Insulation Board Research Articles

Model test investigation on heat and deformation behaviors of canal slopes with protective layers caused by freeze-thaw action

Frost damage is one of the main factors affecting the stability of canal slopes in cold regions. To alleviate the damage, laying protective layers during the construction process has become an indispensable measure. In this study, two slope models were constructed using polyester geotextiles (slope I) and composite geomembranes (slope II) as the protective layer. Additionally, the insulation board in the control group were laid on specific section to examine their anti-frost effect. The temperature, frozen depth, and frost deformations of slope models during the freeze-thaw process were recorded and analyzed. Results suggest that the temperature of slope II is relatively lower than that of slope I in the freezing process. The temperature reduction at all monitoring sections of slope II are larger than that of slope I. The slope I exhibits a significant decrease in maximum frozen depth and maximum frost deformation. In particular, the section with the maximum frost deformation is independent of the type of protective layer, which all occurs in the middle of the slopes. The maximum frost deformations of slope models are 33.60 mm and 37.69 mm, respectively after laying the polyester geotextiles and composite geomembranes. Therefore, the polyester geotextiles have more advantages in reducing frost deformation than composite geomembranes. Additionally, if the insulation board and polyester geotextiles are laid together inside the slope, the maximum frost deformation can be further reduced to 9.72 mm. This study will help in the design and construction of canal slopes in cold regions.

Wood-fiber insulation boards (WFIB) produced with hardwood and softwoods species and polylactic acid (PLA) fibers as a binder

ABSTRACT Wood fiber insulation boards (WFIB) produced with natural binders have been gaining recognition as an eco-friendly material, however there is limited information on the effect of different wood fiber and sustainable binders on WFIB production. This study investigates the impact of density, wood fiber origin, and pertinency of polylactic acid (PLA) as a binder. Flexible WFIB with densities of 80, 100 and 120 kg/m3 were produced by hot-press method with fibers of pine and spruce as softwoods, and beech and birch as hardwoods. Bicomponent fibers, composed by two concentrical layers of polylactic acid (PLA) were utilized as a renewable-origin binder at a proportion of 10%. Technological properties such as short-term water absorption, compression test and thermal tests properties were assessed. The density of the WFIB significantly influences the water absorption, compression strength, and thermal conductivity, with all these values increasing as the density rises. Insulation boards made from hardwood fibers showed greater water absorption and compression values compared than their softwood counterparts. Softwood-WFIB single-samples with a density of 80 kg/m3 reported lower thermal conductivities than hardwoods ones. The present study shows the promising feasibility of producing flexible wood fiber insulation boards from natural fibers and polylactic acid as a renewable binder.

Effectiveness evaluation of cooling measures for express highway construction in permafrost regions based on GPR and ERT

Global warming and human activities are accelerating the degradation of permafrost on the Qinghai-Tibet Plateau (QTP), leading to significant settlement and cracking issues in the local express highway infrastructures. In response, the Gonghe-Yushu Express Highway (GYE) on the east edge of the QTP incorporated extensive cooling measures during its construction to enhance embankment stability. Despite these efforts, field investigations have disclosed that embankment diseases persist across various sections, including those with implemented cooling measures. This study focuses on a specific test and demonstration section of the GYE, employing a suite of cooling measures to assess their engineering effectiveness. Utilizing a combination of multi-time ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) detection, alongside on-site disease investigations and temperature monitoring, this research comprehensively evaluates the efficacy of different cooling interventions. Findings indicate that although cooling measures generally curb permafrost degradation in areas with ice-rich and ice-saturated soils, they fall short in sections with massive ground ice. Of the six cooling measures examined in the demonstration section, ventilation duct embankments emerge as the most effective, whereas crushed-rock layer embankments rank as the least. The study further reveals that the combined use of XPS insulation boards and two-phase closed thermosyphons inadequately addresses the issue of central heat accumulation in broad-width express highways, reducing uneven settlement issues but aggravating longitudinal cracking. Comparative analysis of on-site surveys and monitoring data suggests that regular application of GPR and ERT techniques can proficiently assess the performance of cooling measures.

