Practices to avoid thermal bridges in the building shell, consists one of the key elements in the comprehensive assessment of the energy behaviour of buildings. As we are moving fast to the era of ...nearly zero energy buildings, both the use of non-invasive measurement techniques as well as the use of analytical and numerical models, have intensified research and substantiated best practices around this interesting issue. The sole criterion of the energy assessment of thermal bridges is the reduction of the heat losses, thus heat transfer analysis dominates the field.
This short technical note presents and analyses the thermal behaviour of point thermal bridges, observed in areas of higher thermal transmittance at the joints of windows and supporting structures through different types of fasteners. Specifically, the method of direct support of windows in a layer of stone wool is considered, and the energy performance of three alternative ways of supporting the construction is examined. The heat transfer assessment of the investigated solutions is conducted with the use of numerical analysis, performed with the use of two analytical tools (THERM and HEAT3), in two- and three dimensional domains. The work concludes with substantiated suggestions in relation to the solutions that are proposed, always guided by the reduction in energy consumption. The paper aspires to provide informed answers to engineers and researchers in the field of energy efficiency of buildings, thus creating the field for future developments in the field of point thermal point bridges in window.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper presents the research on theestimation of macrostructure parameters in accordance with the dominated fibresorientation. During experimental tests established the relations of physicaland ...mechanical characteristics with structural parameters of rigid mineral woolproducts (with different structure). Determined that compressive stress ofmineral wool slabs could be predicted by using macrostructure parameters andother (density, organic content) characteristics.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.6193
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The experimental tests established the relations of rigid mineral wool products (with different structure) macrostructure parameters with main their mechanical characteristic – compressibility. The ...products within the nominal density between 45 and 170 kg/m3 were analysed. Determined that strong functional relationship exists between the values of critical compressive stress and macrostructure parameters, density and organic content of mineral wool products, because the value of the multiple correlation coefficient equals 0.95. Using the obtained empirical equation is possible predict and calculate the mechanical behiaviour (compression stress) of mineral wool slabs by using macrostructure parameters and other (density, organic content) characteristics.
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Different envelope solutions are used for the implementation of thermal insulation requirements, assuming that a solution that insures good thermal insulation will automatically insure good sound ...insulation. The use of External Thermal Insulation Composite System (ETICS) may be one of many solutions. The aim of the experiment was to evaluate how thermal insulation (EPS and mineral wool) and coating (plaster) layers of ETICS influence on sound and thermal insulation of a basic element (wall). The experimental results showed that added thermal insulation (EPS and mineral wool) and coating (plaster) layers of ETICS can influence the sound and thermal insulation of the wall differently. The addition of a thermal insulation layer of ETICS changes sound insulation (increases up to 4 dB) of wall with mineral wool, but in using EPS, has no significant influence. The addition of a coating (plaster) layer over the thermal insulation material layer allows an increase in sound insulation in both cases from 3 dB to 7 dB, but does not change the thermal insulation. The addition of a layer of thermal insulation changes the thermal insulation of basic wall – it increases up to 4.88 m2 K/W with EPS and up to 5.09 m2 K/W with MW, respectively. The influence on sound insulation depends on the type of thermal insulation material used, the presence or absence of a coating (plaster layer) and its thickness, while the influence on thermal insulation does not depend on these factors. It only depends on the presence of the thermal insulation layer.
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5.
Sound insulation of slabs in dwellings Miškinis, Kęstutis; Bliudžius, Raimondas; Buska, Andrius
Journal of physics. Conference series,
12/2023, Volume:
2654, Issue:
1
Journal Article
Peer reviewed
Open access
Abstract
The well-being and sleeping quality of people in dwellings depends on appropriate sound insulation efficiency of building structures. In individual apartments, airborne sound is produced by ...people talking and music playing, and impact sound is produced by people walking and falling of various objects on the floor. The inter floor slab separating the individual dwellings is intended for airborne and impact noise insulation, so special attention is paid to its design and installation. Since the composition of this structure is primarily determined by the structural requirements, the improvement of the sound insulation performance is mainly carried out by developing the damping interlayer materials. The stone wool plate has been modified reducing the fiber intertwining to obtain a more uniform fiber directivity, thus reducing its dynamic stiffness. Therefore, the aim of this study was to investigate the sound insulation efficiency of inter floor slabs with a new modification of stone wool damping interlayer in comparison with currently used mineral wool products. The experimental measurements in 50-5000 Hz frequency range were performed in construction site (real structures), the single-number quantities – weighted standardized level difference (D
nTw
) and weighted normalized impact sound pressure level (L‘
nW
) with living adaption term (C) were determined and compared. The research results demonstrated that the modified stone wool with reduced fiber intertwining and lover organic content used for damping interlayer enables to improve living sound insulation of inter floor slab comparing with existing stone wool materials.
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.
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This paper presents the research on the structure and compressive stress or compressive strength of mineral wool products. The products of chaotic, directional and combinative fibres structure have ...been studied visually and microscopically. During mechanical tests it was determined that compressive stress (compressive strength) of the stone wool products is dependent on the direction of the load working to the product major face, test specimen dimensions, force increasing rate, fibres distribution (orientation) and methodical peculiarities.
