Improvement Of Thermal Comfort Research Articles

Indoor Thermal Comfort Improvement of the Naturally Ventilated House in Tropical Climate, Indonesia

Two types of houses in North Aceh, Indonesia, are investigated in this study. Even though the hot and humid conditions throughout the year, most Indonesian stay in a house that uses natural ventilation due to energy poverty and economic conditions. Commonly, they rely on natural ventilation by opening windows to achieve thermal comfort in the indoor environment. Therefore, an on-site survey and questionnaire were performed on more than 240 occupants and 115 naturally ventilated houses to investigate thermal comfort performance between two houses based on thermal sensation vote (TSV) and thermal comfort vote (TCV). In addition, some questions related to thermal preference and body response are employed. This study also examines thermal comfort with a numerical simulations program called THERB for HAM, a coupled analysis software for heat, moisture, and air. The results show that the room comfort level was not optimal, where most occupants' feelings were warm and hot. However, type 1 is more comfortable than type 2, and simulation results confirm indoor environmental conditions. Furthermore, this study presents the adaptive behavior, where most occupants utilize the windows openings in the morning until noon and operate the fans during the night to modify indoor environment conditions to be more comfortable.

Effect of latent heat storage on thermal comfort and energy consumption in lightweight earth-based housings

Embedding PCMs in building materials has attracted great interest due to their ability to store thermal energy. Storage of heat and cold is an efficient way to save energy. Considering a lightweight earth-based material, mixture of soil with a high straw content, the present work aims to improve its thermal properties by using phase change materials (PCM). In this investigation, a laboratory experimental campaign and subsequent numerical analysis were carried out to examine the impact of incorporating PCM within the lightweight earth-based material. Materials' hygro-thermal properties (thermal conductivity, specific heat capacity and water vapor permeability), determined experimentally in laboratory, have been considered to calculate energy consumption and occupant's comfort in a typical single-family housing. Experimental results showed an improvement of the lightweight earth-based material thermal conductivity and specific heat capacity, as well as a slight reduction in its water vapor permeability depending on the PCM content. These modifications in the lightweight earth-based material properties lead to predict an improvement of occupants' thermal comfort and a reduction of energy consumption in buildings that will be made with such a material. Finally, this study underlined the existence of an optimal phase change temperature regarding climate in which the building evolves.

Thermal Comfort Improvement with Passive Design Strategies in Child Development Centers in Thailand

Child Development Centers (CDCs) in Thailand are developed from the same national standard building plan across the country. Due to hot weather conditions, low-cost building materials, and a failure to consider the specific surrounding conditions of each case, thermal discomfort results. This study focuses on an improvement in the thermal comfort of a pilot CDC building in Maha Sarakham province, Thailand. Three CIBSE TM52 model criteria were applied to assess the level of overheating in the CDC building. The IESVE simulation tool was employed to assess the improvement from using passive design strategies (such as orientation, solar protection, thermal insulation, and ventilation). The results showed that passive design strategies could improve the overall thermal comfort of the CDC building. Thermal insulation, especially roof insulation, was the key element in reducing overheating in the building. A fully insulated building with shading devices and a night-time only window-opening pattern could meet the three targeted overheating criteria. Although the limitations of using the CIBSE TM52 model in hot and humid regions have been identified, these findings can be used as an exemplar of passive design strategy integration for other CDC buildings across the country.

Evaluation of Passive Cooling and Thermal Comfort in Historical Residential Buildings in Zanzibar

Indoor thermal comfort is essential for occupants’ well-being, productivity, and efficiency. Global climate change is leading to extremely high temperatures and more intense solar radiation, especially in hot, humid areas. Passive cooling is considered to be one of the environmental design strategies by which to create indoor thermal comfort conditions and minimize buildings’ energy consumption. However, little evidence has been found regarding the effect of passive cooling on the thermal comfort of historical buildings in hot–dry or hot–humid areas. Therefore, we explored the passive cooling features (north-south orientation, natural ventilation, window shading, and light color painted walls) applied in historic residential buildings in Zanzibar and evaluated the residents’ thermal responses and comfort perception based on questionnaires and field surveys. The results showed that the average predicted mean votes (PMVs) were 1.23 and 0.85 for the two historical case study buildings; the average predicted percentages of dissatisfaction (PPD) were 37.35% and 20.56%, respectively. These results indicate that the thermal conditions were not within the acceptable range of ASHRAE Standard 55. Further techniques, such as the use of lime plaster, wash lime, and appropriate organization, are suggested for the improvement of indoor thermal comfort in historical buildings in Zanzibar. This study provides guidelines to assist architects in designing energy-efficient residential buildings, taking into account cultural heritage and thermal comfort in buildings.

