Insulation Options Research Articles

A Comprehensive Review and Recent Trends in Thermal Insulation Materials for Energy Conservation in Buildings

In recent years, energy conservation became a strategic goal to preserve the environment, foster sustainability, and preserve valuable natural resources. The building sector is considered one of the largest energy consumers globally. Therefore, insulation plays a vital role in mitigating the energy consumption of the building sector. This study provides an overview of various organic and inorganic insulation materials, recent trends in insulation systems, and their applications, advantages, and disadvantages, particularly those suitable for extreme climates. Moreover, natural and composite materials that can be used as a low-cost, thermally efficient, and sustainable option for thermal insulation are discussed along with their thermal properties-associated problems, and potential solutions that could be adopted to utilize natural and sustainable options. Finally, the paper highlights factors affecting thermal performance and essential considerations for choosing a particular insulation system for a particular region. It is concluded that the most commonly used insulation materials are found to have several associated problems and there is a strong need to utilize sustainable materials along with advanced materials such as aerogels to develop novel composite insulation materials to overcome these deficiencies.

The effect of size of copper oxide nanoparticles on the thermal behavior of silica aerogel/paraffin nanostructure in a duct using molecular dynamics simulation

Due to the rise in gas prices and the surge in greenhouse gas emissions, individuals have turned to various renewable energy options. Silica aerogels are highly effective to maintain either hot or cold Temps. Insulation options with proficient thermal storage capabilities, such as phase change materials (PCMs), are highly beneficial. This study aimed to determine how the size of copper oxide nanoparticles affected the behavior of a silica aerogel/paraffin nanostructure within a duct. The researchers utilized computer simulation as a means to examine the thermal behavior (TB) and complex properties of the particles. To accomplish this objective, we evaluated the effect of various factors, such as the size of NPs incorporated into the structure, on density, temperature (Temp), heat flux, thermal conductivity, and charging and discharging time. According to the results, by increasing the radius of the nanoparticle to 10 Å, the density value in the atomic sample reached 0.1353 atoms/Å3. Moreover, the velocity (Vel) decreased to 0.0085 Å/fs. As the radius was 10 A, the thermal conductivity decreases from 1.74 W/m.k to 1.65 W/m.K. Also, by increasing the size of the nanoparticle, the charging and discharging time in the target atomic sample increases and decreases to 6.28 ns and 8.52 ns, respectively.

Analysis of noise sources in the cabin of a passenger aircraft and methods for combating them

This paper examined the problem of noise in the aircraft cabin and ways to solve it. Through observations, the following causes of noise were identified: the power plant (acoustic and mechanical vibrations, turbulent boundary layer and others), the location of the engine relative to the airframe, the noise of the propeller (if it is a propeller power plant), the propeller of the power plant itself, the air conditioning system, and so on the same operating device in the cabin. There is a comprehensive way to solve the problem of noise in the aircraft cabin: for aircraft with turbojet engines, measures aimed at changing the design and use of sound- absorbing materials can be effective. For a turboprop aircraft, it is necessary to create low-noise propellers and synchronize the rotation of the propellers. For air conditioning elements, reducing duct and exhaust velocities allows for satisfactory acoustic performance of these sources. The reduction in “cabin noise” is achieved by changing the manufacturing technology of various noisy units. It should be emphasized that the possibility of reduction in the cabin and the aircraft is, in principle, laid down when designing the units and the aircraft as a whole. It is worth noting sound insulation, vibration insulation, as well as the rational location of noisy units, including the power plant, relative to the passenger cabin of the aircraft. From the study on sound insulation, we conclude that it is best to use 2 sound insulation options. Reducing noise is a feasible task and its greatest progress is achieved even at the design stage itself

Development of thermal insulation panels bio-composite containing cardboard and date palm fibers

