thermal insulator
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2022 ◽  
Vol 906 ◽  
pp. 125-133
Author(s):  
Artashes Levoni Petrosyan

One of the basic measures of energy efficiency in residential buildings is the reduction of heat and coolant pressure, when external structures - walls, ceilings - contain thermal insulation material, as a result of which heat and cold losses are reduced, as a result of air-and moisture permeability. Their number is largely determined by the climatic zone of the building, construction, sources of heat and cold, fuel and electricity prices in this region. In such practice, first of all, attention is paid to the problems of the optimal thickness of the thermal insulator, the installation location, since improper installation in the structure can cause water condensation, which will lead to partial wear of the structure, since the properties of reinforced-concrete layers will deteriorate. This concerns the peculiarities of carrying out thermal insulation works and their necessity both in under construction and in buildings in use. However, even in these conditions, when discussing the thermal effect of thermal insulation on structures, due attention is not paid to individual structures, especially walls, moisture problems. Consideration of insulators with more or less efficient energy and heat engineering characteristics, when it was found that there is a significant difference between their results and effects, aroused particular interest in the study of the problem. This is followed by a study of the influence of the presence of thermal insulation in the structure on the cold load required for cooling, revealed a pattern of cost changes in the case of insulating materials with more or less properties - foam.


Author(s):  
Xiao Yuan Chen ◽  
Shinsuke Nagamine ◽  
Masahiro Ohshima ◽  
Denis Rodrigue

2021 ◽  
Vol 891 (1) ◽  
pp. 012001
Author(s):  
N M K S Sruti ◽  
P R Jenaneswari ◽  
M R Rahayu ◽  
FA Syamani

Abstract Generally, the cool box is produced using styrofoam as the main thermal insulation material. However, the use of styrofoam potentially cause pollution to the environment at the end of its useful life because it cannot decompose naturally. The effort to overcome this problem is by producing thermal insulation materials from natural sources such as water hyacinth and corncob. The purpose of this study was to determine the characteristics of biocomposite board made from combination of water hyacinth powder and corncob ash based on physical, mechanical, and thermal conductivity analysis. Biocomposite boards were produced by introducing combination of water hyacinth powder and corncorb ash (5, 10, 15%wt) into epoxy resin. The ratio of water hyacinth powder and corncob ash were 100:0 (P0), 95:5 (P1), 90:10 (P2), 85:15 (P3). The biocomposite boards were also made from water hyacinth powder and corncob powder, which ratio of 15:85 (P4) and 0:100 (P5). The results of this research revealed that type P5 board had the lowest density value (0.927 g / cm3) and the lowest water absorption value (1.53%). The P2 type board shows the highest bending strength (8.6 N/mm2) which met the requirements of JIS A 5908 for particleboards type 8. The highest value of compressive strength was observed at P5 type board which was 2.94 ± 0.53 N / mm2. The lowest thermal conductivity values were observed at P2 type boards (0.305 W / mK). It can be concluded that, P2 type board had the best thermal insulator properties among other boards in this study. The thermal insulation effectiveness assessment of biocomposite board for cool box application was conducted using P2 and P5 type boards. The assessment results demonstrated that the styrofoam cool box and commercial cool box performance for maintaining temperature were superior compared to biocomposite cool box. Therefore, it is necessary to re-examine the biocomposite cool box, especially in terms of panel assembling and the shape of the lid, to produce biocomposite cool box with thermal insulator properties comparable to the commercial cool box.


2021 ◽  
Vol 13 (13) ◽  
pp. 7484
Author(s):  
Gabriel Fernando García Sánchez ◽  
Rolando Enrique Guzmán López ◽  
Roberto Alonso Gonzalez-Lezcano

Buildings consume a large amount of energy during all stages of their life cycle. One of the most efficient ways to reduce their consumption is to use thermal insulation materials; however, these generally have negative effects on the environment and human health. Bio-insulations are presented as a good alternative solution to this problem, thus motivating the study of the properties of natural or recycled materials that could reduce energy consumption in buildings. Fique is a very important crop in Colombia. In order to contribute to our knowledge of the properties of its fibers as a thermal insulator, the measurement of its thermal conductivity is reported herein, employing equipment designed according to the ASTM C 177 standard and a kinetic study of its thermal decomposition from thermogravimetric data through the Coats–Redfern model-fitting method.


