Green buildings model: Impact of rigid polyurethane foam on indoor environment and sustainable development in energy sector

Abstract

The construction and building industry in the modern world heavily relies on advanced techniques and materials such as polymers. However, with the world's population alarmingly increasing, contributing to the greenhouse effect, and severe weather conditions amplifying, it has become crucial to reduce the heat effects in both new and old buildings. To achieve this, 50–70% more energy is necessary, which highlights the importance of energy-efficient construction practices and materials. Consequently, a comprehensive study was conducted to evaluate the efficacy of Polyurethane in indoor environments and energy conservation. Current study was performed due to an innovative application of insulation materials as to reduce the heat and energy costs in construction works. Thermal conductivity at mean temperature 35 °C was found 0.0272 (W/m K) with maximum in burnt clay brick (1.43 W/m K) by using hotplate apparatus. Specific heat was also found less 0.85 (KJ/Kg K) at density 32 kg/m³ while results were at par in reinforcement cement concrete and burnt clay brick 0.91, 0.91 (KJ/Kg K) respectively. Similarly, heat transmittance values of different roof sections by using polyurethane insulation showing satisfaction the ECBC in Buildings deviating standard U-value 1.20% to 0.418 (W/m² K) with its excellent performance. Polyurethane treatments have been found to exert a significant impact on the computation of thermal resistance and overall heat transfer coefficients. In contrast, non-insulated treatments yielded inconclusive results with little to no significance. This highlights the importance of insulation materials in energy-efficient construction practices. Energy consumption in winter and summer also has shown the significant impact by using polyurethane application with cumulative saving of 60–62% electricity. Economic Benefit of polyurethane in RCC and Conventional buildings describes positive and highly significant impact in present study. Application of polyurethane in new and old buildings ultimate enhanced the better quality of life and living standards from people of applied countries and is strongly recommended for future prospects and endeavors as Eco-friendly and energy efficient for sustainable development.

1. Introduction

Pakistan is listed in countries which are most vulnerable to the economics, social and environmental effects of climate change due to its physical location and socio-economic fragility [1]. The main change of climate causes high temperature rising in summer and severs coldness in winter [2]. Recent past significantly increased in climate allied events like extremes hot, heat strokes, and famines, huge amount of precipitation and high intensity cyclones. The construction of green buildings plays a crucial role in promoting energy conservation and mitigating environmental impact by reducing energy use and emissions in the country. Rapid changes in energy standards and codes for both new and traditional construction are necessary to leverage the "hidden costs" and advantageous life cycle characteristics of established and proven technologies [3]. A recent study validates that polyurethane foam, as an insulation material, can facilitate this transition by offering credible evidence of energy savings, radiation prevention, and resilience characteristics [4]. This is achieved through the use of advanced technical tools and rigorous building energy simulation modeling. The study focuses on the integration of energy efficiency and green building standards, as well as the development of a comprehensive market analysis for new residential and commercial building construction, with potential applications for polyurethane. The multidimensional nature of the project described above is used to conduct an impact assessment for the optimal use of polyurethane/poly-isocyanate materials, in accordance with the current energy codes being studied by both supporters and opponents of advanced energy codes [5]. Researchers rely on this study can be effectively helpful and drive forward the short/long terms goals i.e. 50-70% energy saving in future [6]. Green building constructions are state of the art with its high performance potential, mostly LEED-certified houses deliver the source to reduce the climate change impacts of buildings and their residents. The tangible profits of green buildings couldn’t be easily detectable to boarders or visitors, but over justifiable design, structure and actions of green buildings are decreasing carbon emissions, prioritizing healthy materials and lowering our exposure to heat stress. Green building models philosophy advocates towards conservation and sustainable energy sources with safety of building materials according to the weather conditions.

The novelty of this effort is the concept of incorporation of entire polyurethane cat-ionomer chains through a noncovalent functionalization to examine the outcome on the structure, physical and mechanical properties of polyurethanes with improvement of living standards.

1.1. Climate change impacts in Pakistan

1.1.1. Temperature

The final report of the Task Force on Climate Change 2020, conducted by the Planning Commission of the Government of Pakistan, indicated an increase of 0.6 °C in Pakistan's average annual temperature during the last decade. Inter-governmental Panel on Climate Change (IPCC) assessed as compared to globe, Pakistan will have higher increase in average temperature in future [7]. During the 21st century the average surface temperature increase in globe is 2.8°C–3.4 °C [8].

1.2. Precipitation

About 25% increase in average rate of precipitation in Pakistan [9]. The precipitation of monsoon in all areas of Pakistan has been increased except the western Baluchistan and coastal areas as compared to the last century (Planning Commission, Government of Pakistan 2019) [10].

1.3. Climate change impacts on energy and electricity supply of Pakistan

According to Pakistan energy yearbook 2020 more over previous decade, the main commercial energy utilization in Pakistan is increasing at an average annual rate of 4.1% [11]. In 2019 Pakistan commercial energy usage was 62.6 Million Tones Oil Equivalent (MTOE) that demands of energy was fulfilled by 48.3% of gas, 32.7% of oil, 7.6% of coal, and 10.6% by hydroelectricity, 0.6% by nuclear electricity and 0.1% imported electricity [12]. However noncommercial fuels (animals waste, crop residues and wood) more than 20 Million (M) Tones oil Equivalent were consumed in industrial and residential sectors [13]. The residential sector of Pakistan is a prime consumer of energy [14].

1.4. Polyurethane

Polyurethane is a type of polymer created by combining two liquid chemicals: isocyanate (also referred to as side A) and polyol, along with additives and catalysts (collectively known as side B). These chemicals are derived from crude oil refinement [15]. Polyurethanes can be manufactured in either rigid or flexible forms, depending on the chemicals used in the production process. Pakistan has a significant number of polyurethane dealers, and the following are a few examples.

• •Pakistan Air Conditioning Company (PVT) Ltd (Lahore)
• •Pazeb House Lahore
• •Pakistan Polyurethanes Lahore
• •Master Molty Foam
• •Diamond Foam

1.4.1. Polyurethane chemistry

Polyurethanes are a versatile class of polymers that find applications in various fields, including coatings, adhesives, sealants, and foams. They are produced by the reaction of an isocyanate with a polyol in the presence of a catalyst, resulting in the formation of urethane linkages. The general chemical equation for the reaction is:

R–NCO + HO-R'-OH → R-NHCOO-R'-OH

Where R and R' represent organic groups [15]. The reaction can be modified by the addtion. of other compounds, such as blowing agents, cross-linkers, and surfactants, to adjust the final properties of the polyurethane.

