Cooling Buildings for Vulnerable Communities: 2023 YPS Grant Project Insight
As the global housing crisis grows, an estimated 3 billion people will need access to adequate housing by 2030. Meeting that demand would require building roughly 96,000 affordable homes every day, according to UN-Habitat.
In many parts of the world, people ‘self-build’ their housing, making their own building materials like earth-based bricks formed from mud. However, without electricity for cooling, temperatures in these structures can soar. Terra cotta bricks contain cavities, originally intended to prevent cracking or breaking during the firing process. Based on research and pilot programming by the Yale School of Architecture (YSoA), those same spaces may soon serve a new purpose.
Building a knowledge base of local materials, Technological Institute of Monterrey students learned the traditional adobe block-making process from the Hueyapan community, including mixing water with fibers and soil by mashing it with their feet in traditional pits.
Hydrogels are materials that can absorb, hold, and slowly release proportionally large quantities of water without losing their shape. Because of their use in agriculture, healthcare, and other settings, they are affordable and found even in remote markets. By adding hydrogel into the cavities in bricks, it’s possible to simply and naturally cool buildings: as water evaporates, it draws heat away from the surface, allowing walls to “sweat” and lower the temperature of indoor spaces.
“Imagine if students were actually able to learn in some of these schools where it’s currently overheated. Imagine if you were able to provide comfortable living spaces for the elderly,” said Celia Toché, Instructor at the YSoA and Principal Investigator (PI) of the 2023 grant project, Cooling Buildings for Vulnerable Communities. “We’re looking at a great benefit in terms of public health, but we’re also looking at creating better architecture for self-builders all over the world.”
The goal of the project was to develop a building approach that could be easily shared and adapted by communities already using terra cotta brick.
“A lot of people are trying hydrogel in all sorts of applications, and evaporative cooling is being tested in very high-tech scenarios,” Toché said. “What’s different here is that we want to make this open-source architecture. It’s really important that we collaborate with vulnerable communities and learn from them so that a new, slight improvement on how they build is meaningful and they will accept it more readily.”
The project team worked directly with two communities in Mexico in a participatory design process, first in Hueyapan, Morelos, then in San Isidro Catano, Oaxaca. Their initial findings showed that adding hydrogel could reduce indoor temperatures by as much as ten degrees Celsius.
In addition to introducing hydrogel, the team is using 3D modeling and Computational Fluid Dynamics (CFD) simulation technology. These tools help determine the performance of phase-changing materials (like hydrogels) in different climate conditions, how different brick arrangements will affect airflow, and how different building strategies affect internal and exterior temperatures.
Celia Toché, colleagues at the TEC, and students visiting the Novaceramic manufacturing plant in Tlaxcala, Mexico.
Two full-size mock-ups were built in tandem with these simulations to test real-world conditions in different climates: one in Oaxaca and one at the Mexico City Campus of the Monterrey Institute of Technology and Higher Education (TEC). These models allowed a real-world comparison of the cooling efficiency and a chance to learn from local conditions. The insights will be used to help communities arrange bricks in ways that support cooler indoor temperatures.
The TEC has further embraced the project and dedicated a block of classes to training future leaders about this work. In addition to infrastructural support for classes, TEC has provided travel opportunities for their students to visit New Haven to engage in knowledge exchange at Yale.
“The project is not just about helping communities,” Toché said. “It’s also transforming how we teach. Today, students are graduating with so much more knowledge about climate change, how to build, and how to approach community. The impact of this is amazing.”
By combining low-cost, local materials with community-driven design, this project works toward a future where more comfortable, climate-responsive buildings can be constructed to improve the lives of people anywhere.
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Learn more about the YPS Grant Program.