Building Insulation Research Articles

Changes in properties of thermal insulations under certain environmental effects

AbstractSaving energy and reducing greenhouse gas emissions is a priority for the construction sector. Heating of buildings requires the burning of fossil fuels, which can be significantly reduced by insulating the building envelope. Nowadays, the thermal insulation of buildings is essential. There are several important, well-known data about most thermal insulation materials, but there is only negligible information about the change of their properties under installation conditions or if they are already exposed to additional stresses due to structural failures and damages. This study aimed to examine the changes in properties of three common thermal insulation materials when installed in a flat roof or facade and exposed to excess moisture due to the damage of waterproofing or façade and/or when exposed to direct strong sunlight.

The Impact of Residential Building Insulation Standards on Indoor Thermal Environments and Heat-Related Illness Risks During Heatwaves: A Case Study in Korea

This study investigates the impact of building insulation standards on indoor thermal environments and the risk of heat-related illnesses during heatwaves in South Korea. Indoor temperatures were measured in residential buildings located in Chuncheon and Gwangju during the 2022 heatwave, with outdoor temperature data sourced from the Korea Meteorological Administration. Probability distribution fitting was used to estimate the likelihood of indoor temperatures exceeding the critical threshold of 27 °C. Additionally, a linear regression analysis was conducted to examine the relationship between the probability of exceeding the threshold and heat-related illness data from 2017 to 2023 provided by the Korea Disease Control and Prevention Agency. The findings reveal significant variations in indoor thermal conditions during heatwaves, influenced by factors such as building type, year of construction, and climate region, which affect the thermal insulation performance. Buildings with a lower thermal insulation performance were associated with higher indoor temperatures, increasing the likelihood of exceeding the critical threshold and contributing to a higher incidence of heat-related illnesses, particularly in provincial non-metropolitan areas. These results underscore the need for region-specific building insulation standards that address both winter energy efficiency and summer heatwave resilience. Enhancing thermal insulation in vulnerable regions could significantly reduce the risk of heat-related illnesses and improve public health resilience to extreme heat events.

Development of a high-strength lightweight geopolymer concrete for structural and thermal insulation applications

Investigating the thermal insulation properties of lightweight geopolymer concrete is essential. This paper aims to develop a lightweight aggregate geopolymer concrete (LWAGC) with good density, compressive mechanical and thermal insulation properties. The dry density of LWAGC was adjusted by incorporating expanded perlite (EP). The variation in physical and mechanical properties of LWAGC with different EP content was discussed, including dry density, P-wave velocity, ultimate compression strength and elastic modulus. Based on infrared thermal imaging technology, a rapid measurement method was proposed to simulate the indoor temperature change of buildings at high ambient temperatures. The thermal insulation performance of the LWAGC with different EP contents was further evaluated. The findings show that as the EP content in LWAGC increases, there is a corresponding decrease in P-wave velocity, dry density, ultimate compressive stress, and elastic modulus. The lowest dry density of LWAGC reaches 1209kg/m3 while the ultimate compressive stress is still larger than 25.0MPa, which can used as LC25 building materials in load-bearing structures. The results also show that the addition of EP can improve the thermal insulation properties of LWAGC. The LWAGC with 50% EP content has the highest reduction rate of temperature and can maintain the indoor temperature lower than 35 °C under high ambient temperature, which have potential application prospects in the load-bearing structures and thermal insulation of tall buildings.

Multi-season passive variable insulation for buildings using magnetic thermal diodes

Multi-season passive variable insulation for buildings using magnetic thermal diodes

Size effect of typical hygrothermal properties test values for building insulation materials

Thermal and moisture properties of building insulation materials are crucial input parameters for analyzing thermal and moisture transfer phenomena in building environments. Accurate determination of these parameters under different conditions is essential for the correct application and assessment of materials and envelope structures. However, numerous factors influence thermal and moisture properties, and while extensive research has been conducted on this topic, the effects of specimen size on typical thermal and moisture property test values remain unclear. To address the issue of unreliable data caused by random specimen sizes in thermal and moisture property testing of building insulation materials, this study selects three materials—expanded polystyrene (EPS), extruded polystyrene (XPS), and foamed cement—as test subjects to explore the size effects on typical thermal and moisture property test values. The results indicate that specimen size significantly affects the test values for typical thermal and moisture properties, with only a few experiments showing negligible size effects for certain materials. For foamed cement, recommended specimen sizes for thermal conductivity testing using the guarded hot plate method and the transient plane source method are 300 × 300 × 30 mm and 50 × 50 × 30 mm, respectively. Except for equilibrium moisture absorption experiments, the weight of other moisture property tests is generally represented by thickness > planar dimensions.

