Dynamic Thermal Properties Research Articles

Characterization and Properties of Polyurea Elastomer Used as Blast Mitigation Agent

The blast that caused from terrorist activities, explosion and weapons effect on not only the human life, but also the architectural structure. The development of materials used to protect them is needed. Polyurea is a one type of elastomer that derive from the reaction product of an isocyanate component and a synthetic resin blend component through step-growth polymerization. It is revealed that polyurea is a new entrant in the field of elastomer has received enormous attention in view of its excellent blast mitigation properties and ballistic protection. In this work, the microstructure and elemental composition of polyurea samples are studied using scanning electron microscope coupled with energy dispersive X-ray spectrometer (SEM-EDS). The main composition consisted of carbon, oxygen and silica approximately 63-75, 17-29, and 0.15-1.69 wt%, respectively. Sulfur and chlorine present as the chain extender. Titanium is added to modify its structure. Other elements present as the additives, fillers and pigments. Atomic force microscopy (AFM) is conducted to confirm nano-scale composition. Dynamic mechanical, thermal and tensile properties are also studied. It is shown that the modulus and loss factor increase as the increasing of the frequency and temperature. The elongation capacity is greater than 100%. Infrared spectroscopy based on synchrotron radiation (SR IR) shows the various constituents of the composition in the form of the functional groups along with the wave number.

Towards the implementation of periodic thermal transmittance in Spanish building energy regulation

The recent development of the calculation methodology for dynamic thermal properties of buildings has opened new possibilities for reducing their energy demand; however, building codes still rely on the traditional static approach. This research aims at filling in this gap by exploring how periodic thermal properties can be implemented in the Spanish regulatory framework. For this purpose, 2,413 wall typologies were analysed in the two extreme climate zones as per the Spanish regulation pertaining to energy efficiency. Results show that the static U-value itself is not sufficient to optimize the energy demand of buildings, as for a single value of U variations of 4,000 kWh in the energy demand are expected. Regarding periodic variables, decrement factor and time shift were the most effective to minimize the energy demand, along with flexible limitations for the periodic thermal transmittance and the time shift. In warm climates, the former can be disregarded if the latter is greater than 15 h. The findings from this study disscuss the applicability of the static thermal transmittance and propose a methodology to select and limit periodic variables for the two most extreme climates in Spain.

Numerical validation of a method determining thermal diffusivity based on a measurement of a temperature profile

The knowledge of dynamic thermal properties of building elements is necessary to investigate temperature and heat flux changes in natural daily and annual cycles. The basic dynamic parameter is thermal diffusivity. A method for determining its value for real objects has been proposed. This method is based on measuring the temperature in the element’s volume and on assuming that the obtained results meet the Fourier equation. Validation by a numerical experiment was made. The wall of the building with known thermal parameters was assumed and the temperature distribution was calculated over time in the process of non-stationary heat exchange. From the results, the diffusivity value was calculated and compared with the data entered into the model. Validations were performed for several accuracy of the temperature value and for two forms of function which approximated the temperature values obtained from calculation. A preliminary analysis of errors has been carried out. Keywords: measurements of thermal diffusivity, temperature distribution in a building element, approximation, heat transfer

Effect of chemical treatment on impact strength and dynamic thermal properties of Jute/PLA composites

The Untreated jute fiber reinforced composite (UTJFRC) and treated jute fiber reinforced composite (TJFRC) have been fabricated using compression molding processes. For chemical treatment of jute fiber mat sodium bicarbonate (NaHCO3) is used. The solution used for treatment has maintained pH of range 7–8 which show the ecofriendly treatment nature of sodium bicarbonate. Jute fiber mats were treated at three different concentration of sodium bicarbonate at 10, 20 and 30% for 4 h of treatment time. The prepared sample were characterized by dynamic mechanical thermal analysis (DMTA) and Izod impact test. All sample were cut according to ASTM standard to measure izod impact strength on impact tester. The composite sample which were treated at 10% concentration appear high impact strength. Even for dynamic mechanical properties treated jute fiber mat 20% concentration achieved maximum storage and loss modulus values. Even the glass transition temperature (Tg) is maximum shift for 20% concentration treated sample of jute/PLA composites. The improvement in properties because of good interfacial adhesion of jute and PLA achieved by sodium bicarbonate treatment of natural fiber.

