This paper presents five design prototypes for cool urban water environments developed in the 'Really cooling water bodies in cities' (REALCOOL) project. The REALCOOL prototypes address an urgent need: urban water bodies, such as ponds or canals, are often assumed to cool down their surroundings during days with heat stress, whereas recent research shows that this is not always the case and that urban water bodies may actually have warming effects too. There are, however, indications that shading, vaporising water, and proper ventilation can keep water bodies and their surroundings cooler. Yet, it is necessary to explore how these strategies can be optimally combined and how the resulting design guidelines can be communicated to design professionals. The REALCOOL prototypes communicate the spatial layout and biometeorological effects of such combinations and assist design decisions dealing with urban water environments. The micrometeorological simulations with Envimet showed that the prototypes led to local reductions on daytime PET from 1 °C to 7 °C, upon introducing shade. Water mist and fountains were also cooling solutions. The important role of ventilation was confirmed. The paper discusses and concludes about the use of the prototypes as tools for urban design practice.
Does our knowledge about city and urban planning have solid ground? Can historical research promote creative thinking? How can we theorise about urban design and architecture in our age of the media? These questions have guided the creation of this multi-layered, richly documented and illustrated triptych, in which the Dutch architectural theorist Wim Nijenhuis pursues a creative goal: to stimulate new ways of thinking in architectural culture.Each part of the triptych treats distinctive issues with a particular style of writing:I – a treatise on urban history. Using the archaeological-genealogical toolkit Nijenhuis reveals the difference between urbanistic discourse in the modern and the classical age; the first staging the street and public space, the latter adhering to representation and mathematical order. In great detail he shows how modern urbanism did not emerge from idealistic motives and technical urgencies, but from an accidental mix of medical, engineering and aesthetical parlances, and how classical thinking on the city dissociated from Renaissance by an intertwining of military science, political science, anthropology and ethics.II – a bundle of essays about the condition of the city in our media age. In strikingly composed texts the author prophesies how rapid traffic and transmission speed of media will distort the perception of our real cities. This gradual event will profoundly influence the cultural role of architecture.III – a set of meditations about epistemological problems. Questioning the practice of critical writing, Nijenhuis proposes change of subjectivity (and thereby worldview), ethical indifference, parody, curative mythomania and hypermodern dilettantism.The book is composed as a cloud essay that serves to enrich the reader’s theoretical understanding of urban interventions. Dialoguing with philosophers like Bataille, Deleuze, Foucault, Klossowski, Sloterdijk and Virilio, Nijenhuis covers multiple disciplines such as urbanism, architecture, history, media science, philosophy and art. Stretching urbanistic thinking beyond its limits he carries the reader along into the miraculous world of the street, the engineer, the norm, the form, order, fortresses, discipline, army camps, city frontiers, the Temple of Salomon, the quest for beauty, the ‘impressiveness’ of images, speed, the tragedy of the omnipolis, solidification of time, and the liquidising potency of apocalypticism and Taoist non-action.The Riddle of the Real City testifies to four experimental exercises: transitory subjectivism to reveal hidden dimensions of the person, transhistorical verticality to communicate with singular events from the past, theory as toolkit and pursuing a personal path in reading and investigation.
Small urban water bodies, like ponds or canals, are often assumed to cool their surroundings during hot periods, when water bodies remain cooler than air during daytime. However, during the night they may be warmer. Sufficient fetch is required for thermal effects to reach a height of 1–2 m, relevant for humans. In the ‘Really cooling water bodies in cities’ (REALCOOL) project thermal effects of typical Dutch urban water bodies were explored, using ENVI-met 4.1.3. This model version enables users to specify intensity of turbulent mixing and light absorption of the water, offering improved water temperature simulations. Local thermal effects near individual water bodies were assessed as differences in air temperature and Physiological Equivalent Temperature (PET). The simulations suggest that local thermal effects of small water bodies can be considered negligible in design practice. Afternoon air temperatures in surrounding spaces were reduced by typically 0.2 °C and the maximum cooling effect was 0.6 °C. Typical PET reduction was 0.6 °C, with a maximum of 1.9 °C. Night-time warming effects are even smaller. However, the immediate surroundings of small water bodies can become cooler by means of shading from trees, fountains or water mists, and natural ventilation. Such interventions induce favorable changes in daytime PET.