Impact of external wall insulation of office buildings on the interior microclimate

Impact of external wall insulation of office buildings on the interior microclimate

Simulation-based design: minimizing energy consumption in residential buildings through optimal thermal insulation

Purpose This study aims to optimize the energy consumption of residential buildings in mild and humid climates. It investigates the use of thermal insulation to reduce thermal load through energy simulation analysis. Design/methodology/approach A residential building located in Rasht city, Iran (a mild and humid climate zone), is simulated using DesignBuilder software. Subsequently, the minimum thermal resistance for external walls and roof is analyzed along with its impact on building energy consumption and carbon emissions. Findings The simulation results indicated a 26.5% reduction in heat loss through the walls and a 14.2% reduction through the roof due to optimal thermal insulation. Furthermore, optimal insulation led to a 19.2% reduction in cooling system energy use, a 12% reduction in heating system energy use and a combined 15.3% reduction in total energy consumption for cooling and heating. Originality/value This optimization process leads to several benefits: reduced costs associated with thermal and cooling energy losses in buildings, improved building performance against atmospheric factors and, ultimately, a reduction in energy consumption across the building industry. This research can be valuable to various stakeholders, including the construction industry and building sector, municipalities and engineering systems, building owners and contractors and environmental organizations. By implementing these findings, they can improve the state of modern building insulation and achieve greater energy efficiency.

Incorporation of Phase Change Materials in Buildings

This review paper explores the integration of phase change materials (PCMs) in building insulation systems to enhance energy efficiency and thermal comfort. Through an extensive analysis of existing literature, the thermal performance of PCM-enhanced building envelopes is evaluated under diverse environmental conditions. This review highlights that PCMs effectively moderate indoor temperatures by absorbing and releasing heat during phase transitions, maintaining a stable indoor climate. This paper also delves into the detailed concepts of PCMs, including their classification and various applications within building insulation. It is noted that different types of PCMs have unique thermal properties and potential uses, which can be tailored to specific building requirements and climatic conditions. Furthermore, cost–benefit and environmental assessments presented in the reviewed studies suggest that incorporating PCMs into building materials offers significant potential for reducing energy consumption and mitigating environmental impacts. These assessments indicate that PCMs can lead to substantial energy savings by decreasing the reliance on heating and cooling systems, thereby lowering overall energy costs and carbon emissions. However, despite the promising outlook, this review identifies a need for further research to optimize PCM formulations and integration methods. This optimization is essential for overcoming current challenges and facilitating the widespread adoption of PCMs in the construction industry. Addressing issues such as long-term durability, compatibility with existing building materials, and cost-effectiveness will be crucial for maximizing the benefits of PCMs in enhancing energy efficiency and sustainability in buildings. Overall, this review underscores the transformative potential of PCMs in building insulation practices. By providing a comprehensive overview of PCM classifications, applications, and their impacts on energy efficiency and environmental sustainability, this paper lays the groundwork for future advancements and research directions in the field of PCM-enhanced building technologies.

Multi-objective assessment of the retrofit of traditional walls located in a historical city centre using an urban climate model

Historical city centres face two major challenges in the 21st century: heritage conservation and energy retrofitting. Wall insulation in traditional buildings is at the crossroads of these two issues. When studying the retrofit of the walls, other factors also need to be considered, such as the durability of the walls, the life cycle of the materials used for insulation, the indoor and outdoor comfort in summer. The aim is to propose a method for taking all these objectives into account when choosing the insulation technique for historical walls. To do this, the TEB (Town Energy Balance) urban climate model is used, because it considers the urban microclimate, the energy behaviour of buildings and moisture transfer through walls. A VTT model is integrated into TEB, to include the risk of mold growth. The medieval city centre of Cahors (France) was used as a case study. The retrofit of two types of wall was assessed: “massive” brick walls, and “light” walls with a timber-framed structure, filled with bricks. Six renovation scenarios were studied, including four insulation materials and both internal and external insulation positions. The results obtained underline the need to study the retrofit of the two types of building separately, because the recommendations made for insulation vary depending on the type of wall studied.

