scholarly journals Aerogels as Promising Thermal Insulating Materials: An Overview

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Prakash C. Thapliyal ◽  
Kirti Singh

Aerogels are solids with high porosity (<100 nm) and hence possess extremely low density (∼0.003 g/cm3) and very low conductivity (∼10 mW/mK). In recent years, aerogels have attracted more and more attention due to their surprising properties and their existing and potential applications in wide range of technological areas. An overview of aerogels and their applications as the building envelope components and respective improvements from an energy efficiency perspective including performance is given here. This overview covers thermal insulation properties of aerogels and studies regarding structural features which will be helpful in buildings envelope. The improvements of thermal insulation systems have future prospects of large savings in primary energy consumption. It can be concluded that aerogels have great potential in a wide range of applications as energy efficient insulation, windows, acoustics, and so forth.

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
K. Keerthi Sanghamitra ◽  
A. Yamini ◽  
A. Venu Vinod ◽  
Neha Hebalkar

AbstractAerogels are regarded as the superior thermal insulating materials for wide range of temperatures, from cryogenic insulation, cold water diving garments to high temperature applications and even to defense and aerospace applications. For most of such applications, the aerogels are used in composite form rather than monolithic form as aerogels are fragile in nature due to its high porosity of up to 98%. These composites constitute aerogel infiltrated fiber mats to give flexibility, on the other hand, compromises on the insulation performance due to reinforcing aerogel with fibers that have comparatively higher thermal conductivity than silica aerogel. To increase the efficiency, density of the fiber mat needs to be reduced to incorporate higher loading of silica aerogel. Many techniques are being used to study the insulation performance of these composites. This paper presents about the study of insulation performance of fibre mats with different aerogel content and composition using a well-known thermography technique. The morphological, compositional, thermal and physical studies of the fiber mats and its composites using FESEM, EDAX, BET, thermal conductivity etc., are discussed.


2019 ◽  
Vol 13 (3) ◽  
pp. 513-532
Author(s):  
Javad Asad Poor ◽  
David Thorpe ◽  
Yong Wah Goh

Purpose Regarding the contribution of Australian small-size housing in the enhancement of total energy consumption of the country and the roles of the occupants’ preferences in successful implementation of action plans, the purpose of this study is to identify the Australian occupants’ collaborative image of housing energy efficiency. The two main objectives are, therefore, to address the main energy-related housing physical factors that have the potential in representing the housing image of Australian occupants and to explain the causal factors that make the physical factors critical to their energy efficiency perception. Design/methodology/approach This study has been developed through a qualitative approach. Given that the images encompass a wide range of information expressing human perceptions, an online photo-based qualitative survey was developed based on previous research works. The survey includes respondents’ demographic profiles and the evaluation of images, asking for their perception of overall housing energy efficiency, the impacts of building envelope physical attributes on the energy efficiency of the houses and the reasons behind the selection of different attributes. Findings This study has developed a set of attribute-based factors, explaining occupants’ collective perception of energy efficient small-size housing of Brisbane in the area of exterior aspects of the buildings. Specifically, the collaborative image of small-size housing of Brisbane is about the thermal performance of the buildings provided through passive climatic principles by using more efficient envelope features, e.g. material, colour, transparency, texture, openings, balconies and shadowing devices, while ignoring the impacts of architectural composition principles along neighbourhood quality. The key attributes in assessing the small-housing energy efficiency are ventilation, thermal performance and shadowing. The housing images in old traditional architectural style with rural face, built by stone, brick and concrete in high dense vegetation were evaluated to be more energy efficient than those with modern architecture, built by large glass panel and metal cladding with light or no vegetation. Research limitations/implications The main limitation of the paper is related to the nature of an image-based survey, which leads to ignoring some aspects of real spaces such as odour, temperature and noise. Practical implications This research has the potential for developing a practical methodology for assessing housing-resident fit using computer-based methodology and neural networks. Social implications This research has the potential for developing a methodology, assisting the end users in meeting their desires and motivations by helping them in assessing how a housing unit fits with their expectations and preferences. Originality/value This research provides a reliable conceptual platform for dealing with the complexity of occupants’ housing perceptions. This is achieved by establishing a collective conceptual picture of these environmental perceptions, namely, housing image, which is a platform for transferring abstract data related to human perception into measurable and quantitative scales.


2013 ◽  
Vol 57 ◽  
pp. 1288-1294 ◽  
Author(s):  
Jiří Zach ◽  
Jitka Hroudová ◽  
Jiří Brožovský ◽  
Zdeněk Krejza ◽  
Albinas Gailius

2011 ◽  
Vol 335-336 ◽  
pp. 1199-1203 ◽  
Author(s):  
Jiri Zach ◽  
Rudolf Hela ◽  
Jitka Peterková ◽  
Martin Sedlmajer

The thermal insulating of new and existing buildings is of a key influence in reduction of their energetic demand factor resulting in reduction of emissions of gases, carbon particles and dust which directly improves the environment. At development of light thermal insulation plasters with very low thermal conductivity the foam-plastic matters or light porous aggregates are frequently used at present. The foam-plastic materials do not appear as convenient ones in view of the environment and sustainable development as well. In the given case the thermal insulation plasters based on light cellular aggregates appear as more suitable. However a majority of light aggregates (for example expanded perlite) do not show a good ratio of insulation and mechanical properties. The paper describes a design and development of thermal insulation plasters based on expanded obsidian that can be used for thermal insulating of building constructions and for moisture sanitation. Considering the applied type of aggregates the materials show better ratio of thermal insulation and mechanical properties while in practice the plasters can be used as a full- value alternative for classical thermal insulation systems.