This study aims to determine the thermal, acoustic, and hygroscopic properties of materials designed for building thermal insulation. These materials are composed of cardboard reinforced with fibers sourced from date palm trees. The composite formulation involves a mixture of 40% date palm components, including pinnate leaves, clusters, trunk petioles, and palm fibers, along with 60% cellulose-based cardboard waste. Water is used as the binding agent, eliminating the need for additional chemicals or additives.For the assessment, thermal conductivity, thermal diffusivity, normal transmission loss (TL), and the acoustic absorption coefficient were measured using the hot plane method, flash method and acoustic impedance tube, respectively. The results indicate that the developed composites have thermal conductivity values ranging from 0.074 to 0.081 W/m.K for a density ranging from 226.6 to 312.8 kg/m³. Additionally, the sound transmission loss coefficients exceed 5 dB in the frequency range of 500–1400 Hz, and the acoustic absorption coefficient is greater than 0.4 across a wide range of frequencies from low to high frequencies (200 Hz–1400 Hz). Furthermore, after 6 h of water immersion, a minimal capillary water absorption coefficient of 203% is achieved. What sets this study apart is the comprehensive life cycle cost analysis performed, shedding light on the sustainability of these materials. The optimization of insulation thickness was also conducted, determining optimal values based on climate conditions and energy sources. Overall, this innovative approach offers environmentally friendly and sustainable insulation options for the construction industry, integrating thermal and acoustic properties, life cycle cost analysis, and insulation thickness optimization.

Enhancing the hydrophobicity of the mineral wool through surface modification with organo-silane

Mineral wool materials are consistently preferred material to be used for building thermal insulation because of their low heat conductivity, making energy-efficient structures impossible to construct without highly insulating thermal envelopes. A mineral wool with a hydrophobic external surface could be used for several applications where hydrophobicity would be helpful. Organo-silanes are one of the most promising materials to impart hydrophobic character to varied surfaces to achieve performance properties such as dust-resistant coatings on building glass, solar panels with self-cleaning surfaces, biofouling resistant paints, self-cleaning car windshields etc. In this study, mineral wool was treated with methyltrimethoxysilane (MTMS) to achieve hydrophobic surfaces.A Fourier Transform Infrared Spectrometer is used to confirm the successful deposition of organosilane/siloxane networks on glass wool fibre surfaces. The hydrophobicity of treated wool was assessed and quantified using a contact angle measurement. Contact angle measurement was used to quantify the hydrophobicity of treated wool. The thermal conductivity of treated mineral wool fiber was calculated using the portable Lee's disc method. To determine the thermal stability and crystallinity of the treated wool, X-ray diffraction spectroscopy and thermogravimetric analysis were used, respectively. The treated mineral wool exhibited excellent thermal stability up to 800 °C, and wettability tests proved the treated surface highly hydrophobic, allowing water droplets to roll off with contact angles up to 134.9°. Surface modification reduced thermal conductivity by 20%, showing good thermal resistance. Here, we show easy and sustainable methods of treating mineral wool surfaces, which can serve as a thermal insulation option under humid conditions.

On the thermal-energy performance of 3D printed concrete wall panels designed with varying insulation ratios

Three-dimensional printed concrete (3DPC) is a promising construction method that has gained recognition in recent years. With the growing focus on energy-efficient buildings, it is important to understand the thermal-energy performance of 3DPC panels, particularly with different insulation options. However, current knowledge in this area is limited. Therefore, this research investigates the thermal-energy performance of 3DPC walls with various insulation materials and insulation layer heights. Thermal models were developed using THERM 7.8 software and validated against available literature and ISO 10211 thermal test cases. A total of 42 numerical models were developed, varying wall width (100 mm and 200 mm), insulation ratios (0, 0.2, 0.4, 0.6, 0.8, 1.0), and insulation materials (mineral wool, rockwool, fibre glass wool, and E-PLA). The results demonstrated that increasing the insulation ratio leads to a lower U-value. New design equations were developed to capture the effect of insulation ratios, and these equations accurately predicted U-values. This study contributes to understanding the thermal-energy performance of 3DPC walls with different insulation options, and the proposed equations can assist in designing energy-efficient buildings with 3DPC panels.

