2020 AIA/ACSA Intersections Research Conference: CARBON

Ersela Kripa
Texas Tech University

Stephen Mueller
Texas Tech University

The project develops means of uncovering, representing, and designing for the unseen dangers of IRRADIATED SHADE—a growing yet under-explored threat to cities, buildings, and bodies. The project leverages its position on the US-Mexico border, where physiological effects of solar radiation are relentlessly rendered upon vulnerable populations. The region is host to some of the most-traveled international pedestrian bridges between the two countries. Shade, here more than anywhere, is an “index of inequality,” in a desert city subject to unparalleled geopolitical and environmental stresses, where asylum seekers and detainees reside under makeshift shade structures beneath bridges for days at a time. While increased shade in public spaces has been advocated as a strategy for “mitigation [of] climate change,” it is not a panacea to the threat. Even in apparent shade, the body is exposed to harmful, scattered UVB radiation. This indirect exposure is dependent on the amount of sky visible from the position of the observer. And not all shade structures are created equal. Researchers have found that the overall size of the shade structure, and the design of openings along sides can greatly impact the UPF (UV protection factor), leading some structures to provide inadequate protection. Shade, therefore, is not the discrete condition captured in ubiquitous urban and architectural “sun” and “shadow studies,” which focus only on optical qualities of light and shadow, flattening the three-dimensional nature of radiation exposure and the ultraviolet spectrum. Safe shade is contingent on the nuances of the surrounding built environment, and designers must be empowered to observe and respond to a wider context than current representational tools allow. As climate change accelerates desertification, new methods of measuring, mapping, and designing must be enlisted. Situated in heightened environmental scarcity, in the high Chihuahua desert, the project re-invents solar studies towards a more nuanced representation that uncovers insidious health damages. Irradiated Shade works with remote sensing—using satellite data to assess the built environment at urban and regional scales—and direct sensing—using low-cost UV Index, UVA, and UVB sensors with microprocessors to assess local conditions. The team has developed representational tools to uncover the hidden, non-senseable, dangers of UVB radiation within conditions of apparent shade, producing “shade surplus,” shade deficit,” and “irradiated shade” maps to sensitize planners to these conditions. Additionally, algorithmic drawing techniques aim to redraw the built environment from the perspective of UVB scatter, producing spherically-projected sky dome mappings indicating the risk of UVB exposure in a particular location to sensitize designers to this hidden danger. Irradiated Shade is a structure that protects users from UVB radiation while sensitizing them to the degree of UVB exposure within different locations in the project. Studies have noted that heat-stress is a more reliable initiator of a protective response for organisms exposed to UVB radiation than the radiation itself. This is problematic within irradiated shade, as a higher degree of thermal comfort may not initiate the appropriate protective response, leading to skin damage, eye damage, and the inhibition of the immune system of users of public shade.

Farzad Hashemi, Ute Poerschke, & Lisa Domenica Iulo
Pennsylvania State University

Because of the urban heat island (UHI) effect, an urban agglomeration is typically warmer than its surrounding rural area. Today, UHI effects are a global concern and have been observed in cities regardless of their locations and size. These effects threaten the health and productivity of the urban population and cause general discomfort, respiratory difficulties, and heat-related mortality. Moreover, the increase of urban temperatures has a severe impact on building energy uses by increasing the energy consumption for cooling and, on the contrary, decreasing the energy consumption for heating. The negative impacts of UHI on human welfare have been confirmed broadly during the past decades by several studies. However, the effects of increased temperatures on the energy consumption of buildings still need a comprehensive investigation. Building energy performance is influenced by ambient temperature, while buildings themselves are one of the principals for changes to their surrounding temperature through their heat and CO₂ emissions into the atmosphere. Notably, the daily, seasonal, and spatial impacts of the phenomenon on various building typologies need to be studied inclusively. Moreover, considering the UHI effects at the early stages of the design process is still not pervasive due to the lack of straightforward and convenient methodologies to include these effects in the estimation process of buildings’ energy consumption. To fill the mentioned gaps, a novel methodology of coupling the Local Climate Zones (LCZs)¹classification system and the Urban Weather Generator (UWG)² model is proposed in this study to evaluate the UHI impacts on the energy consumption of various building typologies positioned in the most populated area of city of Philadelphia, Center City. The study area has grown so much over the last 15 years that now ranks second only to Midtown Manhattan when it comes to people living in the heart of a city. This parametric methodology provided reliable weather data in the format of .epw called modified Typical Meteorological Year (mTMY) data comprising the canopy heat islands effect in the scale of an urban block or a neighborhood. The initial results of this study show an average of 2.7 ℃ (with the maximum of 3.3 ℃ and the minimum of 2.3℃) temperature difference in three sequential summer days between LCZ1-Compact High-rise and reference TMY3 weather data recorded at Philadelphia International Airport. The generated weather data then were incorporated into an Urban Building Energy Model (UBEM) to simulate the spatiotemporal differentiation of energy demand for cooling and heating end-uses at each building typology inside Center City using two scenarios of weather data i.e. mTMY and TMY3 data. The findings of this study are helpful for climate-sensitive design purposes and will open up the discussion for considering geographically appropriate UHI mitigation policies by designers and policymakers