Comparative study of different programs for sound insulation calculations

Engineering programs for calculating sound insulation in wooden buildings are a shortage, especially when it comes to wooden structures. There are some possibilities today to calculate field values using commercial programs following ISO 12354. However, detailed calculations for each construction part are sometimes crucial to optimize correctly, specifically for CLT or wood beam structures since they are far more complex than traditional concrete structures. Now, some programs are available on the market to calculate sound insulation for CLT structures. StoraEnso offers "Calculatis" online for free, and Marshall Day Acoustics provides "Insul 10". In short, the company Sonusoft will release a software called "Acoulatis". These three programs have slightly different approaches, and their capability to calculate various wall and floor structures differs. Nevertheless, the different programs are all limited to walls or floors construction parts, e.g. the outcome is Rw and Ln,w including spectrum adaptation terms, e.g. junctions are not included. In this paper, a comparison is made using the three different programs, including comparisons to measured values when available.

Sound insulation in different kinds of offices - what is needed for different situations

Some kind of working groups like doctors, priesthood and lawyers are dealing with confidential and personal information in their daily life. In general there is a need to hinder personal information to be spread more than necessary. With loud level of conversation in pressed situations, R'w of minimum 48 dB is needed to hinder spreading of sensitive information to neighbor room. The paper will discuss different concepts for offices like office landscape, client-zone, and when and why proper sound insulation is necessary. There are also other buildings where proper sound insulation is needed between offices, like offices and meeting rooms in schools, kindergarten, social welfare services, banking services, insurance companies and house for family counseling or health care. It is a big need to clarify sound insulation in office buildings or administration rooms based on what kind of conversations are going on or what kind of information are being dealt with. The boundary between necessary sharing of information for proper internal discussion and unnecessary spreading is important issue to consider. Experience shows that duty of confidentiality for employees is not sufficient to hinder spreading of sensitive information.

Extending the frequency range of ISO 717-2 - a look at options and issues

In 2019, the Norwegian Standard NS 8175, which defines requirements for sound insulation in Norwegian buildings, was revised to include low frequency spectrum adaption terms for new dwellings. This change affects the applicability of measurements of weighted improvement of impact sound insulation, delta Lw, as the spectrum for calculating delta Lw, given in ISO 717-2, is limited downwards to 100 Hz. For a floating floor construction, this means that floors with a resonance frequency well below 100 Hz, and correspondingly a relatively high delta Lw, will be overrated in the sense that the measured delta Lw will be unaffected by the poor low frequency performance of the floating floor. To properly address this increased focus on low frequencies, an extended range spectrum is needed. In the work leading to this paper, a selection of extended range values for the reference heavyweight floor have been suggested, starting with a linear extrapolation of the values given in ISO 717-2. Data from laboratory measurements of delta Lw for floating floors have then been used to investigate the suitability of the suggested values. The results are summarised and discussed in this paper.

Investigation of thermal, acoustic, mechanical, and radiation shielding performance of waste and natural fibers

It is crucial to address two pressing global issues, energy shortage and environmental pollution, when producing building insulation materials. Using waste and natural fiber groups can be part of the solution. The insulation material was produced using pumpkin fiber, chicken fiber, cotton waste, vermiculite, and epoxy as binders. The samples were tested for thermal conductivity coefficient, ultrasonic sound transmission rate, density, water absorption rate, compressive and bending strength, and fire resistance at temperatures of 75, 100, 125, and 150C. The samples produced using natural and waste materials yielded a thermal conductivity value of 0.041 W/mK, an ultrasonic sound transmission speed of 0.25 km/s, a compressive strength value of 1.57 MPa, and bending strength values of 0.91 MPa. It has been clearly demonstrated that, with its low volume loss, it can serve as an alternative to the EPS-XPS types available in the market. Furthermore, the linear attenuation coefficients (LAC) were examined to obtain radiation shielding properties of the samples at 1173 and 133 keV energies using a 60Co gamma source. Also, LAC values determined between 0,1167 ± 0,0452 cm−1-0,2315 ± 0,0065 cm−1 for 1173 keV and 0,1042 ± 0,0488 cm−1 - 0,2141 ± 0,0062 cm−1 for 1333 keV. Accordingly, it has been revealed that waste compositions are effective in protecting against radiation.

