Polystyrene Insulation Material Research Articles

The Effect of Radiant Heat on Polystyrene Thermal Insulation Materials

As a result of the increasingly stringent energy requirements of recent years, the issue of façade thermal insulation is gaining more and more prominence. Due to these requirements, layer thickness of insulation increases, or the use of materials with a better coefficient of thermal conductivity is preferred. These requirements are met by polystyrene insulation materials. Therefore, it is extremely important to know as much as possible the behaviour of polystyrene thermal insulation under the influence of fire and radiant heat. Its regulation is not coordinated in Europe, and the effect of radiant heat is not addressed by any country’s standard. In this paper, the behaviour of polystyrene thermal insulations, which are densely used in Hungary is examined, under the influence of radiant heat.

Relative Comparison of Benefits of Floor Slab Insulation Methods, Using Polyiso and Extruded Polystyrene Materials in South Africa, Subject to the New National Building Energy Efficiency Standards

This article aims to assess the benefits of floor slab insulation measures using extruded polystyrene (XPS) and polyisocyanurate (also referred to as polyiso or PIR) insulation materials at various levels of insulation thicknesses for a detached residential building. An EnergyPlus simulation analysis was carried out within the seven energy zones (represented by eight locations) of South Africa in accordance with the South African national code for building energy efficiency (SANS10400-XA). The energy savings and payback periods related to the use of the insulation over a lifecycle period of 50 years were assessed. Cape Town (zone 4) behaved differently from other locations and hardly benefited from the application of floor slab insulation measures. Generally, polyiso (PIR) insulation performed better than XPS for vertical gap insulation, and lower insulation thicknesses required higher insulation depths to maximize energy savings. Similarly, lower insulation thicknesses (25 mm and 50 mm) required higher perimeter insulation widths to maximize energy savings for horizontal perimeter insulation, especially in Sutherland (zone 6) and Cape Town. The maximization of energy savings was also achieved at low insulation thickness for the full floor slab insulation method, except for Sutherland and Fraserburg (zone 7). The locations that benefitted most from the floor slab insulation methods were Pretoria (zone 5), Thohoyandou (zone 3), Sutherland (zone 6), Fraserburg (zone 7), Welkom (zone 1), Ixopo (zone 5H), Witbank (zone 2), and Cape Town (zone 4), in that order. Generally, higher net energy savings are achieved in areas with lower humidity levels and areas with greater annual sums of both cooling and heating degree days.

Thermal and Pyrolysis Kinetics Analysis of Glass Wool and XPS Insulation Materials Used in High-Rise Buildings

This study investigates the kinetics data of glass wool (GW) and extruded polystyrene (XPS) insulation materials used in cladding systems using a systematic framework. The determination of appropriate kinetic properties, such as pre-exponential factors, activation energy and reaction orders, is crucial for accurately modelling the full-scale fire performance of insulation materials. The primary objective of this research is to extract thermal and kinetics data of XPS and GW insulation materials employed in high-rise buildings. To obtain these properties, thermogravimetric analysis (TGA) is conducted at four different heating rates: 5, 10, 15 and 20 K/min. The TGA results serve as the basis for determining the kinetic properties using a combination of model-free and model-based methods. The outcomes of this study are expected to be highly beneficial in defining the pyrolysis reaction steps and extracting kinetics data for fire modelling of such insulation materials. This information will enhance the understanding of the fire behaviour and performance of these materials during fire incidents, aiding in developing more accurate fire models and improving fire safety strategies for cladding systems in high-rise buildings.

Optimal Insulation Assessment, Emission Analysis, and Correlation Formulation for Indian Region

The current study depicts the effects of different insulation materials and fuel types on the cooling and heating performance of buildings situated in hot and dry, warm and humid, composite, and cold climatic conditions in India. Ten different locations chosen from diverse climatic regions were selected, and various potential parameters for expanded polystyrene and extruded polystyrene insulation materials were evaluated. Potential parameters, such as optimal insulation thickness, annual savings, and payback period, were computed for cooling and heating requirements and were found in the ranges of 0.0428–0.891 m, 10.83–19.19 $/m2, and 1.49–2.36 years for cooling, as well as 0.0063–0.1522 m, 0.29–55.92 $/m2, and 0.95–6.52 years for heating, respectively. An emission analysis was also carried out for the estimation of greenhouse gas (GHG) emissions by the engagement of optimal insulation thickness for heating. The GHG emissions from natural gas, coal, and diesel by the employment of various insulating materials were found in the ranges of 5.39–11.28, 9.47–32.68, and 2.26–4.51 kg/m2-year, respectively. A correlation formulation (power) for optimal insulation thickness was also carried out. For checking the preciseness of the developed mathematical models, statistical tools were utilized, and their obtained values in the satisfactory range signified the accurateness of the developed models.

