Aerogel insulation for building applications: A state-of-the-art review

Aerogel is a kind of synthetic porous material, in which the liquid component of the gel is replaced with a gas. Aerogel has specific acoustic properties and remarkably lower thermal conductivity (≈0.013 W/m K) than the other commercial insulating materials. It also has superior physical and chemical characteristics like the translucent structure. Therefore, it is considered as one of the most promising thermal insulating materials for building applications. Besides its applications in residential and industrial buildings, aerogel has a great deal of application areas such as spacecrafts, skyscrapers, automobiles, electronic devices, clothing etc. Although current cost of aerogel still remains higher compared to the conventional insulation materials, intensive efforts are made to reduce its manufacturing cost and hence enable it to become widespread all over the world. In this study, a comprehensive review on aerogel and its utilization in buildings are presented. Thermal insulation materials based on aerogel are illustrated with various applications. Economic analysis and future potential of aerogel are also considered in the study.

Toward aerogel based thermal superinsulation in buildings: A comprehensive review

Heating consumes large amount of energy and is a primary source of greenhouse gas emission. Although energy-efficient buildings are developing quickly based on improving insulation and design, a large portion of energy continues to be wasted on heating empty space and nonhuman objects. Here, we demonstrate a system of personal thermal management using metallic nanowire-embedded cloth that can reduce this waste. The metallic nanowires form a conductive network that not only is highly thermal insulating because it reflects human body infrared radiation but also allows Joule heating to complement the passive insulation. The breathability and durability of the original cloth is not sacrificed because of the nanowires’ porous structure. This nanowire cloth can efficiently warm human bodies and save hundreds of watts per person as compared to traditional indoor heaters.

Personal Thermal Management by Metallic Nanowire-Coated Textile

Energy conservation is an increasingly important issue for the residential sector. Therefore, attention towards the thermal performance of building materials, particularly thermal insulation systems for buildings, has grown in recent years. In this study, a literature review on determining the optimum thickness of the thermal insulation material in a building envelope and its effect on energy consumption was carried out. The results, the optimization procedures and the economic analysis methods used in the studies were presented comparatively. Additionally, a practical application on optimizing the insulation thickness was performed, and the effective parameters on the optimum value were investigated.

A review of the economical and optimum thermal insulation thickness for building applications

In the development of next-generation materials with enhanced thermal properties, biological systems in nature provide many examples that have exceptional structural designs and unparalleled performance in their thermal or nonthermal functions. Bioinspired engineering thus offers great promise in the synthesis and fabrication of thermal materials that are difficult to engineer through conventional approaches. In this review, recent progress in the emerging area of bioinspired advanced materials for thermal science and technology is summarized. State-of-the-art developments of bioinspired thermal-management materials, including materials for efficient thermal insulation and heat transfer, and bioinspired materials for thermal/infrared detection, are highlighted. The dynamic balance of bioinspiration and practical engineering, the correlation of inspiration approaches with the targeted applications, and the coexistence of molecule-based inspiration and structure-based inspiration are discussed in the overview of the development. The long-term outlook and short-term focus of this critical area of advanced materials engineering are also presented.

Bioinspired Engineering of Thermal Materials

This paper presents a status report on solar transparent insulation materials (TIM). It covers a survey of the literature, various physical and other properties of TIM devices, their classifications, applications, fabrication procedures, availability and cost trends. The global resurgence of research is clarified. Subsequently, the development of TIM cover systems (often referred to as advanced glazing) from such products as polymer sheets, capillaries and cellular profiles, is discussed. Their design and performance characteristics are investigated; results corresponding to experimental measurements, as well as computational models, are presented. An explicit comparative study of absorber parallel and absorber perpendicular configurations of TIM cover systems is presented. The TIM covers with black end cover plates, and cellular walls of high emissivity, as well as those with selective cover plates and cellular walls fully transparent to IR radiations, have relatively lower heat loss coefficients.

N.D. Kaushika

Papers

Solar transparent insulation materials: a review