Life cycle carbon and cost assessment comparing milled and whole timber truss systems and insulation options for affordable housing

Increasing demand for housing is one of the biggest challenges facing the world. Affordable housing is a key priority of the UK government in addressing this challenge, which calls for innovative construction methods to address the issue of fuel poverty at an affordable cost. Timber-based modern methods of construction are one of the key solutions to resolve the existing housing crisis while managing climate change. Therefore, this paper presents a case study of “Integra House”, which is a proof of concept of a novel truss technology. The case study is an affordable housing prototype that performs well in both life cycle carbon and cost. The proposed construction uses a novel timber truss technology which makes up the floor, walls and roof of the house, thereby reducing on-site operations and waste while providing a low-carbon low-cost design. The prototype underwent design optimisation and evaluation of options; workshop-based production and performance evaluation of elemental prototypes; production and performance evaluation of a full-scale dwelling prototype; and comparison of capital and life cycle costs and environmental impacts. Further, it underwent a simulation-based optimisation to maximize its performance in cost and carbon by replacing milled timber trusses with whole timber trusses and Rockwool insulation with wood wool insulation. The optimised design option (whole timber) has an EC of 261kgCO2per m2 and costs £682 per m2 (excludes substructure, services and fitout) and its operational carbon is 7.9 kgCO2 per m2/annum and costs £3.30 per m2/annum to operate. Life cycle costs and carbon comparison of the two design prototypes concluded that the whole timber design outperformed the milled timber design in both cost and carbon aspects, by 23% and 30% respectively due to being extremely inexpensive and requiring minimal processing compared to the milled timber option.

Impact of Location and Insulation Material on Energy Performance of Residential Buildings as per Saudi Building Code (SBC) 601/602 in Saudi Arabia

In hot and humid climates, a significant part of the energy is used to cool the building. There are several ways to reduce this air conditioning load, but one standout is through the selection and design of the right building envelope and its components. The thermal characteristics of the building envelope, in particular the thermal resistance of the insulation used, have an impact on the thermal and energy performance of building structures. Thermal conductivity, which indicates the ability of heat to move through a material given a temperature difference, is the primary factor affecting the performance of a thermal insulation material. Both temperature and humidity changes can affect a material's thermal conductivity value, which can then change. In fact, due to the fluctuating ambient air temperature and solar radiation, thermal insulation in buildings is susceptible to significant and continuous temperature variations. Thermal insulation used in building walls and roofs helps to reduce the energy demand of the building. It improves thermal comfort and, if used correctly, reduces the operational cost of the building. The present study has focused on the effects of location and insulation material on the energy performance of a residential building by considering five climatic locations in the Kingdom of Saudi Arabia (KSA). Five commonly used insulation materials with different thermal characteristics, namely polyurethane board (PU), expanded polystyrene (EPS), glass wool (GW), urea-formaldehyde foam (UFF), and expanded perlite (EP), were analyzed under various climatic zones as per the Saudi Building Code 601/602. The selected cities were categorized based on cooling degree days (CDD) and outdoor dry bulb temperature (DBT) as hot, very hot, and extremely hot climatic zones. Insulation improves thermal comfort and, if used correctly, reduces running costs. Experiments were conducted to determine the thermal conductivity, and the energy simulation was performed by employing IES-VE software for various insulation options. The findings indicate that the location has a significant impact on the energy performance of the insulating materials. The energy saving potential of polyurethane board (PU) insulation is more attractive in cities with higher DBTs and CDDs than in cities with lower DBTs and CDDs. The benefit of installing insulation ranged from a 2 to 14% decrease in energy demand for the climate zones studied. The sensitivity analysis showed that the energy saving potential of the insulation materials is sensitive to the set-point temperature (ST) band.

Preparation of Aerogel-like Silica Foam with the Hollow-Sphere-Based 3D Network Skeleton by the Cast-in Situ Method and Ambient Pressure Drying.

Silica aerogels have incomparable advantages among thermal insulation materials because of their ultralow density and thermal conductivity, but cumbersome production processes, high cost, and low mechanical stability limit their practical application. In this study, a novel aqueous process to prepare lightweight aerogel-like silica foams (ASFoams) through the cast-in situ method and ambient pressure drying was proposed with multiblock polyurethane surfactant as the vesicle template. ASFoams possess a unique loose stacking morphology of the silica hollow sphere with a 3D network structure as the skeleton, which endues ASFoams with a low density of 0.059 g/cm3, low thermal conductivity of 36.1 mW·k-1·m-1, and pretty good mechanical properties. These properties make ASFoams a promising option for thermal insulation in industrial, aerospace, and other extreme environmental conditions. In addition, the micromorphology of ASFoams can be adjusted by changing the reaction conditions, which may provide a facile method for the preparation of a silica aerogel-like foam with adjustable microstructure.