Alexandros Tsamis, Youngjin Hwang, & Theodorian Borca-Tasciuc
Rensselaer Polytechnic Institute

In the 1950s, with his ‘Neutralizing Wall’ project, Le Corbusier proposed a radically unique building envelope in which air-based radiant pipes were embedded in its thickness, as mediators between the interior and exterior climate of a building [1]. As a system, it would dynamically optimize heat transfer between distinct environments by reducing their temperature difference. What Le Corbusier proposed is a dynamic “thermal mass” behavior that would allow a more efficient heat transfer between inside and outside. Unlike the predominant model at the time which understood the building envelope as an “isolator” [2], Le Corbusier’s Neutralizing Wall showed great potential in a different type of model for a building envelope, one that can actively exchange heat between interior and exterior climates. Today, it is a well-known fact that the Built Environment (construction and operations) is responsible for nearly 40% of global energy use, significantly contributing to carbon emissions [3]. Targeting a carbon negative future would require a rethinking of the way we heat and cool buildings, distancing ourselves from the predominant model for the building envelope as a boundary that excludes the weather and instead adopting alternatives that transform the building envelope to a mediator that actively regulates heat exchange. In this paper we explore the potential for a building boundary that actively heats and cools a building by forming dynamic relationships with its environment. Most de-carbonizing efforts today focus on realizing net-zero operational carbon either via the production and distribution – locally or through the grid – of renewable energy or via passive house strategies that target the reduction of the active energy demand (figure 1). We propose a third alternative. Instead of an ENDOTHERMIC model for heating and cooling in which energy (renewable or not) is brought in the interior, transformed by an electro-mechanical system and then distributed, we propose an ECTOTHERMIC system that dynamically forms a relationship with its environment, by choosing to absorb or release heat directly from or to the environment. In this case the building skin does not act as an Insulator but instead it becomes an active heating and cooling system. From a design perspective, we will show a modular building energy system, comprised of a double hydronic heating and cooling layer. In essence, we are developing for a building, the equivalent to a vascular system that can move liquids at different locations in order to thermo-regulate. We will show how this vascular system can use renewable energy resources, sun, wind and geothermal, as heating and cooling sources for a building. (figure 2) From a more technical perspective, since all simulation tools available today assume an endothermic approach, we will show results from simulating computationally an ectothermic heating and cooling system [4],[5]. We will also show preliminary results on a physical experiment. We are developing a weather chamber, which can – on an hourly basis – generate an artificial version of the weather from data, in order to test how our system would dynamically respond. (figure 3)

