Pub Date : 2024-03-20DOI: 10.1177/1420326x241240107
Zhu Chang, Haiguo Yin, Yuekun Han, Linfeng Liang
The prevalence of small-scale structures, such as sentry buildings, has become widespread, with many of these buildings exposed to the outdoor environment and exhibiting suboptimal thermal insulation in their envelopes. Through a comprehensive study of outdoor disturbances, the most unfavourable envelope was identified. In light of this finding, we have designed static air layer sentry buildings (SAL-SB) and dynamic air layer sentry buildings (DAL-SB). The study conducted experiments and numerical simulations to evaluate the impact of air layer thickness, vent opening forms, and inlet velocities on the thermal insulation of sentry buildings. The results showed that both the SAL and DAL effectively improved thermal insulation, and a thickness of 25 cm has been found to offer the best thermal insulation. However, considering the balance between thermal insulation and cost-effectiveness, a thickness of 15 cm is recommended. Additionally, for DAL, an inlet velocity of 3 m/s is the threshold for switching the heat transfer direction on the roof. These findings provide novel insights into enhancing the thermal environment.
小型建筑（如哨所建筑）已成为一种普遍现象，其中许多建筑都暴露在室外环境中，其围护结构的隔热性能也不尽人意。通过对室外干扰的全面研究，我们确定了最不利的围护结构。根据这一发现，我们设计了静态空气层哨兵建筑（SAL-SB）和动态空气层哨兵建筑（DAL-SB）。研究通过实验和数值模拟，评估了空气层厚度、通风口开口形式和入口速度对哨兵建筑隔热性能的影响。结果表明，SAL 和 DAL 都能有效提高隔热性能，其中 25 厘米的厚度具有最佳隔热性能。不过，考虑到隔热性和成本效益之间的平衡，建议厚度为 15 厘米。此外，对于 DAL 来说，3 米/秒的入口速度是切换屋顶传热方向的临界值。这些发现为改善热环境提供了新的见解。
{"title":"Design and evaluation of thermal insulation of air layer for sentry building envelopes","authors":"Zhu Chang, Haiguo Yin, Yuekun Han, Linfeng Liang","doi":"10.1177/1420326x241240107","DOIUrl":"https://doi.org/10.1177/1420326x241240107","url":null,"abstract":"The prevalence of small-scale structures, such as sentry buildings, has become widespread, with many of these buildings exposed to the outdoor environment and exhibiting suboptimal thermal insulation in their envelopes. Through a comprehensive study of outdoor disturbances, the most unfavourable envelope was identified. In light of this finding, we have designed static air layer sentry buildings (SAL-SB) and dynamic air layer sentry buildings (DAL-SB). The study conducted experiments and numerical simulations to evaluate the impact of air layer thickness, vent opening forms, and inlet velocities on the thermal insulation of sentry buildings. The results showed that both the SAL and DAL effectively improved thermal insulation, and a thickness of 25 cm has been found to offer the best thermal insulation. However, considering the balance between thermal insulation and cost-effectiveness, a thickness of 15 cm is recommended. Additionally, for DAL, an inlet velocity of 3 m/s is the threshold for switching the heat transfer direction on the roof. These findings provide novel insights into enhancing the thermal environment.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"175 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140196301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-19DOI: 10.1177/1420326x241240112
Kun Han, Jiawei Zhuang, Li’an Zhang, Yongfa Diao
The high-temperature particles produced by air gouging processes are common pollutants in cleaning workshops, which could endanger workers’ health. In this research, a two-way coupled Eulerian-Lagrangian method based on discrete phase modelling (DPM) was used to investigate the transport characteristics of high-temperature particles generated from air gouging processes. The particle group in the movement was divided into core zone and boundary zone, and the kinetic mechanism of particles in different zones was analysed. The results show particles in the boundary zone are more susceptible to the vortex entrainment effect than particles in the core zone, and some particles could be moved from the vortex diffusion zone to the vortex recirculation zone. The smaller the particle size, the better the followability to the hot airflow. The slower the temperature decay of particles, the more significant the thermophoresis effect, which could enhance the diffusion behaviour of the small particles. By analysing the average residence time of particles in the breathing zone, the influence of different factors on the average vertical diffusion height [Formula: see text] of particles is summarized, and a nonlinear regression prediction model of [Formula: see text] is established. The results can contribute to health risk assessment and industrial ventilation design.
