards, placed on the floor, is constantly heated to 28º C, the second one, hanging at a higher point is cooled down to 12ºC. The temperature difference between the two panels creates a convective flow, the air heated on the lower plan becomes less dense and lighter and tends to float towards the second object that gradually cools it down causing it to descend until reaching again the warm plate. This constant air flow is invisible but certainly perceivable by the human body, for the purpose of the exhibition in fact, actors with different clothing (from naked to well dressed) were standing on the plates showing various levels of comfort and doing various activities that had a different impact on the heat production.

Digestible Gulf Stream, Venice Biennale 2008 - Philippe Rahm. Image courtesy of Philippe Rahm.

Digestible Gulf Stream, Venice Biennale 2008 – Philippe Rahm. Image courtesy of Philippe Rahm.

Rahm’s pioneering work in “climatic architecture” is extremely interesting, in this case the space is defined only by its temperature which is something we are not really used to, our normal physical division of space (walls, windows, curtains…) is totally visual but then our comfort is determined by variables like air temperature, this is particularly true in public space, where usually there are no “rooms” and the use (or the avoidance) of space is more often determined by factors like shadow, noise, comfort, etc.

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Public Space for the Extreme: Ventilation

Category: ⚐ EN+architecture+city+networkedurbanism+research+sustainability

Trraditional Badgir in Bahrain, photo courtesy of Emilio P. Doitzua

Traditional Badgir in Bahrain, photo courtesy of Emilio P. Doitzua

Ven·ti·late. The natural or mechanically induced movement of fresh air into or through an enclosed space.

Natural ventilation was widely used in traditional architecture to improve the bioclimatic comfort of tents first, and then rooms and whole houses, before the advent of air conditioning, natural ventilation was one of the few techniques available to lower the temperature of a closed space exploiting the cooler winds blowing outside or just the movement of cooler air.
The first and most important examples of architectures using the wind as a cooling medium to improve indoor environmental conditions are found in Persian traditional architecture, the badgir (or mulqaf in arab) is an extraordinary piece of spontaneous design, using only the natural flow of the wind – often combined with many other bioclimatic arrangements like thick insulating walls, very packed constructions, small apertures, etc. – it is capable of cooling and improving the climatic comfort of a house in the torrid deserts of Iran and the Arabic Peninsula.

Badgirs in Iran's Yazd Desert

Badgirs in Iran’s Yazd Region – Courtesy of Alessandro Longhi CC


The badgir, in arid and dry climates is often combined with the use of water to implement evaporative cooling improving even more its cooling capacity and generating cool breezes even without the presence of winds outside, in this case the thermodynamic effect is not based only on ventilation but also on convection. The windtower, or literally windcatchers, can be found as a traditional element in most of the modern Islamic world area with few regional variations, its usage has been consistent through the ages but in the western gulf region it almost disappeared due to the rapid urban growth and modernization of the cities, in Bahrain, for example, only one ancient badgir remains.

The traditional usage of windcatchers has been nowadays reinterpreted in many ways using both natural and mechanical aided ventilation, the great Egyptian architect Hassan Fathy used it widely in his buildings, but for sure, one of the best practice (at least if we consider this research public-space oriented) is the Qatar University Campus designed by the Egyptian architect Kamal el Kafrawi (with the collaboration of Ove Arup) and opened in 1985.

Qatar University Campus, Photo courtesy of the architect, Source: Aga Khan Trust for Culture

Qatar University Campus, Photo courtesy of the architect, Source: Aga Khan Trust for Culture

In this groundbreaking project the use of windcatchers is systematic and characterizes the whole campus. Based on an octagonal and square plan geometry, the low rise concrete modules the projects makes large use of natural light and natural ventilation through the hundreds of windtowers that top every module and mashrabiyas to protect the classrooms from sunlight and permit the air circulation. The aggregation of the modules juxtapose classroom modules, halls and rest spaces enriched with vegetation and constantly ventilated through the roof.

