Potential of Thermal Energy Storage Using Coconut Oil for Air Temperature Control

Wonorahardjo, Surjamanto; Sutjahja, Inge Magdalena; Kurnia, Dadang; Fahmi, Zulfikar; Putri, Widya A

doi:10.3390/buildings8080095

Cited by 43 publications

(26 citation statements)

References 42 publications

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“…Application of PCMs as a passive air-conditioning system is commonly undertaken in two ways, both of which are integrated into building systems, including exterior walls [55] and ceilings [56], or as additional equipment separate from the building [57][58]. All methods, however, should be analysed from techno-economic and environmental impact perspectives.…”

Section: Resultsmentioning

confidence: 99%

“…Integration of a PCM in brick walls and concrete has a good effect on indoor air temperature [59][60][61]. However, integration of PCM in exterior walls has another effect that has not been widely discussed, namely, heat emission to the exterior environment, leading to the phenomenon generally known as the urban heat island [62], and environmental problems in recycling and treatment of the materials after use [57].…”

Section: Resultsmentioning

confidence: 99%

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Electrofreezing of the phase-change material CaCl2•6H2O and its impact on supercooling and the nucleation time

Sutjahja

Rahman

Putri

et al. 2019

Hem Ind

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This paper reports electrofreezing experiments on the inorganic phase-change material (PCM) CaCl 2 ·6H 2 O by using an insulated copper electrode that is commonly sold in the market. The effect of the applied voltage or electric field to the nucleation process is measured by the nucleation temperature, freezing temperature, supercooling degree, induction time, time for supercooling, and time for crystallisation. It is found that, compared to the zero field, the freezing temperature remains nearly constant while the nucleation temperature increases with increasing applied field, leading to a reduction in the supercooling degree. The decrease in the supercooling degree is approximately 6 K for an applied voltage of V = 5.0 kV or E = 10 7 V m -1 . With the increase in the applied field the induction time decreased considerably along with reduction of the measured data spread as compared to the no-voltage case, while the crystallisation time for the phase transformation prolonged. The overall phenomena are analysed in terms of modification of the Gibbs free energy for crystallisation owing to the applied field, with the mechanism involving bubble generation and formation of a copper-chloride complex. 364A common way to initiate the solidification process and reduce the supercooling of PCMs, and in particular, a salt hydrate, from the solution is by seeding or adding an appropriate nucleating agent, usually in the form of nanoparticle powders, to form a stable suspension with the salt hydrate solution [12]. Lane [13] reported that the choice of the nucleating agent is usually by trial and error, guided by intuition or experience, and by using the chemical dopants which are ready in stock and on a laboratory shelf. From the crystallographic perspective, the nucleators of CaCl 2 ·6H 2 O are classified as isomorphic and non-isostructural nucleators [13]. In general, the nucleator can impact the change in thermophysical parameters, such as the supercooling temperature, supercooling degree, specific heat, and the latent heat enthalpy. Recently, Sutjahja et al. [14] reported the effectiveness of 1 wt% CuO to reduce the supercooling degree and further modify the thermal parameters of CaCl 2 ·6H 2 O by graphite and CuO dopants, although logical explanations for their effectiveness apparent do not exist.The effect of electrical energy on the behaviour of supercooled fluids has been studied since two decades ago [15][16] and is commonly called electrofreezing or electronucleation; see [17][18][19] for the review and references therein. In most of the past experiments water droplets were mainly exposed to high-voltage electric fields, with the success expressed by higher nucleation temperatures, reduction in the supercooling degree, lowering the induction times, and increased nucleation probability. Recently, the effectiveness of electrofreezing has also been reported for some other materials, such as erythritol polyalcohol [20], tetra-n-butyl ammonium bromide (TBAB) clathrate hydrates [21][22], tetrahydrofuran (THF) clathrate ...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Electrofreezing of the phase-change material CaCl2•6H2O and its impact on supercooling and the nucleation time

Sutjahja

Rahman

Putri

et al. 2019

Hem Ind

Self Cite

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“…The concrete dome roof of a mosque acts as a thermal mass that absorbs and stores heat from sunlight. The heat is released at night, which indirectly warms the space (Wonorahardjo et al, 2018). The more heat stored, the more energy released to the environment and for a longer time (Balaras, 1996).…”

