Thermal Performance Of Buildings Research Articles

Analysis of airtightness performance of residential areas in Mediterranean climate: Balıkesir houses

Airtightness is one of the crucial physical characteristics of building envelope that affect the building thermal performance and energy consumption. The airtightness of the building is influenced by the quality of workmanship and various design parameters such as window/wall ratio, type of joinery, size of the usage area, wall material, and thermal insulation on the external wall. In this study aiming to determine the airtightness performance of buildings in the Mediterranean climate of Balıkesir houses, airtightness conditions of 43 different houses were determined by blower door test measurement. The air exchange rate (n50) values of 43 houses/residences were obtained between 1.94 and 49.02 h−1 and compared with the current various standards. The effect level of the design parameters on the air tightness of the building envelope was obtained as a result of the analysis performed with analysis of variance and post hoc methods. According to the analysis, joinery type was the most effective design parameter in terms of airtightness, followed by usage area and transparency of facades. The result will help in deciding on the design parameters affecting the airtightness of the building envelope for energy efficiency in the Mediterranean climate.

3D PRINTING WITH NATURAL MATERIALS IN CIVIL CONSTRUCTION

The construction industry has experienced a number of transformations due to the use of digitalization and automation. Additive manufacturing, also known as 3D printing, is a current example. The purpose of this paper is to analyze the use of natural materials based on soil applied to 3D printing technology, with a focus on the thermal performance of buildings. A exploratory literature review was used to identify applied research that has explored these materials. The data obtained was systematized in a comparative table to identify the main strategies used. The analysis of applied research indicates that construction using 3D printing with materials based on soil is promising, taking advantage of the soil's natural thermal insulation properties and being able to incorporate parametric design and digital fabrication strategies to create complex, customized solutions for different contexts.

Optimization of building thermal environment and VR industrial heritage landscape design enhanced by computer vision algorithms

With the acceleration of urbanization, the optimization of thermal environment of buildings has become an important topic to improve energy efficiency and environmental sustainability. This paper aims to enhance the optimization of building thermal environment through computer vision algorithm, and explore its application in VR industrial heritage landscape design, so as to achieve the dual goals of building energy conservation and cultural inheritance. In this study, advanced computer vision technology is used to monitor and analyze the thermal performance of buildings in real time. Through the construction of thermal environment model, combined with deep learning algorithm to extract building thermal energy data, and use VR technology for visual display, so as to provide scientific basis for design decisions. The research objects include several representative industrial heritage buildings, and analyze their thermal energy consumption characteristics and optimization potential. The results show that the application of the computer vision algorithm reduces the heat loss of the building and significantly improves the energy efficiency. At the same time, the VR visual model intuitively shows the design effect after thermal optimization, enhancing the communication and understanding between designers and stakeholders. Therefore, the combination of computer vision and VR technology can effectively improve the optimization ability of building thermal environment and promote the sustainable design and operation of traditional industrial heritage.

Leveraging drone technology for enhanced thermal performance analysis in sustainable architecture: a case study of GBI-certified buildings in Malaysia

ABSTRACT In recent years, the realm of architecture has witnessed a significant transformation marked by a notable surge in focus on sustainable practices and energy efficiency. Architects and engineers increasingly recognize the innovative role of thermal efficiency in enhancing building performance. Such recognition emphasizes the critical importance of thermal analysis in understanding the thermal attributes of building materials and structures. Against this backdrop, this paper aims to bridge a current gap in architectural practices and sustainable design within the Malaysian context. It proposes a case study leveraging drone thermal mapping techniques on Green Building Index (GBI)-certified buildings. The study seeks to examine how architectural designs interact with environmental conditions and identify areas for improvement in sustainable building practices, particularly within Malaysia’s tropical climate context. The primary objective is to assess the effectiveness of drone technology in analysing building thermal performance and to explore how the findings can inform design interventions to enhance sustainability. To achieve this, a structured methodology comprising five procedural phases is employed in a case study focused on three iconic GBI-certified buildings in Putrajaya, namely Putrajaya Holdings Tower, Energy Commission Building, and Heriot-Watt University Malaysia. By integrating thermal imaging with visuospatial data and 3D modeling techniques, the study demonstrates the effectiveness of drones in analysing heat patterns, highlighting their potential as a tool for strategic design interventions. As an exploratory study, this paper serves as a catalyst for further investigations into the integration of drone technologies with architectural design, particularly within the context of tropical climates.