{"title":"A numerical research on transient transport of high-temperature particles associated with air gouging process","authors":"Kun Han, Jiawei Zhuang, Li’an Zhang, Yongfa Diao","doi":"10.1177/1420326x241240112","DOIUrl":"https://doi.org/10.1177/1420326x241240112","url":null,"abstract":"The high-temperature particles produced by air gouging processes are common pollutants in cleaning workshops, which could endanger workers’ health. In this research, a two-way coupled Eulerian-Lagrangian method based on discrete phase modelling (DPM) was used to investigate the transport characteristics of high-temperature particles generated from air gouging processes. The particle group in the movement was divided into core zone and boundary zone, and the kinetic mechanism of particles in different zones was analysed. The results show particles in the boundary zone are more susceptible to the vortex entrainment effect than particles in the core zone, and some particles could be moved from the vortex diffusion zone to the vortex recirculation zone. The smaller the particle size, the better the followability to the hot airflow. The slower the temperature decay of particles, the more significant the thermophoresis effect, which could enhance the diffusion behaviour of the small particles. By analysing the average residence time of particles in the breathing zone, the influence of different factors on the average vertical diffusion height [Formula: see text] of particles is summarized, and a nonlinear regression prediction model of [Formula: see text] is established. The results can contribute to health risk assessment and industrial ventilation design.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"24 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140167310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-19DOI: 10.1177/1420326x241240438
Dawei Wang, Panxiu Wang, A. Ditta, Gang Chen
The external building walls are significant in mitigating adverse weather conditions. Current research on the thermal insulation of exterior walls often overlooks crucial factors such as human comfort, seasonal changes and environmental dynamics. This study introduced a performance evaluation approach for external walls that considered the human thermal zone, annual air temperature and solar radiation. Taking Nanjing City as a case study, the thermal insulation performance of five distinct types of building exterior walls was investigated. The findings highlight the impact of various insulated wall systems on thermal insulation. While different insulated walls exhibited significant variations in effectiveness during extreme weather episodes, these variations were minor over the course of the year. Analysis revealed a spectrum of performance for insulated exterior walls, ranging from excellent to poor: Outer Insulated Wall > Inside Insulated Wall = Sandwich Insulated Wall = Self-Insulated Wall > Mortar-Insulated Wall. The disparity in thermal insulation performance amongst four wall types was minimal, with the mortar-insulated wall demonstrating the lowest performance. The highest temperature recorded for the mortar-insulated wall surpassed 32.2°C over 68 days. This research contributes insights into the nuanced performance of various insulated walls, paving the way for decision-making in climate resilience strategies.
{"title":"Optimizing thermal insulation in building facades: An examination of human-environment dynamics in Nanjing city, Eastern Asia","authors":"Dawei Wang, Panxiu Wang, A. Ditta, Gang Chen","doi":"10.1177/1420326x241240438","DOIUrl":"https://doi.org/10.1177/1420326x241240438","url":null,"abstract":"The external building walls are significant in mitigating adverse weather conditions. Current research on the thermal insulation of exterior walls often overlooks crucial factors such as human comfort, seasonal changes and environmental dynamics. This study introduced a performance evaluation approach for external walls that considered the human thermal zone, annual air temperature and solar radiation. Taking Nanjing City as a case study, the thermal insulation performance of five distinct types of building exterior walls was investigated. The findings highlight the impact of various insulated wall systems on thermal insulation. While different insulated walls exhibited significant variations in effectiveness during extreme weather episodes, these variations were minor over the course of the year. Analysis revealed a spectrum of performance for insulated exterior walls, ranging from excellent to poor: Outer Insulated Wall > Inside Insulated Wall = Sandwich Insulated Wall = Self-Insulated Wall > Mortar-Insulated Wall. The disparity in thermal insulation performance amongst four wall types was minimal, with the mortar-insulated wall demonstrating the lowest performance. The highest temperature recorded for the mortar-insulated wall surpassed 32.2°C over 68 days. This research contributes insights into the nuanced performance of various insulated walls, paving the way for decision-making in climate resilience strategies.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"51 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140167241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-16DOI: 10.1177/1420326x241236689
Rolains Golchimard Elenga, Li Zhu, Dickson Maigga Tongora, Steivan Defilla
Current building techniques in developing countries have become extremely critical. The net-zero energy concept has emerged as an essential strategy for minimising energy consumption and greenhouse gas emissions. However, its implementation, particularly in developing countries, remains a critical challenge. The purpose of this work is to assess the feasibility of achieving a net-zero energy building by combining energy-efficient design practices and renewable energy systems under the climatic conditions of the Republic of Congo. To achieve the stipulated objectives, DesignBuilder software was utilised for building modelling, energy load assessment and multiobjective optimisation of building energy efficiency measures, and the multicriteria energy optimisation was carried out using the HOMER tool. The optimisation results showed that the implementation of energy efficiency measures resulted in 39.15% energy savings, 43.45% thermal load savings and 55.68% discomfort hours reduction. Furthermore, the renewable energy system can provide 100% of the building’s energy load and a total savings of 3341.84 kgCO2eq/year. The system’s levelised cost of energy was estimated at 0.256 $/kWh, with a net present cost of $20,231, while the overall life cycle cost was calculated at 188.91 $/m2.