On the Emergence of Shipping Container Homes: Adaptation to Future Climate Projections

Upcycling shipping containers for housing is increasingly recognised as a sustainable solution to housing challenges, particularly in developing economies like Nigeria. This study evaluates the thermal comfort and energy efficiency of shipping container homes under climate conditions projected for 2080. Using meteorological data for Abuja and Lagos under the Representative Concentration Pathway 8.5, a stand-alone shipping container home was simulated. The study incorporated fabric optimisation techniques, using polyurethane foam and polyisocyanurate board insulation, high-performance window glazing, and shading strategies. The findings reveal that without intervention, container homes would experience significant thermal discomfort, with annual discomfort hours exceeding 28°C in both cities. However, with insulation and shading, annual discomfort hours were reduced by up to 87%, and energy consumption decreased by 76%. These results highlight the critical role of insulation and shading in enhancing thermal comfort and reducing energy demand, making container homes a viable solution for sustainable housing in hot climates. The study underscores the need for policy support to promote the integration of advanced insulation and adaptive design strategies to ensure the resilience and sustainability of container homes in future climates.

Synthesis of biobased Phosphorus-Nitrogen-Silicon ceramizable flame retardant and its flame retardancy effects on EPS

The rising interest in eco-friendly flame retardants marks a notable trend in the industry. However, the challenge remains that most flame retardants, while achieving high flame retardant properties, struggle to balance environmental sustainability and resource utilization. This work delves into the green synthesis and mechanism of action of ceramizable flame retardants. Using phytic acid (PA) and urea (U) as raw materials, ionic complexation assembly in water, employing polydopamine (PDA) as an adhesive, to develop an environmentally friendly, bio-based synergistic flame retardant (PAU) is conducted. Building upon this groundwork, the addition of the ceramic filler kaolin (KL) and the fluxing agent sodium carbonate (Na2CO3) physically modifies the PAU, resulting in a novel eco-friendly, bio-based, ceramifiable flame retardant (PAUK). Employing the prepared PAUK through an effective surface coating technique, a lightweight and scratch-resistant flame-retardant expanded polystyrene insulation board (EPS-PAUK) is created. The best EPS-PAUK composite in our study exhibits an oxygen index of 52.5, achieves a V-0 UL-94 rating, and features excellent smoke suppression and compression strength up to 67.8 kPa, while nearly maintaining the lightweight characteristics of the EPS insulation boards. This bio-based, ceramifiable flame retardant system offers a new approach for producing lightweight, highly efficient flame-retardant and high-performance polymers.

Experimental investigation of a distributed photovoltaic heating system based on building envelope thermal storage

Low-carbon heating in farmhouses can be achieved using photovoltaic (PV) heating. However, the severe mismatch between the PV energy supply and the building thermal load requires expensive energy storage devices and control systems. In this study, a controller-less PV heating system utilizing the building envelope for thermal storage was evaluated on a farmhouse in northern China. The building envelope simultaneously functions as the heating terminal and is composed of insulation boards, electric heating wires, and the thermal storage wall. PV electricity is fed to be absorbed by the electric heating wire to produce heat. The thermal storage wall absorbs the heat generated by the heating wire before releasing it into the room through convection and radiation. Long-term monitoring reveals that the black bulb temperature of the farmhouse was above 16 °C for more than 60 % of the time throughout the heating season. The building envelope acting as a thermal reserve improved system supply and demand matching by 77 % and the indoor temperature fluctuation was reduced by about 47 %. The thermal storage wall can provide 58 % of the heating energy when there is no PV power supply. The payback period of the heating system is only 6.5 years, verifying the good rate of return of the system. This study proposes a lower cost energy storage solution for PV heating than previous studies, and engages the building envelope into the building energy system.