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This paper presents the research on the structure and compressive stress or compressive strength of mineral wool products. The products of chaotic, directional and combinative fibres structure have ...been studied visually and microscopically. During mechanical tests it was determined that compressive stress (compressive strength) of the stone wool products is dependent on the direction of the load working to the product major face, test specimen dimensions, force increasing rate, fibres distribution (orientation) and methodical peculiarities.
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This paper presents the research on the estimation of mineral wool macrostructure parameters. The orientation of fibres in the mineral wool structure can be described by the macrostructure parameter ...S sub()L-C It was determined that product with a homogeneous structure may be classified based on the numerical values of macrostructure parameters: the product with a quasi-horizontal orientation the value S sub()L-Cis < or =0.75 and if the value S sub()L-Cis > or = 1.10 products are quasi-vertical orientation. Products with intermediate S sub()L-Cvalue (0.76-1.09) have a quasi-chaotic orientation. The developed method may be used to optimize production processes and/or improve the physical-mechanical properties of the mineral wool products.Original Abstract: Straipsnyje pateikiama nauja mineralines vatos gaminiu makrostrukturos nustatymo pagal plausu orientacija metodika, kuri leidzia pagal strukturoje dominuojanciu plausu kryptinguma apskaiciuoti makrostrukturos rodiklius. Bandymams buvo naudotos 7 tipu skirtingo tankio (33 - 200 kg/m super(3)) ir strukturos mineralines (akmens ir stiklo) vatos plokstes, pagamintos ir pazymetos pagal darniojo standarto LST EN 13162 reikalavimus. Plausu ir ju grupiu orientacijos dominavimas strukturoje nustatytas makrostrukturos skaitmeninio fiksavimo ir analizavimo principu. Mineralines vatos ploksciu pavirsiaus (per stori) fragmentai buvo skenuojami, o uzfiksuoti vaizdai perkeliami i kompiuteri. Tuomet kompiuterizuotu skaitmeniniu vaizdu analizes metodu tiriama, kaip plausai issidesto. Eksperimentiniais tyrimais nustatyta, kad kiekybiskai identifikuoti plausu orientacijos kryptinguma strukturoje galima pasitelkus makrostrukturos rodikli, parodanti bandinio ploksciajame pjuvyje dominuojanciu plausu ir ju grupiu orientacijos kampu ismatuotu x ir x' (siuo atveju x' yra statmena x) asyse santyki. Taigi mineralines vatos plausu issidestymas strukturoje gali buti nusakomas makrostrukturos rodikliais S sub(L), S sub(C) arba S sub(L-C). Remiantis teoriniais poringuju kunu, erdviniu kompozitu strukturos pagrindais ir pasitelkus skaitinius makrostrukturos rodikliu dydzius, homogeniskos strukturos gaminius galima suskirstyti taip: gaminiai, kuriuose daugiausiai plausu issideste lygiagreciai su x asimi, vadinami tariamai horizontalios orientacijos, o ju S sub(L-C)< or =0,75. Gaminiai, kuriose dominuoja statmeni x asiai plausai, vadinami tariamai vertikalios orientacijos ir ju S sub(L-C)> or = 1,10. Gaminiai su atsitiktinai issidesciusiais ar su aiskiai neapibreztos krypties ir (arba) orientacijos plausais vadinami tariamai chaotiskos orientacijos, kai ju S sub(L-C) = 0,76-1,09. Klasifikacija leidzia tiksliau apibudinti skirtingos strukturos mineralines vatos gaminiu vertinima sprendziant tradiciniu termoizoliaciniu medziagu efektyvumo didinimo problemas ar prapleciant ju naudojimo sritis, nes pluostines strukturos valdymas, plausu issidestymo krypties keitimas bei skirtingu tankiu ir (arba) sluoksniu naudojimas gamybos procese lemia pagrindines mineralines vatos gaminiu stiprumo ir deformacines savybes. Be to, sukurtas metodas gali buti taikomas neardomajai pluostiniu termoizoliaciniu medziagu stiprumo savybiu (kokybes) kontrolei.
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In recent years, the external thermal insulation composite system (ETICS) has been applied increasingly in a lot of buildings for energy conservation purposes. However, the increased use of different ...combustible insulation materials in the ETICS has raised serious fire safety problems. Fires involving this type of ETICS have caused severe damage and loss. Often, the fire spread depends on the thermal material of ETICS. Products of polymeric foams or inorganic fibrous material are commonly used. Practice and case studies of researchers show that involved expanded polystyrene is the most dangerous case of the fire spread. Therefore, it is important to choose the right material. In order to limit fire spread and improve fire safety, fire barriers from were suggested being installed. These measures may include the installation of a noncombustible lintel above each opening in the façade (windows, doors) to prevent flames penetrating the insulating material. Additionally, firestop barriers can be installed horizontally over the entire façade. The fire barriers have to be made of non-combustible materials, such as mineral wool, and are required on every alternate floor in buildings. Energy renovation is a great chance to increase fire safety in buildings. Therefore, the requirements of additional fire safety and prevention are different in Europe. Currently, there are not much data available on the behaviour of different insulation materials (expanded polystyrene and mineral wool) in ETICS and their relevant characteristics during operating life and ETICS durability time. This paper cites the requirements of additional fire prevention in different European countries. Analysis of the physical properties (vapour resistance, thermal transmittance, water absorption and etc.) of the expanded polystyrene and mineral wool products of is presented. This article presents an investigation of thermographic research of building, which was renovated three years ago and has implemented fire barriers.
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