Justin McCarty
The University of British Columbia

Climate is a dynamic construct that humans have developed to interpret the impact of large physical forces on human culture.¹ It can never be made stable. This is however, not to understate the fact that anthropogenic climate change has dire implications for the entire biosphere. Human-induced warming on a global average reached between 0.8°C and 1.2°C above pre-industrial levels in 2017, a somewhat safe threshold has been set at 1.5°C.² Total warming, spurred by human activity and bio-geophysical feed backs will likely breach this threshold by the middle of the century. The total amount of warming and the impact it will have on the biosphere is an unknown. Climate resiliency is the study and practice of preparing for impacts under this unknown. The source of this uncertainty is the result of a variety of factors from the range in observed historical data to numerical approximation and socioeconomic assumptions. Solving for that uncertainty requires an ensemble of climate models to appropriately characterize the multitude of possible future states of the climate and describe what human actions may lead to those future states instead of others. This range has been characterized through the Representative Concentration Pathways (RCPs) and a suite of narratives that dictate to modelers assumptions about social and economic choice, the Shared Socioeconomic Pathways (SSPs).^3,4 The RCPs and SSPs operate at a global scale and are not necessarily appropriate for use in architectural design, which typically requires much more spatially resolute data. This design project proposes a conceptual framework for managing the uncertainty present in climate change projections through statistical downscaling methods and participatory scenario planning in order to adjust climate model projections for use in architectural design. Through this framework, schematic designs are formulated for a single site and program that characterize possible future states of the climate at the end of the century. These architectural climate models emphasize the quandary that contemporary practice finds itself in – how does one design a more passive building without knowing the exact state of the climate? The models, designed as bioclimatic ideals, are used to design a single building’s trajectory from the present through to the end of the century. The models are employed to find commonalities in design decisions such as siting, orientation, or materiality. They can also be used to evaluate the phasing schedules for a building, determining which aspects of the program may be planned for later in the building’s service life and what is of a more immediate concern. This project is as much about understanding how climate change projections can be downscaled for architectural use as finding a way to interpret the impact a range of projections has on possible architectural outcomes for a site. The result of this process is an architecture that can claim a pathway of resiliency and offer a conceptual map to architects who may find themselves asking these questions as the climate crisis becomes an increasingly significant factor in the design and management of the built environment.

Erin Horn
University of Washington

Gundula Proksch
University of Washington

Myer Harrell
University of Washington/WeberThompson

The adaptive reuse of buildings represents a significant impact on embodied carbon in the building sector. This is critical in the timeframe between the years 2020 and 2050 when embodied carbon impacts outweigh lifecycle operational carbon impacts of new construction. This is especially true in regions with a “clean” electricity grid based on renewable energy (Design for Energy). This research collaboration between an academic research lab and architecture practitioner addresses the intersection of three critical topics affecting the carbon footprint of the built environment – (1) adaptive reuse of existing buildings, (2) increased availability of electric and autonomous vehicles, and (3) food production in cities. Our aim is to measure and compare the relative impact of the embodied carbon reduction of adaptive building reuse, the operational carbon impact reduction of an eventual transition to autonomous electric vehicles, and the potential to sequester carbon as a benefit from living systems in urban aquaponics operations in adapted parking garages. In the near future, existing parking garages in mixed-use structures will have to adapt to a changing fleet of vehicles – specifically as personal vehicles transition to electric, and increasingly autonomous driving. The transition to electric and autonomous vehicles is a current and near-future trend with significant implications for other sectors. It is estimated that by 2050, 50% of cars on the road will be autonomous, reducing the space needs for structured parking garages (Litman 2020). As a result, there will be underutilized parking spaces in buildings, not well suited for residential units or commercial spaces. This newly available space in existing structures provides an opportunity for productive means of carbon sequestration, particularly for advances in indoor growing systems as an increasingly efficient way to provide food in urban centers while managing water, energy, and nutrient resources. Aquaponic (aquaculture + hydroponic growing) systems optimize food, water, energy, and waste flows and reduce the need for resource input through high efficiency, cyclical exchanges. Integrating and scaling up aquaponic food production systems into cities provides an innovative approach to producing sustainable urban food and mitigating urban environmental challenges. The carbon impact in urban food production systems like urban aquaponics affects the agricultural sector as a whole – saving energy and water in the process of growing food, and reducing the distance food travels from production to consumer. Further, the growing process is carbon-dioxide intensive, providing value in carbon sequestration. The revenue generated by food production in adapted urban garages can also exceed the value provided by their use for storage (Design for Economy). Through case study research, resource and scale analysis, and economic assessment, this project leverages collaboration between practice and academia to explore a promising means of carbon impact reduction through the near-future adaptive reuse of parking garages for urban food production. The relative embodied carbon impacts of adaptive building reuse, operational carbon reduction of transition to autonomous electric vehicles, and sequestration of carbon through urban aquaponics operations are measured and compared to advance and assess the viability of an innovative adaptive reuse concept.