The thermal conductivity of graphite composite insulation boards: A theoretical and experimental study

Graphite composite insulation boards (GCIB) have emerged as a promising solution in the construction industry, offering a combination of fire resistance, high temperature stability, and excellent insulation properties. As their usage continues to increase, it is crucial to develop and validate a more accurate theoretical model for the effective design and optimization of building insulation systems. Traditional models including series and parallel models are employed for estimating the thermal conductivity of GCIB but revealed higher relative errors and lower theoretical calculation accuracy. Therefore, the primary objective is to design and validate a more efficient theoretical model for thermal conductivity prediction in GCIB. This paper investigates the thermal conductivity of GCIB under varying composition ratios by designing a novel Parallel-Series Parallel (PSP) approach. The PSP model is designed based on a single basic cell where the graphite polystyrene particles are employed as the matrix material while cement, vitrified microspheres, and silica fume are used as inclusion materials. Then, the thermal conductivity unit is divided into three parallel heat conduction subunits where the matrix materials and inclusion materials in the three subunits are integrated in a series-parallel manner to provide a more realistic representation of the heat transfer mechanisms within the composite. For a comprehensive assessment, the study encompasses theoretical analysis, empirical assessment, and finite element (FE) simulations to illustrate its thermal properties. The predicted thermal conductivity reveals perfect consensus in comparison with the FE and experimental test outcomes by achieving lower relative errors of 2.7 %∼3.8 % and 1.9 %∼ 3.0 % respectively. The model validated through numerical simulations and sample experiments illustrates a significant improvement in accuracy of about 76.4 %∼94.3 % when compared to traditional series and parallel methods. Prominently, the findings indicate that the thermal conductivity of GCIBs declines considerably as the volumetric ratio of graphite polystyrene particles (Ф1/Ф3) increases and stabilizes when the proportion reaches 10, emphasizing the importance of optimizing material composition to enhance the thermal performance of GCIB. Overall, the validated PSP model by accurately determining the thermal conductivity of GCIB serves as a reliable tool for designing and optimizing high-performance insulation materials, contributing to energy efficiency and sustainability in building and construction industries.

Target energy management for sustainable molding companies: Consumption, saving, and enviro-economic investigation

The industrial sector is the world's leading energy consumer and CO2 emitter and yet has not received sufficient focus to reduce its energy consumption and adverse environmental impact. So, this paper addresses this gap by presenting industrial-based research on energy audit and target energy management for a sustainable bulk molding company in Alexandria, Egypt. The management focuses on the hot press hydraulic building section which consumes more than 30 % of the company's total energy. The sources of energy losses within this section are identified and quantified. Energy-saving measures including thermal energy management are proposed, implemented and valorized based on energy savings, cost and environmental impact. The yearly savings on energy consumption, energy bills and CO2 emission reduction for the molding machines are estimated. The results show that the main sources of molds' energy losses are in the preheat stage and convection and radiation from the hot mold surfaces. The maximum energy saving due to modifying the preheat stage duration is about 51 %. The gained energy reduction due to changing the mold insulation boards is about 17.5 % and 55.3 % during the preheat and production stages, respectively. Moreover, using double layer insulation boards with the mold insulation cage reduces energy consumption by about 69.5 %. The payback period falls between 1.53 and 6.11 months where these techniques for one machine can save 1229.3 $/year and reduce 16,651.598 kg/year CO2 emission. The study contributes to a broader understanding of how proactive insulation and thermal management can lead to significant energy and cost savings over a long-term period in industrial operations. Besides its contribution to sustainability goals: SDG7, SDG11, and SDG13, the study's approach proves its efficacity and can serve as a precedent for other industrial sites trying to enhance energy efficiency in their most energy-intensive areas.

