Thermal Performance Of Buildings Research Articles

Preliminary study of the application of thermal mortar in 3D printed concrete walls

3D printing (3DP), as an emerging technology in the construction industry, has the potential to solve the sector’s labour shortages and low efficiency, as well as helping to reduce its negative environmental impact. On the investigative path towards new construction solutions, the thermal performance of buildings must not be compromised. In additively manufactured buildings to date, walls have been printed with cavities that are subsequently manually filled or projected with conventional thermal insulation materials, such as polyurethane and vermiculite. To bridge the gap between conventional building construction and 3DP, it is important to present feasible and effective thermal solutions that can be applied using an automatic mode. This paper explores the viability of applying a commercial thermal mortar as an insulation in 3D printed concrete walls. Therefore, a preliminary experimental campaign was carried out to assess the behaviour of the thermal mortar during and after its application. It was found that concrete walls constrain the drying process of the thermal mortar, generating stresses that lead to the occurrence of cracks. To avoid their formation, some strategies were tested, namely by adding superplasticizer to the mixture, opening joints, drilling holes or opting for an incomplete filling of the cavities.

Multi-criteria decision support framework for climate change-sensitive thermal comfort evaluation in European buildings

This paper proposes a novel multi-criteria decision support framework for climate change-sensitive evaluation of building thermal comfort performance in European buildings. The proposed framework considers various comfort categories based on building use and condition, comfort models based on building operation, sensitivity to climate change, key performance indicators, and their thresholds. The proposed framework is then implemented using a passive house-certified high-performance timber dwelling near Brussels as a case study. The thermal comfort in the free-running reference timber dwelling is assessed using a whole-building energy performance simulation model with a static threshold of 26°C for the bedrooms and an adaptive threshold for the other occupied zones. The analysis found an increase in indoor overheating degree by 1.7°C and ambient warmness degree by 6.5°C during heat waves from the current scenario to the end of the century scenario. However, the reference timber dwelling effectively suppressed the impacts of climate change with varying degrees of success towards the end of the century. The proposed framework is intended to support decision-makers in effectively evaluating performance during the early stages of building design. The study highlights the need for further research on building performance assessment techniques and guidelines in a changing climate.

The interactive indoor-outdoor building energy modeling for enhancing the predictions of urban microclimates and building energy demands

There is a lack of an urban building energy modeling framework that considers the influence of surrounding buildings and local urban climate on building thermal performance. This can lead to inaccurate results since the thermal performance of individual buildings is heavily influenced by their surrounding built and climatic environment. This study establishes an interactive indoor-outdoor building energy modeling method to enhance the predictions of urban microclimates and building energy demands by coupling an urban physics model with a physics-based building energy model. Validation of the interactive coupling scheme uses field measurement datasets. Parametric simulation and analysis are conducted to understand the influence of the roof-to-canyon width ratio, canyon orientation, and ground vegetation fraction on canyon temperature, building energy consumption, and energy demand. Furthermore, the impacts of building energy model complexity (e.g., detailed vs. simplified building models) and coupling approaches on canyon temperature and building energy profiles are demonstrated using two case study buildings. In comparison with the one-way coupling approach, cooling energy consumption predicted with the dynamic two-way coupling approach varies by 3.5 % and 0.5 % for the detailed medium office building model and high-rise building model, respectively, and peak cooling demand varies by 8.4 % and 7.0 % for the detailed medium office building model and high-rise building model, respectively. This study also suggests that adopting a complex two-way coupling approach with environmental data exchange at various elevations is necessary for modeling tall buildings at the urban scale.