{"title":"Feasibility and performance analysis of a net-zero energy residential building in tropical climates: A case of Congo-Brazzaville","authors":"Rolains Golchimard Elenga, Li Zhu, Dickson Maigga Tongora, Steivan Defilla","doi":"10.1177/1420326x241236689","DOIUrl":"https://doi.org/10.1177/1420326x241236689","url":null,"abstract":"Current building techniques in developing countries have become extremely critical. The net-zero energy concept has emerged as an essential strategy for minimising energy consumption and greenhouse gas emissions. However, its implementation, particularly in developing countries, remains a critical challenge. The purpose of this work is to assess the feasibility of achieving a net-zero energy building by combining energy-efficient design practices and renewable energy systems under the climatic conditions of the Republic of Congo. To achieve the stipulated objectives, DesignBuilder software was utilised for building modelling, energy load assessment and multiobjective optimisation of building energy efficiency measures, and the multicriteria energy optimisation was carried out using the HOMER tool. The optimisation results showed that the implementation of energy efficiency measures resulted in 39.15% energy savings, 43.45% thermal load savings and 55.68% discomfort hours reduction. Furthermore, the renewable energy system can provide 100% of the building’s energy load and a total savings of 3341.84 kgCO<jats:sub>2</jats:sub>eq/year. The system’s levelised cost of energy was estimated at 0.256 $/kWh, with a net present cost of $20,231, while the overall life cycle cost was calculated at 188.91 $/m<jats:sup>2</jats:sup>.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"134 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140152201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-16DOI: 10.1177/1420326x241236876
Nedhal Al-Tamimi, Abdultawab Qahtan, Badr Saad Alotaibi, Mohammed Awad Abuhussain
Saudi buildings use approximately 29% of the primary energy and about 80% of the electrical energy. Because of the hot and dry climate, air conditioners consume a lot of electrical energy to attain a comfortable temperature indoors. More than 70% of Saudi buildings need to be thermally insulated. The objective of this study is to assess the existing energy saving of public schools in Saudi Arabia. Indoor thermal environment monitoring of three school buildings has been undertaken by employing LSI LASTEM ‘R-LOG’ data loggers, and electric energy bills of the schools were also collected. The school building was modelled using DesignBuilder software, which was utilized to investigate the impact of various modifications made to the building envelopes, including changes to building orientation, the inclusion of thermal insulation layers, various types of glass and shading devices. According to the findings, implementing appropriate building envelope design techniques for existing schools can lead to significant reductions in cooling and overall energy consumption, with savings of 30% and 19%, respectively. After applying these strategies collectively, the school managed to reduce its total annual electricity consumption by nearly 19.2%, resulting in a decrease from 279.13 MWh to 225.5 MWh per year.