녹지 조성 시나리오에 따른 도시 열환경 개선 효과 분석†

To alleviate the urban heat island phenomenon, this study aims to quantitatively analyze the effects of neighborhood green spaces on the improvement of the thermal environment based on detailed scenarios of five types of green spaces, including parks, pocket parks, parking lot greening, roadside planting, and rooftop-wall greening. The ENVI-met 4.4.6v model, a microclimate simulation program, was used to analyze the effects of green spaces. As a result, it was found that the air temperature decreased as the planting density of the park increased, but the thermal comfort index PET, which is the degree of heat sensation felt by humans, was not directly proportional to temperature. The establishment of a pocket park reduced air temperature up to a radius of 56m, while the range of temperature reduction increased by about 12.5% when three additional pocket parks were established at 250m intervals. Unlike the air temperature, PET was only affected in the vicinity of the planted area, so there was no significant difference in the thermal comfort of the surrounding environment due to the construction of pocket parks. Changing the surface pavement from asphalt to lawn blocks and implementing rooftop or wall greening did not directly act as solar shading but positively affected air temperature reduction; PET showed no significant difference. Roadside planting showed a higher air temperature reduction effect as the planting interval was narrower, but PET was not directly proportional to tree density. In the case of shrub planting under trees, it did not significantly affect the air temperature reduction but positively affected the improvement of thermal comfort. This study can outline strategies for constructing neighborhood green spaces to solve the urban heat island phenomena and establish detailed strategies for efficient thermal environment improvements.

여름철 도시공원의 열환경 개선 효과 – 서울숲 미기상 관측자료 분석을 중심으로 –

This study investigates the heat mitigation effects and thermal comfort improvement due to urban parks during summer. Self-developed monitoring devices to measure long-term microclimate data were installed in three spots, including the park plaza, waterside, and roadside in Seoul Forest Park, and measurements were taken from July 9 to July 30. The results of the measurement are as follows. The daily temperature of the park plaza and waterside were found to be 2.7°C and 2.9°C lower than the roadside and 5.5°C and 7.4°C lower than the roadside from 10:00 to 16:00. In addition, the Universal Thermal Climate Index (UTCI) measurement was applied to measure the thermal comfort at each point. In the average daily analysis, a significant difference was found between the park plaza, the waterside, and the roadside, and a greater difference was found between 10:00 to 16:00. Also, although there was no significant difference due to the weather condition, a statistically significant difference was also found in the average PM₁₀ and CO₂ concentrations. It is found to be higher in the order from the roadside, park plaza, and waterside for PM₁₀ concentration and park plaza, roadside, and waterside for CO₂. In sum, although the difference in measured microclimate data and thermal comfort index results were different depending on the time and weather conditions at the three points, the park plaza and waterside, which are located inside the park, showed improved thermal comfort conditions and lower temperatures than the roadside outside the park.

