Study of Passive Evaporative Cooling Technique on Water-retaining Roof Brick

Han, Rubing; Xu, Zhimao; Qing, Yutao

doi:10.1016/j.proeng.2017.04.258

Cited by 12 publications

(4 citation statements)

References 17 publications

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“…This design effort intended to depict the potential of evaporative interfaces for technical large-scale application. Many thermal systems for buildings based on rainwater collection and evaporative cooling have been proposed, among which: porous face bricks, roof tiles, green roofs, ceramic elements within cooling walls, solar chimneys, downdraft towers, misting techniques and hybrid solutions using nighttime radiative cooling [49][50][51][52][53]. Here we envisioned tiles with three-dimensional protrusions (i.e.…”

Section: Ceramic Tiles For Architectural Applicationmentioning

confidence: 99%

Bio-inspired evaporation from shaped interfaces: an experimental study

Rupp

Gruber

2021

Bioinspir. Biomim.

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Evaporative interfaces help process heat and substances in a variety of technical realms, from electronic to architectural applications. Because geometry affects the hydraulics, thermal properties and aerodynamics of evaporative devices, their performance can be tuned through design. While non-smooth interfaces are widely exploited to enhance transfer passively, surface area extension in packed volumes is a predominant line of research. This leaves aerodynamic structure-transfer relations and the impact of geometry itself unclear. Meanwhile, protrusions in leaves such as lobes and toothed margins have been associated with enhanced vapor dissipation. This experimental study explores the design space of leaf-inspired structures with evaporating protrusions. Three sets of water-absorbing models with fixed evaporating surface area and unlimited hydraulic supply were tested: (1) paper strips with dimension-equivalent protrusions of varied shape and degree of elongation; (2) cellulose sponges with the same designs as their cross-sectional profile, extruded three-dimensionally; (3) ceramic tiles with grooves of varied cross-section, conceived as building elements for evaporative cooling. Overall, results demonstrate that protrusions affect mass transfer rate and surface temperatures and can be integrated in the design of evaporative exchangers with non-smooth geometries. For the paper models, evaporation rate correlated with protrusion aspect ratio, supporting a functional interpretation of leaf design and its utilization in low-wind plate-fin exchangers. However, the same transfer enhancement was not regained from simply extruding an effective design into three-dimensions. For the ceramic tiles, geometry-driven differences in evaporation depended on the aerodynamic roughness and size of the grooved pattern, and on ventilation. Their outdoor thermal behavior was complex due to a multifaceted interaction with the environment and geometry-related factors such as self-shading and thermal mass. Ultimately, this design effort illustrates the potential of structured interfaces for evaporative exchange and thermoregulating the built environment.

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Section: Ceramic Tiles For Architectural Applicationmentioning

confidence: 99%

Bio-inspired evaporation from shaped interfaces: an experimental study

Rupp

Gruber

2021

Bioinspir. Biomim.

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“…It is a surprisingly effective method of returning our body to its core temperature by natural means. As the droplets on our skin transition from liquid to gas, their evaporation pulls warmth away from our body, cooling the blood underneath our skin, which goes back to our body's core, reducing our overall body temperature or building temperature with the water cooling (Han et al, 2017).…”

Section: Mac and Solar-powered Fan Integrated With Rainwater Harvesting System (Design Z)mentioning

confidence: 99%

Rainwater Harvesting System Integrated With Sensors for Attic Temperature Reduction

Yew¹,

Wong²,

Yew³

et al. 2021

Front. Built Environ.

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This cool roof system focuses on utilization of rainwater harvesting systems by integrating the smart sensor to cool the roof and attic temperatures for the improvement of comfort level of building occupants. An ideal cool roof technology system is basically made up of these three components: (1) moving-air-cavity (MAC) ventilation, (2) solar-powered fan and (3) rainwater harvesting system. These three main components integrate to perform and control the cool roof system. Four small-scale cool roof models were designed and constructed to inspect the performance of the rooftop and attic temperatures. The experimental work was carried out indoors by employing the halogen lamp as the replacement for solar irradiation, while the ambient temperature is monitored to be around 29.8 °C throughout the test. The temperatures of the rooftop surface, MAC aluminum tube, and attic region were measured by K-type thermocouples to evaluate the performance of the cool roof designs. The solar-powered fans were incorporated into the MAC, which accelerated the airflow rate within the cavity and rejected the hot air out before transferring it to the attic region. Meanwhile, an innovative rainwater harvesting system was executed to cool the rooftop temperature rapidly by reducing the rate of heat transfer to the attic region. The result of this inventive cool roof system (Design Z) has successfully reduced the attic temperature by 10.8 °C compared to the normal metal deck roof model (Design W). The findings of the project revealed that the integrated cool roofing technology system comprises the ability to enhance the comfortability of building occupants toward a long-term sustainable development for a better world.

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“…4 Therefore, having plants on the roofs of buildings (i.e., green roofing) and using water-retentive materials in construction can result in cooler buildings through transpiration and evaporation, respectively. 5,6 Most materials used in the exterior walls of buildings are made from porous ceramics. Compared with dense ceramics, porous ceramics not only are more lightweight and highly machinable but also exhibit greater sound absorption, heat insulation, and water retention.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Roofs and walls receive stronger direct radiation from the sun for longer periods than do other parts of buildings, and approximately 70% of heat gained in top floor rooms comes through roofs and walls . Therefore, having plants on the roofs of buildings (i.e., green roofing) and using water-retentive materials in construction can result in cooler buildings through transpiration and evaporation, respectively. , …”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Thermosensitive P(NIPAAm-co-AAc)-Grafted Silica Nanocomposites for Smart Architectural Coatings

Diao

2022

ACS Omega

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In this study, a new class of thermosensitive poly(N-isopropylacrylamide)-co-poly(acrylic acid) (P(NIPAAm-co-AAc))-grafted modified silica (msilica) nanocomposites was prepared using a sol−gel technique. The addition of silica to P(NIPAAm-co-AAc) copolymer hydrogel has the potential to open up new applications in the development of thermosensitive building materials by leveraging the favorable thermal characteristics of P(NIPAAm-co-AAc). The silica was prepared using 3-aminopropyltriethoxysilane and 4,4′-azobis(4-cyanovaleric acid) to form the m-silica powder, which increased the adhesion between the organic and inorganic hybrid materials. The P(NIPAAm-co-AAc) copolymer hydrogel was mixed with the m-silica to form the P(NIPAAm-co-AAc)-grafted m-silica nanocomposites. Scanning electron microscopy, X-ray diffraction analysis, thermogravimetric analysis, Fourier-transform infrared spectroscopy, and thermosensitive measurement were conducted to evaluate the structure and water-holding capacity of the nanocomposites. The results indicated that the P(NIPAAm-co-AAc)-grafted m-silica nanocomposites could retain water for more than 300 min at temperatures higher than the lower critical solution temperature. The P(NIPAAm-co-AAc)-grafted m-silica nanocomposites exhibited favorable thermosensitive properties and may therefore be applied in smart architectural coatings.

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Study of Passive Evaporative Cooling Technique on Water-retaining Roof Brick

Cited by 12 publications

References 17 publications

Bio-inspired evaporation from shaped interfaces: an experimental study

Bio-inspired evaporation from shaped interfaces: an experimental study

Rainwater Harvesting System Integrated With Sensors for Attic Temperature Reduction

Synthesis and Characterization of Thermosensitive P(NIPAAm-co-AAc)-Grafted Silica Nanocomposites for Smart Architectural Coatings

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