Experimental and Numerical Analysis of a PCM-Integrated Roof for Higher Thermal Performance of Buildings

Experimental and Numerical Analysis of a PCM-Integrated Roof for Higher Thermal Performance of Buildings

Effect of Natural Ventilation on Thermal Performance of Different Residential Building Forms in the Hot-dry Climate of Jordan

This work presents a simulation study on the impact of natural ventilation on the thermal performance and thermal comfort of residential buildings of different forms in the hot-dry climate of Amman, the capital of Jordan. Three existing triple-storey residential buildings with different forms, i.e., rectangular, L-shape, and U-shape, are taken as case studies. Models with similar construction and dimensions of the buildings under investigation are designed using the OpenStudio plugin SketchUp software. Two rooms within these buildings have been considered for simulation with the aid of the EnergyPlus simulator for two cases: the basic case with no ventilation and the case with ventilation. The thermal parameters, including the air temperature, relative humidity, air speed, and mean radiant temperature of both rooms, have been extracted from the simulation. The thermal performance of these buildings is analyzed based on the indoor air temperature and mean radiant temperature, while the thermal performance is investigated via the ASHRAE-55 adaptive model. The results show that the rectangular-shaped building has the best thermal performance in unventilated conditions for the middle room on the middle floor (Room 1). In contrast, the U-shape shows better results for the west-northern room on the same floor (Room 2). On the other hand, introducing natural ventilation to the buildings reduces the indoor temperature and, subsequently, enhances the thermal performance where the buildings transform to be within the comfort zone most of the time, according to the ASHRAE-55 adaptive model. Generally, rectangular and U-shaped buildings show comparable thermal performance, while L-shaped buildings have relatively the worst performance.

Thermal and Energy Influences of Double Skin Façade Towards Green Buildings in Tropical Classified Countries

Double skin façade (DSF) has emerged as a decisive strategy for improving building thermal performance and energy efficiency. In various climatic conditions, DSF will perform differently and accordingly. However, the whole building performance of the DSF has never been studied in a broad climatic condition. As a result, there will be a high risk that the system will underperform conventional façade. This study adopted a quantitative approach with computational simulation software, EnergyPlus, to analyze the thermal behavior and energy efficiency of both single skin façade (SSF) and DSF systems. The investigation focused on an overall Köppen classified tropical climate category, which encompasses tropical rainforest (Af), tropical monsoon (Am), tropical savanna with dry winter (Aw), and tropical savanna with dry summer (As) climates. The primary finding indicates that the SSF in various tropical-classified groups exhibits diverse thermal behaviors throughout the year, from month to month and from orientation to orientation. The climate of each tropical classification distinctly influences the performance of both façades. The air temperature and relative humidity in both SSF and DSF office zones remained within a predictable range throughout the year. Thermal behavior and energy consumption fluctuated considerably on a monthly basis but only marginally on an annual basis. This similarity explains how buildings in the four cities consumed distinctly comparable cooling energy consumptions. The study also indicates that, even without a shading device, the DSF could still outperform the conventional facades. In all climatic contexts, energy consumption for cooling could be diminished by more than 40%, and the air temperature in the office zones was decreased to around 4°C while relative humidity was increased by 1% to 5%. Hence, an appropriate DSF design could be employed on office buildings in the overall classified tropical climates to attain energy efficiency through thermal enhancement from the façade’s second layers.

Environmental Design Strategies to Improve Thermal Performance of Religious Buildings: A Simulation in Iraq

Environmental Design Strategies to Improve Thermal Performance of Religious Buildings: A Simulation in Iraq

Smart double glazing integrated polymer dispersed liquid crystal for enhancing building's thermal performance in hot-arid climate

Polymer-dispersed liquid crystal glazing is an electrically activated smart switchable glazing that requires an AC power supply to become transparent and remains opaque without power. This dynamic feature, with multiple transparency states, is suitable for building in hot and arid climates. It can effectively reject unwanted solar energy, allowing visible light while contributing to building energy efficiency by reducing the carbon footprint. In this work, the PDLC glazing system was included with a low-e coated glass and this coupled system was investigated with two control approaches for residential buildings in hot arid climates. The first control is a standard On-Off operation based on the tenant preferences, while the second is able to set glazing transparencies according to the solar radiation intensity, in order to minimize the penetration of direct solar radiation and to provide daylighting and indoor privacy protection. The system is reversed to examine the proper positions and layer order in the glazing system. The proposed system demonstrates remarkable enhancements in indoor thermal performance, surpassing clear glass by 21 % in the south orientation and 25.5 % in the west orientation. Furthermore, when the PDLC is oriented towards the outdoor environment, the system achieves an impressive 53.9 % improvement in heat gain control compared to clear glass. Additionally, the system not only enables dynamic control over direct solar radiation but also offers efficient daylighting and indoor privacy protection.

