Rice Husk-Based Insulators: Manufacturing Process and Thermal Potential Assessment.

The development of bio-insultation materials has attracted increasing attention in building energy-saving fields. In tropical and hot-humid climates, building envelope insulation is important for an energy efficient and comfortable indoor environment. In this study, several experiments were carried out on a bio-insulation material, which was prepared by using rice husk as a raw material. Square rice husk-based insultation panels were developed, considering the ASTM C-177 dimensions, to perform thermal conductivity coefficient tests. The thermal conductivity coefficient obtained was 0.073 W/(m K), which is in the range of conventional thermal insulators. In a second phase of this study, two experimental enclosures (chambers) were constructed, one with rice husk-based insulation panels and the second one without this insulation. The measures of the temperatures and thermal flows through the chambers were obtained with an electronic module based on the ARDUINO platform. This module consisted of three DS18B20 temperature sensors and four Peltier plates. Daily temperature and heat flux data were collected for the two chambers during the dry season in Panama, specifically between April and May. In the experimental chamber that did not have rice husk panel insulation on the roof, a flow of up to 28.18 W/m2 was observed, while in the chamber that did have rice husk panels, the presence of a flow toward the interior was rarely observed. The rice husk-based insulation panels showed comparable performance with conventional insulators, as a sustainable solution that takes advantage of a local resource to improve thermal comfort and the reduction of the environmental impact.

Environmentally Responsive Materials for Building Envelopes: A Review on Manufacturing and Biomimicry-Based Approaches.

Buildings must adapt and respond dynamically to their environment to reduce their energy loads and mitigate environmental impacts. Several approaches have addressed responsive behavior in buildings, such as adaptive and biomimetic envelopes. However, biomimetic approaches lack sustainability consideration, as conducted in biomimicry approaches. This study provides a comprehensive review of biomimicry approaches to develop responsive envelopes, aiming to understand the connection between material selection and manufacturing. This review of the last five years of building construction and architecture-related studies consisted of a two-phase search query, including keywords that answered three research questions relating to the biomimicry and biomimetic-based building envelopes and their materials and manufacturing and excluding other non-related industrial sectors. The first phase focused on understanding biomimicry approaches implemented in building envelopes by reviewing the mechanisms, species, functions, strategies, materials, and morphology. The second concerned the case studies relating to biomimicry approaches and envelopes. Results highlighted that most of the existing responsive envelope characteristics are achievable with complex materials requiring manufacturing processes with no environmentally friendly techniques. Additive and controlled subtractive manufacturing processes may improve sustainability, but there is still some challenge to developing materials that fully adapt to large-scale and sustainability needs, leaving a significant gap in this field.

Numerical Assessment of Zebra-Stripes-Based Strategies in Buildings Energy Performance: A Case Study under Tropical Climate.

Urban growth has increased the risk of over-heating both in the microclimate and inside buildings, affecting thermal comfort and energy efficiency. That is why this research aims to evaluate the energy performance of buildings in terms of thermal comfort (operative temperature (OP) levels, satisfied hours of natural ventilation SHNV, thermal lag), and energy efficiency (roof heat gains and surface temperatures) in an urban area in Panama City, using superficial-heat-dissipation biomimetic strategies. Two case studies, a base case and a proposed case, were evaluated using the Designbuilder software through dynamic simulation. The proposed case is based on a combined biomimetic strategy; the reflective characteristics of the Saharan ant applied as a coating on the roofs through a segmented pattern such as the Zebra's stripes (one section with coating, and another without). Results showed that the OP decreased from 8 to 10 °C for the entire urban zone throughout the year. A reduction of 3.13% corresponding to 8790 kWh per year was achieved for cooling energy consumption. A difference of 5 °C in external surface temperature was obtained, having a lower temperature in which the biomimetic strategy was applied. Besides, it was evidenced that a contrasted-reflectivity-stripes pitched roof performed better than a fully reflective roof. Thus, the functionality of Zebra stripes, together with the reflective characteristics of the Saharan ant, provide better performance for buildings' thermal regulation and energy needs for cooling.

An Inspection of the Life Cycle of Sustainable Construction Projects: Towards a Biomimicry-Based Road Map Integrating Circular Economy.