Improving the building's thermal performance by using untraditional building blocks

AbstractIraqi buildings consume high-level electrical energy for air conditioning purposes to provide the standard human comfort condition. This paper adopted an experimental study by using Styrofoam adhesive or white cement as an alternative to ordinary Portland cement to manufacture building blocks with dimensions of 200 × 200 × 200 mm containing an internal core with dimensions of 90 × 130 × 130 mm, which were filled by using corrugated scratch-up or closed air gap. The samples were divided into two sets: the first had an aluminium foil layer applied to the external surface of the samples (reflective surface), while the second was without any layer (ordinary surface). The samples were tested under the climatic conditions of Baghdad city during the summer months (May to September) of 2021. These blocks were also evaluated by different structural tests. It can be seen from the test results that the use of Styrofoam adhesive with a reflective surface with panels of corrugated scratch-up increased the thermal insulation of the wall. It leads to reduce thermal leakage and the electrical energy consumed to provide comfortable thermal conditions by 52.7%, in addition to decreasing the mass density by 14.1% while compressive strength decreased by 21%.

Characterization and Energy Performance of WO3 Doped and Undoped Photochromic Films

When exposed to light sources, photochromic (PC) materials change their optical properties and can lessen the transmission of UV and infrared radiation. This results in optimal thermal comfort and a pleasing visual contrast between the internal and external settings. This study uses computer modeling to analyze the annual energy usage in a home with natural ventilation in order to compare the effectiveness of photochromic films with commercial glass. The study is carried out using the EnergyPlus program in the cities of São Carlos and Cuiabá ‐ Brazil. Experiments and numerical simulations with data from doped and undoped tungsten trioxide (WO3) PC films are used in the study. Given the rise in energy usage and the pursuit of thermal comfort, this method is essential for assessing the thermal performance of buildings. Evaluations included a comparison of air conditioner performance and energy savings analysis, which leads to a noteworthy annual reduction in energy usage of up to 216.55 kWh and a 40% improvement in visual comfort. It is determined that PC film's dynamic behavior is the best option for comfort in terms of heat, illumination, and visual comfort.

Properties of foam concrete containing phase change material impregnated pumice

Energy consumption rises as a result of numerous electrical devices used to maintain thermal comfort of interior building areas. Using building materials with low thermal conductivity and density as well as an effective thermal energy storage plan can help to mitigate this. In order to enhance thermal performance of building, phase change material (PCM) was incorporated to foam concrete mixture in this study. Capric acid (CA)-palmitic acid (PA) eutectic mixture was prepared and impregnated with pumice (50 % by weight), a light and porous material. DSC results indicated that pumice/CA-PA composite exhibited a melting temperature of 22.84˚C and a freezing temperature of 20.85˚C, with corresponding enthalpy values for melting and freezing determined to be 85.4 J/g and 85.1 J/g, respectively. TGA analyses demonstrated that operational temperature of pumice/CA-PA composite was significantly below its thermal degradation temperature (194˚C). The prepared pumice/CA-PA composites were replaced with silica aggregate at different rates and incorporated in foam concrete mixture. Porosity and water absorption values rose as pumice/PCM content increased, yet there was a 7.2–41.1 % drop in dry unit weight when compared to reference. Compressive strength also showed a linear decrease and the lowest compressive strength value was recorded as 4.71 MPa in the presence of 40 % pumice/PCM. Thermal conductivity dropped from 0.487 W/mK to 0.167 W/mK, suggesting that foam concrete samples that were produced are all suitable as insulation materials. In peak solar radiation hours, PCM-impregnated pumice foam concrete (PFC) provided about 11.8 % and 8.72 % surface and room center temperatures compared to that of the reference in maximum case. PFC with PCM provided 6.54 % warmer surface temperature in cold weather. PFC-PCM can provide a cooler indoor temperature during peak temperature hours. Therefore, it may have a great potential to decrease the cooling load of a building.