Metamodel to predict annual cooling thermal load for commercial, services and public buildings: A country-level approach to support energy efficiency regulation

The energy sector significantly impacts the environment, with energy production contributing to greenhouse gases emissions and climate change. In Brazil, buildings account for a substantial portion of energy consumption, making energy efficiency essential for sustainable development. Building simulation is an efficient way to provide valuable insights into the thermal performance of buildings, but it requires expertise, time, and computational resources. To overcome these simulation constraints, metamodeling has emerged as an easy-to-use and fast-response alternative to analyse the thermal performance of buildings. This study focuses on developing a metamodel to predict cooling thermal loads in Brazil's commercial, services, and public buildings, supporting the country's building energy efficiency labelling program. It is expected from the metamodel a high capacity to reproduce the variability of climates, contexts, and heterogeneity of buildings from a country-level perspective. A parametric sampling process was used to develop a comprehensive simulated database considering several variations of building-related, occupancy patterns, and weather parameters. The metamodel was trained, validated and tested using optimisation techniques and an artificial neural network. Afterwards, it was compared with actual models, considering different typologies and climates. While the metamodel demonstrates high accuracy and generalisation, limitations were found regarding its application in warmer temperatures and complex building shapes. Further refinement is needed to improve its applicability and reliability in real-world scenarios. The proposed metamodel offers a practical and widely applicable tool for supporting energy code compliance and energy efficiency assessment in buildings.

Thermal energy storage performance evaluation of bio-based phase change material/apricot kernel shell derived activated carbon in lightweight mortar

The synergy between phase change materials (PCMs) and activated carbon (AC) obtained from biomass is an energy-efficient method for creating composite materials with enhanced thermal performance. This study presents such a leak-proof composite with enhanced properties through the impregnation of bio-based lauric acid (L)-capric acid (C) eutectic mixture (LCEM) as a PCM in the AC derived from apricot kernel shells (AC-AKS) framework. The manufactured AC-AKS/PCM composite was subsequently incorporated into cement-pumice based mortar (CPM) in various proportions. This was done to produce energy-efficient construction materials aimed at increasing the thermal performance of buildings. Morphological, physical, thermal stability, mechanical strength, thermal energy storage (TES) and solar thermoregulation performances of the obtained leak-proof composite PCM were experimentally determined. The compressive strength of CPM samples with TES ability (TESCPM) was found 6.8 MPa, 4.3 MPa and 2.1 MPa for TESCPM1, TESCPM2 and TESCPM3, respectively. The relatively lower mechanical strength values can be accepted when considering their thermal regulation performances. The apparent porosity was around 26 %, while water adsorption around 24 % for TESCPM3. FTIR results proved the presence of well chemical compatibility between AC-AKS and PCM. The DSC results exposed that the AC-AKS/PCM composite had a melting temperature and a latent heat capacity of 21.58 °C and 126.8 J/g, respectively, while these values were within the range of 18.93–20.51 °C and 10.55–30.32 J/g for the TESCPMs. TGA results exposed that the functioning temperature of the AC-AKS/PCM was greatly lower than the limit temperature value measured for its thermal degradation. The solar thermoregulation performance test indicated that the fabricated TESCPM exhibited noteworthy advantages by providing the cooling effect throughout the daytime as well as the heating effect throughout the nighttime. All of these favorable properties make the proposed AC-AKS/PCM-integrated CPM promising materials for innovative TES applications in construction elements.

Thermal energy simulation of the building with heating tube embedded in the wall in the presence of different PCM materials

A large part of energy consumption around the world is spent on buildings. Improving and optimizing the thermal performance of buildings can reduce energy consumption. Phase change materials inside an envelope can act as a latent thermal energy storage tank and also prevent energy loss. In the present study, we have investigated the effects of adding PCM inside the wall of buildings, and a tube for heating is embedded inside the wall. The performance of the system has been evaluated based on computational fluid dynamics simulation in Open Foam software. PIMPLE algorithm and finite volume method were used to solve the governing equations. Three different arrangements of tubes are considered at the upper, middle, and bottom of the wall introduced as UTA, MTA, and BTA, respectively. Furthermore, it is assumed that the heat flux is in the range of solar heat flux that enters the system from the embedded tube. Three different tube arrangements, three heat fluxes, and two different types of PCMs have been investigated in this study to find the best integration of the system. The simulation results revealed that for Lauric acid, by increasing the heat flux from 200 to 400 Wm2, the melting time decreases from 9 to 2 h. Also, for Paraffin the melting start time reaches 2.5h from 10 h. Also, Lauric acid can store or discharge thermal energy for the long term. The highest percentage of stored energy is related to Lauric acid, which saves 13.8 % of the total input heat flux as latent energy and Paraffin stores up to 11.8 % of latent heat energy.

