scholarly journals Static and dynamic thermal characterization of facade with mineral foam insulation using a hot-box apparatus

2021 ◽  
Vol 2069 (1) ◽  
pp. 012089
Author(s):  
Edouard Gengembre ◽  
Karine Jacquemet
Keyword(s):  
Heat Loss ◽  
Concrete Block ◽  
Thermal Characterization ◽  
Cold Weather ◽  
Insulation Material ◽  
Thermal Transmittance ◽  
Hot Season ◽  
European Standards ◽  
Finite Volume Simulation ◽  
Indoor Comfort

Abstract Reducing heat loss through the envelope of the building had been an efficient way to save on heating and reduce energy consumption of buildings. In Europe, typical exterior walls need to prevent heat loss during cold weather but more and more allow comfortable temperature condition during the hot season. Indoor comfort in hot seasons is dependent on the thermal transmittance and on its dynamic response during hot days. The study presents guarded hot-box measurements of exterior walls build with insulating masonry and insulation boards made of innovative mineral foam used as an insulation material. The masonry is a composite system of concrete block filled with mineral foam to reduce the thermal transmittance. Insulation boards are made of mineral foam and are added to achieve the overall thermal transmittance targeted. Static and dynamic measurements were performed in order to compare thermal transmittance and decrement delay. The results are compared with those obtained from calculations carried out of the same walls through the application of European standards and a finite volume simulation. Uncertainties of the guarded hot-box measurement and calculation methods are discussed. Results shows that with equivalent U-values, the solution offer higher decrement delay compared to a traditional wall using conventional masonry and polystyrene insulation boards.

scholarly journals Thermal Performance Optimization of Double and Triple Glazing Systems for Slovenian Climate Conditions

2021 ◽  
Vol 13 (21) ◽  
pp. 11857
Author(s):  
Anita Prapotnik Brdnik
Keyword(s):  
Heat Loss ◽  
Thermal Performance ◽  
Performance Optimization ◽  
Carbon Dioxide Emissions ◽  
Climate Data ◽  
Climatic Zones ◽  
Climate Conditions ◽  
Thermal Transmittance ◽  
Heating And Cooling ◽  
Indoor Comfort

Glazing elements are an important part of the thermal envelope of a building. Therefore, good thermal performance of glazing elements can improve indoor comfort and reduce annual maintenance costs and CO2 (carbon dioxide) emissions by reducing heat loss. Reducing heat loss through glazing elements during the heating season can be achieved by combining low thermal transmittance with high solar heat gain. Using standardized calculation methods and measured climate data for three Slovenian locations representing typical continental, mountainous and Mediterranean climates, this study predicts the best combination of optical properties (emissivity, transmittance and reflectance) of glass panes in double and triple glazing systems that contribute to minimal heat loss. It was found that for the double glazing system, the minimum heating and cooling demand for buildings with low solar gains or high solar gains and applied shading is achieved by an inner pane with high transmittance without low-emissivity coating, and an outer pane with low-emissivity coating with minimum possible emissivity. In Maribor and Portorož climatic zones, the panes with low emissivity coating should be used as inner panes in buildings with high solar gains. For triple glazing, the minimum heating and cooling requirements are achieved with two or three panes with low emissivity. For buildings with low solar gains, an emissivity of the coating of 0.03 is preferable, but for buildings with high solar gains, lower emissivity values should be used.

Considerations in Design of Centralizers for Pipe-in-Pipe Systems

2018 ◽  
Author(s):  
Soheil Manouchehri
Keyword(s):  
Heat Loss ◽  
Thermal Insulation ◽  
Insulation Material ◽  
Loading History ◽  
Pipe Systems ◽  
Main Components ◽  
Outer Pipe

For un-bonded (sliding) Pipe-In-Pipe (PIP) systems, one of the main components is the centralizers (also called spacers). The main functions of the centralizers are to centralize the inner pipe inside the outer pipe, to transfer the loads between inner pipe and outer pipe and to safeguard the insulation material in the annulus from excessive compression during fabrication, installation and operation. Centralizers must also have good thermal insulation properties so that the heat loss is minimized. Different designs are now available for centralizers but the majority are based on two half shells which are bolted together. During fabrication, installation and operation, centralizers subject to different loads under which they are required to continue functioning properly. This paper provides an overview of centralizer design aspects and then focuses on the loading history during installation using reeling method. The main contributing parameters to centralizer loading during reeled installation technique are discussed and conclusions are drawn. It is believed that this will enable Pipeline Engineers to select the most appropriate material and design for centralizers.