1.4.2. Types of Polyurethane

• •Polyurethane foam with rigid properties
• •Polyurethane foam with flexible properties
• •Coatings, adhesives, sealants, and elastomers
• •Polyurethane with thermoplastic properties
• •A molding process known as reaction injection molding
• •Binding agents made with polyurethane
• •Dispersions of polyurethane that can be mixed with water

1.4.3. Applications of Polyurethane

Application varies from high rise office buildings, hospitals, airfields and manufacturing facilities to beverage and food industry cold storage warehouse. Long span composite building unit is formed when bonded on metal. Older buildings exteriors were renovated due to high value of insulation and light in weight of the polyurethane products. Cast in-situ form of rigid polyurethane foam is also available to fill voids and cover uneven surfaces. These foams are one component foams, cast in-situ and spray foams such capabilities of poly-iso foam and rigid polyurethane make them reducer of heat transfer, resistant to moisture, stability in dimension, airtight and helps in structural properties. Polyurethane and poly-iso foams are not disorder or distort in extreme temperature and there is no issue with dampness which may cause by condensation.

1.5. Environment and health hazards of polyurethane

During spray a lot of sever health risks connected with airborne aerosol, vapors and mist pointed by EPA [16]. When the workers or other peoples of near areas are direct exposed to chemicals through the application process may suffer from irritation and chronic lungs disease. However the eyes and non-covered area the body is also on potential hazard. The personal protective equipment’s are obligations when the application process is carried out. The EPA summarizes good aeration practices and rules to minimize the health risks associated by exposure. Worker will be less vulnerable to chemicals exposures by obligating of such practices and rules. Extra preventive actions should be taken to make assured that workers will not exposed directly in applying practice however they should be aware of the risks of chemical exposure and hazards.

1.6. Impact of polyurethane on construction/buildings

Polyurethane padding goods play essential task in considerably downsizing the energy Polyurethane padding goods play essential task in considerably downsizing the energy usage of U.S and helps to reduce the greenhouse gases release [17]. The mandatory and continuous application of polyurethane insulation in standards of ASHRAE 90.1–2010P and 189.1 P shows the huge decrease in energy and greenhouse gases [18]. A considerable amount of energy saving and the opportunities of greenhouse gasses will be mislaid when these standards should be implemented now. There is a loss of 1,900 T Btu of energy and discharge of 134 million metric tons of carbon dioxide if the implementation of ASHRAE 90.1–2010P until 2015 [19]. History of polyurethane industry depicted the innovation and performed task at the requirement of new technology and to face every challenge which warn its market. Phelan and Pavlovich. G. 2009 reported that no more quires in the advanced developed technologies, like the renewable energy area by providing chances to innovative application of polyurethane, however large and strong polyurethane insulation goods, such as poly isocyanate board sheets, metal panels of poly isocyanate and spray polyurethane foam [20]. Polyurethane products manufactures and suppliers are confident enabled to address the issues related to energy conservation and emission due to the high insulating efficiency of polyurethane, broadly market availability with highly resistivity of flame in roofs and walls application. It is mandatory to make the policy regarding the implementation of polyurethane application and demonstrate the advantages and credible impact of polyurethane to house owners and builders to achieve the valuable market in reality. In Pakistan, new buildings, homes, and offices require high energy usage due to the composite climate, which includes severe winters and warm summers. The primary objective of this study is to improve the quality of life by recommending insulation material thickness to determine the thermal conductance coefficient (U-Factor) and R-Values, despite the electricity shortage in the country. This will pave the way for the establishment of an Energy Conservation Building Code (ECBC). The objectives of this study include reducing greenhouse effects and improving indoor comfort by: • Enhancing the property value and living standards. • Estimating energy savings and lowering heat costs. • Calculating the cost-benefit ratio through the use and comparison of Polyurethane.

According to a report by the Pakistan Meteorological Department in 2020, there is an impact of Polyurethane on Construction/Buildings in Pakistan, which has resulted in anomalies in the annual mean temperature from 1961 to 2016. Fig. 1 shows a black line indicating the 7 years stirring average while the black dotted line shows the trend over the periods (Pakistan Meteorological Department, 2020) [21]. While Fig. 2 displays an annual temperature map of Pakistan, showing the maximum, minimum, and mean temperatures during 2020 (Source: Pakistan Meteorological Department, 2020) [21].

Fig. 1.

Pakistan anomalies annual mean temperature (from 1961 to 2016). Where the black line indicated the 7 years stirring average while the black dotted line showed trend over the periods. (Source: Pakistan Meteorological Department 2020) [21].

Fig. 2.

Annual temperature Map showing maximum, minimum and mean temperature during 2020 in Pakistan. (Source: Pakistan Meteorological Department 2020) [21].

2. Materials and methods

2.1. Experiment site

This study was carried out in Vehari, Punjab, Pakistan. The purposed investigational work is concentrated at 35 °C mean temperature to evaluate the insulation materials thermal conductivity. To investigate the thermal resistance and heat coefficient of conventional and insulated roofs in prototype buildings, a study was conducted using 10 randomly selected samples. Measurements were conducted utilizing an automatic guarded hot plate apparatus, utilizing varying thicknesses of insulation materials. The building roofs were divided into two groups: one group had 50 mm of external thermal padding, while the other group had no insulation materials. The experimental setup included a hot plate, a cryostat, and two cold plates. The temperature of the cold plates was maintained by circulating fluid at a low temperature. The monitoring device helps to observe the value and the supply and temperature controllers regulated the monitoring device.

2.2. Hot plate apparatus

The temperatures of cold and hot plates were traced by the assist of thermocouples and statistic logger. When constant state of temperature was achieved voltage and current were measured by voltmeter and ampere meter. Following equation was used to calculate the thermal conductivity.

K= I x V x d/ (2 X A (T_H _ T_C) (1)

In order to calculate the thermal conductivity of the polyurethane insulation used in our green building project, we applied the hot plate apparatus and used (Equation (1)), where K represents thermal conductivity, I is the current passing through the hot plate, V is the voltage across the hot plate, d is the thickness of the insulation, A is the area of the hot plate, and T_H and T_C are the temperatures of the hot and cold plates, respectively [22].

