scholarly journals Analysis of Thermal Parameters of Hemp Fiber Insulation

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6385
Author(s):  
Baiba Gaujena ◽  
Vladislavs Agapovs ◽  
Anatolijs Borodinecs ◽  
Ksenia Strelets
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Large Scale ◽  
Moisture Absorption ◽  
Holistic Approach ◽  
Raw Material ◽  
Added Value ◽  
Sustainable Construction ◽  
Hemp Fiber ◽  
The Impact

Nowadays, sustainable construction is a key factor for reaching net-zero emissions of carbon dioxide all over the world. This goal is impossible to achieve by merely reducing the energy consumption of end-users. A more holistic approach should be taken, adopting sustainable industrial practices that use environmentally friendly materials on a large scale. This paper presents the analysis of the hydrothermal properties of hemp thermal insulation plates. We carried out extensive measurements and the analysis of the thermal conductivity coefficient, drying-out dynamics, and water absorption. The study was performed with experimental insulation samples based on the fiber obtained from hemp stems, prepared using different adhesive powders. The dimensions of the analyzed samples were 300 × 300 mm. The proposed samples are not yet available in mass production. Hemp does not flower in the Baltic region and was traditionally used for soil regeneration. Thus, using this raw material increases the added value of agricultural residues. Three series of hemp fiber samples with different substances and pressing modes were evaluated in the study. Each set of samples consisted of four plates with varying thicknesses and two different densities: 200 kg/m3 and 300 kg/m3. All samples exhibited a significant increase in moisture absorption and a strong correlation with the increase in thermal conductivity. The average thermal conductivity of the test samples ranged from 0.0544 to 0.0594 W/mK. The impact of the adhesive powder on the thermal conductivity was found to be extremely small. However, the values obtained were much higher than those for traditional thermal insulation materials, allowing to utilize the local agriculture residues and providing material for the construction of eco-friendly buildings.

scholarly journals Thermal Behavior of Worsted Fabrics Produced from Different Yarn Spinning Systems

2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800 ◽  
Author(s):  
Abolfazl Mirdehghan ◽  
Siamak Saharkhiz ◽  
Hooshang Nosraty
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Behavior ◽  
Thermal Insulation ◽  
Weft Yarn ◽  
Spun Yarn ◽  
Finishing Process ◽  
Yarn Structure ◽  
Fabric Structures ◽  
The Impact

This paper describes an experimental study of the impact of yarn structure on the thermal properties of worsted fabric. In this study, four different spun yarn structures (Solo, Siro, and single ply and two ply Ring) were woven into four fabric structures (Plain, Twill2/1, Twill2/2 and Basket2/2) and their thermal properties were studied. In addition, the thermal behavior of finished and unfinished samples was also evaluated. Results showed that the finishing process causes an increase in thermal conductivity and warmth to weight factor and a decrease in thermal insulation. Different spinning systems, also affect the thermal properties of the worsted fabrics. Samples with Siro yarns in the weft were found to have the highest thermal conductivity and those made from single ply weft yarn the lowest thermal conductivity. A relation between fabric thermal insulation and air permeability and thickness was also found.

Carbonation Experimental Study on Thermal Insulation Glazed Hollow Bead Concrete

2013 ◽  
Vol 639-640 ◽  
pp. 325-328
Author(s):  
Yan Jia Guo ◽  
Zhu Li ◽  
Yuan Zhen Liu ◽  
Shang Song Qin
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Raw Materials ◽  
Influence Factors ◽  
Intensity Level ◽  
Construction Technology ◽  
Test Results ◽  
Ordinary Concrete ◽  
The Impact ◽  
Better Than

Based on the compressive strength, the thermal conductivity, the elastic modulus and the steel bond strength of thermal insulation glazed hollow bead concrete, referring to the carbonation mechanism and the influence factors of the ordinary concrete, considering the impact of raw materials and the influence of construction technology, the study on thermal insulation glazed hollow bead concrete anti-carbonation was proposed. From the test results, it can conclude that for the same intensity level, the anti-carbonation capacity of the thermal insulation glazed hollow bead concrete is better than that of the ordinary concrete. For different strength grade of thermal insulation glazed hollow bead concrete, to some extend, the higher the intensity level is, the stronger the ability of thermal insulation glazed hollow bead concrete anti-carbonation is.

scholarly journals The Influence of Different Facings of Polyisocyanurate Boards on Heat Transfer through the Wall Corners of Insulated Buildings