2013 ◽  
Vol 855 ◽  
pp. 39-42 ◽  
Author(s):  
Richard Jedinák

Energy efficiency of buildings is one of the basic requirements of current architectural engineering. The new recast of the Energy Performance of Buildings Directive (EPBD) calls for all new buildings to be nearly zero energy buildings by the end of 2020. To achieve this target is quite challenging. Nowadays some of the buildings that are realized are reaching these objectives. The current market is able to offer a wide range of thermal systems and thermal insulation materials themselves and the right choice of thermal system or thermal insulation material is a difficult task. Considering the significant impact that energy consumption has, is particularly important to implement policies aimed at improving energy efficiency in buildings. Highly energy efficient buildings can either save primary energy or disseminate the use of the most suitable technologies to be used in new constructions. The building may be considered as an example to study and optimize the benefits of higher energy efficiency together with the use of renewable energy systems. This article is going to discuss the characteristics of these solutions, trends in their research and development and their conceptual bases.


2015 ◽  
Vol 1122 ◽  
pp. 35-38
Author(s):  
Jitka Peterková ◽  
Jiri Zach ◽  
Martin Sedlmajer

The paper describes the results of research in the field of thermal insulation plasters suitable for thermal insulation and rehabilitation of historical buildings. The aim was to develop energy-efficient, lightweight plasters, using both common and alternative binders. These were mainly materials based on lime slurry and light porous aggregates that are compatible with the original plaster and masonry materials. These materials are, given their high porosity, capillary active materials and can therefore be used in the restoration of historical buildings, which are often burdened with higher moisture.


The article describes main points and characteristics of the building envelope design considering life-cycle cost and compliance with the codes for energy efficiency parameters in Ukraine. This article contains of the problem analysis of the requirements development for the energy-efficient buildings parameters in Ukraine considering life-cycle cost in the walling design. The structural concepts for the thermal insulation of building exterior walls and roof coatings and their impact on energy efficiency are considered. Designing rational structural concepts for thermal insulating envelope of energy-efficient buildings. The role of the life cycle cost criterion in making decisions on the choice of building envelope is clarified. Analysis of activities, publications and regulatory documents in Ukraine and the EU-countries for the design of rational thermal insulating building envelope considering life-cycle cost to reducing energy consumption. The requirements of regulatory documents on the design of energy-efficient buildings in Ukraine are systematized. The variants of construction solutions for building envelope are considered in terms of the life-cycle cost and energy saving requirements. The tasks of choosing optimal solutions for enclosing structures of external walls and building coatings are multicriteria of a cardinal choice of alternatives with different important measures from a finite set of feasible solutions when considering a weakly structured problem with clearly defined separated parameters. Thermal insulating building envelope using modern insulation systems should be used in all types of buildings.


Fire Safety ◽  
2018 ◽  
pp. 80-89
Author(s):  
R. Yakovchuk ◽  
A. Kuzyk ◽  
O. Miller ◽  
A. Lyn

The paper analyzes the problems associated with the fire hazard of the application of thermal insulation and finishing systems of facades of buildings, which directly depends on the design solution of the thermal insulation system and the type of thermal insulation material. The generalized requirements for physical and technical indicators of the quality of heat-insulating materials; the possibility of applying facade heat insulation structures depending on their class, the height of the houses and the combustibility of the materials of the heat-insulating and finishing layers; fire-technical characteristics of expanded polystyrene are considered. The threats of fire spreading by thermal insulation systems of facades are analyzed and possible ways of its propagation between floors are considered. It is concluded that the use of combustible thermal insulating materials poses an increased danger to life and health of people during a fire. The problem of ensuring the fire safety of buildings, in which the insulation and finishing systems of exterior walls are used, depends on a number of factors and requires a more thorough study.


2013 ◽  
Vol 64 ◽  
pp. 123-131 ◽  
Author(s):  
Dionysios I. Kolaitis ◽  
Emmanouil Malliotakis ◽  
Dimos A. Kontogeorgos ◽  
Ioannis Mandilaras ◽  
Dimitrios I. Katsourinis ◽  
...  

2014 ◽  
Vol 1020 ◽  
pp. 591-596 ◽  
Author(s):  
Aleš Břenek ◽  
Vojtěch Václavík ◽  
Tomáš Dvorský ◽  
Jaromír Daxner ◽  
Vojtech Dirner

The article deals with energy rehabilitation of a building with damaged waterproofing of its lower structure. The reference construction is made of fired bricks, whose functional properties are perfectly fine, but the thermal insulation properties are insufficient for this time. The most common solution of such a problem is the application of a thermal insulating material based on expanded polystyrene on the building envelope. Unfortunately, these solutions often entail the risk of moisture problems in places that appeared to be dry before. The article compares the current solution with the new one relying on material based on calcium silicate [4] with high moisture transport capabilities as an alternative insulation of these buildings.


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