Transient temperature change within a wall embedded insulation with variable thermal conductivity

This paper examines the change of the temperature through a typical wall assembly comprising a polystyrene insulation material (EPS) with constant and variable thermal conductivity (λ). Four levels of the insulation density, namely, low density (LD), high density (HD), super high density (SHD), and ultra-high density (UHD) impeded at three different locations within the wall have been considered in this study. During the day, the evolution of temperatures through the wall section was observed on inner wall surface when EPS is located at different positions of the wall section. Thereafter, the thermal performance across the wall section incorporating insulation layers at different positions applying variable λ-value was compared to a non-variable thermal conductivity case by quantifying the net heat reduction due to the λ-relationship with time. As a result obtained, the change of the temperature through the wall with variable λ is higher compared to the case of constant λ. The temperature change on the inner wall surface with constant and variable λ is shown to decrease as the position of the insulation material is located toward the inner wall surface. Therefore, locating the insulation material in the middle of the wall assembly will provide the best dynamic thermal performance.

A PBPK model to study the transfer of α-hexabromocyclododecane (α-HBCDD) to tissues of fast- and slow-growing broilers

ABSTRACTA physiologically based pharmacokinetic (PBPK) model was developed to investigate the production-specific factors involved in the transfer of α-hexabromocyclododecane (α-HBCDD) to broiler meat. The model describes growth and lipid deposition in tissues of fast- (FG) and slow- (SG) growing broilers from hatching to slaughter and simulates the exposure through the ingestion of contaminated feed or expanded polystyrene insulation material. Growth parameters were obtained from the literature while parameters relative to uptake, distribution, and elimination of α-HBCDD were adjusted using results of a previous experiment involving broilers exposed through feed throughout the rearing period or allowed to depurate before slaughter. The model was used to compare the two main edible tissues, breast and leg meat, as well as skin, and to investigate the variability within strain. Between strains and within strain, α-HBCDD assimilation efficiency (AE) is higher when the animals are slaughtered young or heavy. However, increasing slaughter age will lower α-HBCDD concentration in tissues, due to dilution. Based on fresh weight, the concentration of α-HBCDD in breast muscles and skin tends to be lower in SG than in FG broilers (−30 to +10%), while it is 10% to 80% higher in leg muscles. Compared to breast muscles, consuming leg muscles would elicit an exposure 9 and 16 times higher in FG and SG broilers, respectively. The consumption of skin together with muscles would multiply the exposure by up to 36 times compared to breast muscle alone. In case of acute exposure, the α-HBCDD concentration in tissues increased sharply, all the more since the animals are lighter in weight, and then decreased rapidly. In FG broilers, dilution through growth contributed for up to 37%, 28% and 97% to the decontamination of breast muscles, leg muscles and skin, respectively, depending on the duration of depuration before slaughter.

Energy consumption based on insulation thickness of exterior walls in public buildings

The rectorate building of Balikesir University located in the north-western part of Turkey is evaluated. The energy consumption of the building with an outer wall of optimum insulation thickness has been determined theoretically and practically in the heating + cooling (annual) periods. The rectorate building consists of one main building including offices with service facilities, and one printing house used as a machine shop. The facade of the main building has a metal curtain wall. The efficiency, coefficient of performance values and the heat-transfer coefficient of the outer walls are determined by obtaining measurements of the outer walls and, at some points, of heating and cooling systems. Depending on these values, the optimum insulation thickness for the outer walls, fuel consumption and fuel savings are found. Measured values and theoretical calculations are compared to identify the differences. The lowest value of the optimum insulation thickness for both theoretical and measured values is achieved by type 1 extruded polystyrene insulation material, while the highest value is observed in type 3 expanded polystyrene.