Experimental study on thermal bridge effect of steel-concrete-steel tunnel elements under fireproof board insulation schemes

Steel embedded parts welded on the surface of steel-concrete-steel tunnel elements serve as thermal bridges in tunnel fires. Their influence on temperature field and macroscopic thermal damage of steel-concrete-steel structure were investigated through fire tests, and their heat transfer forms were analyzed. Then, a thermal bridge disposal scheme was proposed and examined. The results show that steel embedded parts significantly cause an increase and an uneven distribution of steel shell temperature in tunnel fires. As time exposed to fire increases, the extent and range of these influences grow. Thermal bridges raise the average temperature by 45.2 % inside the steel-concrete-steel structure, worsen the unevenness of temperature distribution in horizontal and vertical directions. Thermal bridges worsen surface macroscopic damage, lengthening cracks by more than 32.5 % and widening them by more than 22.6 times. Within a distance of 30 cm from the embedded part, heat provided by embedded parts accounts for over 79.9 % of the steel shell's total heat, and heat conveyed along the steel shell through thermal conduction accounts for over 53.7 %. GX-3 high-temperature adhesive is an effective method for thermal bridge treatment. These detailed findings offer new insights into the design of fire insulation schemes for the steel-concrete-steel structure.

Comparison of the Economic and Environmental Sustainability for Different Peatland Strategies

Previous studies of the literature show that there are great uncertainties regarding costs and gains for peatland restoration strategies and that the monetary estimation of peatland restoration and possible alternatives can be complicated. The research aims to compare the economic costs and benefits of existing peatland restoration strategies and alternative use of peat and peatlands. A core method for the evaluation of the economic aspects of each strategy used is the composite index method. Information for constructing the composite index is based on data from the scientific literature, reports, and local project studies. In the study, peatland strategies, peat extraction, and alternative use in products were mutually compared with existing strategies. The highest composite index among strategies was for the production of insulation boards and cultivation of paludicultures using cattail or sphagnum farming. Cultivation of paludicultures can be an economically viable strategy if costs and gains are evaluated. Cultivation of cattail or sphagnum can make economic gains for landowners and farmers, and solutions for the reduction in necessary initial investments should be sought. Harvested biomass can be used for high-added-value products, in this case, insulation boards from cattail (Typha). Therefore, peat biomass can be used as an economically valuable resource, and raw material for insulation board production is obtained without the extraction of peat. Also, ecosystem services and potential income are not reduced.

Mitigation of shady-sunny slopes effect on subgrade by photovoltaic sheltered boards in permafrost regions

With the great demand of global carbon reduction, a novel method, such as photovoltaic shelter board (PSB), is proposed to mitigate the shady-sunny slope effects in permafrost. The idea of PSB is an extension of traditional shelter board, which can potentially eliminate the shady-sunny slope effect in theory. However, its quantitative performance is still unclear due to limited application and research. To overcome this gap and explore the application possibilities of PSB in cold regions, this paper introduces a novel photovoltaic sheltered board subgrade and numerically investigates its effectiveness in mitigating the shady-sunny slope effect. Initially, a heat transfer model incorporating solar radiation and air convection was developed and validated with field-monitored ground temperature data. Analyses based on this model compare the thermal imbalance effects on exposed subgrade, traditional insulation boards subgrade, and the novel photovoltaic sheltered board subgrade. Results indicate that the photovoltaic sheltered board exhibits superior mitigation effects to traditional insulation boards, primarily due to enhanced heat dissipation by air convection in the suspension region. In the study area, the photovoltaic sheltered board significantly lowers sunny slope temperatures by over 3 ℃ on average and thaw depth by more than 1m compared to exposed subgrade. The photovoltaic sheltered board’s suspension height should not be less than 5.3cm to mitigate the sunny-shady slope effect effectively in this region. In summary, this study provides a reference for mitigating the shady-sunny slope effects and reducing carbon release in permafrost subgrade engineering.