In this study, roof sections made of Reinforced Cement Concrete (RCC) were examined with varying thicknesses, including 165, 150, 140, 127, and 114 mm. Various waterproofing membranes were installed on the sections, including 50 mm thick mud, 50 mm thick brick tile, and 50 mm thick thermal insulating material (such as polyurethane). The U-factor and R-values were calculated to comply with the ECBC requirements. The U-Factor was calculated using the following formula:.

$$\mathrm{U}=\mathbf{1}/(\mathbf{1}/{\mathit{h}}_{\mathit{i}}+\sum _{\mathit{i}=\mathbf{1}}^{\mathit{n}}{\mathit{L}}_{\mathit{i}}/{\mathit{K}}_{\mathit{i}}+\mathbf{1}/{\mathit{h}}_{\mathbf{0}})$$ (2)

In order to calculate the overall heat transfer coefficient (U) for our experimental system, we used the following equation (Equation (2)): here hi represents the convective heat transfer coefficient on the inside of the system, Li and Ki represent the thickness and thermal conductivity of the i-th layer, and h₀ represents the convective heat transfer coefficient on the outside of the system [23].

In this context, the term U represents heat diffusion, which is the rate of heat conduction per unit time from a unit area of a material, along with the adjacent air films, induced by a unit temperature difference between the atmospheres on each side. The units of U are W/m²-°C. The parameters hi and ho represent the film heat transfer coefficients of the inner and outer sides, respectively, and n denotes the number of layers. Meanwhile, Ki and Li denote the thermal conductivity and thickness of the material layers.

2.3. Typical roof construction

The objective was to calculate the overall U-factor for a standard roof assembly, which involved combining the factors for the standard roof assembly type with the actual U-factor for insulation, as per the given equation. We calculated the overall heat transfer coefficient (U) for our roof system using the following equation (Equation (3)):

U-_{Total Roof} ¼ 1 = 1 = U-_{Typical Roof} + U-_{Typical Insulation} (3)

Where U-Typical Roof represents the heat transfer coefficient of a typical roof, and U-Typical Insulation represents the heat transfer coefficient of typical insulation material used in the roof." We used Equation (3) to calculate the overall heat transfer coefficient (U) of our roof system [24].

2.4. Observations

The U-factor for thermal resistance and heat coefficient was determined by considering the following parameters.

• •Building envelope (measured in m⁻²)
• •Heating system
• •Mechanical equipment
• •Air conditioning system
• •Ventilation system
• •Hot water arrangement
• •Interior and exterior lighting structure
• •Electrical control
• •Motors (used in non-AC homes)

2.5. R- value

The thermal resistance of a building envelope can be calculated from its U-value, which is the reciprocal of the overall heat transfer coefficient U, as given by Equation (4):

R = 1/U (4)

The thermal resistance (R) [25] is the inverse of the time rate of heat flow through a unit area caused by a unit temperature difference between two specific surfaces of a material or construction during steady-state conditions. The unit of R is m^{−2 0}C.

2.6. Statistical analysis

The collected data was subjected to rigorous analysis using suitable statistical software to identify patterns, trends, and significant differences among the variables. Specifically, the means of the collected data were compared using ANOVA [26] to determine the degree of variation among the groups and to identify any significant differences between them. The results and discussion chapter of the study presents a detailed interpretation of the findings, based on the statistical analysis. To perform the statistical analysis, Statistica 8.1 software was used.

3. Results

3.1. Samples data and experiment

Thermal conductivity of insulating materials was measured keeping in view the available mean temperature in Pakistan and Saudi Arabia at 35 °C.10 samples were randomly presented in Table 1 with average mean temperature at 35 °C in summer season with polyurethane applications. Whereas, 5 samples were taken from non-insulated roof sections of different thickness. Thickness of concrete were taken as 165 mm, 150 mm, 140 mm, 127 mm and 114 mm. While the thickness of polyurethane insulating materials were selected 50 mm in polyurethane treated roof sections and same thickness of mud and brick tile were taken in traditionally/non-insulated buildings i.e. 50 mm. It has been noticed that application of thin polyurethane layers provided with improved and significant values of results than non-insulating materials due to insulating gas with its compactness within the closed cell structure providing better quality. As a result it proceeds less energy to heat/cold in homes and salable buildings, saving on carbon dioxide radiations from burning fuels to cool and heat the constructions of new buildings.

Table 1.

Mean temperature of 35 °C of 10 different samples and thickness of polyurethane.

Sr. No.	Temperature 0C	Roof sections Thickness (mm)	Insulation Thickness (mm)
1	38 °C	315 (mm)	50 (mm)
2	38 °C	300 (mm)	50 (mm)
3	37 °C	290 (mm)	50 (mm)
4	33 °C	277 (mm)	50 (mm)
5	34 °C	264 (mm)	50 (mm)
6	35 °C	265 (mm)	Non-insulated
7	33 °C	250 (mm)	Non-insulated
8	33 °C	240 (mm)	Non-insulated
9	35 °C	227 (mm)	Non-insulated
10	34 °C	214 (mm)	Non-insulated

The limits of sensors was found ±6.7% through comparative error of the K-type thermocouples with error 0.3%.

3.1.1. Uncertainty analysis

Due to the inherent variability in experimental measurements, there is always a chance of some level of uncertainty in the results. To account for this, it is essential to perform an uncertainty analysis. In statistical terms, uncertainty arises from the probability of a result occurring or not. The variance is commonly regarded as the most widely accepted measure of uncertainty. Statistical methods are highly effective for analyzing and interpreting experimental data. The 'analysis of variance' (ANOVA) is a powerful tool for testing hypotheses and comparing means of multiple groups. An uncertainty analysis was conducted using ANOVA to evaluate thermal conductivity with different insulating materials. The results revealed a P-value of <0.05 and an F-value > F-critical at a 95% confidence level for 2 and 27° of freedom. Therefore, the conclusions drawn from the results were deemed significant, while differences within and among the measured groups were insignificant.

3.2. ECBC U-factor and R-value requirements

In new buildings, envelope states to the external cover-up, and is included of dense components in walls, windows, door and roofs. Table 2 showed how composite climate impact on day time use buildings and 24 h engaged buildings include homes, hotels, hospitals, call centers and educational institutes along with banks etc. Maximum U-factor and R-values were observed and found variation with and without insulating materials. It was also observed that U-factor remained high and significant in 24 h engaged buildings as well as buildings with full day light utilization. U-factor was calculated by the area weighted method, including U-value of glass, windows, walls and roof. According to ECBC recommendations for minimum energy standards of new commercial buildings having a connected load of 100 kW or contract demand of 120 kVA. Buru of energy efficiency (BEE) is also promoting the execution of energy efficiency measured in existing buildings through Energy Service Companies (ESCOs) that are innovative business model of energy-saving potential in existing building captured the risk faced by building owner.