Qatar University Campus external view, photo courtesy of the Aga Khan Award for Architecture

Qatar University Campus external view, photo courtesy of the Aga Khan Award for Architecture

In contemporary architecture, and specifically in the climatic improvement of public space, the use of ventilation devices, especially in high-humidity environments is quite a new thing and mechanical ventilation is generally used as a cost-efficient way to overcome tropical humidity especially in southeast Asia. Two projects are to be considered references in this case, one is Will Alsop’s Clarke Quay in Singapore and the other is Ecosistema Urbano’s Air Tree for the Shanghai Expo 2010.

In this 2006, project, Alsop is called to regenerate the Clarke Quay riverfront and the market with the objective of drawing tourists and locals back to the old Singapore’s waterfront. The most interesting thing of this bold design is certainly  the bioclimatic intervention in the market, refusing to create a closed shopping mall the architect designed a mitigated semi-external space, protected from frequent rains and with improved environmental conditions.

Clarke Quay Redevelopment, Singapore. Image courtesy of Will Alsop.

Clarke Quay Redevelopment, Singapore. Image courtesy of Will Alsop.

The market intervention is composed by two main parts, the roof and the ventilation devices.
The roof is constituted by giant umbrella-like structures covering the internal streets of the market, the ETFE canopies covering the streets offer protection from both the rain and solar radiation that in this climate are equally detrimental for the use of public spaces. This roof maintains the temperature in the central square and the four streets of the market at around 28º Celsius when outside temperatures can rise up to a mean of 31ºC. But the most important and innovative feature are the “whale-tail” shaped ventilators placed in the vertical supports of the roof structure. These big fans have a fundamental role in maintaining good environmental conditions in the market streets, considered the high relative humidity level(year average 84%) ventilation is the only way to make the air tolerable. Using slow rotation fans these sculptural objects blow a constant breeze in the lower part of the market favoring the natural evaporation cooling of the skin.

Clarke Quay Redevelopment, Singapore. Image courtesy of Will Alsop.

Clarke Quay Redevelopment, Singapore. Image courtesy of Will Alsop.

The Air Tree that Ecosistema Urbano realized in Shanghai for the 2010 Expo is a prototype of an intervention in contemporary urban space. It is conceived as a new kind of public space, a technological urban furniture, which also serves as a virtual node of connectivity where users can actively interact. Its different technical layers enables multiple final configurations and a myriad of intermediate positions (opaque, translucent, transparent, bright, interactive, open, etc.). Different textiles for video projections allow an unlimited combination of scenarios adaptable to citizen needs. Its appearance can be transformed over the daily cycle, as well as through the different seasons. By sensors it is connected in real-time with the climatic conditions of Shanghai, constantly adopting the optimal physical and energy consumption configuration to generate climatic comfort for the citizens.

Air Tree Shanghai, 2010. Image Courtesy of Ecosistema Urbano

Air Tree Shanghai, 2010. Image Courtesy of Ecosistema Urbano

To improve climatic and environmental conditions, that in Shanghai basically have to deal with high temperature during summer and high relative humidity during all year, a 7.3 m diameter fan suspended by a tensegrity structure in the center of the space, at a height of 11.5 m provides air flows inside the space. Through a telescopic system the fan can be lowered several meters to come closer to the ground. The exact position and speed at each moment is determined according to the instant climatic conditions of the environment, real time monitored in the surroundings of the structure. Together with the variable configuration of the tree’s skin the flow of air generated with the fan can effectively improve the environmental conditions inside the tree.