EFFICIENCY OF IMPLEMENTATION OF THE ENERGY MANAGEMENT SYSTEM AT 'RESEARCH AND PRODUCTION COMPANY 'ZOND' LTD

To ensure the correct approach to energy management and efficient use by enterprises and organizations, an energy management system is being implemented. The article is about effectiveness of the energy management system at the 'ZOND' LLC. An analysis of the use of fuel and energy resources is carried out, taking into account the structure of energy consumption and cost. It is established that in order to ensure rational consumption, it is necessary to apply a comprehensive approach to analyzing and prioritizing the proposed energy efficiency measures. The constructive and operational shortcomings of the heating system are described. The implemented measures for the rational use of gas are presented. Lighting aspects are considered, including the transition to LED lamps and the use of natural light. Significant heat losses by external envelope structures are revealed and the implemented measures for the building insulation with polystyrene insulation boards (EPS) are described. The results of the economic analysis are presented. The effectiveness of the measures taken by the enterprise to ensure backup power supply in the conditions of prolonged power outages is analyzed. The analysis of the enterprise's work during prolonged emergency power outages is carried out. A number of both minor and significant shortcomings of the described measures to provide electricity to the company's consumers have been identified. Particular attention is paid to the selection and use of uninterruptible power supply units to keep critical consumers running. The use of special skylights, also known as solar daylight tubes or light tubes, to reduce the use of artificial lighting is proposed. A conclusion is made about the effectiveness of an integrated approach to managing the energy efficiency of an enterprise in the context of modern challenges and a high level of energy efficiency management at this enterprise is confirmed.

Impact of thermal conductivity of aerogel-enhanced insulation materials on building energy efficiency in environments with different temperatures and humidity levels

New building thermal insulation materials, such as aerogel-enhanced insulation materials, are constantly emerging. To study how cement-based aerogel-enhanced thermal insulation materials perform under temperature and humidity changes, various aerogel-enhanced hollow glass microsphere insulation boards (HGBs) have been developed as building thermal insulation materials. The thermal conductivity of aerogel-enhanced HGBs, expanded polystyrene (EPS), and foamed cement (FC) was measured at various relative humidity levels and temperatures, and the summer cooling load of buildings with aerogel-enhanced HGBs, EPS, or FC as the insulation layer was simulated for different building heights and thermal zones. The results show that (1) the new aerogel-enhanced HGB materials are more suitable for building insulation in humid and hot areas than FC; (2) the cooling load of small buildings with fewer floors is more sensitive to the variation in the thermal conductivity with temperature and humidity; (3) for buildings in areas with hot summers and warm winters, the impact of the outdoor relative humidity should be fully considered when calculating summer cooling loads.

Hygrothermal behaviour of external thermal insulation composite systems (ETICS) to withstand biological colonisation

ETICS are multilayer building solutions applied to the building external walls to provide an improved thermal performance to the building envelope. However, several questions have been raised concerning the durability of ETICS, namely related to biological colonisation phenomena. Considering the high susceptibility of ETICS to bio-colonisation, the following research questions arise: (i) what is the impact of surface temperature (ST) and surface relative humidity (SRH) fluctuation on mould growth in ETICS facades? (ii) is it possible to predict mould growth on ETICS under fluctuating conditions considering favourable and unfavourable growth conditions? This study aims to investigate the influence of the hygrothermal behaviour of five different ETICS (with thermal mortars and insulation boards) on mould growth. ETICS were exposed for one year at an urban site in Lisbon, Portugal, facing North, during which the ST and the SRH were monitored. Concurrently, numerical simulations were performed to evaluate the hygrothermal behaviour of the ETICS. Three theoretical indices were applied, using numerically and experimentally obtained values of ST and SRH as input to provide an indication of the risk of mould growth. The results were complemented and validated by assessing the bio-colonisation, water performance and aesthetic properties of the ETICS. Index 1 (percentage of time with SRH ≥80%) indicated similar potential of mould growth for all systems. Both index 2 (percentage of time with SRH = 100%) and index 3 (percentage of time with SRH ≥80% and 15 °C ≤ ST ≤ 30 °C) indicated a higher potential of mould growth for the lime-based ETICS and a lower potential for the acrylic-based ETICS with an EPS-based mortar. Moreover, the lime-based system obtained the highest rate of mould growth after one year of outdoor exposure. Therefore, results suggested that indices 2 and 3 are in agreement with field observations and thus can provide an indication on mould growth for the analysed ETICS. Results also showed that an increase of capillary water absorption after ageing to levels higher than 1 kg/m2 after 24 h in direct contact with water can favour mould growth. Thus, the combination of unfavourable microclimatic conditions (SRH <80%; ST < 15 °C or ST > 30 °C) and surface hydrophobicity are fundamental to avoid mould growth on ETICS, regardless of the incorporation of biocide in the finishing coat composition.