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1991 ◽  
Author(s):  
Tomas Makaveckas ◽  
Raimondas Bliūdžius ◽  
Arūnas Burlingis
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Flux ◽  
Thermal Insulation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Thermal Bridge ◽  
Thermal Bridges ◽  
The Impact ◽  
Heat Flow Meter

Polyisocyanurate (PIR) thermal insulation boards faced with carboard, plastic, aluminum, or multilayer facings are used for thermal insulation of buildings. Facing materials are selected according to the conditions of use of PIR products. At the corners of the building where these products are joined, facings can be in the direction of the heat flux movement and significantly increase heat transfer through the linear thermal bridge formed in the connection of PIR boards with facing of both walls. Analyzing the installation of PIR thermal insulation products on the walls of a building, the structural schemes of linear thermal bridges were created, numerical calculations of the heat transfer coefficients of the linear thermal bridges were performed, and the influence of various facings on the heat transfer through the thermal bridge was evaluated. Furthermore, an experimental measurement using a heat flow meter apparatus was performed in order to confirm the results obtained by numerical calculation. This study provides more understanding concerning the necessity to evaluate the impact of different thermal conductivity facings on the heat transfer through corners of buildings insulated with PIR boards.

THE EFFECT OF VERTICAL AIR GAPS TO THERMAL TRANSMITTANCE OF HORIZONTAL THERMAL INSULATING LAYER

2009 ◽  
Vol 15 (3) ◽  
pp. 309-315 ◽  
Author(s):  
Jolanta Šadauskienė ◽  
Andrius Buska ◽  
Arūnas Burlingis ◽  
Raimondas Bliūdžius ◽  
Albinas Gailius
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Thermal Insulation ◽  
Standard Method ◽  
Mineral Wool ◽  
Insulating Layer ◽  
Air Gaps ◽  
Thermal Transmittance ◽  
Thermal Insulating ◽  
The Impact

In order to reduce the amounts of work at the construction site, single‐ply dual density thermal insulating roofing boards are used with increasing frequency for thermal insulation of flat roofs. In this case, the joints between boards are not overlapped by the other ply over it; therefore gaps of varying width form between the sides of the boards through the entire thickness of the insulating layer, whose effect on the effective thermal conductivity of the thermal insulating layer must be evaluated. The aim of this project was to assess the reliability of standard method, used to determine the impact of such air gaps on the effective thermal conductivity of the thermal insulating layer by comparing the results of calculations and the results of measurements of thermal conductivity, also to determine the correction factors for thermal transmittance of horizontal thermal insulation layers due to the forming vertical air gaps between the single‐ply mineral wool boards. After measurements of thermal resistances of 50 mm thick thermal insulation board with the air gaps which width varied from 3 mm to 20 mm, it was determined that the thermal conductivity value of the air gaps increases with the increment of the width of air gaps. After completion the experimental measurements of thermal conductivity it was determined that the height of closed and unventilated or partly ventilated air gaps has no effect on the properties of effective thermal conductivity of the thermal insulation layer when the air gap width is up to 5 mm. When wider unventilated or partly ventilated air gaps occur, the effective thermal conductivity coefficient increases proportionally as the height of the air gaps increases. Calculated according to the standard method the affix to the thermal transmittance is overly general and not always appropriate. In some cases it is 6 times higher or 4 times lower than the measured one. In this paper a method to evaluate the effects of air gaps by the use of correction factor to the thermal transmittance of the horizontal thermal insulating layer is proposed. Santrauka Nornt sumažinti darbų apimtis statybos vietoje, stogams šiltinti vis dažniau naudojamos vienu sluoksniu klojamos dvitankės termoizoliacinės plokštės. Šiuo atveju plokščių sandūros neperdengiamos, todėl tarp plokščių kraštinių susidaro įvairaus pločio plyšių, kurių įtaka termoizoliacinio sluoksnio šilumai perduoti turi būti įvertinta. Šio darbo tikslas yra įvertinti standartinio metodo, taikomo tokių plyšių poveikiui sluoksnio šilumos laidumui, patikimumui nustatyti lyginant skaičiavimo ir šilumos laidumo matavimų rezultatus, nustatyti horizontaliojo termoizoliacinio sluoksnio šilumos perdavimo koeficiento pataisas dėl vertikaliųjų oro plyšių susidarymo. Apskaičiavus 50 mm storio termoizoliacinio sluoksnio oro plyšių šilumines varžas, kai plyšių plotis yra nuo 3–20 mm, nustatyta, kad oro plyšių šilumos laidumo koeficiento vertė didėja didėjant oro plyšio pločiui. Atlikus eksperimentinius šilumos laidumo matavimus, nustatyta, kad susidarančių uždarų ir nevėdinamų arba iš dalies vėdinamų oro plyšių aukštis neturi įtakos termoizoliacinio sluoksnio šilumos laidumo savybėms, kai oro plyšys yra iki 5 mm pločio. Esant platesniems uždariems ir nevėdinamiems oro plyšiams, šilumos laidumo koeficientas proporcingai didėja didėjant oro plyšių aukščiui. Pagal standartinį metodą skaičiuotas šilumos perdavimo koeficiento priedas yra per daug apibendrinantis ir ne visada tinkamas. Kai kuriais atvejais jis yra 6 kartus didesnis arba 4 kartus mažesnis už išmatuotąjį. Šiame darbe pasiūlytas horizontaliojo termoizoliacinio sluoksnio šilumos perdavimo koeficiento priedo, naudojamo plyšių įtakai įvertinti, skaičiavimo metodas.

