A Biophysical Framework of Heat Regulation Strategies for the Design of Biomimetic Building Envelopes

Biomimetic Strategies for Sustainable Resilient Cities: Review across Scales and City Systems

Biomimicry applications in different domains, from material science to technology, have proven to be promising in inspiring innovative solutions for present-day challenges. However, biomimetic applications in the built environment face several barriers including the absence of biological knowledge of architects and planners and the lack of an adequate common means to transfer biomimetic concepts into strategies applicable in the urban context. This review aims to create a multidimensional relational database of biomimetic strategies from successful precedent case studies in the built environment across different city systems and on different application scales. To achieve this, a thorough systematic search of the literature was implemented to map relevant biomimetic case studies, which are analyzed to extract biomimetic strategies that proved to be applicable and successful in an urban context. These strategies are then classified and documented in a relational database. This will provide a guide for architects and planners on how to transfer biomimetic strategies to strategies applicable in the urban context, thus bridging the gap of their lack of biological knowledge. The resulting matrix of strategies provides potential strategies across most of the different city systems and scales with few exceptions. This gap will be covered in a future work, currently in progress, to expand the database to include all city systems and scales.

Biomimetic Design for Adaptive Building Façades: A Paradigm Shift towards Environmentally Conscious Architecture

A change in thinking has been ongoing in the architecture and building industry in response to growing concern over the role of the building industry in the excessive consumption of energy and its devastating effects on the natural environment. This shift changed the thinking of architects, engineers, and designers in the initial phases of a building’s design, with a change from the importance of geometry and form to assessing a building’s performance, from structure to a building’s skin, and from abstract aesthetics to bio-climatic aesthetics. In this context, sustainable, intelligent, and adaptive building façades were extensively researched and developed. Consequently, several typologies, strategies, and conceptual design frameworks for adaptive façades were developed with the aim of performing certain functions. This study focuses on the biomimetic methodologies developed to design adaptive façades because of their efficiency compared to other typologies. A comprehensive literature review is performed to review the design approaches toward those façades at the early stage of design. Then, the theoretical bases for three biomimetic frameworks are presented to gain an overall understanding of the concepts, opportunities, and limitations.

Biomimetic building facades demonstrate potential to reduce energy consumption for different building typologies in different climate zones

Greenhouse gas (GHG) emissions leading to anthropogenic global warming continue to be a major issue for societies worldwide. A major opportunity to reduce emissions is to improve building construction, and in particular the effectiveness of building envelope, which leads to a decrease in operational energy consumption. Improving the performance of a building's thermal envelope can substantially reduce energy consumption from heating, ventilation, and air conditioning while maintaining occupant comfort. In previous work, a computational model of a biomimetic building façade design was found to be effective in temperate climates in an office context. Through a case study example based on animal fur and blood perfusion, this paper tests the hypothesis that biomimetic building facades have a broader application in different building typologies across a range of climate zones. Using bioinspiration for innovation opens new ideas and pathways for technological development that traditional engineering design does not provide. This study exemplifies the process in a building façade, integrating a new form of insulation, heating and cooling. Methods of mathematical modelling and digital simulation methods were used to test the energy reduction potential of the biomimetic façade was tested in a set of operational applications (office, school, and aged care) and across different climate zones (tropical, desert, temperate, and cool continental). Results indicated that the biomimetic façade has potential to reduce energy consumption for all building applications, with the greatest benefit shown in residential aged care (67.1% reduction). Similarly, the biomimetic building façade showed potential to reduce operational services energy consumption in all climate zones, with the greatest energy reductions achieved in the tropical (55.4% reduction) and humid continental climates (55.1% reduction). Through these results the hypothesis was confirmed suggesting that facades engineered to mimic biological functions and processes can improve substantially decrease building operational energy consumption and can be applied in different building classifications and different climate zones. These results would significantly decrease operational greenhouse gas emissions over the lifetime of a building and provide substantial savings in energy bills. Such facades can contribute to the further reduction in greenhouse gas emissions in a broad range of contexts in the built environment and other areas of technology and design. The flexibility and adaptability of biomimetic facades exemplify how biological strategies and characteristics can augment and improve performance in different environments, since the organisms that inspire innovation are already well-adapted to the conditions on earth. This study also exemplified a method by which other biomimetic building envelope features may be assessed. Further work is suggested to assess economic viability and constructability of the proposed facades.