Preface

The 2022 International Conference on Advanced Materials and Chemical Engineering (AMCE 2022) was successfully held on 16-18 September, 2022 in Maoming, China (online conference). AMCE 2022 created a platform for experts, scholars, and engineers to share research findings and cutting-edge technologies, and gain an understanding of academic trends, fostering cooperation and transformation of academic outcomes.We were greatly honored to have Prof. Rujin Zhou from Guangdong University of Petrochemical Technology, China to serve as our Conference General Chair. There were 100 individuals attending the conference. Divided into three parts, the conference agenda covered keynote speeches, oral presentations, and online Q&A discussion. Firstly, keynote speakers were each allocated 30-45 minutes to hold their speeches. Then in the oral presentations, the excellent papers selected were presented by their authors by turns.During the conference, nine sophisticated professors were invited to address their keynote speeches. Among them, Prof. Saidur Rahman from Sunway University, Malaysia delivered a speech on the topic: Emerging Nano-materials in Heat Transfer Applications. His team was the first in Malaysia who successfully synthesized this new material using state of art lab equipment available in Research Centre for Nano-Materials and Energy Technology (RCNMET), Sunway University. He introduced to us about the emerging nano-materials and its various capabilities and explored the heat transfer behavior of MXene in solar energy applications. Additionally, Assoc. Prof. Muhyiddine Jradi from University of Southern Denmark, Denmark gave a report on: Research on Phase Change Materials (PCMs)-enhanced Building Envelope for Improved Thermal Comfort and Energy Efficiency. This presentation presented and evaluated PCM-enhanced building envelope under Danish conditions, simulated the impact of PCM integration on Dynamic energy models, and introduced the impact on the energy consumption, energy capacity, and thermal comfort. Their wonderful and dramatic speeches had triggered heated discussion. Moreover, every participant praised this conference for disseminating useful and insightful knowledge.After months of well preparation and hard work, the proceedings of AMCE 2022 covering a bunch of papers are smoothly published. These papers feature but are not limited to the following topics: Magnetic Materials, New Building Materials, Artificial Band Gap Materials, Colloid and Interface Chemistry, etc. All the papers have been checked through rigorous review and processes to meet the requirements of publication.On behalf of the organizing committee, we would like to express our heartfelt appreciation to all the keynote speakers, peer reviewers, and all the participants. Particularly, we would like to acknowledge the Journal of Physics: Conference Series, for the endeavor of all its colleagues in publishing this paper volume. We firmly believe that all the attendees have had fruitful discussions and gained valuable knowledge, and will enjoy the opportunity for future collaborations.The Committee of AMCE 2022List of Committee member is available in the Pdf.

Experimental Study of Thermal Conductivity of Concrete with Biosourced Material for Saved Energy in Buildings

Abstract This study aims to improve the thermal efficiency of concrete slabs by introducing a plant material. This can contribute to the improvement of internal thermal comfort for buildings and this by lower energy consumption. For this, several experiments were carried out at the laboratory, to find the thermal properties of a new innovative building material produced by inserting ALFA (STIPA TENACISSIMA) into a concrete slab. Several mass percentages of ALFA relative to the total mass of the concrete slab (0%, 0.4%, 0.8%, 1.2% and 1.6%) were studied to see the effect of the introduced quantity of this plant on the thermal conductivity of concrete. It was concluded that the insertion of ALFA in the concrete, decreases considerably the thermal conductivity. The best results are noticed for 1.2% of ALFA, whose thermal conductivity of the concrete is reduced up to 50.61%. As a result, heat gains and losses, through wall or slab, are significantly reduced, which reduces the energy consumed by cooling and heating of homes. In addition, the degree-day method was used to calculate the costs of cooling and heating energy for 58 regions in Algeria. The lowest total energy cost is noticed in the TENES region, while the highest energy cost is noticed in the BORDJ B. MOKHTAR region.

ASSESSMENT OF THERMAL COMFORT IN URBAN PUBLIC SPACE IN A TROPICAL CITY: A STUDY OF RAJSHAHI, BANGLADESH

Sustainable design approaches reduce energy consumption of urban form and the environment. Urban public space design is an efficient sustainable strategy to improve thermal and microclimatic conditions of outdoor spaces. A tropical city like Rajshahi, Bangladesh, an example of a rapid urbanization, is now dealing with the challenge of sustainable urban development, especially in the urban public space where thermal comfort makes a vital role for active to use of outdoor space in the various time. People’s activities and usages of outdoor space particularly urban public place which is the most viable and sustainable features of urban design is directly affected by thermal setting and thus affect people’s activities. This research aims to calculate the thermal comfort indices to find out the comfort condition of the urban public space by using a CFD based simulation software “ENVI-Met”. Online sources are used to collect site specific microclimatic data for thermal comfort. Data is then synthesized to find out MRT and thermal comfort condition. The aim is to develop and recommend a checklist of comfortable urban form and potential design and materials features to investigate the scope of improvement of outdoor thermal comfort of urban public space of study area. Both the physical (height width ratio of urban form, vegetation, water features, orientation, materials) has strong impact on improving thermal comfort and activities. This research suggests some urban design options for an effective and comfortable outdoor space in the context of tropical city like Rajshahi in the end.