Evaluation of Machine Tool Spindle Using Carbon Fiber Composite

Spindle is one of the most important component of machine tools because spindle’s performance including thermal property and dynamic property greatly influences the accuracy and productivity in machining process. This study investigates the effect of the application of carbon fiber reinforced plastic (CFRP) to the spindle shaft on the performance of machine tool spindles. CFRP and steel spindle shafts with the same geometry were developed for fair comparison. Thermal and dynamic properties of the developed shaft and spindle unit were evaluated and compared. The experimental and simulation results showed that the CFRP spindle shaft improved the axial thermal displacement and dynamic stiffness. The axial thermal displacement was decreased to 1/3 of that of the steel spindle. The compliance was also decreased to 1/2. The design of the thermal displacement distribution around the bearing should be an important issue in the CFRP spindle for the thermal stability of the dynamic property.

Correlations between dynamic thermal properties, energy consumption, and comfort in wood, concrete, and lightweight buildings

An office building located in Québec City (QC, Canada) with different envelope assemblies has been simulated to determine the energy consumption and thermal comfort that they provide. The resistance, thermal mass, and materials (concrete, cross-laminated timbers (CLT), and light-frame) were varied in a series of 164 different scenarios, and the energy intensities for heating and cooling were determined in each case, along with the discomfort index. Results show that the materiel used to provide thermal mass has a larger impact on comfort and energy consumption than the value of the thermal mass thickness itself. It was also attempted to correlate the performance of the envelope assessed through energy simulations with four dynamic thermal properties (i.e., dynamic transmittance, areal heat capacity, decrement factor, and time lag). The internal areal heat capacity appeared to be the most important variable to explain variations of performance of the envelope.

Thermal performance of unfired lightweight clay bricks with HDPE & PET waste plastics additives

The main objective of this study is to investigate the effect of incorporation of wastes plastics additives in the thermal performance of unfired clay bricks. The low adhesion between the clay and polymer molecules, in general, is one of the major challenges faced while blending the two components. In this paper, an innovative brick preparation technique known as the melt compounding preparation is suggested to ensure a homogenous clay-polymer dispersion and a maximum polymerization intensity inside the brick matrix. Various proportions for both polymeric, High Density Polyethylene (HDPE) & Polyethylene Terephthalate (PET), plastics wastes additives, in three grain-size are added to the earth clay. Prepared samples were tested for thermal conductivity, specific heat capacity, time lag and decrement factor properties. Collected findings showed that thermal conductivity and specific heat capacity properties improved by 40% and 55%, respectively, with the incorporation the largest polymeric-grain additives (3 mm < δ ≤ 6 mm) compared to the smallest ones (δ ≤ 1 mm). This can be explained by the high porosity produced while using larger grain-size additives. Maxwell thermal-porosity mathematical model is also used to assess the theoretically predicted thermal properties of the brick samples and compare it the experimental findings. The computed Pearson Correlation Coefficient ‘R’ is found to be very close to 1; hence, reflecting a positive association between the experimental and theoretical results. Next, a dynamic thermal inertia via a thermal simulation of a 6 m × 5 m x 2 m reference house, with variable external wall thicknesses, is executed to analyze the time lag and decrement factor of the studied brick samples. The composition of the wall is based on the experimental results of the brick samples with the optimum compressive strength, deduced from previous work, and thermal performance, in the current study. An improvement in thermal stability, with increased time lag and decreased decrement factor, is observed with larger grain size additives and thicker external walls. As a matter of fact, for a 0.3 m thick external wall made of PET based samples, the recorded time lag and decrement factor was 13.50 h and 0.148, respectively, compared to 8.99 h and 0.346 for reference values. This represents very high gains in dynamic thermal inertia properties in the range of 50% and 57% for time lag and decrement factor, respectively, compared to reference values, meaning cutting the house's energy expenses in half.

Modeling of an Optically Heated MEMS-Based Micromechanical Bimaterial Sensor for Heat Capacitance Measurements of Single Biological Cells

Detection of thermal activities of biological cells is important for biomedical and pharmaceutical applications because these activities are closely associated with the conformational change processes. Calorimetric measurements of biological systems using bimaterial microcantilevers (BMC) have increasingly been reported with the ultimate goal of developing highly sensitive and inexpensive techniques with real-time measurement capability techniques for the characterization of dynamic thermal properties of biological cells. BMCs have been established as highly sensitive calorimeters for the thermal analysis of cells and liquids. In this paper, we present a simulation model using COMSOL Multiphysics and a mathematical method to estimate the heat capacity of objects (treated here as a biological cell) placed on the surface of a microcantilever. By measuring the thermal time constant, which is obtained from the deflection curve of a BMC, the heat capacity of a sample can be evaluated. With this model, we can estimate the heat capacity of single biological cells using a BMC, which can potentially be used for the thermal characterization of different biological samples.