Machine learning-based predicting of PCM-integrated building thermal performance: An application under various weather conditions in Morocco

As is now stands, the building sector is among the “big three” significant energy consumer and greenhouse gas contributor in the world. Consequently, there has been a growing movement towards the development and adoption of renewable energy sources, energy efficient measures and energy management strategies. Phase change materials (PCMs) are considered as an alluring option for energy efficiency measures in building. In this paper, a case study building, based on typical residential construction in Morocco, was selected to assess the potential energy savings of adding PCM to the roof for twenty-four cities using the dynamic simulation tool, TRNSYS. Thereafter, thirteen machine learning techniques, including ANN, DT, SVM, ELM, GB, RF, TB, GLRM, GPR, LR, GAM, KRRM and LRR were assessed for predicting the hourly heating, cooling, and total energy consumptions. The models were trained and tested on a dataset that was gathered from the simulations in twenty-four locations in Morocco. The outdoor dry-bulb temperature, the relative humidity, the wind velocity, the wind direction, and the total solar radiation were considered as the key features. The obtained results revealed that using PCM, can effectively lower the total energy demand for all the cities under study, with exception for very cold climate given by Ifrane and Midelt, where the annual total energy consumption shows an increasing trend. Furthermore, comparing the statistical results for each machine learning model, it is found that the SVM model consistently outperforms all models and can be successfully employed to predict the hourly network's outputs of the building.

Enhancing Thermal and Daylight Performance of Historic Buildings with Passive Modifications; A Tropical Case Study

Historical buildings worldwide hold immense potential for adaptive reuse within the framework of the circular economy, a concept gaining traction in the building construction industry for its role in reducing carbon emissions. Many of these structures boast passive building design strategies, which inherently lower energy demands. Among these, thermal mass and daylight harvesting emerge as pivotal strategies for achieving indoor thermal and visual comfort, respectively. However, with the advent of significant climate change and evolving built environments, the efficacy of these historical passive strategies is subject to debate. This study focuses on a residential building constructed in the 17th century by Dutch settlers in Galle, Sri Lanka, serving as a case study. The research targets improvements in both thermal and visual comfort. Thermal performance analysis was conducted through air temperature measurements, revealing a notable 3-hour time lag and a 2.5°C reduction in peak air temperature during the day. Conversely, nighttime measurements indicated a rise in indoor temperature compared to ambient conditions. Using Design Builder software, the building was modelled to assess its daylighting conditions. Drawing upon thermodynamic principles and daylight harvesting techniques, the study proposes building envelope interventions and ventilation strategies to address nighttime overheating and enhance daylight utilization. The results demonstrate that these modifications can potentially reduce nighttime heat by 2-3°C, while also decreasing the energy requirement for lighting comfort from 51.10 kWh/m² per annum to 44.84 kWh/m² per annum. This research showcases the effectiveness of judiciously implemented interventions in historical buildings, illustrating tangible improvements in both thermal/visual performance and energy efficiency. Leveraging inherent qualities of historical structures and integrating modern design strategies to these buildings can play a vital role in sustainable urban development and energy conservation efforts.

A simplified modeling method for studying the thermal performance of buildings with vertical greening systems

Vertical greening systems (VGS) are considered an effective strategy to enhance the insulation performance of the building envelope. Existing methods predicting the performance of this strategy usually require a combination of mathematical modeling and building performance simulation, hence difficult for practical use. To simplify this work, this study has proposed a prediction method requiring building simulation only, by considering VGS as a shading component in the simulation work. To compare its performance, a model using conventional methods has also been proposed. A further simplification by neglecting the impact of transpiration has been investigated as well. To justify the implementation of the new method, it has been used to optimize the design of VGS for buildings located in the hot summer and cold winter areas in China. The validation result confirmed the accuracies of both methods, with the simpler method giving an insignificant lower accuracy than the conventional method, which can be compensated by its simpler prediction procedure. The implementation justification showed that for buildings in the HSCW area, VGS is suggested to be installed on the west facade, with a leaf area index of 4. This can help to reduce the heat transfer of the wall by 56.6%.