According to the National Energy Plan in Panama, the construction sector is one of the most prosperous and impactful sectors in the economy and it is expected to expand due to population growth by almost 300% by 2050. However, this sector must work on the transition towards sustainability and resilience in the face of climate change, since its growth implies a high consumption of resources and the contribution of greenhouse gases. The need to establish practices and strategies that embrace the dimension of sustainability and a circular economy is imminent. Currently, there is little guidance in the reference framework beyond certifications in planning, management and evaluation tools for its implementation. Different studies vary in the number of phases and considerations for projects. Therefore, the present work proposes the development of a unified road map, with defined phases, practices and indicators based on principles inspired by nature, such as biomimicry (Greek words: "bio" means life and "mimesis", imitation), and focuses on a circular economy, validated by construction professionals, where strengths, opportunities, skills and threats are identified with a high level of acceptance. This contributes to strengthening the field of sustainable construction project management and a precedent for Panama.

Sustainability Assessment of the Anthropogenic System in Panama City: Application of Biomimetic Strategies towards Regenerative Cities.

To understand the sustainability problem for Panama's metropolitan area, its urban metabolism was investigated. A way to evaluate its current state was obtained by estimating a sustainable indicator based on the Green City Index. With the abstraction of the identified problems, the biomimetic strategy "problem-based approach" was carried out, where different pinnacles of nature were selected as a reference for the design of regenerative solutions. These were inspired by the understanding of the living world and how to include ecosystems in urban designs. Therefore, a framework was proposed for positive generation and natural solutions in cities to take advantage of the regenerative potential in Panama City. Using ecosystem services, a set of indicators were developed to measure regeneration over the years at the city scale. The results indicate that from the 11 selected pinnacles, 17 solutions inspired in nature were proposed to regenerate cities. Consequently, a SWOT analysis was realized along with a questionnaire by experts from different fields. The findings obtained show that the feasible solutions were: arborization, green facades, solar roofs, e-mobility, green corridors, bicycle lanes, sidewalks, and biofilters. This research represents a step towards creating and developing regenerative cities, thus improving the quality of life of living beings and ecosystems present in society.

Bio-Inspired Electricity Storage Alternatives to Support Massive Demand-Side Energy Generation: A Review of Applications at Building Scale.

This work has its origin in the growing demands of energy regulations to meet future local targets and to propose a global implementation framework. A literature review related to conventional electrical energy storage systems has been carried out, presenting different cases analyzed at building scale to deepen in nature-inspired processes that propose reductions in environmental impact and present improvements in these storage devices. The use of batteries, especially lithium-ion batteries, is the most prominent among the electrical storage applications; however, improvements have been proposed through hydrogen batteries or the implementation of more environmentally friendly materials to manufacture the electrodes. In this sense, oriented to creating systems designed to protect the environment, important advances have been made in the development of storage systems based on biomimetic strategies. The latter range from the generation of energy through the respiratory processes of microorganisms to the recreation of the generation, storage, and release of energy using the thermoelectric and thermoregulatory characteristics of some insects. These facts show that the trend in research towards improving existing systems continues but reinforces the idea that new solutions must be environmentally friendly, so there is still a long way to improving the processes established thus far.

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.

Inspection of Biomimicry Approaches as an Alternative to Address Climate-Related Energy Building Challenges: A Framework for Application in Panama.

In the Panama context, energy consumption in the building sector is mostly related to the conditioning of indoor spaces for cooling and lighting. Different nature strategies can be mimic to strongly impact these two aspects in the building sector, such as the ones presented here. A comprehensive analysis regarding literature related to biomimicry-based approaches destined to improve buildings designs is presented here. This analysis is driven by the increasing energy regulations demands to meet future local goals and to propose a framework for applications in Panama. Such biomimicry-based approaches have been further analyzed and evaluated to propose the incorporation of organism-based design for three of the most climate types found in Panama. Consequently, a SWOT analysis helped realized the potential that biomimicry-based approaches might have in improving the odds of in meeting the local and global regulations demands. The need for multidisciplinary collaboration to accomplish biomimicry-based-designed buildings, brings an increment in the competitivity regarding more trained human-assets, widening the standard-construction-sector thinking. Finally, the analysis presented here can serve as the foundation for further technical assessment, via numerical and experimental means.