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Biomimicry-Based Strategies for Urban Heat Island Mitigation: A Numerical Case Study under Tropical Climate

In recent years, demographic growth has caused cities to expand their urban areas, increasing the risk of overheating, creating insurmountable microclimatic conditions within the urban area, which is why studies have been carried out on the urban heat island effect (UHI) and its mitigation. Therefore, this research aims to evaluate the cooling potential in the application of strategies based on biomimicry for the microclimate in a historical heritage city of Panama. For this, three case studies (base case, case 1, and case 2) of outdoor thermal comfort were evaluated, in which the Envi-met software was used to emulate and evaluate the thermal performance of these strategies during March (highest temperature month) and October (rainier month). The strategies used were extracted from the contrast of zebra skin, human skin, evaporative cooling, and ant skin. The results showed a reduction of 2.8 °C in the air temperature at 11:00, the radiant temperature decreased by 2.2 °C, and the PET index managed to reduce the thermal comfort indicator among its categories. The importance of thinking based on biomimicry in sustainable strategies is concluded; although significant changes were obtained, high risks of discomfort persist due to the layout and proximity of the building.

Development and Validation of a Roadmap to Assist the Performance-Based Early-Stage Design Process of Adaptive Opaque Facades

Adaptive Opaque Facades (AOF) is an innovative concept with potential to achieve low carbon energy buildings. However, so far AOF are not integrated in the construction industry. One remarkable issue that designers have when dealing with alternative low-carbon technologies, such as AOF, is the absence of previous built experiences and the lack of specialised technical knowledge. Design roadmaps can be convenient solutions to guide pioneer low carbon technology applications. This work presents a roadmap to assist the performance-based early-stage design process of Adaptive Opaque Facades. Previous research developed new approaches and tools to assist on the construction definition of AOF, so that their adaptive thermal performance was considered when specific design decisions needed to be made. The roadmap presented in this paper organises the implementation sequence of each methodological approach and tools in different design stages, which aims to provide a holistic design approach for AOF. The usability of the roadmap was validated in a workshop called “Performance-based Design and Assessment of Adaptive Facades” with master students representing the target group of this roadmap. Even though these students had never heard about AOF before, they could successfully design, define the early-stage characteristics of an AOF and quantify the thermal performance of their AOF designs. The roadmap was proven to be a useful support, which might make the implementation of AOF more approachable in the future.

Thermoregulation: A journey from physiology to computational models and the intensive care unit

Thermoregulation plays a vital role in homeostasis. Many species of animals as well as humans have evolved various physiological mechanisms for body temperature control, which are characteristically flexible and enable a fine-tuned spatial and temporal regulation of body temperature in different environmental conditions and circumstances. Human beings normally maintain a core body temperature at around 37°C, and maintenance of this relatively high temperature is critical for survival. Therefore, principles of thermoregulatory control have also important clinical implications. Infections can cause the body temperature to rise internally and several diseases can cause a dysfunction of thermoregulatory mechanisms. Moreover, the utilization of thermotherapies in treating various diseases has been known for thousands of years with a recent resurgence of interest. An increasing amount of research suggests that targeted temperature management is of paramount importance to patient outcomes in certain clinical scenarios. We provide a concise summary of the basic concepts of thermoregulation. Emphasis is given to the principles of thermoregulation in humans in basic pathological states and to targeted temperature management strategies in the clinical environment, with special attention on therapeutic hypothermia in postcardiac arrest patients. Finally, the discussion is focused on the potential offered by computational thermophysiological models for predicting thermal responses of patients in various clinical circumstances, for proposing new perspectives in the design of novel thermal therapies, and to optimize targeted temperature management strategies. This article is categorized under: Cardiovascular Diseases > Cardiovascular Diseases>Computational Models Cardiovascular Diseases > Cardiovascular Diseases>Environmental Factors Cardiovascular Diseases > Cardiovascular Diseases>Biomedical Engineering.

Animal thermoregulation: a review of insulation, physiology and behaviour relevant to temperature control in buildings

Birds and mammals have evolved many thermal adaptations that are relevant to the bioinspired design of temperature control systems and energy management in buildings. Similar to many buildings, endothermic animals generate internal metabolic heat, are well insulated, regulate their temperature within set limits, modify microclimate and adjust thermal exchange with their environment. We review the major components of animal thermoregulation in endothermic birds and mammals that are pertinent to building engineering, in a world where climate is changing and reduction in energy use is needed. In animals, adjustment of insulation together with physiological and behavioural responses to changing environmental conditions fine-tune spatial and temporal regulation of body temperature, while also minimizing energy expenditure. These biological adaptations are characteristically flexible, allowing animals to alter their body temperatures to hourly, daily, or annual demands for energy. They exemplify how buildings could become more thermally reactive to meteorological fluctuations, capitalising on dynamic thermal materials and system properties. Based on this synthesis, we suggest that heat transfer modelling could be used to simulate these flexible biomimetic features and assess their success in reducing energy costs while maintaining thermal comfort for given building types.