Development and performance evaluation of active insulation systems using solid-state thermal switches

Traditional building envelopes have passive insulation systems that cannot respond to dynamic changes in the environment. An Active Insulation System (AIS) consists of Active Insulation Materials (AIMs) that dynamically vary the thermal conductivity of the insulation system. Several researchers have evaluated the impact of AIS on building thermal and energy performance by using simulation tools. Up to 70% savings in annual heating and cooling energy and significant reductions in peak demand have been predicted for some climates with wall systems employing AIS. However, materials and assembly development still need a cost-effective product that achieves the required performance. In this study, we present the process of developing an AIS that we will install in a test hut for its performance evaluation. Minimum performance criteria of the AIS system are developed based on R-low/R-high ratio, required time and efficiency to switch states, and cost estimates. The following steps during this study are creating the concept to meet the requirements, predicting the performance via simulations, developing the experimental setup for bench-scale testing, and finally, constructing a full-scale wall assembly and monitoring the performance when exposed to environmental chamber tests. The selected approach uses off-the-shelf products to create an AIS that can switch R-value between 0.98 ft2·°F·h/BTU (0.173 m2·K/W) and 5.81 ft2·°F·h/BTU (1.02 m2·K/W) and have a switching time of less than one minute between R-high and R-low.

Thermoelectric active window frame: Constructive integration and preheating analysis

Building heating and cooling systems using thermoelectricity appear to be a feasible alternative, as it presents several features including versatility and high reliance. While most applications of thermoelectricity in buildings are found in wall systems, window integration shows excellent potential for enhancing the thermal performance of buildings at the façade level, compensating heat losses that take place in windows. Combining energy efficient ventilation with heat recovery leads to a significant reduction of the required energy, keeping desired comfort conditions inside buildings. Thus, the following study presents the design of an active window frame with an integrated thermoelectric system, attaining two functions: pre-heating the supply air, while simultaneously recovering the waste heat energy from exhaust air. Two full-scale prototypes were built, each featuring a different airflow pattern, and preliminary tests for heating mode were carried out under laboratory conditions. The results revealed a similar performance comparing both prototypes, achieving a COP ranging 1.56 to 2.71 for prototype A, while prototype B ranged from 1.62 to 2.65. The results showcase superior heating efficiency compared to a previous experiments conducted by the research group, where a maximum COP of 1.91 was achieved. From a building perspective, wider adoption of thermoelectricity applied to thermal conditioning is hindered by lack of suitable products for architectural integration. Therefore, the system's innovation stems from optimized design, integrated construction, and industrialized production, enhancing energy efficiency in buildings via a compact façade integrated system without space compromise.

Optimizing the thermal performance of residential buildings in Jordan

This work investigates the influence of building form, natural ventilation, and window shading passive strategies on the thermal performance and thermal comfort of three residential building forms, namely rectangular, L-shape, and U-shape, in the hot-dry summer in Amman, Jordan. The thermal performance of buildings is studied using indoor air temperature, and the thermal comfort is evaluated according to ASHRAE-55 and Fanger’s models. The buildings’ models are designed using the SketchUp plugin OpenStudio and then plugged into the EnergyPlus simulator. It is obtained that when natural ventilation and shading devices are considered together, the indoor air temperature is notably dropped up to 8.85 °C in the daytime and 12.70 °C at nighttime, which improves the thermal comfort of all building forms. Generally, rectangular building exhibits the best thermal behavior under optimum conditions. U-shape presents the best thermal behavior for the primary conditions, and it records the lowest out-of-comfort percentage time during the day and achieves the highest comfortable percentage after considering the window’s area control.