Effect of Operating Temperatures on Thermal Conductivity of Polystyrene Insulation Material: Impact on Envelope-Induced Cooling Load

2014 ◽  
Vol 564 ◽  
pp. 315-320 ◽  
Author(s):  
Maatouk Khoukhi ◽  
Mahmoud Tahat
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Energy Performance ◽  
Building Envelope ◽  
Insulation Material ◽  
Cooling Load ◽  
Thermal Insulation Material ◽  
Insulation Materials ◽  
Energy Performance Of Buildings ◽  
The Impact

The impact of the thermal conductivity (k-value) change of polystyrene insulation material in building envelope due to changes in temperature on the thermal and energy performance of a typical residential building under hot climate is investigated. Indeed, the thermal and energy performance of buildings depends on the thermal characteristics of the building envelope, and particularly on the thermal resistance of the insulation material used. The thermal insulation material which is determined by its thermal conductivity, which describes the ability of heat to flow cross the material in presence of a gradient of temperature, is the main key to assess the performance of the thermal insulation material. When performing the energy analysis or calculating the cooling load for buildings, we use published values of thermal conductivity of insulation materials, which are normally evaluated at 24°C according to the ASTM standards. In reality, thermal insulation in building is exposed to significant and continuous temperature variations, due essentially to the change of outdoor air temperature and solar radiation. Many types of insulation materials are produced and used in Oman, but not enough information is available to evaluate their performance under the prevailing climatic condition. The main objective of this study is to investigate the relationship between the temperature and thermal conductivity of various densities of polystyrene, which is widely used as building insulation material in Oman. Moreover, the impact of thermal conductivity variation with temperature on the envelope-induced cooling load for a simple building model is discussed. This work will serve as a platform to investigate the effect of the operating temperature on thermal conductivity of other building material insulations, and leads to more accurate assessment of the thermal and energy performance of buildings in Oman.

Production of Thermal Insulation Composite Material Based on Polymers

2012 ◽  
Vol 535-537 ◽  
pp. 239-242
Author(s):  
Alena Kalužová ◽  
Jan Pěnčík ◽  
Libor Matějka ◽  
Libor Matějka ◽  
Tomáš Pospíšil ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Composite Material ◽  
Thermal Insulation ◽  
Raw Materials ◽  
Sustainable Construction ◽  
Glass Waste ◽  
Particle Composite ◽  
Coefficient Of Thermal Conductivity ◽  
Uniform Dispersion

Recycling of materials is an important point of sustainable construction. The aim is to find a compromise between energy saving, economy and ecology. The contribution discusses the production of thermal insulation composite material made of polymers. Uniform dispersion of grains of foamy glass waste (filler) in polymer filling from recycled thermoplastics induces formation of particle composite. The production supports usage of secondary raw materials. Decisive properties in choosing the materials to be applied include mainly the coefficient of thermal conductivity, density, compressive strength and water absorption.

scholarly journals Students and education for sustainable development – what matters? A case study on students’ sustainability consciousness derived from participating in an ESD project

2019 ◽  
Vol 13 (2) ◽  
pp. 6
Author(s):  
Majken Korsager ◽  
Eldri Scheie
Keyword(s):  
Sustainable Development ◽  
Teaching And Learning ◽  
Large Scale ◽  
Holistic Approach ◽  
Education For Sustainable Development ◽  
Social Dimension ◽  
Economic Dimension ◽  
Explicit Teaching ◽  
The Impact