Assessing the vertical synergies between outdoor thermal comfort and air quality in an urban street canyon based on field measurements

Outdoor thermal comfort and air quality are two key aspects of urban environmental quality. Understanding the synergies between outdoor thermal comfort and air quality in urban street canyons is of great importance to human health and well-being. Therefore, outdoor thermal factors, PM2.5, SO2, CO, NO2, O3 concentrations were recorded, and the correlation between them was analyzed at pedestrian, middle, and roof levels in an urban street canyon. Physiological equivalent temperature (PET) at middle level was 1.3 °C higher than that at roof level, and higher than that at pedestrian level. O3 concentration showed a stronger synergistic relationship between PET than all other air pollutants. It increased as PET increase in an exponential equation at three height levels. SO2 and CO concentrations increased with thermal perception at pedestrian and roof levels, whereas they decreased and then increased with thermal perception at middle level. Moreover, NO2 increased with PET in a linear equation at pedestrian level, but decreased with PET at roof level. PM2.5 concentrations fit PET at pedestrian level better than that at either middle or roof level. Overall, this study provides an in-depth understanding of the synergistic relationship between air pollutants and thermal comfort, and contributes to strategies for improvement of outdoor air quality and thermal comfort.

Influence of User Behaviour on the Functioning and Performance of Passive Phase-Change Material Systems after More Than a Decade of Operation

Phase-change materials (PCM) in buildings are considered a promising option to prevent overheating in warm seasons. Numerous studies have shown a noticeable improvement in thermal comfort through PCM, but in real applications they have often underperformed. User behaviour is often neglected as an important factor in determining PCM performance and might be a limiting factor. Another factor could be time-dependent degradation, which has also been scarcely researched so far. We used simulations within two case studies to investigate whether the PCM applications, each of which had been in operation for more than ten years, were still functioning from a technical perspective and what influence user behaviour had on their performance. We found that the PCM applications still had a positive influence on the thermal performance of the rooms, although the effect due to behavioural optimizations was significantly greater. The PCM was able to reduce the time of discomfort by 9–45% in the baseline scenario with real documented user behaviour in both rooms. Improved user practices increased the reduction in discomfort to 33–52%. For future studies evaluating PCM and its use, we recommend considering realistic user habits, as implementing optimal behaviour could lead to an overestimation of PCM performance and dissatisfaction with the technology.

The building plan automatic design optimization based on CFD numerical intelligent simulation

To apply the thermal comfort to the optimization of building layout, a variable design method based on Kmeans clustering is proposed. The evaluation was based on numerical simulation, genetic algorithm and universal thermal climate index (UTCI) to implement the building layout optimization on Matlab. Finally, the building layouts with centralized type, decentralized type and edge flow type water configuration were optimized, respectively. The results show that after the optimization, a reduction of 0.1∼0.6°C of UTCI was observed. We concluded that under moderate heat stress, the increase in wind velocity is the key to thermal comfort improvement.

Incorporating an atrium as a HAVC element for energy consumption reduction and thermal comfort improvement in a Polish climate

The form, attractiveness, functionality, and exterior appearance of buildings have been important considerations in architecture for centuries. Large common spaces, sharing of daylight, and the use of large glazing are also important. Combining many of these factors, buildings with atriums form a focal point, create a social meeting place, and contribute to the attractiveness of the building by providing a large open interior space. In cold and moderate climates, the atrium roof is important as the climate is often not conducive to outdoor activities.Using an IES-VE simulation, variants of a building in which the atrium was an independent element of the building or integrated into the ventilation system as a passive heater were analyzed. Additionally, two lighting systems were analyzed: on/off time-dependent control and daylight-dependent control (using dimming profiles for artificial lighting). Integrating the atrium into the HVAC system reduced the primary energy consumption for air heating by 17–22%. Using regulated lighting lowered the number of overheating hours. Factoring when the building was used (academic year), the atrium variants met thermal comfort requirements for 90% of its useful time, which did not occur when the atrium was not integrated. Therefore, integrating an atrium with an HVAC system can reduce energy consumption while providing thermal comfort to users.