Evaluating thermal performance of double-skin facade using response factor

Modern office buildings frequently adopted Double-skin façades (DSFs) to save energy use for heating and cooling. The operable layers of a DSFs are designed to control the heat and airflow in its flow domain. The dynamic thermal properties of the operable layers should be well understood for the successful design of a DSFs. The objective of this study was to provide easy and reliable calculation method for cooling or heating load of a DSFs under dynamic weather conditions. The heat transfer in the operable layers was expressed by using the response factor which was got from field monitored data as a transfer function of incident solar radiation and exterior surface temperature at the inner glass of a DSFs. The proposed model was validated by the energy simulations with TRNSYS and field monitoring conducted during 35 days in summer, 6 August to 9 September 2012. From the results, it was found that the response factor is a very useful index to predict the thermal performance of a DSFs. The exterior surface temperature of the DSFs predicted by the response factor was fitted well with the field monitored data in both blind rolling and rolling off conditions. The mean bias error (MBE) and root mean square error (RMSE) of the predicted temperature were within 1.5% and 2.1%, respectively. The models can be helpful to evaluate the thermal performance of DSFs at the early building design stage.

Effects of Golden Flaxseed Flour on Ice Recrystallization in Uvaia (Eugenia pyriformis Cambess.) Diet Sherbet

In this study, the effects of golden flaxseed flour (GFF; Linum usitatissimum) concentrations (0, 1, 2, and 3%; w/w) on ice recrystallization in uvaia (Eugenia pyriformis Cambess.) diet sherbets fortified with iron were evaluated. Experiments were performed to simulate the conditions of temperature fluctuations. Samples were transferred from storage (− 25 °C) to a freezer programmed to perform 14 temperature fluctuation cycles ranging from − 20 °C/12 h to − 10 °C/12 h (each cycle, 48 h). The chemical composition and pH were determined before the temperature cycles. Physical parameters such as overrun, rheological properties of steady and dynamic shear, hardness, thermal properties, and ice crystal sizes were measured before the temperature cycles and every 7 days for 4 weeks. The sensory attributes were evaluated using an optimized descriptive profile (ODP). The ash content and pH results were statistically significant, and their values increased as the GFF concentration increased. The results were significant for instrumental hardness, initial melt resistance, rheological behavior, frequency and temperature sweeps, ice crystal size, and recrystallization. In the sensory evaluation, scores for coarse texture decreased and scores for GFF flavor increased as the GFF concentration increased. The ODP results were consistent with those for the rheological parameters, which justified the ice crystal size and ice recrystallization observed in the sherbets.

Effect of Surface Functionalization of SiO2 Nanoparticles on the Dynamic Mechanical, Thermal and Fire Properties of Wheat Straw/LDPE Composites

The scope of the present article is to study the effect of surface functionalization of SiO2 nanoparticles on the dynamic mechanical, thermal and fire properties of wheat straw flour (WSF) reinforced low-density polyethylene (LDPE) composites. Firstly, the SiO2 nanoparticles were modified by 3-aminopropyl-trimethoxysilane (APTMS), and then the WSF/LDPE composites containing different percentages of modified nano-SiO2 were prepared via a melt compounding using an internal mixer followed by injection molding. Changes in the chemical structure of treated SiO2 were tracked by Fourier transform infrared (FTIR). The appearance of N–H bond at 695 cm−1 and aliphatic C–H bonds at 2841 cm−1 and 2947 cm−1 were indications of successful grafting of APTMS on the SiO2 nanoparticles. Finally, the viscoelastic behavior, thermal stability and fire retardancy of the nanocomposites were evaluated by means of DMTA, TGA, DSC and CCT techniques. Results indicated that the dynamic modulus of the composites was greatly improved through the addition of functionalized SiO2 nanoparticles. In general, the specimens filled with 3 phr modified nano-SiO2 showed the highest values of storage and loss modulus compared with the other ones. Moreover, the tan δ peak signifying the glass transition temperature of nanocomposites shifted to higher temperature. The TGA results demonstrated that the introduction of APTMS grafted SiO2 nanoparticles can distinctly enhance thermal stability of the composites by increasing the thermo-oxidation decomposition temperature and char residues. The maximum activation energy value represents a higher thermal stability of the nanocomposites was obtained with modified nano-SiO2 at 5 phr content. In addition, the DSC data revealed that both the melting temperature and the degree of crystallinity of the specimens tended to substantially increase in presence of modified nano-SiO2. The surface functionalization of SiO2 particles produced remarkable evolution in the fire performance as indicated by reductions in the heat release rate, burning rate and mass loss rate. Furthermore, promoting the time to ignition and limiting oxygen index of the specimens equally to accommodate the addition of treated SiO2 nanoparticles.