scholarly journals THE INFLUENCE OF THE METHOD OF LAYING PIPELINES ON THE ENERGY EFFICIENCY OF THE HEATING NETWORK

2019 ◽  
Vol 10 (2) ◽  
pp. 59-66
Author(s):  
E. A Biryuzova ◽  
A. S Glukhanov
Keyword(s):  
Energy Efficiency ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Thermal Energy ◽  
Great Influence ◽  
Temperature Fields ◽  
Insulation Material ◽  
Design Work ◽  
Heat Networks ◽  
Insulation Thickness

Through pipelines of heat networks, due to their large length, a large amount of thermal energy is lost. Identification of technical solutions related to improving the energy efficiency of heating networks is an urgent task at present. The article is devoted to the consideration of options for laying pipelines of heat networks during design work. In the conducted studies, two main methods of underground laying of pipelines of heat networks with the choice of the most energy-efficient, with minimal losses of thermal energy are considered. Channel and channelless laying methods are investigated with the same design features and technological conditions of operation of pipelines of heat networks using the same thermal insulation material. For each option, the required thickness of the thermal insulation is determined by the normalized density of the heat flow, thermal calculations are performed to determine the heat loss and the value of the temperature fields generated around the operating pipelines of the heat networks. The obtained values of the thermal insulation thickness in the channel method of laying pipelines are 30-50 % lower than those in channelless laying. The heat loss values, according to the results of the heat calculation for the options under consideration, in the channel method of laying are reduced by 47-65 %. The temperature fields formed around the pipelines of thermal networks with channelless laying significantly exceed the natural value of the soil temperature at the depth of the pipeline. What has a great influence on the determination of the distance to adjacent pipelines and other utilities, laid underground, in the zone of the thermal network. A comparative analysis of the results obtained makes it possible to single out the choice of the method of laying the pipeline into a group of measures aimed at energy saving and increasing energy efficiency in heating systems.

scholarly journals Full-scale Studies of Improving Energy Performance by Renovating Historic Swedish Timber Buildings with Hemp-lime

2019 ◽  
Vol 9 (12) ◽  
pp. 2484 ◽  
Author(s):  
Paulien Strandberg-de Bruijn ◽  
Anna Donarelli ◽  
Kristin Balksten
Keyword(s):  
Energy Saving ◽  
Material Properties ◽  
Energy Use ◽  
Building Design ◽  
Energy Performance ◽  
Full Scale ◽  
Space Heating ◽  
Original Material ◽  
Insulation Material ◽  
Thermal Transmittance

With an increased focus on reducing greenhouse gas emissions, energy saving is of great importance in all sectors of society. EU directives set targets for member states to reduce energy use in buildings. Energy saving in historic buildings requires special measures, balancing energy-saving renovations against the preservation of heritage values. Traditional constructions are open to vapor diffusion and generally work differently from modern constructions. Modern materials in traditional constructions sometimes damages the original material as they are usually diffusion-tight. The aim of this study was to investigate whether hemp-lime could be used as an insulation material to improve the energy efficiency of historic timber building envelopes with a rendered façade in Sweden. The objective was to determine the actual energy savings for space heating. An additional objective was to determine the actual thermal transmittance and to study thermal buffering through in-situ measurements in a full-scale wall renovated with hemp-lime. Two full-scale wall sections were constructed at the Energy and Building Design laboratory at Lund University: A traditional post-and-plank wall with a lime render (80 mm), and a post-and-plank wall with a hemp-lime render (90 mm). Energy use for space heating was monitored continuously over a period of one year. The wall with a hemp-lime render required 33% less energy for space heating than the traditional post-and-plank wall with a lime render. This was accomplished without changing the framework, appearance or material in the render and without drastically changing the hygric properties of the façade. From the gathered data, the thermal transmittance (U-values) for both walls was calculated using two different methods, one based on material properties and the other based on energy use data. For both walls, thermal transmittance based on actual energy use data during the heating period was lower than what was expected from their material properties. This indicates that more material properties than thermal conductivity and material thickness need to be taken into account when performing energy use calculations. With hemp-lime, a renovation can be accomplished without damaging the timber structure and wooden slats, and it can be done with local traditional materials and building methods with no difference in appearance to a traditional lime render. This allows for heritage values to be preserved, while also allowing the building to comply with modern standards and with increased thermal comfort and reduced energy use.