Air Tree Shanghai, 2010. Image Courtesy of Ecosistema Urbano

Air Tree Shanghai, 2010. Image Courtesy of Ecosistema Urbano

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Public Space for the Extreme: Shading

Category: ⚐ EN+architecture+city+networkedurbanism+research+sustainability+urbanism

Manama Souq - Photo courtesy of Emilio P. Doitzua

Manama Souq – Photo courtesy of Emilio P. Doitzua

Sha·ding, to cover or shield from direct sun exposure […]

Direct solar radiation has the largest impact on the comfort in open spaces, the enormous energy of the sunlight can be useful in certain seasons and cold climates but is generally excessive and certainly unwanted in hot and arid climates. Sun shading, and sun protection, has been, and still is, the fundamental way to improve a public space bio-climatic behavior. Reducing the solar radiation that reaches the people or gets reflected by the ground, both by the means of vegetation or shading artifacts, is the most efficient way to reduce temperature and it is widely used at all latitudes from temperate areas to arid ones.
In this short post we are going to present some projects that we consider interesting because of their use of shadow or shadowing devices, we tried to stick to projects that make use only (or mainly) of the shadow leaving other mixed projects for later.

A milestone project in the use of shading devices to create a bioclimatic space in the gulf region is the Hajj Terminal part of the King Abdulaziz International Airport, designed by the NYC based firm S.O.M. architects. The use of tensile structures, wasn’t surely something new at the time (i.e. Frei Otto tensile structures for the Olympic games in Munich date back to 1972) but the scale and the effectiveness of this project made it one of the best and most replicated examples of open shaded spaces. Although not being a true public space the Hajj terminal is quite peculiar, designed to host the massive flow of pilgrims that pass by during the ritual pilgrimage to the Holy Mecca it is composed of two parts, the first is a fully air-conditioned terminal where the offices, customs, and luggage claiming areas are hosted and the second, and far more interesting part, is the famous open space tent-like structure that hosts the pilgrims until their departure to the Mecca (the waiting time can be up to 36 hours).

Hajj Terminal, S.O.M. Architects, Jeddah, Saudi Arabia, 1982. Image courtesy SOM. Image © Jay Langlois | Owens-Corning

Hajj Terminal, S.O.M. Architects, Jeddah, Saudi Arabia, 1982. Image courtesy SOM. Image © Jay Langlois | Owens-Corning

The whole structure covers more than 42 hectares (60 football fields), and it’s composed by 210 tent-shaped cones made of Teflon coated fiberglass fabric arranged in modules of 45,72m (150ft) with an oculus on the top to allow the heated air to escape. Published data demonstrate how effective the design is, reflecting roughly the 76% of the solar radiation, the structure can maintain a notable 27 ºC temperature under the tent even with temperatures reaching up to 54ºC outside providing also a soft diffused light to the whole terminal.

In the late 80s, for the International Expo that took place in Sevilla, the Spanish architect José Miguel de Prada Poole designed the main pavilion for the events in the exhibition area. The “palenque” although resembling the Hajj terminal for the shape of its tensile roof is a much more advanced piece of bioclimatic architecture, Sevilla’s climate can be really harsh during summer and the designing teams put a big effort on the climatic comfort of both the pavilions and the open spaces. The palenque sits in between a pavilion and an open space, it was the main arena for shows and other events and it was, substantially, a covered open space filled with finely designed mechanisms to guarantee a high degree of climatic comfort even during hot summer days. The design used both natural (the pavilion had no walls at all, only vegetation enclosed it a bit) and forced ventilation and air conditioning to ensure the best possible conditions to its visitors but in this case the most interesting part it’s its cover.

The "palenque" during the Sevilla EXPO in 1992

The “palenque” during the Sevilla EXPO in 1992

In this project the bioclimatic design of the Hajj terminal was substantially improved, at a smaller scale indeed, the oculus was substituted with an improved ventilation topping cone and to decrease the temperature of the fiberglass fabric under the Andalusian sun hundreds of watering nozzles were installed around the cones. The water vaporizers were computer controlled activating only when the temperature and humidity rose over a certain value, their function was to continuously wet the roof with a fine mist, the quick evaporation of the water subtracted heat from the fabric and contributed to lower the transmitted heat to the underlying arena.