Table 2.

ECBC recommendations for U-factor and insulation R-value requirements in roofs and opaque walls.

Climate Zone	24/7 buildings (Hotels, Call Centers & Hospitals)		Buildings used during daytime (Educational institutes, Banks etc)
Compound	The highest U-factor of the entire assembly (measured in W/m2-0C)	Minimum R-value (W/m2-0C)	The highest U-factor of the entire assembly (measured in W/m2-0C)	Minimum R-value (W/m2-0C)
Roof	0.256	3.7	0.408	2.10
Wall	0.444	2.1	0.439	2.10

A well-established building envelop not only conserve energy but also reduced the extra cost paid by the resident according to ECBC. Amount of heat gained or loss with aeration inside depends on the key determinants of building envelop codes which not only protect the buildings from external/internal weather conditions and relieved the occupants. U-factors with R-values also considerably internal/external heat loads and sunlight that effects on energy consumption [27,28].

Maximum U-Factors values were observed in roof and walls of 24 h engaged buildings with 0.256 (W/m²-⁰C) and 0.444 (W/m²-⁰C) while in day time used buildings were recorded 409 (W/m²-⁰C) and 0.438 (W/m²-⁰C). Similarly, minimum R-values were found 3.6 (W/m²-⁰C) and 2.1(W/m²-⁰C) with at par values of R-factor in walls and roof of said buildings i.e. 2.1 (W/m²-⁰C).

According to the reference study by M.A. Akbar et al. (2017), "Fig. 3 illustrates the maximum and minimum U-factor and R-Values during 24 h use of buildings." The U-Factor and R-Value requirements for buildings in accordance with the Energy Conservation Building Code (ECBC) are also discussed in the study.

Fig. 3.

Maximum and minimum Ufactor and R Values during 24 h use buildings [29].

According to the reference study by Siddiqui et al. (2019), "Fig. 4 shows the U-Values identification chart [30]

Fig. 4.

U-Vales identification chart [30].

The pictorial research activity consists of two main parts, as shown in Figs. A and B. Fig. A displays the process of material selection and installation, while Fig. B illustrates the subsequent energy performance analysis of a building. In Fig. A, various insulation materials are considered for selection, including polyurethane, expanded polystyrene (EPS), extruded polystyrene (XPS), rock wool, and glass wool. Once the insulation material is chosen, it is installed in the building envelope, such as walls, roofs, or floors, as shown in the top row of Fig. A. The bottom row of Fig. A shows the installation of insulation material in the HVAC ductwork. In Fig. B, the energy performance of the building is analyzed by measuring the U-factor and R-value of the building envelope and HVAC ductwork. The analysis is carried out during 24-h usage of the building to determine the maximum and minimum U-factor and R-value.

3.3. Thermal conductivity of construction materials

Using a guarded hot plate apparatus at 35 °C, the thermal conductivity of different construction materials, such as polyurethane, burnt clay brick, reinforced cement concrete (RCC), brick tiles, mud phuska, and cement mortar were measured. Table 3 displays the density (Kg/m³), thermal conductivity (W/m K), and specific heat (KJ/Kg K) of these materials. Maximum density was found in burnt clay brick (1920 kg/m³) constructed material while brick tile was at par (1820 kg/m³). While minimum constructed material density was found in material where polyurethane were applied i.e. 32 kg/m³. Density defines the mass per unit volume of a material with expressing in kg/m³. Overall weight reflected a high density material with low thermal diffusivity and high thermal mass. While measuring thermal conductivity was found maximum in burnt clay along with brick tile with at par i.e. 0.829 W/m K and 0.792 W/m K. Minimum thermal conductivity were also again found in application of polyurethane material (0.027 W/m K). Specific heat transfer revealed less in polyurethane material with 0.85 kJ/kg K and remained at par in case of burnt clay, Reinforced cement concrete (RCC), Brick tiles and Mud phuska 0.91 kJ/kg K. Densities of each sample were measured before taking the thermal conductivity. The critical examination of calculated values of thermal conductivity, specific heat and density of materials illustrated that there is enormous consequence on indoor temperature. The practical information shown that the materials with lower K- value and smaller thickness fulfill the ECBC recommendations. Insulation materials are designed to mitigate the transfer of heat flux into the building during its useful life that is essential feature. The interchange of temperature with in two different objects is known as heat transfer. According to 2nd law of thermodynamic heat always moves from hot entity to colder one. When the environment conditions of different involved objects attain the similar temperature that point is called thermal equilibrium. Heat transfer take place in three ways.

• 1-Conduction: Transfer of heat in solids that are interconnected or within the solid object by the way of conduction. Molecules in hot area of entity shakes quicker as compared to the fragments in cold portion. Some share of energy from fast traveling molecules to nearby slow moving particles. In all metals excluding gases heat transfer by conduction method.

• 2-Convection: Transfer of heat with the help of current is termed as convection from hot portion heated particles moves towards colder side. In liquid when the molecules get hotter they start vibrating quickly. Convection current occurs due to the repeated action of increasing and decreasing of heating and cooling gas or fluids. Convection current transmits heat to another portion when heating liquid container one solid side.

• 3-Radiation: Every object intake and discharge thermal radiation. Transfer of thermal energy through waves without including any object. By thermal radiation of sun earth get heated. Irregular actions of molecules and atoms with in substance causes thermal radiation emission. Charged particles means electrons and protons present in such molecules and atom their movement create the discharge of electromagnet radiations which take away the energy from the body surface.

Table 3.

Guarded hot plate apparatus at 35 °C was used to measure the thermal conductivity of Polyurethane and various construction materials.