Static and Dynamic Thermal Properties of a Pd40Ni40Si20 Glassy Alloy

The thermal properties of a Pd40Ni40Si20 glassy alloy with the largest supercooled liquid region among the glassy alloys containing Si as a metalloid element are studied using static and dynamic measurement methods. The relatively wide supercooled liquid region of 45 K, defined by the temperature interval between the glass transition temperature (Tg) and the onset temperature of crystallization (Tx), and the viscosity of the supercooled liquid, varying from 2.7 × 1010 to 3.2 × 1011 Pa·s, make this glass suitable for the introduction of controlled pores by a viscous flow in the temperature range Tg~Tx. The obtained activation energy for crystallization, 272 ± 19 kJ/mol, is slightly higher than that of Tg (228 ± 11 kJ/mol), indicating the dominant contribution of the atomic transport barrier in the overall energy barrier for crystallization.

Benchmarking the simplest slave-particle theory with Hubbard dimer**Project supported by the National Natural Science Foundation of China (Grant Nos. 11674139, 11704166, and 11834005), the Fundamental Research Funds for the Central Universities, China, and Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT-16R35).

Slave-particle method is a powerful tool to tackle the correlation effect in quantum many-body physics. Although it has been successfully used to comprehend various intriguing problems, such as Mott metal–insulator transition and Kondo effect, there is still no convincing theory so far on the availability and limitation of this method. The abuse of slave-particle method may lead to wrong physics. As the simplest slave-particle method, slave spin, which is widely applied to many strongly correlated problems, is highly accessible and researchable. In this work, we will uncover the nature of the slave-spin method by studying a two-site Hubbard model. After exploring aspects of properties of this toy model, we make a comparative analysis of the results obtained by three methods: (i) slave-spin method on mean-field level, (ii) slave-spin method with gauge constraint, and (iii) the exact solution as a benchmark. We find that, protected by the particle–hole symmetry, the slave-spin mean-field method can recover the static properties of ground state exactly at half filling. Furthermore, in the parameter space where both U and T are small enough, the slave-spin mean-field method is also reliable in calculating the dynamic and thermal dynamic properties. However, when U or T is considerably large, the mean-field approximation gives ill-defined behaviors, which result from the unphysical states in the enlarged Hilbert space. These findings lead to our conclusion that the accuracy of slave particle can be guaranteed if we can exclude all unphysical states by enforcing gauge constraints. Our work demonstrates the promising prospect of slave-particle method in studying complex strongly correlated models with specific symmetry or in certain parameter space.

Static and dynamic thermal properties of construction components: A comparison in idealized and experimental conditions using lumped parameter models

The U values assumptions for construction components represent a significant source of uncertainty when estimating the energy performance of buildings. This uncertainty affects decision-making processes in multiple ways, from policy making to design of new and refurbished buildings. The correct estimation of both static (e.g. thermal transmittance) and dynamic thermal properties is crucial for quality assurance in building performance assessment. Further, while today many sophisticated simulators are available for building performance modelling, lumped parameter models can help reducing computational time for parametric simulation or optimization and enable inverse estimation of lumped thermal characteristics. A lumped parameter approach for construction components is proposed, for example, by the ISO 52016-1:2017 norm, introducing simplifications that are intrinsically dependent on component’s stratigraphy. This approach complements ISO 13786:2017 norm method, which is limited to steady-state periodic temperature and heat flux boundary conditions. In this research we consider these two different approaches, detailed and lumped modelling, comparing them first in idealized conditions and then in experimental conditions to analyse the robustness of methods.