But shading can also be declined at a temporary and smaller scale. An extreme example, in this sense, is Asif Khan’s Public Space Shadow Canopy Kit, a portable kit that can be easily distributed and installed in any place without any tool or machinery, it can be moved, can be dismounted and installed in another place or can create a successful temporary public space.

Public Space Shading Canopy Kit courtesy of Asif Khan Architects

Public Space Shading Canopy Kit courtesy of Asif Khan Architects

Public Space Shading Canopy Kit courtesy of Asif Khan Architects

Public Space Shading Canopy Kit courtesy of Asif Khan Architects

This extremely low-tech and inexpensive piece of design is particularly meaningful for informal areas, unused or temporary spaces that can easily be converted in playful shaded spaces.

The Bab al Bahrain pavilion is a temporary public space designed by Noura Al Sayeh & Leopold Banchini in one of the most symbolic and historic sites in Manama, Bahrain. The pavilion had an extraordinary success during its permanence and it was constantly used and visited, it held events and even workshops. It’s success can be attributed to a good mix of factors, the first one surely being the special value of the place and the second one the it’s good bioclimatic design based mainly on shadowing.
Bab al Bahrain square was one of the main public spaces in the city, very close to the main historical souk and still connected to a natural pedestrian network, it is a privileged place but it slowly lost its status and it has been converted in a roundabout often crowded with cars and very unfriendly for the pedestrians. The first good virtue of this project is the creation of the public space itself, closing the crossing to the traffic and giving back this historical place to the citizens, although it was only for a limited time this demonstrated the power of this kind of intervention and the need for quality public space that this city has.

Bab al Bahrain Pavilion, image courtesy of Eman ali

Bab al Bahrain Pavilion, image courtesy of Eman ali

The second important virtue was the design of a comfortable public space using only the perks of the site, a minimal light structure and a low tech element to protect from the sun. Based on a regular grid of thin steel columns the project is basically made by its “canopy”, a light sun-reflecting fabric (generally used in greenhouses) that reflects most of the energy of the sun giving to the place a nice diffused illumination. To make this design really effective the architects took advantage of a large fountain already existing in the site, the fountain with its fresh water contributes to lower the temperature of the air crossing the pavilion and also generates a cooler spot in the middle of it favoring the creating of a light breeze.

 

Previous posts of the series:

Public Space for the Extreme: Defining the Extreme
Public Space for the Extreme @ GSD-Harvard
Do you want to contribute to our research about public space for extreme climate? Have a look here.

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Public Space for the Extreme: Call for Papers

Category: ⚐ EN+architecture+city+networkedurbanism+research+sustainability+Uncategorized+urbanism+work in progress

Woody Allen starring in The Front, Martin Ritt, 1976. Copyright of Columbia Pictures.

Woody Allen starring in The Front, Martin Ritt, 1976. Copyright of Columbia Pictures.

The Book

As you may have noticed from our last posts, it has been a while since we have started researching on the possibilities of designing better public spaces for those cities and regions that have to deal with extreme climate conditions. Extreme heat, very often combined with extreme humidity are conditions that, more or less seasonally, affect wide areas of the world. These regions, classified under the Köppen-Geiger climate map mainly as Equatorial and Arid (although with many sub-classifications) comprise various densely populated areas that all face a common problem: the harsh climate, combined with a generic design of the city, results in a scarce and difficult relationship of the citizens with the public space. Our goal is to publish a book that will serve as a design manual and reference for architects, urban planners, public administrators, decision makers, and citizens. This book, containing good practices examples, technical solutions and theoretical essays, will help designers imaging and designing better public spaces considering the local climate, the bioclimatic-comfort needs of the citizens and the responsiveness to the changing environmental conditions.