Modeling of heat gain through green roofs utilizing artificial intelligence techniques

Green roofs have recently been popular in buildings for saving energy. A reliable model is required to include green roofs' role in the thermal performance of buildings. This study applies artificial neural networks (ANN) to estimate the buildings’ heat gain through green roofs. By comparing different ANN architectures (feedforward, recurrent, and cascade), the best model to estimate heat flux from four significant design factors (plant height, leaf area index of plant, soil depth, and overall heat transfer coefficient of support layer) is determined. The relevance test clarifies that the overall heat transfer coefficient of the support layer and the leaf area index of the plant have the highest correlation with the target variable. The modeling results prove that the multilayer perceptron (MLP) neural network with 4-5-1 topology and the logarithm sigmoid and liner activation functions in hidden and output layers has the best accuracy for the given task. This model predicts 2700 literature data with the regression coefficient = 0.9999, mean absolute errors = 0.025, and root mean squared errors = 0.035. Our topology-engineered MLP can analyze the effect of design factors on the heat flux through green roofs and help quickly determine its impact on building thermal performance.

Experimental analysis of building envelope integrating phase change material and cool paint under a real environment in autumn

The application of phase change material (PCM) and cool paint (CP) to building envelope is one of the effective solutions to improve thermal comfort of passive buildings. Therefore, the thermal performance of buildings in Hefei, China in autumn is compared and analyzed by integrating PCM and CP into the building envelope. According to the comprehensive analysis of indoor thermal environment and the ability to maintain indoor thermal comfort, it is concluded that the combined application of PCM and CP is better than the application of PCM or CP alone. And the combination of PCM and CP laid on the south wall and roof respectively is the best. It is more suitable for commercial buildings, which can prolong indoor air temperature (Ti) in the thermal comfort zone for more than 10 h during the day. The combination of PCM and CP laid on the roof can prolong Ti in the thermal comfort zone for more than 8.05 h, which is more suitable for residential buildings. The purpose is to explore the best combination mode of residential and commercial buildings according to the characteristics of temperature change and building types (according to people's main use time) in the real environment.

A comparative life cycle assessment of building sustainability across typical European building geometries

In recent years, significant progress has been made in the sustainability assessment of building materials and buildings. The introduction of Environmental Product Declarations (EPDs), the development of Level(s), and the release of relevant series of standards have helped to improve the sustainability of buildings. However, a research question that remains unresolved is the lack of information related to the comparison of the sustainability performance of building units across Europe and the significance of conducting such research. This study addressed this question by implementing a comparative whole-building Life Cycle Assessment (LCA) across buildings in Europe. The study emphasizes the necessity of considering typical building geometries and thermal performance of buildings across Europe and introduces six typical building geometries for three different European clusters (northern-western, central-eastern, southern cluster). The results of this study revealed that the sustainability performance of buildings is not similar across the EU and that cost-optimal minimum thermal performance requirements for building structures have a significant impact on their environmental performance. Particularly, single-family houses in Central and Eastern Europe are responsible for 324.42 kgCO2e/m2. Contrary to this, Northern and Western European single-family buildings have the lowest environmental impact with 268.97 kgCO2e/m2. Multifamily houses in Southern Europe are responsible for 321.82 kgCO2e/m2, in Northern and Western Europe the environmental impact is 275.37 kgCO2e/m2. The outcome of this study is significant for the scientific community involved in assessing the sustainability of buildings in Europe, as it provides valuable insights into their environmental performance, considering the energy efficiency and sustainability aspects of buildings. The study's findings should be considered when setting minimum LCA-related requirements, in view of the provisions of the new EU policies expressed in the Energy Performance of Buildings Directive (EPBD) recast for defining the Global Warming Potential (GWP) of new buildings.

Contribution of advanced windows and façades to buildings decarbonization: A comprehensive review