Research on influences of wall design on embodied and operating energy consumption: A case study of temporary building in China

Building energy conservation has received attention globally due to the significant environmental effects of the building industry. Because of the dual character of energy saving measures, it is important to weigh the overall advantages of embodied and operating stage under local conditions.This study compared the influence of exterior wall materials on energy consumption of light-framed temporary buildings. The exterior wall was divided into four layers and different materials and thickness options were selected in accordance with the design and related research. There were a total of 3 outermost materials, 16 exterior insulation options, 7 air gap thickness, and 4 inner filling insulation materials, which can be combined to generate 1344 design schemes. In order to compare the embodied and operating energy consumption of all schemes, a framework of building energy consumption prediction method was established. The rapid energy consumption prediction was realized by combining building model, Ecoinvent Database and EnergyPlus software with programming language. The calculation program could be adjusted based on the results to support the analysis of the materials' influence mechanism on energy consumption. This study verified the feasibility of the prediction method through an example analysis. The research results demonstrated that different materials and thicknesses have distinct or even opposing impacts on embodied and operating energy consumption, which needs to be considered comprehensively. Additionally, suggestions on the selection of materials for each layer of exterior wall are proposed for this case.

MEASURES AND MEANS TO IMPROVE THE ENERGY EFFICIENCY OF FOOD PRODUCTION

Improving the energy efficiency of modern enterprises, including the food industry as one of the priorities for the life support of the population, is of strategic importance for Ukraine. The purpose of the study is an analysis of the energy-saving potential of food industry enterprises and the search for ways to reduce the energy intensity of technological processes, devices, and equipment, as well as transmission heat losses of buildings and structures. For field tests of industrial and technological objects, a combined thermal imaging and thermometric research methodology was chosen, which combines thermal imaging of characteristic thermal zones to detect anomalous areas and contact measurements of thermophysical parameters in these zones. A computerised information and measuring system equipped with a set of primary sensors of temperature, heat flux, humidity, etc. was used for long-term monitoring of thermophysical parameters simultaneously at different sites of the facilities. As a result, an array of data was obtained and processed, the parameters of complex convective and radiation heat transfer were calculated, and the heat transfer resistance was determined, which allows assessing the degree of danger of the detected thermal anomalies and developing measures for thermal modernisation of facilities using modern thermal insulation materials. Reduction of heat loss in production processes is also achieved by organising high-quality thermal insulation of technological apparatuses, pipelines and refrigeration equipment. The main parameter for selecting the required material is its low thermal conductivity in the operating temperature range of the equipment. For the effective heat insulator selection, the thermal conductivity of a number of popular materials of world-famous manufacturers was studied based on the certified information-measuring system of Ukrainian design by the stationary plate method with the use of heat flux and temperature sensors. The thermophysical parameters of heat-insulating materials in the range of 0.02...0.045 W/(m·K) were estimated and thereby revealed the thermal conductivity of materials with a closed microporous structure to be half that of fibrous ones and not dependent on the density of the material, which makes them the best option for high-quality insulation of buildings and equipment of food production

A COMPARATIVE LIFE CYCLE ANALYSIS OF NEAR-ZERO ENERGY BUILDINGS WITH A FOCUS ON ENVELOPE INSULATION

ABSTRACT Near-zero energy buildings are known to have the potential to reduce energy consumption and consequent emissions. This article uses a life cycle analysis approach to evaluate the effects of using different insulating materials on the lifetime energy consumption of a near zero conditioning energy case study house in Wellington, New Zealand, by assessing the environmental impacts of a number of insulation options. The question addressed is whether using thick layers of insulation with high R-values in a building envelope is always a reliable approach to mitigating the impact of the built environment on the planet. The results show no significant difference between the environmental impacts of insulating the house using polyurethane and using no insulation in the first 28 years. The further discussion shows the energy profile used for processing the materials, construction and operating the buildings are not always the same, and this has a significant impact on the building’s environmental footprint. There needs to be a balance between both the value and profile of building operating and embodied energy. HIGHLIGHTS