The Call

We would like to announce a call for papers inviting authors (architects, urban planners, designers, sociologists, engineers, scholars, etc.) to submit an abstract, no longer than 250 words, for a paper that will be published in the book. The content of the paper must necessarily be related with the topic of the book that can be summarized in the“design of bioclimatic responsive public spaces under extreme climate conditions” and can be either about a general original investigation on the topic or related to a more specific field within the main subject, like for example specific bioclimatic control techniques, technologies or principles, specific open air comfort conditions, the relationship between climate and public space usage, etc. Any other idea, even loosely connected with the main topic, that offers an original and innovative point of view is welcome and will be considered by the editors.
The abstracts will be blind reviewed by the editors: prof. Jose Luis Vallejo, prof. Belinda Tato and Marco Rizzetto; they must be written in English and be the result of an original and high quality research. Selected abstracts will be then discussed with the authors to develop the final paper according to the indications of the editorial board, the publication of the paper(s) will, in any case, depend on the quality of the final work.

The Deadlines

Deadline for the submission of the abstract: November 12th 2016
Notification of acceptance: November 19th 2016
Deadline for final paper submission: January 20th 2017

Submit!

If you are interested please send your abstract to sorry you have to write it down with the Subject: “Extreme Public Space CFP”

A street in Bahrain, photo by Emilio P. Doitzua

A street in Bahrain, photo by Emilio P. Doitzua

All submissions will be treated as confidential prior to publication in the proceedings; rejected submissions will be permanently treated as confidential.
The final book will be both digitally published under a CC-NC-SA licence and made available for download and physically printed, a limited number of copies will be distributed to key institutions related with design and planning all around the world, especially in regions directly interested by extreme climate conditions. The author, or authors, of the selected essays will be credited and acknowledged. For any other information or doubt please do not hesitate to contact us at the address provided below.

If you want to know something more about our current ongoing research you can take a look at the previous posts belonging to this same series:
01 – Defining the Extreme
02 – Public Space for the Extreme @ GSD Harvard
and stay tuned for upcoming updates.

 

Bonus link

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Public Space for the Extreme @ GSD-Harvard

Category: ⚐ EN+architecture+city+networkedurbanism+research+sustainability+urbanism+work in progress

Breathing Streets, courtesy of Nan Liu and Adelene Yu Ling Tan

Breathing Streets, courtesy of Nan Liu and Adelene Yu Ling Tan

During 2015 spring semester Ecosistema Urbano principals Jose Luis Vallejo and Belinda Tato taught a studio at the GSD in Harvard, focused on the design of socio-environmentally responsive public spaces for the city center of Muharraq, in Bahrain. During the semester the students worked to develop ideas and designs to improve the few remaining public spaces in the city, almost completely wiped out by the continuous transformation of the antique city fabric into a contemporary -and rather generic- one, that basically followed the “wide car street + housing block” development pattern, during the last 50 years the city has completely lost its contact with the water, substituted by a wide belt of highways and also its interstitial, small public spaces, almost completely transformed into parking lots. Always considering the climatic conditions that can be easily defined harsh and extreme, the aim of those projects was to foster the use of public space, in a city where public space is not only often abandoned and absent but also where the right to meet and gather is strongly discouraged.


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Public Space for the Extreme: Defining the Extreme

Category: ⚐ EN+architecture+city+networkedurbanism+research+sustainability+urbanism+work in progress

Manama, Bahrein. Photo: Emilio P. Doiztua

Four years ago Ecosistema Urbano held a workshop in Manama, Bahrain, to revitalize and improve the public space around the Bab al Bahrain souk, an area that is historically important for the city but that it is nowadays a mere street crossing rounded by parking lots, without any tree or shadow. The workshop was held in a remarkable temporary pavilion that for a few weeks converted a roundabout into a vivid and often crowded space, a light textile roof offered shadow and protection to the participants contributing to the success of the workshop. The workshop has been also the occasion for us to start a long term project on Bahrain, under the auspices of the UNESCO Arab Regional Center for World Heritage we started a research project mainly focused on the city of Muharraq, its antique public spaces and how could we revive and improve them. This research has been carried on during 2014 and 2015 spring semesters with the GSD-Harvard students and it emerged immediately that one of the main conditions to make use of the public space in Muharraq was the improvement of the extreme environmental conditions that, combined with a low quality design of the space, prevented and discouraged the people to go out and live the remaining public spaces.