AbstractThis article presents a qualitative case study exploring how students’ partici-pation in a project about sustainable development (SD) influences their sustainability consciousness. Sustainability consciousness is a concept that integrates the environmental, economic and social dimensions of SD with knowledge, skills and attitudes. This study follows up the results from a recent quantitative large-scale study conducted in Sweden, investigating the impact of education for sustainable education (ESD) on students’ sustainability consciousness. Results from our study show that the students’ sustainability consciousness is dominated by a mono-dimensional approach from the environmental perspective. However, their motivation to act (Attitudes) was highest within the economic dimension. The skills they expressed they had attained, were mainly practical and mostly within the environmental dimension and to some extent the social dimension. Analysis of the project showed both a lack of collaboration between the teachers and a lack of explicit teaching, which could explain why the holistic approach to SD was under-communicated to the students. The students’ sustainability consciousness seemed improved after a re-design of the ESD project, where the main changes were more explicit teaching and learning goals, and adding Norwegian as a subject. The results are discussed in relation to what should be emphasized in ESD projects in order to empower pupils and students for action competence for SD.Keywords: education for sustainable development, students’ sustainability consciousnessElever og utdanning for bærekraftig utvikling – hva er viktig? En case-studie om elevers bærekraftbevissthet etter deltakelse i et prosjekt om bærekraftig utviklingSammendragDenne artikkelen presenterer en kvalitativ case-studie som utforsker hvordan elevers deltakelse i et prosjekt om bærekraftig utvikling påvirker deres bærekraftbevissthet. Bærekraftbevissthet er et konsept som integrerer den miljømessige, økonomiske og sosiale dimensjonen av bærekraftig utvikling med kunnskap, ferdigheter og holdninger. Denne studien følger opp resultatene fra en nylig kvantitativ storskalaundersøkelse gjennomført i Sverige, der effekten av utdanning for bærekraftig utvikling (UBU) på elevers bærekraftbevissthet er undersøkt. Resultatene fra denne studien viser at elevenes bærekraftbevissthet domineres av en mono-dimensjonal tilnærming fra miljøperspektivet. Men deres motivasjon til å handle (Holdninger) var høyest innenfor den økonomiske dimensjonen. De ferdighetene de uttrykte de hadde oppnådd, var hovedsakelig praktiske og for det meste innenfor miljødimensjonen og noen innen den sosiale dimensjonen. Analyse av prosjektet viste at det var både mangel på samarbeid mellom lærerne og mangel på eksplisitt undervisning, noe som kunne forklare hvorfor den holistiske tilnærmingen til bærekraftig utvikling ble underkommunisert til elevene. Elevenes bærekraftbevissthet ble forbedret noe etter re-design av prosjektet, hvor hovedendringene var mer eksplisitt undervisning og læringsmål samt å inkludere norsk som emne. Resultatene diskuteres med sikte på hva som bør vektlegges i prosjekter i bærekraftig utvikling for å gi elever og studenter handlingskompetanse i bærekraftig utvikling.Nøkkelord: utdanning for bærekraftig utvikling, elevers bærekraftbevissthet

scholarly journals Recycling of Nonwoven Polyethylene Terephthalate Textile into Thermal and Acoustic Insulation for More Sustainable Buildings

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3090
Author(s):  
David Antolinc ◽  
Kristina Eleršič Filipič
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Water Glass ◽  
Fire Behavior ◽  
Acoustic Properties ◽  
Glass Dissolution ◽  
Acoustic Insulation ◽  
Added Water ◽  
Materials Used ◽  
The Impact

The construction and building sector is responsible for a large share of energy and material used during the life cycle of a building. It is therefore crucial to apply a circular economy model within the process wherever possible to minimize the impact on the environment. In this paper, the possibility of producing thermal and acoustic boards from industrial nonwoven waste textile is studied and presented. The nonwoven polyester textile obtained directly from the production line in the form of strips and bales was first shredded into smaller fractions and then in the form of pile compressed with a hot press to form compact thermal insulation boards. The first set of specimens was prepared only from waste polyester nonwoven textile, whereas the second set was treated with sodium silicate in order to check the material’s reaction to fire performance. The experimental work was conducted to define the acoustic properties, reaction to fire behavior and thermal conductivity of the produced specimens. The obtained results show that the thermal conductivity coefficient of specimens without added water glass dissolution is near to the values of conventional materials used as thermal insulation in buildings. The reaction to fire testing proved that the addition of water glass actually propagates the progressive flame over the entire product. It can be concluded that the presented thermal insulation can be used as an adequate and sustainable solution for building construction purposes.