Energy and indoor thermal performance analysis of a glazed façade high-rise building under various Nordic climatic conditions

Research has shown that glazed buildings can have higher energy use and are more prone to overheating than other types of buildings. However, few studies have explored the performance of glazed buildings in cold climates. This article aims to evaluate the energy and indoor thermal performance of a high-rise residential building with glazed façades and balconies under Nordic climatic conditions, through a parametric study. Dynamic, whole-year simulations are used to evaluate the impact of four design parameters (with and without glazed balconies, type of balcony glazing, window to wall ratio, and building location within the Nordic region) on the energy and indoor thermal performance of the building. The results show that the building without glazed balconies outperformed that with glazed balconies. Changing from single- to double-pane glazing also helped to reduce energy use and overheating, as did lowering the window-to-wall ratio. Overheating of apartments was found to occur during the summer in five of the six locations simulated, which suggests that solar control strategies might be needed for glazed buildings even in a Nordic climate. This study highlights the importance of further research on glazed residential buildings, which are becoming more common in contexts subject to such climates.

A Numerical Investigation of the Thermal Performance of a Gabion Building Envelope in Cold Regions with a Mountainous Climate

Applying rock-filled gabion to buildings in cold regions with mountainous climates has multiple potentials, such as utilizing rock resources, improving building sustainability and saving building energy. Therefore, it is necessary to analyze the thermal performance of gabion buildings. Based on the CFD method, this paper establishes a numerical model of buildings with gabion enclosure structures, analyzes the influence of the gabion structure on the external convective heat transfer coefficient (CHTC), wind pressure, air infiltration, room temperature and building load, and further uses the building energy consumption simulation method to analyze the heat load of gabion buildings. The results showed that the adverse impact of climate on the building thermal performance is significantly diminished by the gabion. Under different weather conditions, the CHTC, the maximum wind pressure difference on the exterior surface, and the air infiltration rate are reduced by different rates. Further, the room base temperature increases throughout the heating season, and the maximum heat load and the cumulative heat load of the building are, respectively, reduced by 10.6% and 24.8%. This work revealed that the gabion is an eco-friendly and adaptive measure to improve thermal performance and indoor thermal comfort.

A Methodology for Designing an Automated System to Improve the Thermal Performance of a Large Building in Operation

Many buildings built before energy performance regulations are actually in a situation of thermal discomfort and energy inefficiency. The creation of intelligent environments is moving towards new opportunities, based on real-time monitoring and on the development of sensors and technologies. Furthermore, building automation and electronic systems standards enable interoperability and interconnection between control devices and systems. The application of soft computing has significantly improved the energy efficiency; however, it requires prior assessment to design the automation functions. Temperature, humidity, air quality and energy consumption are the most commonly measured parameters, but their relationships with other operational variables such as occupancy or some building states remain as a research challenge. This article presents a methodology to develop the automation of a large existing public building. This methodology consists of two stages: 1. Assessment and diagnosis to set appropriate functions, using EN ISO 52120-1 and EN 50090 for open communication networks, and EN ISO 52120-1 to assign the technical building management. 2. System control deployment of low-cost and low-consumption input and output devices. It has been proven that it is possible to effectively automate an obsolete building with a low-cost, open-source system that can be easily applied to other buildings.

Study on Health and Comfort in Buildings based on Home Thermal Comfort Survey

Thermal comfort referred to the satisfaction of human beings with the surrounding environment. This report aimed at investigating thermal comfort in the domestic space. By comparing the internal condition recorded by data logger with provided external conditions, discuss the factors affecting the condition difference between inside and outside, then analysis the rationality of Predicted Mean Vote (PMW) comparing to activity diary, followed by suggestions to improve the building thermal performance.

