Collaboration with Peter Raab and Terah Maher
This project presents an ongoing interdisciplinary research project in Lubbock, Texas, a region within the South Central Semi-Arid Prairies ecoregion that explores the potential of a 3D-printed ceramic block system for creating vegetated microclimates. The study focuses on two block typologies: those designed for evaporative cooling and those intended to sustain local flora and fauna, such as keystone plants and native bee species. The project is part of an interactive living wall constructed using additive manufacturing and clay due to its porous properties that enable effective evaporative cooling and suitability for housing drought-adapted plants. The project also engages the local community by providing educational opportunities related to sustainable design and technology and enhancing the aesthetic and functionality of the local environment. The current stage involves testing the system’s viability by constructing a 2-square-foot vertical pollinator’s garden with an integrated irrigation system. The project demonstrates bio-climatic material assemblies’ positive impacts on habitable spaces while preserving semi-arid ecosystems and providing cooling effects with minimal carbon emissions. This paper will discuss the design process, the system’s current state, plans for future iterations, the challenges faced, and the results obtained. The findings suggest that future research combining evaporative cooling and ecosystem creation could contribute significantly to sustainable design in semi-arid and arid bioclimatic regions.
Fabrication Process. A. Reclaiming clay material, B. Pugmill filling polycarbonate tube with clay, C. Potterbot 3-D printing a customized block, D. Placing dowels within the vertical irrigation channels during printing to create drip holes, E. Puncturing hardware holes with use of a template, F. Puncturing airflow holes in evaporative blocks once leather hard, G. Glazing evaporative blocks, H. Kiln-firing of all blocks, I. Partial assembly showing 1” aluminum frame substructure and block channels, J. Prototype assembled, K. Flora planted in blocks.
The wall design began with a regular, stacked, rectilinear modular hollow block wall. The modules were then customized in both form and purpose. Block tops were pulled into various cantilevers to provide openings for plants and to maximize the rainwater catchment of individual blocks during precipitative events. Pollinator plants were chosen to support an ecosystem of bees and butterflies. Flowering plants often have deeper root balls; therefore, there were select blocks that had their base planes removed to allow for plants with longer roots to thrive. Blocks on the bottom row have bases to retain moisture and soil. The block section cut (above) illustrates the irrigation channels that supply water to the plants and the evaporative cooling blocks. With their varying hole sizes, these blocks utilize the Venturi effect to accelerate airflow and lower the pressure, facilitating the evaporation of the collected water.
Block printing using a Potterbot 10 Pro 3D printer.
The diagram above shows a mock-up structural diagram with callouts detailing the assembly process. The current half-scale mock-up is two square feet. The blocks were printed on a Potterbot Pro 10 with a 5-millimeter nozzle with a similar resulting wall thickness when fired. A one-square-inch extruded aluminum frame was constructed to support the wall. The aluminum members were held on custom 3D-printed plates composed of polylactic acid (PLA). A channel was incorporated into the design of the back of the clay blocks for inserting the aluminum frame. Quarter-inch dowels drilled holes for the hardware within these channels. To find the right ten millimeters of offset for the channel to fit the aluminum extrusion after it shrank during the drying and firing process, 5 tests with variable offsets were 3D printed and fired.
The graph documents changes in humidity and temperature over a 4-hour period using the evaporative cooling testing device illustrated in the section perspectives. The FLIR One ® Pro LT Thermographic camera took the bottom images.
An evaporative cooling testing device was designed to test the efficacy of the blocks. Its design incorporated a fan, acrylic, magnets, off-the-shelf hardware, and 3D-printed joints. (Figure3) The device consisted of two separate chambers. The first chamber housed a fan on the rightmost wall. An acrylic frame held the ceramic evaporative cooling block inside a cardboard frame in the center. The frame utilized magnets for easy attachment and separation of the chambers. The second chamber featured a series of quarter-inch diameter holes on its leftmost wall, allowing air to exit the system. The humidity and temperature in both chambers were monitored using two DHT11 Arduino sensors. This sensor was connected to an Arduino Uno Rev3 microcontroller via jumper cables. Both circuits were subsequently connected to a laptop, which received sensor readings every 20 minutes.
In addition to the evaporative cooling testing, the half-scale mockup was placed outdoors, facing south at midday. It was photographed using a FLIR One ® Pro LT Thermographic camera attached to an iPhone 14, figure 3. This process provided vital information on how dissimilar materials react to sunlight and temperature changes, contributing to our understanding and design of a more energy-efficient design. The weather during the experiment was sunny, with an air temperature of 21°C and 24% relative humidity. After an hour of acclimation, several regions of the mock-up were photographed over the next hour.
Building on the initial studies, several additional iterations were digitally explored. Full-scale visualization encompassed the structure within two layers of blocks. This design further insulated the irrigation channel and reservoir blocks within the living wall’s interior, as illustrated above (speculative render of the final pavilion). With the increase in block numbers and size, the total number of blocks would be 17 evaporative blocks and 41 soil blocks. The system can accommodate approximately 3 gallons of water storage within the glazed units.
The roof was designed as a butterfly roof to collect rainwater and direct it towards the central irrigation channels, equally hydrating each vessel below. The roof can collect about 1 gallon of rainwater for every 0.25 inches of rainfall. However, rain exceeding 0.75 inches would overflow, swiftly moving through the permeable soils and porous, unglazed clay vessels.
The roof was designed as a butterfly roof to collect rainwater and direct it towards the central irrigation channels, equally hydrating each vessel below. The roof can collect about 1 gallon of rainwater for every 0.25 inches of rainfall. However, rain exceeding 0.75 inches would overflow, swiftly moving through the permeable soils and porous, unglazed clay vessels.
The larger site strategy envisions a translucent polycarbonate roof to maintain indirect solar exposure for plants on the wall’s north side while providing shade for anyone underneath. The bench is constructed from rammed earth and features a wooden seat and backrest. This design protects the wall’s top part and keeps children clean from the dirty seat. Except for the polycarbonate roof, most materials are bio-based and locally sourced. Rammed earth, ceramic clays, soils, and wood all have low thermal emissivity, ensuring a cool touch in this hot, semi-arid climate.