Materials' names	Mass per unit volume in kg/m³	Rate of heat transfer in W/mK	Heat capacit (KJ/Kg K)
Rigid Polyurethane Foam	32	0.027	0.85
Burnt clay brick	1920	0.829	0.91
Reinforced cement concrete	234	1.43	0.91
Brick tile	1820	0.792	0.91
Mud phuska	1620	0.515	0.91
Cement mortar	1650	0.725	0.97

3.4. Heat transmittance values

In construction material the specific heat capacity is measured as the amount of heat required to increase temperature of 1 kg of the material by 1 K or by 1 °C. Polyurethane has higher specific heat capacity due to its absorbent quality prior its raising temperature and transfer the heat. Materials having thermal mass or buffering thermal shown high heat capacity than those having less thermal mass. We analyzed the U-values (W/m2 K) for various roof thicknesses (in millimeters) using both polyurethane and non-insulated materials. We compared our findings to the recommended U-values outlined in the ECBC guidelines and identified instances where our results deviated from those standards. Table 4 revealed the 50 mm thickness shown U-value (0.418 W/m² K) while samples of others compared roof section on 300 mm, 290 mm, 277 mm and 264 mm were remained at par while achieving the U-value of 0.412 w/m² k. We observed notable deviations from the recommended ECBC U-values when polyurethane was applied, whereas non-insulated materials showed less significant deviations. Specifically, we found deviations of −2.98%, −3.00%, −3.21%, −3.4%, and −2.90% in our analysis. This is done due to the insulation distance from the floor/roof surface and leaving air gap on the upper surface of insulation materials. Furthermore, depends on air mass on the materials. Usually, conventional constructions have ability to gain more solar heat while polyurethane is an insulating material with its low gaining property to solar heat. Solar heat radiation transfer rates of transmittance in insulated and non-insulated materials is not equal to heat transmitted directly due to absorbed material quality and re-emitted into space.

Table 4.

Heat transmittance values of different roof sections by using polyurethane insulation satisfying ECBC inBuildings.

Sr.No	Roof Sections Thickness (mm)	Polyurethane Width (mm)	U-value (W/m2 K)	Deviation from the u-value suggested by ECBC standards
1	315	50	0.418	1.20%
2	300	50	0.414	1.00%
3	290	50	0.412	0.02%
4	277	50	0.412	0.02%
5	264	50	0.41	0.02%
6	265	Non-insulated	3.630	−2.98%
7	250	Non-insulated	3.721	−3.00%
8	240	Non-insulated	3.793	−3.21%
9	227	Non-insulated	3.875	−3.40%
10	214	Non-insulated	4.012	−2.90%

+Upper side deviation; -lower side deviation.

3.5. U-factor

The U Factor indicates the rate of non-solar heat transfer for a window. In order to comply with ECBC standards, the thermal resistance and overall heat transfer coefficients were determined for various material thicknesses, enabling the calculation of U-factor and R-values. We analyzed a total of 10 roof section combinations, including Reinforced Cement Concrete (RCC) with thicknesses of 165 mm, 150 mm, 140 mm, 127 mm, and 114 mm, as well as waterproofing membrane, 50 mm mud phuska, 50 mm brick tile, and thermal insulation material such as polyurethane foam. The U-factor measures heat transmission per unit time and area of a material, including the boundary air films, due to a unit temperature difference between the environments on each side. It is expressed in units of W/m²-C. Thermal resistance, or R-value, is the measure of a material or structure's ability to impede heat flow per unit area caused by a unit temperature difference between two specific surfaces in steady-state conditions, with units of m²-C/W. When it comes to the prescriptive building envelope option, the R-value pertains solely to insulation and does not factor in building materials or air films. Results indicate that roofs insulated with polyurethane demonstrate reduced U-values, leading to a more comfortable indoor setting and lowered electricity expenses (see Table 5).

Table 5.

The roof section consists of a 50 mm layer of polyurethane insulation (with a thermal conductivity of 0.0272) and 50 mm of mud phuska (thermal conductivity: 0.515), as well as 50 mm of brick tile (thermal conductivity: 0.792). This configuration results in a U-value of 0.4356 W/m²-K for the polyurethane insulation layer and a U-value of 2.32 W/m²-K for the entire roof section.

Insulated R.C.C Roof	Thickness	K-values	R-value-1 (R.C.C)	R-value-2 (Polyurethane)	R-value-3 (Mud Phuska)	R-value-4 (Brick tile)	U-value (W/m2 k)
R.C.C	165	1.43	0.1153	1.851	0.0970	0.06313	0.4710
	150	1.38	0.1086	1.851	0.0970	0.06313	0.4723
	140	1.35	0.1035	1.851	0.0970	0.06313	0.4737
	127	1.30	0.0970	1.851	0.0970	0.06313	0.4750
	114	1.28	0.0889	1.851	0.0970	0.06313	0.4777
Non-insulated R.C.C
R.C.C	165	1.43	0.1153	Non	0.0970	0.06313	3.630
	150	1.38	0.1086	Non	0.0970	0.06313	3.721
	140	1.35	0.1035	Non	0.0970	0.06313	3.793
	127	1.30	0.0970	Non	0.0970	0.06313	3.875
	114	1.28	0.0889	Non	0.0970	0.06313	4.012

The roof section lacking insulating materials has a U-value of 4.012 W/m² K.

3.6. Time lag and decrement factors

The concept of decrement delay and thermal buffering is explained through feelings of two person in which one spent a day in a Caravan and other in a stone house with closed shutter will definitely express their experience and escalate the meanings of Decrement delay. It is happened so due to thoroughly maps the rise and fall temperature outside that directly affect the resident. Whereas, occupant feel less internal temperature who stayed in stone house during midday heat and will be relatively more comfortable from the sun heat.

In Table 6 Time lag (ɸ) has been derived by using experiential roof upper surface temperature and ceiling temperature and decrement factor was determined by upper outdoor and indoor air temperatures. Corresponding U-value and heat resistance R-value for insulated by polyurethane roofs and non-insulated roofs were shown clearly in the above table. Time lag, ɸ in hours is the time delay of reaching maximum outdoor temperature to maximum indoor surface temperature given by formula. We calculated the time lag (ɸ) of our building envelope using the following equation (Equation (5))

Time Lag ɸ = TOS – TIS (5)

Table 6.

Decrements and time lag of polyurethane treated roof sections and untreated roof sections.