Bionics in textiles: flexible and translucent thermal insulations for solar thermal applications

2009 ◽  
Vol 367 (1894) ◽  
pp. 1749-1758 ◽  
Author(s):  
Thomas Stegmaier ◽  
Michael Linke ◽  
Heinrich Planck
Keyword(s):  
Heat Loss ◽  
Incident Light ◽  
Visible Spectrum ◽  
Solar Thermal ◽  
Wave Radiation ◽  
Insulation Material ◽  
Heat Insulation Material ◽  
Solar Thermal Collectors ◽  
Solar Thermal Applications ◽  
Thermal Insulations

Solar thermal collectors used at present consist of rigid and heavy materials, which are the reasons for their immobility. Based on the solar function of polar bear fur and skin, new collector systems are in development, which are flexible and mobile. The developed transparent heat insulation material consists of a spacer textile based on translucent polymer fibres coated with transparent silicone rubber. For incident light of the visible spectrum the system is translucent, but impermeable for ultraviolet radiation. Owing to its structure it shows a reduced heat loss by convection. Heat loss by the emission of long-wave radiation can be prevented by a suitable low-emission coating. Suitable treatment of the silicone surface protects it against soiling. In combination with further insulation materials and flow systems, complete flexible solar collector systems are in development.

Experimental Study on Compressive Property of New Concrete Block Masonry with Multi-Row Cores

2014 ◽  
Vol 501-504 ◽  
pp. 461-465
Author(s):  
Zhao Yan Cui ◽  
Fu Sheng Liu ◽  
Shun Ke Zhang
Keyword(s):  
Energy Saving ◽  
Diffusion Mechanism ◽  
Concrete Block ◽  
Compressive Property ◽  
Insulation Material ◽  
Test Results ◽  
Failure Characteristics ◽  
New Energy ◽  
Heat Insulation Material ◽  
Block Wall

With the development of energy-saving in buildings, new energy-saving block masonry with multi-row cores is commonly used. In this paper, from the study of typical bearing capacity of multi hole concrete block masonry of combining multiple rows of holes, holes in the multi block wall masonry capacity test of heat insulation material characteristics. Test results show that, in the process of multi hole masonry brittle failure characteristics, built-in straw block in the insulation at the same time, can improve the compressive strength of masonry; masonry local diffusion mechanism under the action of stress is significant; and offer the engineering measures.

scholarly journals Thermal characterization of fibrous aerogel blanket

2019 ◽  
Vol 282 ◽  
pp. 01001 ◽  
Author(s):  
Ákos Lakatos ◽  
Anton Trnik
Keyword(s):  
Thermal Annealing ◽  
Thermal Insulation ◽  
Thermal Characterization ◽  
Insulation Material ◽  
Scanning Calorimetry ◽  
Solid Materials ◽  
Plastic Foams ◽  
Isothermal Heat Treatments ◽  
New Buildings

Nowadays, the application of thermal insulation materials both by the existing and by new buildings is one of the most important actions in order to reduce the energy loss of buildings. Besides the use of the conventional insulations (plastic foams and wool materials) aerogel is one of the most promising thermal insulation material. Aerogels, one of the lightest solid materials available today, are manufactured through the combination of a polymer with a solvent forming a gel. For buildings the fibre reinforced ones are the mainly used types. It is produced by adding the liquid-solid solution to the fibrous batting. In this paper changes in the thermal performance of the aerogel blanket will be followed after thermal annealing. The samples will be put under isothermal heat treatments at 70 °C for 6 weeks, as well as they will be put under thermal treatment at higher temperatures (from 70 °C till 210 °C) for 1 day. The changes in the thermal conductivity will be followed by Holometrix Lambda heat flow meter, as well as, Differential Scanning Calorimetry results will be presented. From the measured values, thermal properties will be calculated. In this paper we will try to clarify the role played by thermal annealing in thermal diffusivity.

scholarly journals Concrete block structural masonry beam shear design: theoretical and experimental analysis and recommendations to the brazilian standards

2019 ◽  
Vol 12 (4) ◽  
pp. 884-909
Author(s):  
R. D. PASQUANTONIO ◽  
G. A. PARSEKIAN ◽  
J. S. CAMACHO
Keyword(s):  
Shear Strength ◽  
Literature Review ◽  
Experimental Tests ◽  
Concrete Block ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Transverse Reinforcement ◽  
Extensive Literature ◽  
Shear Design ◽  
European Standards