A COMPARATIVE LIFE CYCLE ANALYSIS OF NEAR-ZERO ENERGY BUILDINGS WITH A FOCUS ON ENVELOPE INSULATION

ABSTRACT Near-zero energy buildings are known to have the potential to reduce energy consumption and consequent emissions. This article uses a life cycle analysis approach to evaluate the effects of using different insulating materials on the lifetime energy consumption of a near zero conditioning energy case study house in Wellington, New Zealand, by assessing the environmental impacts of a number of insulation options. The question addressed is whether using thick layers of insulation with high R-values in a building envelope is always a reliable approach to mitigating the impact of the built environment on the planet. The results show no significant difference between the environmental impacts of insulating the house using polyurethane and using no insulation in the first 28 years. The further discussion shows the energy profile used for processing the materials, construction and operating the buildings are not always the same, and this has a significant impact on the building’s environmental footprint. There needs to be a balance between both the value and profile of building operating and embodied energy. HIGHLIGHTS

Novel conventional and modular LSF wall panels with improved fire performance

Fire performance of Light-gauge Steel Frame (LSF) constructions is being extensively investigated recently, due to the critical behaviour of cold-formed steel structures at elevated temperatures. Among the many design parameters involved with LSF constructions, the effect of cavity insulation inside LSF walls at different ratios on the Fire Resistance Level (FRL) has not been addressed yet. Hence, Finite Element Models (FEMs) were developed for the LSF walls to simulate the full-scale fire tests conducted applying the standard fire temperatures, where the Finite Element Analyses (FEA) results were very well agreeing with the experimental results. Thereafter, the validated FEMs were extended to study the fire performance of the conventional and modular LSF wall systems with different cavity insulation ratios, where 0.4 cavity insulation ratio was found to be most efficient when structural FRL is of concern while producing satisfactory energy performance at reduced material costs. To calculate the structural FRLs of conventional and modular, single and double plasterboard layers sheathed LSF walls, 4 empirical models have been proposed where more than 97% accuracy was achieved. Moreover, incorporating back blocking panels and discontinuous insulation options, several novel conventional and modular LSF walls have been proposed with up-to 70% improvement in structural FRL.

Energy performance of fire rated LSF walls under UK climate conditions

Light-gauge Steel Frame (LSF) systems, one of the emerging building practices can be susceptible for catastrophic failure in fire accidents and less energy efficient due to the high thermal conductance of Cold Formed (CF) steel elements and resulting thermal bridging effect. Apart from independent investigations and optimization on LSF walls against fire and energy performance, it is vital to build-up knowledge on energy performance of fire rated LSF walls. Therefore, a series of fire rated conventional and modular LSF wall panels, which covers a wide range of industrial practices in European countries, have been investigated for their thermal transmittance, U-Value in the present study. Firstly, Finite Element Models (FEM) for three LSF wall panels were developed and validated against previous results. Subsequently, these models were extended to analyse the U-Values of the parametric specimens. The results show that, the concepts of back-blocking panels and discontinuous insulation options account for only slight improvements of U-Value (3–5%). Moreover, the variation of U-Value with respect to the cavity insulation ratio is found to be quite interesting, that adding cavity insulation at very low Insulation Ratios (IR) like 0.2 to 0.4, a 40%–60% reduction in the U-Value is obtained while further increase in IR results in less than 10% U-Value reduction. Therefore, 0.2 to 0.4 IR is proposed for conventional and modular LSF walls for appreciable energy performance avoiding unnecessary compensation in terms of costs, weight of the structure and structural fire performance.

A novel hybrid composite phononic crystal plate with multiple vibration band gaps at low frequencies

The low-frequency vibration isolation of a new hybrid phononic crystal plate are numerically and experimentally demonstrated in this paper. The proposed structure is composed of two types of periodic double-sided composite resonators deposited on a two-component plate. The dispersion relations, transmission spectra, and displacement fields of the eigenmodes are calculated by the finite element method. Compared to the classical phononic plate, the proposed structure can generate multiple flexural and longitudinal band gaps (BGs) at low frequencies. The formation mechanisms of the BGs can be explained by the corresponding “analogous-rigid modes”. The results of the parametric analyses show that the BGs can be significantly modulated by adjusting the material and geometric parameters. Furthermore, shake tests on a fabricated specimen were performed to verify the attenuation performance for elastic waves of specific frequency ranges. This research indicates that the proposed structure is a promising option for broadband low-frequency vibration insulation.