Utilization of geopolymer in wood wool insulation boards: Design optimization, development and performance characteristics

This study investigates the substitution of ordinary Portland cement (OPC) with geopolymer in the production of wood wool geopolymer boards (WWGB), offering insights into manufacturing methods, design parameters, and performance characteristics. The composite formulation involves fibre pre-treatment, adjustment of precursor components, and control of activator compositions. The optimized formulation results in a lightweight composite with a density of 392 kg m−3 and porosity of 76 %, meeting prescribed minimum compressive (20 kPa) and bending strength (1700 kPa) requirements. The inclusion of natural fibres influences the optimal Na2O concentration and modulus for strength, with treated fibres recommended for higher modulus applications and improved strengths. Furthermore, it exhibits low thermal conductivity at 77 mW m−1 K−1, minimal moisture sorption, and low vapour resistance, offering a sustainable alternative in the field of insulation materials.

Reusing Thermal Insulation Materials: Reuse Potential and Durability Assessment of Stone Wool Insulation in Flat Roofs

In the building renovation industry, a growing volume of discarded insulation materials, such as stone wool insulation, prematurely finds its way to landfills or incinerators after building demolitions. However, these materials often did not reach their complete service life potential, and the reuse of insulation materials is usually not considered in current building practices. This study provides a comprehensive overview of the potential challenges associated with repurposing stone wool insulation from existing flat roofs. By means of detailed assessments via dismantling and performance evaluations of collected stone wool insulation boards up to 28 years old, this research reveals the unavoidable damages that occur upon dismantling yet emphasizes that this does not impede reuse. While density and thermal performance remain stable over time, water absorption and mechanical stability are affected. In total, 48% of all short-term tests revealed an increase in water absorption, possibly due to hydrophobic substance degradation. Mechanical performances of aged SW insulation from flat roofs depend on various factors, with 43% and 33% of compression and puncture resistance tests, respectively, not meeting current standards. Beyond a durability assessment, this study advocates for a multidisciplinary approach, uniting materials science, construction engineering, and sustainability insights, to creatively repurpose used insulation materials into future projects.

Experimental Study on Seismic Performance of Prefabricated Monolithic Concrete–Polystyrene Panel Composite Wall Panels

A normal composite wall panel is a structural component composed of polystyrene insulation boards and concrete surface layers reinforced with steel wire mesh. It can be entirely prefabricated in a factory or constructed with the concrete surface layers cast on-site. A novel prefabricated monolithic concrete–polystyrene panel composite wall panel (CPC wall panel) is proposed in this study. The CPC panel features a middle part that is prefabricated in the factory while the reinforced concrete regions at its two side ends are cast on-site. To evaluate the seismic performance of the wall panel, 18 CPC specimens were designed, manufactured, and quasi-statically tested, through which the structural behaviors, failure mode, and load-bearing capacity were studied. In addition, the influences of the height-to-width ratio and the vertical compressive stress level on the seismic performance of the CPC panels were also investigated. The test results showed that the connectors spaced at 400 mm × 500 mm could ensure the concrete layers on both sides of the polystyrene board worked collectively under seismic conditions. When subjected to lateral loads, the interface between the newly poured concrete and the existing concrete exhibited good bonding. Moreover, the failure mode of the CPC wall panel was largely correlated to the height-to-width ratio that, for specimens having four steel bars of 12 mm diameter and a height-to-width ratio greater than 1, the flexural failure was initially developed, followed by diagonal shear failure. In specimens with a height-to-width ratio of 1, flexural and diagonal shear failures occurred almost simultaneously. For specimens with a height-to-width ratio of less than 1, the final diagonal shear failure was predominant. The longitudinal reinforcing bars at the two ends of the CPC panels could effectively improve their lateral load-bearing capacity, with the enhancement influenced by the height-to-width ratio, the vertical load applied to the wall panel, and the cross-sectional area of the steel bars. In practice, the lateral load-bearing capacity of the CPC panel can be conservatively evaluated using the calculation method of the reinforced concrete shear walls. Finally, the ductility of the CPC specimens was affected by the height-to-width ratio and the axial compressive stress level, such that the specimens with a larger height-to-width ratio and lower axial compressive stress exhibited better ductility.