Abstract Beams are subject a flexure and shear, with the last as the theme of this research. The purpose of this paper is to analyze specifications for the shear design of concrete block structural masonry beams, based on an extensive literature review and experimental tests here reported. From this scope, specifications for revision of Brazilian standardization are suggested. In the theoretical part, literature review from both national and international researchers were considered and the specifications of Brazilian standards, in addition to North American, Australian, Canadian and European, ABNT NBR 15961-1/2011, ABNT NBR 6118/2014TMS 402/2016, AS3700/2001, CSA S304/2014 and EuroCode6.1/2001, respectively. To analyze and validate the specifications of the literature, an experimental program was carried out assessing ten concrete block masonry beams results tested mainly to shear loads. Two-course high beams with three vertical load positions (position a/d) and two transverse reinforcement rates were tested. The specifications from the Brazilian and European standards led to considerably higher results than the experimental results, while those presented in the standards TMS 402/2016, AS3700/2001, CSA S304/2014 and NBR6118/2014 lead to results close to those obtained experimentally. As a conclusion, it can be noted that the rupture pattern is similar to that expected for reinforced concrete beams, the cracks were conditioned by the position of the loading point and by the mortar joints positions, the increase in the transverse reinforcement ratio led to an increase in the shear force. Results indicate that the consideration of apparent increase in shear strength by the ratio M ⁄ (V∙d) is not consistent. Eliminating this recommendation, considering the masonry shear strength equal to 0.35 MPa, limiting the stirrups tension to 0.90 of fyk and considering the contribution of the longitudinal reinforcement, it was possible to estimate the shear value at the rupture of each beam between 73% to 106% of the values verified in the tests.

scholarly journals Analisis Rugi-Rugi Panas pada Tangki Penyimpan Panas dalam Sistem Pembangkit Listrik Tenaga Matahari

2012 ◽  
Vol 1 (1) ◽  
pp. 13-18
Author(s):  
Ghalya Pikra ◽  
Agus Salim ◽  
Tri Admono ◽  
Merry Indahsari Devi
Keyword(s):  
Heat Loss ◽  
Storage Tank ◽  
Storage Time ◽  
Heat Storage ◽  
Ceramic Fiber ◽  
Insulation Material ◽  
Generation System ◽  
Insulation Thickness ◽  
Power Generation System ◽  
Selection Of

Analysis of heat loss on heat storage tank in solar power generation system is intended to determine the heat loss value during storage. Selection of insulation material, insulation thickness, time of storage and heat storage fluid affects the heat losses. The research was initiated by determining the dimension of the tank and its insulation material, and determining the heat storage time in the tank. Fluid and operating temperature is determined to get the fluid specification to be used as data analysis. The analysis begins with the calculation of storage capacities, followed by making of thermal nets to get the thermal resistance equation which is then used to calculate the heat loss in the tank. The result shows that the heat storage tank with 0.4 m diameter and 0.45 m height and uses ceramic fiber wool insulation with 0.1m thickness gives the value of heat loss of 63.43 W. 

scholarly journals Effect of Granular Silica Aerogel as Filler on Tensile and Flexural Strengths and Moduli of Stone-Wool-Fibre-Reinforced Composite as Rigid Board Roof Insulation Material

2021 ◽  
Vol 945 (1) ◽  
pp. 012061
Author(s):  
Nadzhratul Husna ◽  
Syed Ahmad Farhan ◽  
Mohamed Mubarak Abdul Wahab ◽  
Mohamed Mubarak Abdul Wahab ◽  
Nasir Shafiq ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Silica Aerogel ◽  
Strength Properties ◽  
Cold Weather ◽  
Wool Fibre ◽  
Insulation Material ◽  
Compression Moulding ◽  
Living Space ◽  
Stone Wool ◽  
Hot Weather

Abstract Installation of stone wool as thermal insulation in the roof assembly can be adopted to store heat in the living space, if the building is exposed to cold weather, and, inversely, to retard heat from entering the living space, if it is exposed to hot weather. In spite of the effectiveness of stone wool as a roof insulation material, during installation, it can cause irritation to the skin and can be hazardous to the lungs. Therefore, incorporation of stone wool with other materials to form a rigid board, without compromising its effectiveness as a roof insulation material, is imperative. Strength properties of a stone-wool-fibre-reinforced high-density polyethylene (HDPE) composite roof insulation material were studied. Granular silica aerogel, which possesses an ultra-low thermal conductivity, was added as filler to reduce the thermal conductivity of the composite. Hot compression moulding was performed to prepare samples of the composite with varying silica aerogel content of 0, 1, 2, 3, 4, and 5 wt. %. Findings suggest that 2 wt.% is the optimum silica aerogel content as it resulted in the highest flexural strength and modulus, which is 24.4 MPa and 845.85 MPa, respectively, even though it reduced the tensile strength and modulus by 10% and 4.45% respectively, relative to 0 wt. %, which can be considered as inconsequential. Higher silica aerogel content above 2 wt. % may result in poor interfacial adhesion and low compatibility to the stone wool fibre and HDPE, which further reduces the tensile and flexural strengths and moduli of the composite.

Sign in / Sign up

Export Citation Format

Share Document