Bab Al Bahrain Workshop 2012

Bab Al Bahrain Workshop 2012

Following this same path of research we are now working on a publication to finally release all the knowledge we have accumulated during these years of work, teaching, and research in the form of a book. Our objective is to address the problems that the designers have to face every time they are called to design a public space in an area with a particularly extreme climate (make it extremely hot, arid, tropical, etc.), we would like to provide decision makers, designers and citizens with a solid base of knowledge to help them consider new technologies and concepts to design public spaces optimized for a certain climate, responding to bio-climatic needs and site specific conditions making it more livable, comfortable and accessible.
Beginning today, we start a series of posts dedicated to the design of bio-climatic public spaces, we will periodically publish part of the content we have produced for the book exposing the problems and the good practices that we have found, our concerns, the work of our students, etc. We would like to foster a debate around these themes that might help us developing our book but also raise the awareness around the climatic comfort in public spaces which is a true challenge for architects and designers in many areas of the world.
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Ecosistema urbano working for the urban transformation of Grenoble

Category: ⚐ EN+architecture+competitions+ecosistema urbano+news+sustainability+urbanism+work in progress

accessibility

We are proud to share our success in the competition for the Master Plan for ZAC Flaubert in the city of Grenoble. It is the result of a collaboration with Sathy, TN Plus,  OGI (Engineering), Res Publica, and VPEAS. Our candidature has just been selected to lead this great urban transformation and revitalization process in the very center of Grenoble city.

The project deals with the urban transformation of an underused area: ZAC Flaubert. This is currently a 90 hectares transition area at the crossing of a North-South axis and an East-West one, both important for the city. Being a strategic part of the city and its inhabitants, this huge project has various stakes and raises one question: How to give an identity to this area which is now a cluster of micro-identities?

The mayor, from the Ecologist party, wants to integrate citizens in an ambitious co-construction process that would start with Flaubert to spread across the whole city. He is committed to involving residents, shop owners, citizens at each step of the co-construction project. In addition, various other stakeholders are to be involved in the process thanks to different formats such as debates and discussions to exchange points of view and possible visions for Flaubert’s future.

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City Splash! for Copa Cagrana Neue | ecosistema urbano + transform.city proposal for Vienna

Category: ⚐ EN+architecture+city+ecosistema urbano+landscape+news+sustainability+technologies+urbanism



Last November we were selected, in collaboration with Transform.city, to participate in the Neue Copa Cagrana International shortlisted competition in Vienna (Austria). The scope of the competition was the urban revitalization and definition of the Master Plan in the area Neue Copa Cagrana defining an urban proposal and the relationship of this part of the city with the river.
We were selected along with other 8 teams, including renowned firms such as Dominique Perrault, AZPML, or West 8.

The context: Donau City, Vienna

The study area is located next to Donau City, on the left bank of the new Danube Canal, Neue Donau, passing through the city of Vienna. It is a neighborhood of mainly tertiary character with office buildings of great height, developed in the last 20 years, including the Vienna International Centre.

Copa Cagrana – the intervention area, between the Danube and the new urban area with the D. Perrault’s tower

Despite the good connection with the city center, the large number of buildings and the excellent existing natural qualities, the area is almost deserted during day and night. This is mainly due to the lack of variety of uses, commercial facilities and recreational areas.
The proposal develops a series of strategies to revitalize an area that already has the optimal conditions to become a landmark for the city of Vienna:

FOUR OBJECTIVES

1 – Increase density and urban mixture

The proposal aims to incorporate urban, commercial and leisure life at a time when Vienna is starting to look for other forms of identity for the river area. It is important to bring new residents to help to create urban activity throughout day and night, summer and winter seasons by permanent and temporary uses. The mixed-use and residential functions in the first row, including the urban boulevard, have the potential to complete and complement the existing urban fabric and establish, for the first time, the necessary connections to make Donau City a functioning and exciting neighbourhood.