Green Residential Building Design Scheme Optimization Based on the Orthogonal Experiment EWM-TOPSIS

A multi-objective decision method is proposed based on the combining orthogonal test, entropy weight method (EWM) with TOPSIS (technique for order preference by similarity to an ideal solution) in this article. The method is more objective and efficient than traditional methods in the design of green residential buildings. A villa in Nanjing was taken as an example, and the cost, building energy consumption, and daylight factors were used as decision-making indexes. A total of six control factors were selected: terrain elevation, window area, building orientation, the opening ratio of exterior windows, roof structure, and window glass material. Each factor was designed with three levels. First, a design scheme index system was constructed, and the orthogonal experimental design was used to select representative design schemes. Then, the EWM and the TOPSIS method were used to determine the weight of each index, a comprehensive evaluation of the residential building design scheme was conducted, and, finally, the optimal scheme was confirmed via range analysis. The results show that the multi-objective decision-making model based on the orthogonal experiment EWM-TOPSIS is suitable for green residential building design and the optimal solution obtained is “15 m elevation, a 1200 × 1500 mm size vacuum glass, an orientation of 170° and an external window opening ratio 45% with a 40 mm thick expanded insulation board roof”.

Factors affecting the daytime cooling effect of cool materials: A case study combining experiment and simulation

Cool materials, with their high reflectivity, can significantly reduce the heat absorbed by buildings in summer and thus reduce energy consumption. The amount of solar radiation received by building surfaces varies with their orientation, so the effectiveness of cool materials on different building surfaces may vary. This study investigated the effects of using cool materials on scaled-down building models and full-scale real buildings through a combination of experiments and simulations, considering factors including building surfaces of different orientations, material properties, and weather conditions. Both experimental measurements and simulation studies showed that applying cool materials on roofs has the best cooling effect, reducing indoor temperatures by 0.93 °C in full-scale models. The south and west façades also showed good cooling effects when using cool materials. The north façade has the least cooling effect when using cool materials. Compared to exposed cement boards and regular materials, cool materials showed significantly better cooling effects, similar to those of 2 cm thick XPS insulation boards. Overall, buildings with poorer thermal insulation performance benefit more from the cooling effect of cool materials in summer. Additionally, the cooling effect of cool materials is ineffective on cloudy and rainy days. We found that the cooling effect of cool materials was significantly reduced when the solar radiation was less than 400 W/m2. The findings of this study provide guidance for the use of cool materials in energy retrofitting of existing buildings and the construction of low-carbon cities.

Effect of Applied Pressure on the Performance of Biodegradable Fiber Insulation Board Manufactured from Camphor Branches (Cinnamomum camphora)

Currently, the predominant thermal insulation materials in the construction industry are primarily derived from inorganic sources. While these materials demonstrate commendable thermal insulation capabilities, their widespread use raises significant environmental concerns. The utilization of wood fiber materials presents a promising solution to mitigate these drawbacks. This study focuses on the fabrication of biodegradable fiber insulation board (BFIB) using camphor branches. The manufacturing process avoids the use of chemical additives, employing a physical method that utilizes hot pressing and relies on the formation of intermolecular hydrogen and hydroxide bonds between the fibers. The study evaluates the influence of applied pressure on the properties of BFIB. SEM images reveal that, with an increase in applied pressure, the fibers exhibit a more regular pattern, subsequently enhancing the mechanical properties, hygric behavior, and fire resistance properties of BFIB. As an environmentally friendly and renewable material, BFIB holds the potential to substitute conventional insulation materials. It is particularly intriguing for energy-saving purposes when applied as building insulation for walls or ceilings.