scholarly journals Influence of Particle Size on the Properties of Boards Made from Washingtonia Palm Rachis with Citric Acid

2020 ◽  
Vol 12 (12) ◽  
pp. 4841
Author(s):  
Maria Teresa Ferrandez-Garcia ◽  
Antonio Ferrandez-Garcia ◽  
Teresa Garcia-Ortuño ◽  
Clara Eugenia Ferrandez-Garcia ◽  
Manuel Ferrandez-Villena
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Citric Acid ◽  
Thermal Insulation ◽  
Single Layer ◽  
Raw Material ◽  
Modulus Of Rupture ◽  
Plant Fibers ◽  
Thermal Insulating ◽  
Ecological Resources

The manufacture of technical materials of mineral and synthetic origin currently used for thermal insulation in buildings consumes a large amount of energy and they are not biodegradable. In order to reduce the environmental problems generated by their manufacture, an increasing amount of research is being carried out on the use of renewable and ecological resources. Consequently, the use of plant fibers and natural adhesives in the development of new thermal insulating products is increasing worldwide. Palm trees were used as a replacement for wood in some traditional constructions in places with scarce wood resources. This paper discusses the use of palm pruning waste in the manufacture of particleboards, using citric acid as a natural binder. Five particle sizes of Washingtonia palm rachis were used as the raw material for manufacturing the boards and the citric acid content was set at 10% by weight, in relation to the weight of the rachis particles. Single-layer agglomerated panels were made, applying a pressure of 2.6 MPa and a temperature of 150 °C for 7 min. Twenty panels were produced and their density, thickness swelling, water absorption, modulus of rupture, internal bonding strength and thermal conductivity properties were studied. Smaller particle size resulted in better mechanical properties. The boards had an average thermal conductivity of 0.084 W/m·K, meaning that these boards could be used for thermal insulation in buildings.

scholarly journals Diversification as a strategic direction for sustainable development of enterprises in the agricultural sector of the economy

2021 ◽  
Vol 2 (99) ◽  
pp. 326-336
Author(s):  
S. Sokolyuk ◽  
◽  
M. Koroteev ◽  
O. Zharun ◽  
O. Tupchiy ◽  
...  
Keyword(s):  
Large Scale ◽  
Agricultural Sector ◽  
Raw Materials ◽  
Environmental Safety ◽  
Financial Economic ◽  
Raw Material ◽  
Added Value ◽  
Industrial Processing ◽  
Agricultural Enterprises ◽  
Rational Combination

The diversification of the activities of agricultural enterprises is considered as a process of mastering the production of new or expanding the range of traditional types of products, which makes it possible to more fully realize the existing natural, biological, resource, production potential and helps to strengthen financial, economic and environmental safety, increases the competitiveness and efficiency of economic entities. Today, the need to diversify the activities of domestic agricultural enterprises is determined by a set of prerequisites, both general economic and specific. In modern realities, the overwhelming majority of farmers are focused on the production of the most liquid and least capital- and labor-intensive types of products with a short payback period. The economic results of agricultural enterprises in most cases directly depend on the efficiency of production of grain and oilseeds. Narrow specialization, and sometimes practically monoculture, increases the threats of agrobiological, ecological, and economic nature Diversification of their activities allows minimizing the risks of agricultural enterprises from unfavorable phenomena of agrotechnical and weather-climatic nature and unforeseen changes in market conditions. Optimization of the sectoral structure on the basis of a rational combination of the main, additional, and subsidiary industries ensures more efficient use of land and means of production, leads to the leveling of seasonality, and creates conditions for an enterprise to receive a guaranteed stable income. The priority for the diversification of large-scale agricultural production is its investment and innovative development with a rational combination of crop and livestock industries, the revival of the traditional for Ukraine industries of beet growing, vegetable growing, horticulture, cattle breeding, pig breeding, sheep breeding. Diversification of the activities of small and medium-sized producers provides for an orientation towards the production of products with a high level of labor intensity, environmentally friendly organic products, niche agriculture, the production of non-traditional agricultural products, green, agritourism, etc. The need to change the raw material nature of the agricultural sector of the Ukrainian economy determines the need to increase the industrial processing of agricultural raw materials. This will not only make it possible to obtain greater added value, but will also ensure the creation of additional jobs, will contribute to the growth of incomes of the population, and an increase in the revenues of budgets of all levels. The development of diversification processes guarantees a stable income and an increase in the profitability of agricultural producers and will also contribute to the implementation of national priorities for ensuring the country's food security, increasing employment, and solving social and material problems of peasants.

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