Roof Sections	Decrement Factor ƛ	Time Lag ɸ	Rvalue	U-value (W/m2 k)
TREATED SECTIONS t	0.052	11.24	0.117	0.4710
2	0.055	11.2	0.116	0.4723
	0.058	11.11	0.113	0.4737
4	0.059	10.95	0.121	0.4750
	0.061	10.81	0.101	0.4777
UNTREATED SECTIONS
1	0.172	4.5	0.078	3.630
2	0.178	4.44	0.078	3.721
3	0.1792	4.32	0.078	3.793
4	0.1799	4.22	0.078	3.875
5	0.181	4.11	0.078	4.012

where TOS represents the time of occurrence of the maximum outdoor temperature and TIS represents the time of occurrence of the maximum indoor temperature [[22], [23], [24], [25], [31]].

The time constant of our building envelope was calculated using Equation (6), which is given by with decrement factor ƛ, ratio of indoor temperature amplitude to outdoor temperature amplitude.

ƛ = Ti max –Ti min/ TO max –Ti max (6)

where Ti max and Ti min represent the maximum and minimum indoor temperatures, respectively, and TO max represents the maximum outdoor temperature during the same time period [37]. Lower value of ƛ and higher value of time lag ɸ is the criteria for better building section. Results shown that decrements statistics were significantly high in all treatments where insulated materials were applied with decrement factor ƛ 0.052, 0.055, 0.058, 0.059 and 0.061 accordingly. Whereas, ƛ value were found high with non-significant impact with following results 0.172, 0.178, 0.179, 0.179 and 0.181 respectively. Similarly, time spam were found high to pass heat inside the room where polyurethane were applied with 11.24 min, 11.20 min, 11.11 min, 10.95 min and 0.18 min. But on the other hands less time duration is required to heat up the building inside with 4.5 min, 4.4 min, 4.32 min, 4.22 min and 4.11 min. U-value were found significant in all treated buildings 0.47 W/m². While in non-treated block shown unsatisfactory non-significant results all treatments. Reason clearly described that external covering starts to heat up, output is noticed that heat is quickly transferred from non-insulated material due to light weight composite, whereas, due to insulation material heat is absorbed by the polyurethane and entered slowly from outside to inwards. After many hours heat transferred into the occupancy while remained is exhausted back to the air. Interesting aspect of this phenomena is due to similar U-Value of the building. For this reason heat transferred rate is on its steady sate over a period of time from outside of the treated material and reduced the heat.

3.7. Monthly energy budget

Results described the high energy consumption during summer and winter season in Punjab-Pakistan while being used with conventional/traditional buildings as well as low energy usage by using polyurethane application in proposed study areas with same climate. Table 7 shown the results of energy consumption and saving percentage during 2020 with different daily home appliances. This table contains two conditions of weather i.e. summer and winter. While in winter experiment was set out with achieved winter temperature at 22 °C, 25 °C respectively. During winter home appliances were used under studied at set point 22 °C including electric heaters, electric geysers, lighting, ventilation (Exhaust Fan) and hair dryer. Energy units were taken in Kwh/month with assumed reference 350 at 22 °C while 500 at set point 25 °C. Results reveals energy usage of electric heater at reference 350 were 50 kwh/month to achieve the set point 22 °C in conventional/traditional/old constructions but 25% energy were saved by using polyurethane application at same reference and same electric heater usage at set point 22 °C. It was found that 30% saving were observed by using electric geyser with reference 350 with insulating material of polyurethane and 30 kwh/month were consumed with saving of 0% energy on set point 22 °C. Similarly, 52% energy were saved by using polyurethane in winter at reference 350 kwh/month by achieving set point 22 °C. Meanwhile same techniques were applied by gaining 25 °C set point while reference was set out 500 kwh/month in winter. Results were highly significant by the application of polyurethane with electric heater and saved 30% while used 100 kwh/month. Again home appliances in shape of electric geyser were found 110 kwh/month at reference 500 to achieve the set target 25 °C. This high saving energy is with highly significant application of polyurethane in new constructions in Vehari-Punjab, Pakistan. Lighting and ventilation impact were at par in reference point 500 by attaining 25 °C in winter with saving of 50% energy saving while taking in account energy consumption of 30 kwh/month and 15 kwh/month. Table 7 shown the results of energy consumption and saving percentage during 2020 with different daily home appliances. In summer experiment was set out with achieved summer temperature at 16 °C, 20 °C respectively. During summer home appliances were used under studied at set point 16 °C including ceiling fans, pedestals fan, air coolers, air conditioners, refrigerators, water dispensers, ventilation (Exhaust Fan) and lightning. Energy units were taken in Kwh/month with assumed reference 800 at 16 °C while 600 at set point 20 °C. Results depicted energy usage of ceiling fans at reference 800 were 38 kwh/month to achieve the set point 16 °C in conventional/traditional/old constructions but 40% energy were saved by using polyurethane application at same reference and same ceiling fan usage at set point 16 °C. It was found that 30% of energy saving in pedestals fan to achieve the set point of 16 °C by using the polyurethane as an insulating material and consuming 40 Kwh/month at assumed reference 800 Kwh/month. In summer at set point 16 °C the air cooler consumes 40 Kwh/month while 50% energy saving of reference 800. While using air conditioners to achieve the set point 16 °C it consumes 50 Kwh/month and shown the saving 38% of the re reference 800 Kwh/month. Similarly there is 20% and 15% reduction of energy consumption refrigerator and water dispensers respectively to achieve the set point 16 °C by using polyurethane roof insulation. The results are significant and shown the feasible reduction of energy usage of ventilation and lightning at the set point 16 °C. Meanwhile same techniques were applied by gaining 20 °C set point while reference was set out 600 kwh/month in summer. Results were highly significant by the application of polyurethane with ceiling fans and saved 36% while used 45 kwh/month. Again home appliances in shape of pedestals fan were found 35 kwh/month at reference 600 to achieve the set target 20 0C. The energy usage of air coolers, air conditioners were reduce to 40%–34% respectively to achieve the set point 20 °C at reference 600 kwh/month and consuming the 50 kwh/month and 55 khw/month. While in summer at set point 20 °C the consumption of energy by refrigerators and water dispensers was downsized to 25% and 20% of reference point 600 Kwh/moth. This high saving energy was with highly significant with application of polyurethane in new constructions in Vehari-Punjab, Pakistan. Lighting and ventilation impact were at par in reference point 600 by attaining 200C in summer with saving of 49% energy saving while taking in account energy consumption of 35 kwh/month and 10 kwh/month.

Table 7.

Monthly energy consumption of insulated buildings in winter and summer with different temperatures.