Activity diagram for the different seasons

The project proposes a high density urban prosthesis, combining housing, office, commercial and public space, in order to create an active urban spot connected to the surrounding, improving its identity and multiplying the possibilities of use.
The proposal seeks to make Donau City easier to be understood and perceived, with a clear connection to Danube river and its waterfront. Therefore, the proposal is the missing link to the completion of the Donaustadt and is, at the same time, the necessary catalyst to enable the urban regeneration in the area.

2 – Create new urban spots

Copa Cagrana will be an exciting new urban spot in Wien, which is perfectly connected to the city network thanks to the transport connectivity and subway line. Through the physical proximity with existing Donau City, Donau Insel and surrounding neighborhoods, the area will increase popularity and will offer more attractions to the users.
The newly created waterfront will be an urban catalyser with a variety of urban functions, with uses according to the seasons and day and night time:
The FILTER ZONE is a more quiet area free of commercial activities.
The TEMPORARY ZONE changes according the different seasons, with beach bars in the summer, pop-up restaurants, terraces and platforms, etc.
The WATERFRONT is an enjoyable walkable strip with piers and exciting water activities for summer and winter.

The FILTER ZONE

3 – Renaturing (urban+nature landscape)

A new urban and natural environment intrinsically connected with surrounding nature.
It will be the connecting environment between Donauinsel and Donau Park but also extending its limits over the water landscape of Neue Donau to create a vibrant and diverse waterscape.

 

Masterplan 1:1000

4 – Digital Identity – web app strategy

It is important to create the communication channels in order to advertise and share information about the ongoing activities and as a way to share potential ideas to be implemented. This web APP is thought to work as a social network that provides information for the citizens of Copa Cagrana on what kind of activities they can do on this renewed urban area.
Users will be able to register and create a user profile, with this, they will have the opportunity of proposing activities that will make use of the beautiful surroundings and installations of this urban space. The commercial sector will also have their own space. They will have the possibility of creating a profile which will allow them to publicize their products and business, as well as invite and inform citizens about special deals, offers, events and other celebrations.

 

FIVE NEW URBAN ZONES

Cross Section

Seeking to achieve these four objectives, the proposal creates 5 zones acting together and related to each other:

Zone C+: Infiltration city

The energy of city life will splash towards Donau City and the urban plinth will extend its limits to bring activity and reconfigure the public spaces around the corporative and residential buildings. These urban tentacles will extend urban plinth limits with linear and small scale pavilions, pop-up stores and cafes, etc. reconnecting and renewing the pedestrian pathways of the Donau city.

Elevation

Zone C: Social life city

Zone C proposal is the most powerful urban energy boost, as it provides a large amount of overlapped new programs and public spaces easily accessible at different levels.
Areas:
Urban plinth: fragmented construction from 1 to 4 stories high, multiple programs with predominance of commercial spaces overlapped with public spaces at different levels.
Vertical ecosystems: housing towers with a myriad of different typologies to create a diverse neighbourhood. The housing units help to create a dense neighbourhood with urban life throughout the day.
Urban bridge: On the tenth floor, same level as the top terrace of the existing linear building of social housing, a bridge is creating connections between semi public spaces, with diverse programs within the vertical ecosystems.
Public peaks: the top floor of the different towers is also part of the network of semi public spaces within the vertical ecosystems. These spaces can hold multiple programs and part of their success will be the privileged point of view of the city (terraces, cafes, common spaces,… )

Zone B: nature city

This is a zone where nature is predominant and the urban plinth is melting its limits with the landscape. At the same time, the natural character of this area helps to make the transition between the bigger, urban scale of zone C and both the lower scale of zone B and the waterscape towards Donauinsel, combining natural areas with paths for soft mobility.