Fabric Retrofit of a Hard-to-Treat, Pre-1919 House in Preparation for Heat Pump Use

The uptake of low-carbon domestic heating systems is a significant strategy towards global targets of reducing greenhouse emissions and mitigating climate change. Pre-1900 hard-to-treat houses will still be existing in the next 25 years, and they have the greatest potential for improved energy-efficiency. This study investigates the potential of fabric retrofit to prepare an older, hard-to-treat house type for heat pump use. The house type was modelled in DesignBuilder and validated using the Ulster University test house. The wall, loft and floor insulation, as well as glazing upgrades can yield up to 50% reduction in heating demand for a hard-to-treat house type, thereby preparing it for heat pump installation. Additionally, upgrading insulation and glazing in line with the current building standards was cost-effective, with a net present value of approximately GBP 12,000.

OPTIMIZATION OF HEAT CONSUMPTION IN CENTRAL HEATING SYSTEMS AT COMMERCIAL FACILITIES

Rising energy prices and stricter environmental regulations are exacerbating the problem of inefficient heat consumption in the commercial sector. Central heating systems of office buildings, shopping malls, and industrial complexes are often characterized by excessive thermal energy consumption, which leads to significant economic losses and a negative impact on the natural environment. The purpose of the study is to study the directions and trends of optimization in the field under consideration (taking into account modern technological capabilities, and economic factors). There are disagreements in the professional community about the priority of measures to improve energy efficiency: some experts prefer improving the thermal insulation of buildings, others — the introduction of intelligent control systems, and others — the integration of renewable energy sources. The present study demonstrates that the greatest effect is achieved with a systematic approach combining various initiatives. The conclusion is formulated that in the current conditions and the future, a comprehensive application of modern thermal insulation materials, highly efficient heating equipment, intelligent management mechanisms, and alternative energy sources is required. The article is of interest to engineers-designers of heating systems, energy managers of commercial facilities, specialists in energy efficiency of buildings, and heads of companies interested in optimizing operating costs and improving the environmental friendliness of their real estate.

Bioinspired polylactic acid/polyethylene glycol @ silicon dioxide microfibrous tarpaulin with dual-layer heterogeneous structure for enhanced daytime radiative cooling

Fibrous tarpaulin serves as the core barrier that protects goods, people, or areas from the adverse impacts of the external environment, such as rain, dust, and sunlight. However, conventional tarpaulins exhibit inadequate mechanical properties, a low solar reflectance, and are susceptible to pollution. To address these issues, a bioinspired polylactic acid/polyethylene glycol @silicon dioxide (PLA/PEG@SiO₂) microfibrous tarpaulin with a dual-layer heterogeneous structure was fabricated via in-situ drafting melt-blowing combined with thermal bonding, inspired by the layered structure of shells. This bioinspired dual-layer heterogeneous structure, with an adjustable heterodyne angle and SiO₂ size gradient, significantly improved the mechanical performance of the PLA/PEG@SiO2 microfibrous tarpaulin, and specifically manifested as an increase in the bursting strength of the sample to 25.5 N. Moreover, PLA/PEG@SiO2 microfibrous tarpaulin demonstrated excellent anti-pollution properties, effectively repelling liquids and dust. Additionally, its radiative cooling efficiency was notably enhanced, achieving a temperature reduction of ~9.8 °C compared with conventional fabrics, with reflectance of ~88.6 % and emissivity of ~98.3 %. These findings suggest that dual-layered PLA/PEG@SiO₂ microfibrous tarpaulin with multifunctional capabilities is a promising candidate for radiative cooling in outdoor shelters, wearable cooling devices, and energy-efficient building insulation materials.