Evaluation of climate change effects on residential building cooling and heating demands in New Zealand: implications for energy efficiency standards and building codes

PurposeClimate change reports from New Zealand claim that climate change will impact some cities such as Auckland from a heating-dominated to a cooling-dominated climate. The benefits and risks of climate change on buildings' thermal performance are still unknown. This paper examines the impacts of climate change on the energy performance of residential buildings in New Zealand and provides insight into changes in trends in energy consumption by quantifying the impacts of climate change.Design/methodology/approachThe present paper used a downscaling method to generate weather data for three locations in New Zealand: Auckland, Wellington and Christchurch. The weather data sets were applied to the energy simulation of a residential case study as a reference building using a validated building energy analysis tool (EnergyPlus).FindingsThe result indicated that in Wellington and Christchurch, heating would be the major thermal load of residential buildings, while in Auckland, the main thermal load will change from heating to cooling in future years. The revised R-values for the building code will affect the pattern of dominant heating and cooling demands in buildings in Auckland in the future, while in Wellington and Christchurch, the heating load will be higher than the cooling load.Originality/valueThe findings of this study gave a broader insight into the risks and opportunities of climate change for the thermal performance of buildings. The results established the significance of considering climate change in energy performance analysis to inform the appropriate building codes for the design of residential buildings to avoid future costly changes to buildings.

Enhancing building thermal performance in Saudi's extreme climates through reversible smart insulated window glazing: Laboratory-scale experiments

The positioning and type of double-glazing layers effectively regulate heat gain and heat loss during both summer and winter seasons. This study aims to evaluate the thermal performance of the Reversible Smart Insulated Window Glazing (RSIWG) system in controlling solar heat gain in Saudi Arabia's extreme climates. Laboratory-scale experiments and analytical methods were employed to examine four glazing scenarios, each characterized by the positioning and states of the Polymer Dispersed Liquid Crystal within the insulated double-glazing system. The findings indicate that SIWG-colo significantly reduces heat gain by 26 % and 78 %, respectively, compared to double insulated glazing and clear glass, making it suitable for cooling seasons. On the other hand, SIWG-rev-colo exhibits slightly less heat loss, rendering it suitable for heating seasons, especially in situations where solar radiation is absent. The RSIWG system provides added advantages such as dynamic privacy protection, glare reduction, and flexibility in response to daylighting and outdoor connection. Further research is recommended on multi-layer PDLC incorporating vacuum glass.

Assessment of Solar Radiation's Impact on Thermal Performance and Indoor Comfort of Building

Assessment of Solar Radiation's Impact on Thermal Performance and Indoor Comfort of Building

The influence of the urban heat island effect on the energy performance of residential buildings in a city with an oceanic climate during the summer period: Case of Valdivia, Chile

The intensification of urban growth and climate change are affecting the energy and thermal performance of buildings. In recent years, the issue of building resilience to urban heat island (UHI) conditions has become increasingly relevant. The energy performance of buildings can vary significantly in different areas of the same city, regardless of their size. The aim of this study was to evaluate the energy effects of UHI intensity differences in various local climate zones (LCZs) of Valdivia city, Chile, on a typical residential dwelling. A simplified methodology was used, based on the assessment of cooling degree days variations and heat gains variations inside the studied house through the thermal envelope. Valdivia has a homogeneous urban morphology, and three types of low-rise LCZs prevail in the city (LCZ 3, 6, and 9). The results showed that the average cooling demand for a 66 m2 residential dwelling during 39 summer days was 158 kWh for LCZ 9, 219 kWh for LCZ 6, and 289 kWh for LCZ 3, compared to the rural demand of 114 kWh. These results suggest that the energy effects of UHI can be significant, and that it is important to study the microclimatic conditions in various LCZs for a correct understanding of the UHI energy effects on different buildings.

Enhancement of Building Thermal Performance: A Comparative Analysis of Integrated Solar Chimney and Geothermal Systems

Enhancement of Building Thermal Performance: A Comparative Analysis of Integrated Solar Chimney and Geothermal Systems