Electric Gadgets’	WINTER
	Achieved Set point 22 °C		Achieved Set point 25 °C
	Energy (KWh/M)	Savings %	Energy (KWh/M)	Savings %
	Reference 350	0	Reference 500	0
Electric Heaters	50	25	100	30
Electric Geysers	70	30	110	34
Lighting	30	0	30	0
Ventilation	10	52	15	50
Electric Gadgets’	SUMMER
	Set point 160C		Set point 200C
	Energy (KWh/M)	Savings %	Energy (KWh/M)	Savings %
	Reference 800	0	Reference 600	0
Ceiling Fans	38	40	45	36
Pedestal Fans	40	30	35	33
Air Coolers	40	50	50	40
Air Conditioners	50	38	55	34
Refrigerators	45	20	48	25
Dispensers	40	15	45	20
Ventilation	30	30	34	49
Lighting	10	0	10	0

3.8. Estimated cost of non-insulated buildings

Table 7 illustrated estimated cost of Non-Insulated building having covered area 875 m² was recorded 21,183750 @ Rs 24210/m2 during 2015–16. Operational units consist of substructure/foundation cost, roofing and finishing. It was observed that structural cost found Rs = 1,376,943.75 including Earthwork in Excavation and filling ½ %, Concreting in foundation 5%, Damp proof course 1%. While Rs = 4,236,750 were spent in roofing. Finishing cost was also high in this case and total cost were spent Rs. 7,202,475. On an average Rs = 21, 183750 were calculated during this case. Cost breakup of different construction activities such as substructure, superstructure, roofing, finishing and miscellaneous charges has been shown in subtotal A, B, C, D and E [32] (see Table 8).

Table 8.

Estimated cost of Non-Insulated building having covered area 875 m².

Operation/Input	Cost/m2 (Rs.)
A) Substructure/Foundation operations
•Earthwork in Excavation and filling ½ %	105918.75
•Concreting in foundation 5%	1059187.5
•Damp proof course 1%	211837.5
Sub Total A	Rs = 1,376,943.75
B) Super Structure
•Brick work up to roof 34%	7,202,475
Sub Total B	Rs = 7,202,475
C) Roofing 20%	4,236,750
Sub Total C	Rs = 4,236,750
D) Finishing
•Flooring 6%	1,271,025
•Doors and windows 16%	3,389,400
•Plastering and painting 10%	2,118,375
•White washing, colour washing, painting etc 2%.	423,675
Sub Total D	Rs = 7,202,475
E) Miscellaneous 5.5% Sub Total E	1,165,106.25
Grand Total = A + B + C + D + E	Rs = 21,183750

3.9. Estimated cost of polyurethane treated buildings

The cost of building that having covered area 875 m² that building roof was treated by polyurethane has been depicted in Table 9. Cost breakup of different construction activities like substructure, superstructure, roofing and insulation, finishing and miscellaneous charges were shown in subtotal A, B, C, D and E. The cost was 22.031 (M) initial capital cost of that building has been increased because building roof was insulated with 50 mm thick polyurethane to save the energy and reduce electricity bills cost.

Table 9.

Estimated cost of Polyurethane treated buildings in Vehari region.

Operation/Input	Cost/m2 (Rs.)
A) Substructure/Foundation operations
•Earthwork in Excavation and filling ½ %	105918.75
•Concreting in foundation 5%	1059187.5
•Damp proof course 1%	211837.5
Sub Total A	Rs. = 1,376,943.75
B) Super Structure
•Brick work up to roof 34%	7,202,475
Sub Total B	Rs. = 7,202,475
C) Roofing and its treatment
•Roofing 20%	4,236,750
•Polyurethane Installation cost (PKR 847350)	847350
Sub Total C	Rs. = 5,084,100
D) Finishing
•Flooring 6%	1,271,025
•Doors and windows 16%	3,389,400
•Plastering and painting 10%	2,118,375
•White washing, color washing, painting etc 2%	423,675
Sub Total D	Rs. = 7,202,475
E) Miscellaneous 5.5% Sub Total E	1,165,106.25
Grand Total = A + B + C + D + E	Rs. = 22,031,100

3.10. Economic Benefit of polyurethane

A benefit-cost ratio (BCR) described the Cost-effectiveness key amount indicator, used in economic analysis for computed the expenses and profitability. BCR not only tries to précis the total cost of a project/proposal. It is also the share of margin and profit of project/proposal. Relative to its actual costs. All expenditures are expressed according to its applications. Benefit cost ratio (BCR) proceeds the amount of financial gain grasped by execution of a project against the costs to perform a proposal/project. Investment is consider better and profitable when achieved higher BCR which followed the general thumb rule i.e. higher profit than cost is good investment. Table 10 depicted the different concrete thickness of roof sections with an average electricity billing cost and economic returns per annum in Pakistan. Rupees. It has been observed that an average annual electricity bills cost of polyurethane insulated buildings was 30% less than non-insulated buildings. The initial capital investment was higher to insulate the building but this investment has been returned in the shape of electricity bills. Polyurethane cost saving achieved within 3.3 years. The total cost increased with increasing the thickness of insulation per until. It has been reached the optimum thickness where the total cost saving start to drop. Different thickness were selected with non-insulation materials as well as insulated material (Polyurethane) to check out the electricity bills. It was found that annual electricity billing was gained Rs = 252,00 in treatment having applied by polyurethane with concrete thikness of 165 mm. While Rs = 596,400 were calculated in non-insulated buildings. Although economic cost were found high as compared to non-insulated constructed buildings i.e. Rs = 847,350. Return benefit were definitely found high in treatment where polyurethane were applied (see Table 11) (see Fig. 5).

Table 10.

Cost benefit ratio with application of Polyurathene.

Concrete Thickness (mm)	Average Annual Electricity Bills Cost (Rs)		Total Saving (Rs/Year)	Polyurethane Installation Cost Rs =	Return benefit ratio (Year)
	Without Polyurethane Application	With Polyurethane Application
165	840,000	588,000	252,000	847,350	5.36
150	842,400	589,680	252,720	847,350	3.35
140	846,000	592,200	253,800	847,350	3.33
127	849,600	594,720	254,880	847,350	3.32
114	852,000	596,400	255,600	847,350	3.31

Table 11.

Comparision and properties of different insulation materials available in Pakistan [33].

Material	Thermal conductivity	Density Kg/m3	Monolithic	Seamless
Polyurethane	0.01	35–40	Yes	Yes
Polystyrene	0.037	30	No	No
Glass wool	0.041	65–160	No	No
Polyethylene	0.0348	32–38	No	No

Fig. 5.