Research on preparation and microscopic mechanism of heat-insulating & flame-retardant EP/PI composite aerogel

Polyimide aerogels, with their lightweight, thermal insulation, and flame-retardant properties, have found extensive applications in aerospace, military, and other fields. However, their use in the building insulation materials market is rare. This paper focuses on polyimide (PI) aerogels and incorporates expanded perlite (EP) of different mesh sizes and qualities to prepare expanded perlite/polyimide (EP/PI) aerogels, aiming to enhance the performance of building insulation materials and reduce energy consumption in buildings. The research results indicate that the incorporation of EP not only protects the aerogel framework from complete destruction and improves its high-temperature stability but also significantly affects the pore distribution of PI aerogels. Specifically, doping a mass of 0.2g of expanded perlite with a mesh size of 80 can increase the specific surface area of PI aerogels by 15 times, effectively increasing the number of pores and the quantity of non-communicating pores in the aerogel, while also reducing the thermal conductivity of PI aerogels by 10 %, thereby hindering heat transfer and enhancing their thermal insulation and flame-retardant properties. To gain a deeper understanding of the thermal insulation mechanism of aerogels, the study combines molecular dynamics principles to analyze the diffusion of nitrogen molecules within the aerogel, thereby elucidating the heat transfer process and explaining the thermal insulation mechanism of EP/PI aerogels. Overall, the findings of this study demonstrate low density, low thermal conductivity, good high-temperature stability, and excellent thermal insulation and flame-retardant effects, indicating significant application potential and socio-economic benefits in building insulation materials.

Health implications of housing retrofits: Evidence from a population-wide weatherization program

This study provides the first population-representative quasi-experimental estimates on the impact of housing upgrades on occupant health. We analyze the exceptional period of renovations in East Germany following the German reunification during the 1990s. Triggered by one of the largest governmental loan programs in history, 3.6 million dwellings were renovated, focussing on upgrades to the building insulation, windows and heating systems. Using rich survey data based on the Socio-Economic Panel (SOEP) as well as administrative records of hospital admissions in Germany, we consistently show that housing weatherization upgrades sustainably reduce the demand for health care among the elderly sample of the population.

Wealth as an obstacle and a support for environmental protection

Wealthy populations appear prone to protecting the environment. By contrast, wealthy individuals appear prone to harming it. In other words, wealth appears to have opposing effects on the environmental protection efforts of individuals and populations. In our secondary analysis of Eurobarometer data (N = 27,998) from 28 countries, we demonstrate that wealth represents a behavioral benefit that supports populations' efforts to protect the environment (e.g., via government subsidies). Wealth also represents a behavioral benefit that supports individuals’ efforts to protect the environment (e.g., by making effective home insulation affordable), but it simultaneously represents a behavioral cost that appears to prevent individuals from protecting the environment (e.g., by making excessively large homes affordable). We conclude that when behavioral scientists recognize that wealth can be a cost and a benefit simultaneously, they will ultimately understand when and why populations and individuals engage in environmentally protective actions or fail to do so.

THE PROSPECT OF USING GEOTECHNICAL SEISMIC INSULATION MADE OF GRUNTOSILICATE TO PROTECT ARCHITECTURAL MONUMENTS

The article explores the prospects of utilizing geotechnical seismic insulation made from gruntosilicate to protect architectural monuments from seismic influences. It highlights the advantages of this technology, including the preservation of the integrity and authenticity of historical buildings, minimal interference with their original construction, and the durability of the materials used. The article outlines the primary methods and technologies of seismic insulation, such as insulating layers, dampers, and shock-absorbing materials. Additionally, it provides examples of successful applications of seismic insulation in various historical buildings. The importance of adopting modern technologies to safeguard cultural heritage in regions with heightened seismic activity is emphasized throughout the discussion. The primary aim of the article is to demonstrate the effectiveness of geotechnical seismic insulation in preserving architectural heritage. Experimental studies have shown that gruntosilicate, when used as a seismic insulation material, significantly reduces the amplitude of seismic vibrations, thereby enhancing the safety and longevity of buildings. The article posits that geotechnical seismic insulation represents a promising approach in earthquake-resistant construction, necessitating an integrated approach that takes into account technical, economic, and geological factors. This research underscores the potential of this technology to provide sustainable solutions for the protection of cultural heritage in seismically active regions.