The life cycle assessment related to insulation thickness of external walls of the airport

In this study, energy savings to be gained by the insulation of the external walls of airport buildings are examined according to Turkish Building Insulation Standard (TS 825) which is renewed in December 2013. In addition, life cycle total (LCT) cost and life cycle savings (LCS) are calculated. Unlike the residences, the airport buildings indoor temperatures should be 20°C during the heating period according. The optimum insulation thickness was determined for the external walls of the airport buildings. The degree-of-day method is used in calculations. Optimum insulation thickness is the lowest polyurethane insulation material in the highest glass wool insulation material. The optimum insulation thickness is calculated as 0.044-0.090 m for the polyurethane insulation material and 0.122-0.233 m for the glass wool insulation material. Also, extruded polystyrene (XPS) insulation material was found between 0.062-0.125 m.

The life cycle assessment related to insulation thickness of external walls of the airport

In this study, energy savings to be gained by the insulation of the external walls of airport buildings are examined according to Turkish Building Insulation Standard (TS 825) which is renewed in December 2013. In addition, life cycle total (LCT) cost and life cycle savings (LCS) are calculated. Unlike the residences, the airport buildings indoor temperatures should be 20°C during the heating period according. The optimum insulation thickness was determined for the external walls of the airport buildings. The degree-of-day method is used in calculations. Optimum insulation thickness is the lowest polyurethane insulation material in the highest glass wool insulation material. The optimum insulation thickness is calculated as 0.044-0.090 m for the polyurethane insulation material and 0.122-0.233 m for the glass wool insulation material. Also, extruded polystyrene (XPS) insulation material was found between 0.062-0.125 m.

Thermal characterization of different graphite polystyrene

The development of high performance insulating materials incorporating nanotechnologies has enabled considerable decrease in the effective thermal conductivity. Besides the use of conventional insulating materials, such as mineral fibers, the adoption of new nano-technological materials such as aerogel, vacuum insulation panels, graphite expanded polystyrene, is growing. In order to reduce the thermal conductivity of polystyrene insulation materials, during the manufacturing, nano/micro-sized graphite particles are added to the melt of the polystyrene grains. The mixing of graphite flakes into the polystyrene mould further reduces the lambda value, since graphite parts significantly reflect the radiant part of the thermal energy. In this study, laboratory tests carried out on graphite insulation materials are presented. Firstly, thermal conductivity results are described, and then sorption kinetic curves at high moisture content levels are shown. The moisture up-taking behaviour of the materials was investigated with a climatic chamber where the relative humidity was 90% at 293 K temperature. Finally, calorific values of the samples are presented after combusting in a bomb calorimeter.

Simulation of energy- efficient building prototype using different insulating materials

The objective of this work is to analyze the energetic efficiency of an individual building including an area of 130 m2 multi-zone, located in the region of FEZ which is characterized by a very hot and dry climate in summer and a quite cold one in winter, by incorporating insulating materials. This study was performed using TRNSYS V16 simulation software during a typical year of the FEZ region. Our simulation consists in developing a comparative study of two types of polystyrene and silica-aerogel insulation materials, in order to determine the best thermal performance. The results show that the thermal insulation of the building envelope is among the most effective solutions that give a significant reduction in energy requirements. Similarly, the use of silica-aerogels gives a good thermal performance, and therefore a good energy gain.

The combined effect of heat and moisture transfer dependent thermal conductivity of polystyrene insulation material: Impact on building energy performance

The aim of this article is to elucidate the combined impact of heat and humidity transfer on the thermal conductivity of polystyrene used as an insulation for building envelope. In building energy assessment, the conductivity of the insulation material is assumed to be constant. This yields inaccurate results, as the thermal conductivity, k-value, of any material is a complex function of many factors, such as temperature, moisture, and density. This dependence has been shown in extant studies and linear variation of the thermal conductivity vs. temperature have been proposed for fibrous materials. Accurate evaluation of building thermal comfort and energy assessment, which requires a precise calculation of the cooling load, and thus the sizing of the HVAC equipment, depends on the accurate determination of the thermal resistance of the building envelope components, the insulation material in particular. The aim of this work is thus to inspect the combined effect of operating temperature and moisture content on the thermal conductivity of polystyrene insulation material and its impact on the energy performance of buildings. The results reveal that the k-value of the polystyrene insulation is significantly influenced by its moisture content at different operating temperatures. Indeed, an 8% increase in the total cooling load calculated at 28 °C and 30% moisture was measured relative to the base case evaluated at 24 °C and 0% moisture.