2021 ◽  
Vol 11 (1) ◽  
pp. 483-501
Author(s):  
Luis Miguel Llamos Tulumba ◽  
◽  
Raúl Yamil Hidalgo Sandoval ◽  
Hugo Diaz Avalos ◽  
Hugo Guillermo Diaz Panduro

The purpose of this research was to demonstrate that the use of residual oil as a heat transport fluid and the use of rice husk as a thermal insulator is an efficient alternative for the greater use of solar energy. For this, a prototype of a solar dryer was designed and built consisting of a flat solar thermal concentrator and a parabolic cylindrical thermal concentrator (CCP), this was validated by drying Guazuma crinita, Mart. (White ball) and monitored by a contact hygrometer. Five tests were carried out, the first test was considered as a control, in which heat transport fluid and thermal insulators were not used, and in the following four tests two types of heat transport fluids were combined (residual motor oil and brine) and two types of thermal insulators (wood sawdust and rice husk), obtaining as a result that the most efficient test was number three, consisting of residual motor oil as heat transport fluid and rice husk as thermal insulator. With the most efficient test, the prototype was validated by drying low-density wood, reducing the humidity of the wood from 45.8% to 12.3% in ten sunny days.


2021 ◽  
Vol 15 (2) ◽  
pp. 183-190
Author(s):  
Badia Imene Cherifi ◽  
◽  
Mohammed Belbachir ◽  
Souad Bennabi ◽  
◽  
...  

In this work, the green polymerization of vinyl acetate is carried out by a new method which consists in the use of clay called Maghnite-Na+ as an ecological catalyst, non-toxic, inexpensive and recyclable by a simple filtration. X-ray diffraction and scanning electron microscopy showed that Maghnite-Na+ is successfully obtained after cationic treatment (sodium) on crude maghnite. It is an effective alternative to replace toxic catalysts such as benzoyl peroxide and azobisisobutyronitrile which are mostly used during the synthesis of polyvinyl acetate (PVAc) making the polymerization reaction less problematic for the environment. The synthesis reaction is less energetic by the use of recycled polyurethane as a container for the reaction mixture and is considered as a renewable material and a good thermal insulator maintaining the temperature of 273 K for 6 h. The reaction in bulk is also preferred to avoid the use of a solvent and therefore to stay in the context of green chemistry. In these conditions, the structure of obtained polymer is established by 1H NMR and 13C NMR. Infrared spectroscopy (FT-IR) was also used to confirm the structure of PVAc. Thermogravimetric analysis showed that it is thermally stable and starts to degrade at 603 K while differential scanning calorimetry showed that this polymer has a glass transition temperature Tg of 323 K.


2021 ◽  
Author(s):  
Badia Imene Cherifi ◽  
Mohammed Belbachir ◽  
Abdelkader Rahmouni

Abstract In this work, the green polymerization of vinyl acetate is carried out by a new method which consists in the use of clay called Maghnite-Na + as an ecological catalyst, non-toxic, inexpensive and recyclable by simple filtration. X-ray diffraction (XRD) showed that Maghnite-Na + is successfully obtained after cationic treatment (sodium) on raw Maghnite. It is an effective alternative to replace toxic catalysts such as benzoyl peroxide (BPO) and Azobisisobutyronitrile (AIBN) which are mostly used during the synthesis of polyvinyl acetate (PVAc) making the polymerization reaction less problematic for the environment. The synthesis reaction is less energetic by the use of recycled polyurethane as container for the reaction mixture and which is considered as a renewable material and a good thermal insulator which maintains the temperature at 0°C for 6h. The reaction in bulk is also preferred to avoid the use of a solvent and therefore to stay in the context of green chemistry. In these conditions, the structure of obtained polymer is established by Nuclear Magnetic Resonance Spectroscopy 1H NMR and 13C NMR. Infrared spectroscopy (FT-IR) is also used to confirm the structure of PVAc. Thermogravimetric analysis (TGA) showed that it is thermally stable and it starts to degrade from 330°C while Differential Scanning calorimetry (DSC) shows that this polymer has a glass transition temperature (Tg = 50°C). The composition in PVAc/maghnite-Na+ (7wt% of catalyst) is the most tensile resistant with a force of 182 N and a maximum stress of 73.16 MPa, the most flexible (E = 955 MPa) and the most ductile (εr = 768 %)


2021 ◽  
Author(s):  
Sameer Rao ◽  
Mathieu Francoeur ◽  
Keunhan Park
Keyword(s):  

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