The Impact of Small-Scale Greening on the Local Microclimate—A Case Study at Two School Buildings in Vienna

Strategies to mitigate urban heat islands are a recent issue in the Austrian capital, Vienna. In this study, the uhiSolver-v2106-0.21 software was used to evaluate the summer cooling effects and humidity production of small-scale facade greening and a green pergola located in two schools within the city. Based on on-site measurement data, the study revealed that small-scale greening measures are not able to substantially reduce ambient air temperature. On a hot summer day, at 3 p.m. local time (CEST), the maximum decrease amounted to 0.3 °C at 0.1 m from the facade greening as well as inside the green pergola. As for the apparent (perceived) temperature, a reduction of up to 4 °C was observed under the green pergola compared to the unshaded roof terrace. Hence, the simulation results show that, within urban areas, a significant improvement of thermal comfort in summer can only be achieved through large-scale greenery that provides shade for pedestrians.

Watering on porous pavement for improvement of environmental human thermal comfort in an ecological community in arid area: A case study in Lanzhou, China

• A method of watering on porous pavement for improvement of thermal comfort is proposed. • Universal thermal climate index for thermal comfort evaluation is introduced. • A complex correlation coefficient with relationship between UTCI and environmental parameter is studied. A method of watering on porous pavement was put forward to improve environmental thermal comfort of human body in an ecological community arid area in Lanzhou, China. A mathematic-physical coupling model was established based on water evaporation of porous pavement. Universal thermal climate index (UTCI) was introduced to evaluate environmental thermal comfort level. Multiple linear regression analysis between meteorological factors and UTCI was conducted. A complex correlation coefficient was calculated to study relation between UTCI and each environmental parameter. Variation of environmental parameters under water evaporation on porous pavement and ordinary pavement were also compared. Watering interval based on environmental parameters for porous pavement was studied. Results show that UTCI will be in range of human thermal comfort when relative humidity reaches more than 65% under air temperature of 16 °C. Relative humidity becomes more and more sensitive to thermal comfort when air temperature is less than 20 °C. While the thermal discomfort of human body gradually increased with the increase in relative humidity when air temperature is higher than 26 °C. When air temperature is around 20 °C, watering measure should be taken. Amount of watering in a single time should meet the requirement of water evaporation for 1.67 h under local climatic weather conditions. Watering interval should be the sum of evaporation time of a single watering, and time period required for UTCI within comfortable range. Regularly watering on porous pavement can significantly improve environmental human thermal comfort in ecological community in arid areas.

A Machine Learning Approach for Improved Thermal Comfort Prediction in Sustainable Built Environments

Thermal comfort prediction within sustainable built environments stands as a pivotal challenge intertwining human well-being and environmental sustainability. This paper presents a pioneering framework leveraging machine learning methodologies to advance predictive models for thermal comfort. Drawing upon a comprehensive dataset sourced from ASHRAE field studies and the RP-884 database, comprising 107,463 entries, our study unfolds a novel approach to enhancing thermal comfort predictions. The integration of diverse physiological parameters, environmental data, and occupant preferences forms the foundation of our machine learning-driven framework. Through meticulous analysis and model development, our approach not only refines predictive accuracy but also underscores adaptability across varying environmental contexts. The study contributes not only to the discourse on thermal comfort prediction but also emphasizes the crucial nexus between sustainable design, occupant well-being, and energy efficiency.

Nature-based solutions for urban heat mitigation in historical and cultural block: The case of Beijing Old City

Urban heat island can exacerbate the harmful influence on human health and urban environment in historical and cultural block within Beijing Old City, China. To improve urban resilience and human well-being, protect historical and cultural heritage, nature-based solutions for urban heat mitigation are being the hotspot of research. However, only few studies focused on the comprehensive thermal environment of historical and cultural block from the social, ecological and technical aspects. Thus, we set-up scenarios combining with the three domains, to explore the cooling effect and thermal comfort improvement of Dashilar Block through ENVI-met. The results showed that 1) The areas with highest air temperature (Ta) and physiological equivalent temperature (PET) were mainly distributed in Peizhi Hutong and Zongshu Toutiao. 2) Five mitigation scenarios adapting to historical protection requirements and public preferences were vertical greening, traditional greening, quality improvement greening, high-albedo paving, and comprehensive. 3) The comprehensive and vertical greening scenarios could reduce the mean Ta of whole block by 1.01 °C or 0.38 °C, decrease the percentage of Ta hotter zone by 13.87% or 19.63%, and reduce the local Ta inside the block by 0.65°C–1.80 °C or 0.33°C–1.05 °C, respectively, which turned out the cooling effect and thermal comfort improvement of abovementioned two scenarios could significantly alleviate the heat stress. The comprehensive and vertical greening can act as the preferred nature-based solution for heat mitigation in Dashilar Block. We believed that this study would provide novel insights into the balance between urban heat mitigation and heritage protection during the renewal of Beijing Old City.