Laser and the Tuber: Thermal Dynamic and Volumetric Factors Influencing Seizure Outcomes in Pediatric Subjects With Tuberous Sclerosis Undergoing Stereoencephalography-Directed Laser Ablation of Tubers

Abstract INTRODUCTION Tuberous Sclerosis (TSC) is a well-known cause of Medically Refractory Epilepsy (MRE). It is well documented that early surgical management can improve patient outcomes. Stereoencephalography-directed Magnetic Resonance guided Laser Interstitial Thermal Therapy (SEEG-directed MRgLITT) is an emerging minimally invasive technique that appears aptly suited for the surgical management of this condition. Our aims are to present our experiences with patients who had undergone prior SEEG-directed MRgLITT to identify and treat cortical tubers responsible for clinical seizures and to perform an in-depth analysis of volumetric and thermal dynamic factors that may be related to seizure outcomes. METHODS We studied all pediatric patients with MRE due to TSC who underwent SEEG-directed MRgLITT, investigating seizure outcomes in relationship to thermal dynamic and volumetric factors of MRgLITT when applied to cortical tubers. RESULTS About 8 cortical tubers from 3 pediatric patients were analyzed. About 2 out of 3 patients had Engel I outcomes at last follow-up. Median follow-up was 15 mo. Average A/T (ablation volume/tuber volume) ratio for Engel I outcomes was 1.28 (variance, 0.16) and 0.84 (variance &lt; 0.01) for all other outcomes (P = .035). When assessing thermal dynamic properties of cortical tuber tissue, there was a moderate positive correlation when comparing ablation energy to ablation volume (R2 = 0.65). When the calcified tuber is excluded from regression analysis, the correlation is stronger (R2 = 0.77). Thus, the calculated volume to ablate 1 cm3 of cortical tuber tissue is 1263.6 J (calcified tuber) or 1089.5 J (noncalcified tuber). CONCLUSION SEEG-directed MRgLITT is a safe and effective technique in the management of pediatric patients with MRE due to TSC. It appears that the A/T ratio is a useful indicator in predicting seizure outcomes.

Structural, elastic, thermal and lattice dynamic properties of new 321 MAX phases

A new series of the MAX family designated as 321 phases are recently reported with Nb3As2C, V3As2C, Nb3P2C and Ta3P2C. Most of physical properties of these new MAX phase compounds are unexplored and the present study aims to investigate their structural, elastic, thermal and lattice dynamic properties. Though all the phases are elastically anisotropic and brittle in nature, Nb3As2C is the most anisotropic and Ta3P2C is the most brittle. V3As2C compared to Nb3As2C and Ta3P2C compared to Nb3P2C should exhibit superior mechanical properties, as they possess larger elastic constants and moduli. Shear strength, bond covalency as well as the average bond strength and materials’ brittleness are predicted to follow: Ta3P2C > Nb3P2C > V3As2C > Nb3As2C. The estimated Debye temperature and lattice thermal conductivity are highest for Nb3As2C. Lattice dynamical features are investigated in detail and the infrared and Raman active modes are identified. The high melting temperatures of these compounds are beneficial for their potential applications at elevated temperatures.

Theoretical prediction on the stability, electronic structure, room and elevated temperature properties of a new MAB phase Mo2AlB2

Abstarct Mo2AlB2 is a new MAB phase that has been observed in thin foils of MoAlB during TEM observation and in NaOH etched MoAlB samples. However, the structural characteristics, chemical bonding and properties of this new compound have not been investigated. In this work, geometry optimized crystal structure of Mo2AlB2 is obtained and its stability, elastic and thermal dynamic properties are investigated. Mo2AlB2 is stable in Al lean conditions, which is consistent with the exiting experimental results. It is also gauged as a damage tolerant or quasi-ductile ceramic based on the low Pugh’s shear to bulk modulus ratio (G/B = 0.544) and positive Cauchy pressure in all three crystallographic directions, which is underpinned by the metallic bonding. Mo2AlB2 also exhibits high stiffness which is attributed to the strong B–B covalent bond chains within its crystal structure. Due to the anisotropic chemical bonding, Mo2AlB2 has anisotropic thermal expansion coefficients αa = 6.19 × 10–6 K1, αb = 12.13 × 10−6 K–1, αc = 6.66 × 10−6 K–1, respectively, along a, b and c directions in the temperature range between 300 and 1500 K. The heat capacity from 300 to 1500 K can be described as Cp = 120.32 + 0.01648T − 2.597 × 106T−2 (J∙mol–1∙K–1). The elastic constants decrease almost linearly with temperature. The elastic constants representing the resistance to principle deformation (c11, c22 and c33) decrease in faster rates than those representing shear deformation resistance (c44, c55 and c66). Correspondingly, bulk and Young’s modulus decrease in faster rates than shear modulus. In light of the structure-property relations of Mo2AlB2, it is suggested that future damage tolerant ceramics can be designed by putting stiff covalent bonding units into soft metallic bonding box to obtain both high stiffness and quasi-ductility.