Comparative Analysis of Various Insulation Materials for Building Envelope Components

Due to growing environmental and economic concerns in recent years there has been a renewed interest in building energy efficiency as building contribute a huge consumption of energy across world. Among the effective and compatible ways of energy conservation technologies available today, insulation of buildings is most relevant as it also reduces negative environmental impacts and annual energy costs. The building envelope comprises of different components which are pre-dominant in evaluating thermal performance of a building. A proper selection of insulation materials results in a low energy demand process. In any material selection procedure, the ultimatum is of addressing material properties, parameters, criteria and performance characteristics. Hence this study aims to provide a knowledge base on identified insulation materials for corresponding building components with respect to material properties and performance parameters and recommend best material. Study presents comparative analysis of insulation options available for various building components.

Towards open-source LOD2 modelling using convolutional neural networks

The aim of this paper is to classify and segment roofs using vertical aerial imagery to generate three-dimensional (3D) models. Such models can be used, for example, to evaluate the rainfall runoff from properties for rainwater harvesting and in assessing solar energy and roof insulation options. Aerial orthophotos and building footprints are used to extract individual roofs and bounding boxes, which are then fed into one neural network for classification and then another for segmentation. The approach initially implements transfer learning on a pre-trained VGG16 model. The first step achieves an accuracy of 95.39% as well as a F1 score of 95%. The classified images are segmented using a fully convolutional network semantic segmentation model. The mask of the segmented roof planes is used to extract the coordinates of the roof edges and the nexus points using the Harris corner detector algorithm. The coordinates of the corners are then used to plot a 3D Level of Detail 2 (LOD2) representation of the building and the roof height is determined by calculating the maximum and minimum height of a Digital Surface Model LiDAR point cloud and known building height data. Subsequently the wireframe plot can be used to compute the roof area. This model achieved an accuracy of 80.2%, 96.1%, 96.0%, 85.1% and 91.1% for flat, hip, gable, cross-hip and mansard roofs, respectively.

Thermal suit connected to a forced-air warming unit for preventing intraoperative hypothermia: A randomised controlled trial.

Inadvertent intraoperative hypothermia is a common occurrence in surgical patients. A thermal suit is an option for passive insulation. However, active warming is known to be more effective. Therefore, we hypothesised that a forced-air warming (FAW) unit connected to the thermal suit is superior to a commercial FAW blanket and a warming mattress in breast cancer surgery. Forty patients were randomised to this prospective, clinical trial to wear either the thermal suit or conventional hospital clothes under general anaesthesia. The Thermal suit group had a FAW unit set to 38°C and connected to the legs of the suit. The Hospital clothes group had a lower body blanket set to 38°C and a warming mattress set to 37°C. Core temperature was measured with zero-heat-flux sensor. The primary outcome was core temperature on admission to the recovery room. There was no difference in mean core temperatures at anaesthetic induction (P=.4) or on admission to the recovery room (P=.07). One patient in the Thermal suit group (5%) vs six patients in the Hospital clothes group (32%) suffered from intraoperative hypothermia (P=.04, 95% CI 1.9%-49%). Mean skin temperatures (MSTs) were higher in the Thermal suit group during anaesthesia. No burns or skin irritations were reported. Two patients in the Thermal suit group sweated. A thermal suit connected to a FAW unit was not superior to a commercial FAW blanket, although the incidence of intraoperative hypothermia was lower in patients treated with a thermal suit.

Energy-efficient indicators of panel housing mass construction in the climatic conditions of central Russia

For the design of energy-efficient buildings, it is only necessary to ensure balanced energy consumption. The definition of energy efficiency is inextricably linked to compliance with requirements and economic costs. The concept of energy efficiency does not only apply to a new building. The new design used all the necessary elements. The use of single-layer prefabricated panels in new construction allows for external insulation taking into account the overlap of all monolithic joints. One of the potentially promising methods of thermal insulation of outdoor structures is the use of liquid-ceramic (thermal insulation) coatings. In the course of the study, it was concluded that the surface temperature of the reinforced concrete panel when using two different insulation options has similar indicators. But the difference in the values of the heat flux is 36.2%, i.e. when using liquid-ceramic insulation, the amount of heat transferred through the wall panel is more by 9.67 W / m2. Economic calculation shows that the use of liquid-ceramic insulation has a positive economic effect in comparison with the classical method of wall insulation by 19.56%.