Trombe walls with porous medium insertion and their influence on thermal comfort in flats in Cusco, Peru

The Trombe wall is a passive indirect heating system which should be used in Cusco, Peru to improve thermal conditions against the typical frosts and low temperatures during winter in the high Andean regions. Due to this problem, the use of a modified Trombe wall with insertion of porous medium is proposed to improve thermal comfort in flat buildings in Cusco. This research aims to analyse and compare the performance of dwellings without Trombe wall, with traditional Trombe wall, and with Trombe wall with glass and plastic pellets insertion in thermal comfort improvement. Autodesk® CFD was used to simulate and analyse the system. The simulation was performed with three prototype flats (55 m2, 75 m2 and 95 m2) for six months of the year. From the results obtained, the level of thermal comfort in the traditional scenarios is low with an average PMV of -1.86, in the scenarios with Trombe wall is good and in the scenarios with Trombe wall with insertion of porous medium is slightly better than the previous one, reaching an average PMV of +0.10 and a temperature of 21.90°C. The study carried out is important because it represents an efficient eco-sustainable heating alternative that improves the thermal comfort sensation in houses during the coldest months of the year.

The actual performance of retrofitted residential apartments: post-occupancy evaluation study in Italy

ABSTRACT Housing retrofits are undertaken to reduce energy use and to improve ‘occupants’ indoor environmental conditions. Despite increased retrofitting of the Italian housing stock, there is a lack of data on their energy use and indoor environmental quality (IEQ). This paper fills this gap by a post-occupancy evaluation (POE) study of seven retrofitted apartments in northern Italy; a non-retrofitted case study was included as a comparison. The study aimed to understand aspects of IEQ and occupant satisfaction after energy-efficiency retrofits. A mixed-method approach encompassed occupant satisfaction surveys, energy bill comparisons, in-situ indoor air temperature, and relative humidity measurements. Results highlighted ‘occupants’ thermal comfort improvement and heating energy consumption reduction after retrofits. Furthermore, reported preferred indoor temperatures w within a broader range than the recommended Italian regulations and CIBSE guide A standard. However, some participants reported unintended consequences, including mould growth and noise from the mechanical ventilation system. This study shows the potential of POE to understand the actual performance of retrofitted residential buildings. However, the difficulties of conducting a POE in retrofitted existing residential buildings show the need of further research on how to effectively conduct POE in retrofitted residential buildings, including improved digital quality monitoring methods.

Improving thermal comfort in the urban landscape of housing communities in tropical climate: A case study of Bang Chalong Community, Thailand

In developing countries, low-income housings seem to sacrifice quality over quantity. For a tropical country such as Thailand, where the temperature remains consistently high throughout the year, thermal comfort impacts living quality, especially in urban areas. Bang Chalong Community is a cluster of densely arranged mid-rise apartments in Samut Prakan, the peri-urban area of Bangkok, chosen by the NHA (National Housing Authority) to improve its living quality as a pilot project. While current literature investigates and explores solutions to mitigate thermal comfort in buildings, few studies focus on outdoor areas adjacent to buildings. This research aims to assess the outdoor hot-spot of the community, proposes appropriate attributes and design approaches to improve urban landscape elements leading to comfortable conditions, and recommends landscape design strategies for similar future development. The thermal condition was conducted using the Wet Bulb Globe Temperature (WBGT) data logger on 25 locations. The ambient temperature (TG) was used as the indicator for thermal comfort. It is found that critical attributes affecting the thermal condition are 1) the type of surfaces – hardscape or soft scape, and 2) the amount of surface and time exposed to solar energy – shade or sunlight. The thermal comfort improvement, including potential uses by landscape design, was proposed under four strategies; shading, added green, orientation & ventilation, and functional refinement. They are recommended to create suitable thermal comfort by landscape design for future development of a similar type