Different cross sections in zones A and B

Zone A: Leisure city

Leisure cityscape to allow the transition between the formal city and the vibrant and ever changing new waterscape of zone C+. It will hold multiple permanent uses but also temporary programs and seasonal activities. There are multiple temporary and permanent uses in small buildings with similar language, as well as a new riverside walk that will extend to create a comfortable linear space. The relationship with water and the elevation difference will be resolved with a wooden platform that will act as an urban sofa to relax and enjoy the presence and proximity of the river.

Zone A+: Water city

Vibrant and ever changing waterscape in continuous evolution. It will extend the activities of the new urban spot towards the water.

Masterplan 1:2000

+ water pier: permanent pier, water thematic. Light structure with indoor and outdoor spaces to allow the creation of different bathing experiences. The use will change seasonally, during the winter, outdoor and indoor climatized pools will allow the user to be in connection with the surrounding natural landscape while having a pleasant bathing experience.

The water pier for summer activities

+ ice pier: permanent pier, ice and climbing sports oriented. Light structure with a strong seasonal connection. During the winter, part of the structure will be a huge frozen and faceted vertical surface to practice ice climbing, while the lower platform will host different ice skating outdoor rinks to practice in connection with the water and natural landscape. During the summer the ice surface is transformed into a huge waterfall falling from the upper level into the river.

ice pier_con nieve

The ice pier for winter climbing

+The urban archipelago: big modular and floating ever changing extension of the waterfront. The different seasons and uses will dramatically transform its configuration. This mutant landscape is built with modular floating platforms/barges that can be combined to create larger flat surfaces if necessary. These platforms can be connected to the limit line of the waterfront to extend its surface.

If you want to know more about the proposals you can download the competition panels here:
Panel 1   Panel 2   Panel 3   Panel 4

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UCJC | Encarnación y el Máster en Arquitectura y Energía 2015

Category: ⚐ EN+⚐ ES+architecture+arquitectura+colaboraciones+educación+encarnacion más+sostenibilidad+sustainability

DSC_0495 rec

⚐ ES – Como ya comentamos anteriormente, desde el pasado mes de Octubre nos hemos incorporado como docentes en el Máster en Arquitectura y Energía (MAE) en la Escuela de Arquitectura y Tecnología UCJC.  

El MAE, en su VI edición, profundiza en la nueva suma de conocimientos para la gestión de los recursos, la reducción de la demanda energética y el aprovechamiento de las fuentes renovables en el actual contexto global de crecimiento asimétrico y agotamiento de los recursos, que supone un 40% de la energía consumida en el mundo.

En este contexto, se ha optado por trabajar en una ciudad con una vocación por diminuir su gasto energético como es la ciudad de Encarnación, Paraguay, a través de su Plan de Desarrollo Sustentable en el que llevamos trabajando varios meses. Todos los departamentos del Máster y sus diferentes asignaturas trabajarán en esta ciudad investigando soluciones bioclimáticas para viviendas sostenibles, sistemas constructivos pasivos, un urbanismo en red o fuentes de energía alternativa, con las que encontrar soluciones extrapolables a otras partes del mundo.

DSC_0523

⚐ EN – Last October we joined as faculty at the Master in Architecture and Energy (MAE) at the School of Architecture and Technology UCJC.  

In the current global context of uneven growth and the depletion of resources, the construction sector accounts for 40 per cent of the energy consumed worldwide. Any work carried out on the land, be it urban, architectural, infrastructural or landscaping, should include strategies for resource management, the reduction of energy demand and the use of renewable sources. The sixth edition of MAE looks in depth at this new body of urgent and essential knowledge, identifying the tools needed to create a development model that is compatible with environmental balance.

We have chosen to work in an emblematic city in terms of energy consumption and new sustainable policies: Encarnación, Paraguay. For the last few months we have been working on the Urban and Territorial Planning and Sustainability Plan for the city, making of Encarnacion a pioneer case study in sustainable urban development.

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