Section: Discussionmentioning

confidence: 99%

Space Quality of Two Indonesian Mosques: Architectural Style, Development Process and Environmental Condition

Kusyanto

Sinaga

Triyadi

et al. 2019

American Journal of Environmental Sciences

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Mosque buildings in Indonesia show the influence of architectural styles from the Middle East and other parts of the world. Today, information technology and the development of architectural schools play important roles in mosque styles in Indonesia. This study compared two Indonesian mosques (the Cabean and Eco Pesantren mosques in Central and West Java, respectively) in different architectural styles and considered construction processes, development actions and environmental conditions (highlands and lowlands close to the coast). Architectural quality was measured in terms of thermal comfort in the mosques. Field surveys and environmental quality measurements were undertaken at both mosques, consisting of T DB°C , T WB°C , T BG°C and v m/s. The results showed differences in mosque quality in the following aspects affecting thermal comfort: (1) the size and location of ventilation openings, (2) building aspect ratio and distance to other buildings, (3) thermal mass and (4) outdoor design quality. Horizontal and vertical openings play a significant role in thermal comfort in terms of airflow, which is affected by the distance between buildings. Building materials also play an important role in thermal comfort with regard to the penetration of direct solar radiation through the roof.

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“…The heat accumulated during the day on the walls of the buildings in the tropics is released into the air during both day and night, which will accumulatively raise the air temperature of the region over a long period of time. However, the use of an indoor heat-storage type wall will provide a cooler and more comfortable interior environment [56,57]. 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7…”

Section: Profiling Wall Temperaturementioning

confidence: 99%

Characterising thermal behaviour of buildings and its effect on urban heat island in tropical areas

Wonorahardjo

Sutjahja

Mardiyati

et al. 2019

Int J Energy Environ Eng

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The heat island phenomenon in major cities is partly due to the excessive use of concrete and brick, which causes many problems regarding thermal comfort and energy expenditure. The thermal behaviour of the envelope wall material depends on its density, heat capacity, and thermal conductivity, and its effect on the heat island intensity (HII) is reported in this paper. Experiments and simulations were carried out on the four most popular building materials: brick, aerated concrete, wood with glass-wool insulation, and glass fibre-reinforced concrete with glass-wool insulation, with each material having a dimension of 1 m × 1 m. Experiments to analyse the thermal behaviour of the wall materials were performed by exposing each material to heat radiation from 2 × 1000 W halogen lamps for 4 h, followed by 4 h of cooling. The HII simulations were carried out in a simple urban kampong in a tropical area using Energy2D software. Heat flow analyses confirmed the thermal behaviour of the four walls, which can be categorised into two types: heat storage of block wall (BW) type and heat flow inhibition of insulated sandwich wall (ISW) type. The BW type showed 0.32 °C higher indoor air temperature than the ISW type, while the HII simulation showed ISW to be 0.74 °C higher than BW; however, both types increase the intensity and need mitigation treatment. The results of this study are important for the technological approach for dealing with local warming to lower the energy expenditure of poor people in an urban area. Keywords Urban heat island • Thermal behaviour • Block wall type • Insulated sandwich wall • Urban kampong List of symbols ρ Density c Specific heat κ Thermal conductivity avg Average density c avg Average specific heat avg Average thermal conductivity T so Outer surface temperature T si Inner surface temperature T m1 Temperature of the core wall at a depth of 2.5 cm T m2 Temperature of the core wall at a depth of 7.5 cm T m3 Temperature of the core wall at a depth of 12.5 cm P so Heat flow at outer surface P m1 Heat flow at a depth of 2.5 cm P m2 Heat flow at a depth of 7.5 cm P m3 Heat flow at a depth of 12.5 cm P si Heat flow at inner surface T ao Outdoor air temperature T ai Indoor air temperature T ac Outdoor air temperature above the canopy layer

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Potential of Thermal Energy Storage Using Coconut Oil for Air Temperature Control

Cited by 43 publications

References 42 publications

Electrofreezing of the phase-change material CaCl2•6H2O and its impact on supercooling and the nucleation time

Electrofreezing of the phase-change material CaCl2•6H2O and its impact on supercooling and the nucleation time

Space Quality of Two Indonesian Mosques: Architectural Style, Development Process and Environmental Condition

Characterising thermal behaviour of buildings and its effect on urban heat island in tropical areas

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