Thermal property values of a central Iowa soil as functions of soil water content and bulk density or of soil air content

AbstractSoil thermal properties play important roles in dynamic heat and mass transfer processes, and they vary with soil water content (θ) and bulk density (ρ b). Both θ and ρ b change with time, particularly in recently tilled soil. However, few studies have addressed the full extent of soil thermal property changes with θ and ρ b. The objective of this study is to examine how changes in ρ b with time after tillage impact soil thermal properties (volumetric heat capacity, C v, thermal diffusivity, k, and thermal conductivity, λ). The study provides thermal property values as functions of θ and ρ b and of air content (n air) on undisturbed soil cores obtained at selected times following tillage. Heat pulse probe measurements of thermal properties were obtained on each soil core at saturated, partially saturated (θ at pressure head of −50 kPa) and oven‐dry conditions. Generally, k and λ increased with increasing ρ b at the three water conditions. The C v increased as ρ b increased in the oven‐dry and unsaturated conditions and decreased as ρ b increased in the saturated condition. For a given θ, a larger ρ b was associated with larger thermal property values, especially for λ. The figures of C v, k and λ versus θ and ρ b, as well as C v, k and λ versus n air, represented the range of soil conditions following tillage. Trends in the relationships of thermal property values with θ and ρ b were described by 3‐D surfaces, whereas each thermal property had a linear relationship with n air. Clearly, recently tilled soil thermal property values were quite dynamic temporally due to varying θ and ρ b. The dynamic soil thermal property values should be considered in soil heat and mass transfer models either as 3‐D functions of θ and ρ b or as linear functions of n air.Highlights Thermal property values for a range of θ and ρ b were measured on undisturbed soil cores. Freshly tilled soil thermal property values were quite dynamic temporally. The thermal property values of a tilled soil were described as 3‐D surfaces with θ and ρ b. The thermal property values of a tilled soil varied linearly with n air.

Three dimensional porous alumina network for polymer composites with enhanced thermal conductivity

In this work, a desirable continuous alumina (Al2O3) framework with honeycomb-like morphology was realized in epoxy/Al2O3 composites through a well-designed protein foaming technique followed with infiltration. High sintering was employed to reduce the interfacial thermal resistance between fillers, as well as improving the mechanical strength of the framework in the meantime. Owing to the well-ordered filler network in epoxy, the interfacial thermal resistance was decreased by one order of magnitude. Besides, the maximum thermal conductivity reached 2.58 W/m·K, 3.6 time higher than that of epoxy/Al2O3 composite with randomly dispersed Al2O3 at the filler loading of 23.32 vol%. In addition, the prefabricated 3D-Al2O3 scaffold also has a great strengthen effect on thermal stability, dimensional stability, and dynamic mechanical property for the composites due to the unique structure. This strategy paves an effective way for developing epoxy composites with good thermal performance in electronic packaging applications.

Calculation of the Thermal Dynamic Performance of the Residential Buildings’ Walls

Abstract Calculation of the thermal dynamic properties of the multi-layer wall isolation of residential buildings is presented in this paper. Taking into account that the final objective is to create a building with the highest energy efficiency ratio, i.e. with the lowest energy consumption, both for heating and cooling, it is necessary to realize the good thermal characteristics of the multi-layer wall. To obtain the optimal solution for the wall's structure, various wall structures with different thicknesses of the individual layers, were analyzed. Based on results, presented in this paper, one can conclude that for walls with the same total thickness, but various thicknesses of the individual layers, that constitute the complete wall structure, the differences appear in the delay of the change of the walls outside temperature. In that way, by varying those individual layers' thicknesses, one can obtain the optimal solution for the wall structure with the highest savings of energy.