Flame Spread Characteristics of Inclined Extruded Polystyrene Thermal Insulation Material

Abstract A set of small-scale flame spread experiments was conducted to explore the effects of sample orientation on the flame spread characteristics of extruded polystyrene (XPS) insulation material. The obtained data were employed to show the variation law of flame angle, pool fire zone length and flame spread rate when the tilt angle of XPS material changes from -90° to 90°. The flame angle decreased when the inclined angle increased from -90° to 90° and there are two different variation trends of flame angle in different inclined angle ranges. Meanwhile, both pool fire length and flame spread rate of the inclined XPS material depend on gravity controlled flow of flammable and molten drops produced by heating XPS material. Furthermore, the fitting relationship between flame spread rate and tilt angle was put forward when the tilt angle was less than or equal to 0°. This work is a supplement to the fire risk study on the XPS insulation materials and system.

The impact of changes in thermal conductivity of polystyrene insulation material under different operating temperatures on the heat transfer through the building envelope

The cooling/heating load calculation requires an accurate evaluation of the heat transfer through the envelope components of the building. This depends mainly on the accuracy of the thermal resistance of the different building envelope components, particularly the insulation materials. Indeed, the accuracy of the thermal conductivity (k) of the insulation material, which describes the ability of heat to flow across the material in the presence of a temperature gradient, has an important effect on the heat exchange between the building interior and the ambiance. In practice, the k-value is calculated under specific laboratory conditions at 24°C, according to relevant ASTM standards. In reality, however, the thermal insulation materials comprising the building envelope are exposed to significant and continuous temperature and moisture changes, due to the variations in the external conditions, including the outdoor temperature, solar radiation, and air moisture content. In addition, the thermal resistance of most thermal insulation materials depends on the operating temperature, the location of the insulation layer within the assembly system, and the effective temperature. Indeed, empirical evidence shows that the change in the polystyrene insulation thermal conductivity with temperature at the mid-thickness of the insulation material during the daytime can be very significant. At high temperatures, in the order of 100°C, commonly encountered in the roof insulations of buildings in hot climates such as Oman, the percentage increase of k-values relative to k24 for wall and roof can be as high as 9.4% and 20%, respectively. This change affects the cooling load calculation when operating at temperatures exceeding 24°C. This article evaluates the effect of changes in the conductivity of polystyrene insulation material, as a function of the operating temperature, on the cooling load calculation required by the building, and thus the sizing of the heating, ventilating, and air-conditioning equipment.

The Impact of Optimum Insulation Thickness of External Walls to Energy Saving and Emissions of CO<sub>2</sub> and SO<sub>2</sub> for Turkey Different Climate Regions

In this study, the optimum insulation thickness of the external walls of the housing and it’s energy saving and environmental impact in the provinces—Ardahan, Aydin, Eskisehir and Samsun—located in four different climate regions of Turkey was calculated for the expanded polystyrene and polyurethane insulation materials. Natural gas and coal were selected as fuels. Ardahan in the coldest climate region and Aydin in the hottest climate region, for the coal and optimum thickness of expanded polystyrene and polyurethane insulation materials, the reduction of CO2 and SO2 emissions. In the study, the relations between annual energy cost saving and insulation thickness are given. The value of energy cost saving increases up to optimum insulation thickness and beyond this level, the energy cost saving is decreased. For coal and optimum thickness of expanded polystyrene and polyurethane insulation materials, the energy cost savings was higher for the cold climate regions when it was compared with the hot climate regions.

Effect of Temperature and Density Variations on Thermal Conductivity of Polystyrene Insulation Materials in Oman Climate

The thermal and energy performance of buildings depends on the thermal characteristics of the building envelope and particularly on the thermal resistance of the insulation material used. The ability of a thermal insulation material to transmit heat in the presence of a temperature gradient is determined by its thermal conductivity. The thermal conductivity values of building insulation materials are generally given at 24°C according to ASTM standards. Actually, such a material when used in a building envelope is exposed to significant and continuous temperature changes, essentially due to the changes in outdoor temperature and solar radiation, especially in harsh climate. The main objective of this study is to investigate the relationship between the temperature and the thermal conductivity of polystyrene, which is widely employed as a building insulation material in Oman, at various densities, using the developed experimental setup based on the guarded hot plate method. The results show that higher temperatures lead to higher thermal conductivities and the lower is the material density, the higher is the thermal conductivity. The envelope-induced cooling load for a simple building is also calculated, and it is shown that a lesser cooling load is needed for a high-density insulation.