On a global level the building sector consumes about 45.00% of energy consumption, contributes about 40.00% to emission, uses 30.00% of water and impacts the environment by generating 30.00% of waste. Although windows are important components of a building that provide natural lighting and ventilation and establish necessary contact with the external environment necessary for healthy indoor ambient, they permit entry of undesirable solar heat in summer and allow escaping heat from the indoor ambient in cold seasons, which aggravate the building needs for energy and increase its contribution to atmospheric emissions. The present investigation provides a review on research, development, and applications of advanced windows in the building sector. The introduction highlights the importance and contribution of advanced glazing technology to improving energy, comfort, and thermal performance of buildings. The review includes natural illumination and ventilation, thermal comfort and discusses the effects of window to wall ratio on natural illumination and ventilation of windows and façades. The review also covers recent developments in glazed windows and façades including performance enhancements by using reflective solar films, vacuum glazing, windows with filling materials, windows with water flow, window with phase change material, window with stagnant inert gas filling, ventilated windows and façades and windows with aerogel. A special section was also included on smart glazing for windows and façades showing the new tendencies and applications in the building industry. Since commercial programs and open access codes are handy tools for simulation and performance calculations a section is dedicated to these codes. The conclusion section contains the most relevant conclusion of the review as well as future trends in research and developments in the area. The topics included in this review can be helpful for experienced and young researchers, practicing engineers and general readers interested in windows and façades.

How to improve the thermal performance of buildings with one simulation run? The heat exchange index applied to hot climates

Improvements in the thermal and energy performance of buildings usually involves techniques with high computational costs, such as multi-objective optimization and parametric simulation. However, sometimes, achieving the optimal case is not desirable, though only the refinement of thermal performance. Hence, methods that enable this analysis are helpful for designers and researchers. Then, this study proposed a framework based on the Heat Exchange Index to assist thermal performance analysis of buildings. The framework consists of two phases and begins by exploring air and surface heat balance derived from the base case building simulation. This analysis is based on the Heat Exchange Index, an index developed in this work, and its result indicates the impact of each heat exchange on the thermal performance. The next phase is the improvement, where strategies are defined and implemented, and the thermal performance of the improved case is evaluated against the base case. A single-family house was modeled using EnergyPlus to demonstrate the framework application. Results showed that the Heat Exchange Index could be used to enhance the thermal performance of buildings since the strategies adopted in the base case increased its thermal autonomy and decreased thermal load.

Development of ReShadS, a climate-responsive shading system: Conception, design, fabrication, and small-scale testing

Integrating computational technologies to produce dynamic and intelligent architecture that can enhance building thermal performance and meet users' requirements and routines is broadly classified as responsive architecture. This seems to be a viable solution for façades, reducing energy demand during the building operational phase. However, scientific content regarding responsive components' fabrication, operation, and performance evaluation is not yet consolidated. This paper comprehensively presents the design and fabrication processes of a low-cost responsive shading system prototype, accounting for materials' characterization, software, responsive functionality, and its performance evaluation regarding thermal and illuminance management. The analysis is based on the Adaptive Comfort Model and Useful Daylight Illuminance parameters. Preliminary results indicate the system's feasibility in managing temperature and illuminance within the comfort zone by 58 % and 82 % of data points, respectively. The resulting prototype and the responsive management strategy contribute to the emerging responsive architecture field toward reducing building energy consumption.

Multiple regional climate model projections to assess building thermal performance in Brazil: Understanding the uncertainty

Understanding the trends and uncertainties in Building Energy Simulation (BES) performance indicators under future climate conditions is crucial for mitigating issues such as overheating and power outages. To address this, we generated a set of weather files for all 27 state capitals in Brazil, considering six climate model projections (three General Circulation Models as driving models and two nested Regional Climate Models) and two distinct emission scenarios from the CORDEX project. We analyzed the variability in climatic variables and subsequently performed BES on a representative Brazilian social housing unit to evaluate its impact on the performance indicators outcomes. Consistent with previous studies, a substantial increase in cooling-related demands was observed in the more pessimistic scenario (RCP8.5) and mild increases in the more optimistic scenario (RCP2.6), with a trend toward stabilization after 2050. Regarding uncertainties, we found higher Relative Standard Deviation (RSD) values for the cooling degree hours indicator. The capitals in the Central-West, Southeast, and South regions exhibited greater uncertainty regarding temperature indicators, whereas the irradiation parameters displayed higher uncertainties in the Northeast region. For the BES outcomes, RSD values as high as 19.9% were found for cooling load values. It was also demonstrated that locations, periods, and scenarios exhibit different extreme climate model projections. Ideally, employing an ensemble of weather files developed from other models would help assess associated uncertainties in the building performance indicators.