(a) Application of foam polyurethane (b) Yellow color stunt of polyurethane at CUI-Vehari building on an area of 25000 ft².

Fig. 6 illustrates two aspects of the study. In Fig. 6(a), the thickness of the concrete (in mm) is plotted against the number of polyurethane layers applied. This shows the observations made during the study. In Fig. 6(b), a field experiment is conducted on an area of 25000 ft2 at COMSATS University Islamabad, Vehari Campus to prepare the materials for the study.

Fig. 6.

(a) Concrete Thickness (mm) vs polyurethane layers observations; (b) Field experiment with preparation of materials on an area of 25000 ft² at COMSATS University Islamabad, Vehari Campus.

4. Discussion

Vast amount of raw materials were consumed by construction field which also contain high level of energy usage. Buildings consume high amount of energy in construction phase as well as in its useful life to achieve its cooling, heating and ventilating needs when the material used in it of highly embodied energy. Raw material which is take out with mining has consumed nearly 60% in building execution and civil projects. While from this amount 40% signifies by buildings in further confrontations 24% of world take out. Material extraction in Europe is 64 times higher than the usual mass of human being which is 4.8 tons/occupier/year this amount is planned for building which is alarming to the direction of less consumption of material in building works. The construction materials which are used like cement, sand, crush, bricks, steel and glass etc. During its manufacturing, transportation and installation consume large amount of energy while they are expressing a small part of cost of the capital investment this inconsistency is called Notary Rule. Moreover, the materials which are applied in buildings are copper, iron and aluminum along with percentage of 6%, 24% and 63% respectively this percentage depicted the large amount mining of material from earth crust ultimately this ratio cause shortage at the end.

In current days the climate change promptly disturbing the economy of different sectors of the country. The consumption of electricity is highly affected and is correlated to the weather conditions electricity sector is very sensitive. By the increase of temperature and social economy the need of electricity has been increased. Usually in summer the month of July the usage of electricity is very high and it has been predicted up to 6785.6 GWh in 2020 due to the rapid increasing of temperature. It is acknowledged that in every country the electricity plays and essential role in the technology development, country economy growth and planning. Several scholars predicted the energy demand which is impacted by global warming in the area. Plentiful economic development caused weather changes which finally affect the estimated revenue. Extreme atmospheric actions are rare like weather frequency, heat strokes, coldness, cyclone, precipitation rate, floods etc. Electricity consumption is highly affected by weather extremes so power region is most sensitive. Electricity instantly spend after the production it cannot be stocked so this indicates there should be suitable model is necessary to estimate the upcoming electricity needs.

The conventional materials applied for insulation purpose are highly industrial processed materials like extruded polyurethane, polyurethane, expended polyurethane etc. Their impact as compared to natural or organic materials included wool of sheep’s, cork, wood fiber, or any material which are recycled like cellulose fiber. However the average emission of carbon dioxide by EPS around 7 kg CO₂-Eq/kg along the high amount combustion of petrol and natural gas on the other side the insulation materials generated by nature like sheep wool their emission of carbon dioxide is 98% low if their final discarding process is incineration. When these materials recycled at the end of useful life they would drain carbon dioxide.

Insulation of buildings plays a vital character in saving of energy because on the way of heat flux insulating materials work as obstacle. Therefore extensive saving of cost will be attained by the appropriate insulation of buildings. It is sound acknowledged that the insulation of buildings is very essential to cut down the thermal requirement and minimize the heating and cooling cost. Additional focus is given to the insulation of buildings due to the new building codes revisions, fossil fuels high cost and one utmost aspect to minimize the emissions of CO₂. Reduction of carbon dioxide emission means decreasing of air pollution assist by insulation of buildings. Effective measures for buildings energy efficiency is very essential because the energy acquired by building industry is responsible for the emission of CO₂ greater than 40% of Europe. The main focus on polyurethane foam due to thermal insulation is the key factor because to minimize thermal conductivity of the materials. Closed cells structure of rigid PUFs normally formed due to having density greater than 32 kg/m³. Closed cell foams thermal conductivity depends upon the amount of content and conductivity of trapped blowing gas in between the cells. For PUF insulting features thermal conductivity is most vital aspect. PUF having density within the range of 30 kg/m³ to 45 kg/m³ normally preferred for the insulation of buildings but in some cases its density rises to 100 kg/m³. Construction trends and buildings designed just entails polyurethane as an environmental safe for human health and surroundings.

5. Conclusions

Reducing carbon dioxide emissions is crucial in decreasing air pollution, and one way to achieve this is through building insulation. Thermal insulation plays a significant role in energy conservation and sustainable development in civil engineering. Older construction materials such as roof and wall units have high thermal transmittance, but this can be significantly reduced by adding insulation material. In this study, we aimed to evaluate the performance of different insulation materials on conventional buildings. We found that while U-values were low in non-insulated conventional buildings with subsequent high temperatures, insulated roofs and walls had high U-values. We measured the thermal conductivity values of different insulating materials and found that polyurethane foam had a K-value of 0.01 with a density of 35–40 kg/m³. We applied various thicknesses of insulation and non-insulation materials to achieve the recommended U-factor and R-value according to the ECBC criteria for conventional buildings.

Keeping in view the above objective following conclusions were found with the application of polyurethane.

• •Sustainable and better quality of life can be achieved through application of new and modern concepts of constructions with ecofriendly technologies.
• •Insulation material must be used in conventional and new constructions.
• •People should adopt the new and modern technology of Polyurethane as it is cost effective, heat reduction and way forward to sustainable energy technology in Vehari, Punjab, Pakistan.

Author contribution statement

Saeed Ahmad Qaisrani: conceived and designed the experiments; performed the experiment; analyzed and interpreted the data.

Farhad Jamil: performed the experiments; analyzed and interpreted the data;

Muhammad Mubeen, Zoobia Abbas: analyzed and interpreted the data; wrote the paper.

Amnah Mohammed Alsuhaibani, Moamen S. Refat: conceived and designed the experiments; contributed reagents, materials, analysis tools or data.

Anum Zehra: conceived and designed the experiments; analyzed and interpreted the data .

Khaqan Baluch, Jung-Gyu Kim: analyzed and interpreted the data; contributed reagents, materials, analysis tools or data.

Funding statement

Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2023R65), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.

Data availability statement

Data will be made available on request.