Trends of non-CFC insulation materials and thermal characteristics of CO2-foamed plastic insulation materials

This study has been conducted to analyse the domestic trends of non-CFCs (Chlorofluorocarbon) insulation materials and the thermal characteristics of carbon dioxide-foamed insulation materials. With a growing interest in low-energy building, the insulation market has developed towards high performance insulation materials. Under the Montreal Protocol to phase out the use and production of CFCs, the extruded polystyrene insulation materials have to replace Hydro-chlorofluorocarbon (HCFC) with other foaming agents, for example, carbon dioxides. This study also analysed the correlation of cell size, void fraction and thermal conductivity through literature review. As a result, the thermal conductivity was found to be decreased with a higher void fraction and smaller cell size if the cell size of CO2-foamed extruded polystyrene becomes under 100 µm.

Experimental study of altitude and orientation effects on heat transfer over polystyrene insulation material

In order to reveal the altitude and orientation effects on the flammability behaviors of insulation material of polystyrene, a series of comparative lab-scale experiments was carried out in plain area of Hefei and plateau area of Lhasa. The piloted ignition time was identified for EPS and XPS with sample orientations of 0°, 15°, 30° and 90°. It was found that the piloted ignition time was shorter in Hefei than that in Lhasa for the same slab at the same inclination. Meanwhile, for EPS, due to the greater shrinkage, the ignition time was not influenced by thickness obviously, while for XPS, it was decreased with thickness for the receiving heat flux enhanced. The ignition time during flame spread case was longer than that in piloted ignition, attributed to the longer time of shrinking and melting. The combustion characteristics including pool fire length, flame length and mass loss rate were also explored. With the sample thickness increase, the maximum pool fire length and mass loss rate were both increased, leading to greater fire hazard. For the dripping and smoke influence, the slope of flame length against pyrolysis length at 90° would increase from slope1 to slope2.

Influence of Reflective Insulation Coating on Heat Transfer Characteristics of Composite Thermal Insulation Wall

In the downstream of Yangtze River where there is abundant silt resources, perforated brick which fired by sludge, supplemented by reflective insulation coating to replace the widely used polystyrene insulation materials. It can achieve requirement of A-class fire prevention for heat preservation wall. The heat insulation performance of not painted thermal wall and composite thermal insulation wall painted by reflective insulation coating were compared. Data results show that heat insulation performance of the wall painted is much better than that of the not painted wall.

Effect of Operating Temperatures on Thermal Conductivity of Polystyrene Insulation Material: Impact on Envelope-Induced Cooling Load

The impact of the thermal conductivity (k-value) change of polystyrene insulation material in building envelope due to changes in temperature on the thermal and energy performance of a typical residential building under hot climate is investigated. Indeed, the thermal and energy performance of buildings depends on the thermal characteristics of the building envelope, and particularly on the thermal resistance of the insulation material used. The thermal insulation material which is determined by its thermal conductivity, which describes the ability of heat to flow cross the material in presence of a gradient of temperature, is the main key to assess the performance of the thermal insulation material. When performing the energy analysis or calculating the cooling load for buildings, we use published values of thermal conductivity of insulation materials, which are normally evaluated at 24°C according to the ASTM standards. In reality, thermal insulation in building is exposed to significant and continuous temperature variations, due essentially to the change of outdoor air temperature and solar radiation. Many types of insulation materials are produced and used in Oman, but not enough information is available to evaluate their performance under the prevailing climatic condition. The main objective of this study is to investigate the relationship between the temperature and thermal conductivity of various densities of polystyrene, which is widely used as building insulation material in Oman. Moreover, the impact of thermal conductivity variation with temperature on the envelope-induced cooling load for a simple building model is discussed. This work will serve as a platform to investigate the effect of the operating temperature on thermal conductivity of other building material insulations, and leads to more accurate assessment of the thermal and energy performance of buildings in Oman.