{"title":"Innovative retrofitting approaches for energy saving in Saudi public schools","authors":"Nedhal Al-Tamimi, Abdultawab Qahtan, Badr Saad Alotaibi, Mohammed Awad Abuhussain","doi":"10.1177/1420326x241236876","DOIUrl":"https://doi.org/10.1177/1420326x241236876","url":null,"abstract":"Saudi buildings use approximately 29% of the primary energy and about 80% of the electrical energy. Because of the hot and dry climate, air conditioners consume a lot of electrical energy to attain a comfortable temperature indoors. More than 70% of Saudi buildings need to be thermally insulated. The objective of this study is to assess the existing energy saving of public schools in Saudi Arabia. Indoor thermal environment monitoring of three school buildings has been undertaken by employing LSI LASTEM ‘R-LOG’ data loggers, and electric energy bills of the schools were also collected. The school building was modelled using DesignBuilder software, which was utilized to investigate the impact of various modifications made to the building envelopes, including changes to building orientation, the inclusion of thermal insulation layers, various types of glass and shading devices. According to the findings, implementing appropriate building envelope design techniques for existing schools can lead to significant reductions in cooling and overall energy consumption, with savings of 30% and 19%, respectively. After applying these strategies collectively, the school managed to reduce its total annual electricity consumption by nearly 19.2%, resulting in a decrease from 279.13 MWh to 225.5 MWh per year.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"74 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140152209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The utilization of the district heating system (DHS) thermal inertia is greatly influenced by heating regulation modes and time steps, however, which has been rarely analysed in almost all integrated heat and power dispatch system (IHPD) models, for the purpose of wind power integration. In this study, an IHPD model considering the thermal inertia of the DHS was established, in which a data interaction problem amongst the power sources, heat sources and district heating networks was solved. Thereafter, four most commonly used heating operation modes and different heating regulation time steps were applied to the IHPD model, respectively, to analyse and compare their effects on the IHPD system under different operation conditions, mainly considering the operation cost and the wind power integration. Results of the case studies showed that the variable flow and variable supply temperature mode produced the lowest operation cost of the IHPD system during a whole heating season. Consequently, this mode is recommended to be applied in the optimization operation of the IHPD system with the wind power integration. Meanwhile, a heating regulation time step within 3 h could make full use of the DHS thermal inertia, thus to improve the operational flexibility of the IHPD system.
{"title":"Operational cost and wind power integration capacities of the integrated heat and power dispatch (IHPD) system under different heating regulation modes and time steps","authors":"Xuexiang Zhang, Jinfu Zheng, Hui Zhu, Songtao Hu, Shimin Liang","doi":"10.1177/1420326x241239237","DOIUrl":"https://doi.org/10.1177/1420326x241239237","url":null,"abstract":"The utilization of the district heating system (DHS) thermal inertia is greatly influenced by heating regulation modes and time steps, however, which has been rarely analysed in almost all integrated heat and power dispatch system (IHPD) models, for the purpose of wind power integration. In this study, an IHPD model considering the thermal inertia of the DHS was established, in which a data interaction problem amongst the power sources, heat sources and district heating networks was solved. Thereafter, four most commonly used heating operation modes and different heating regulation time steps were applied to the IHPD model, respectively, to analyse and compare their effects on the IHPD system under different operation conditions, mainly considering the operation cost and the wind power integration. Results of the case studies showed that the variable flow and variable supply temperature mode produced the lowest operation cost of the IHPD system during a whole heating season. Consequently, this mode is recommended to be applied in the optimization operation of the IHPD system with the wind power integration. Meanwhile, a heating regulation time step within 3 h could make full use of the DHS thermal inertia, thus to improve the operational flexibility of the IHPD system.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"21 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140152164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-13DOI: 10.1177/1420326x241238914
Zhihong Zhai, Jingfu Cao, Mingcai Li, Jun Shi
Energy consumption of air-conditioning in wet and hot climates is not only for cooling but, to a large extent, for dehumidification. Taking urban agglomeration in the Pearl River Delta region as a case study, this study analysed the cooling and dehumidification loads during the past 20 years. In addition, the impacts of cooling and dehumidification loads on carbon emissions were determined. The results showed that there was large spatial heterogeneity in the variations of the cooling and dehumidification loads. The cooling design loads in 1991–2020 was increased 1.83% to 5.56% compared to those in 1971–2000, while the loads for dehumidification was decreased 0.92% to 5.5%. Carbon emissions from cooling were increased, exceeding the carbon reduction from dehumidification, which leads to a weak increase in total carbon emissions. This study revealed that air-conditioning design should fully consider climate change impact by separating cooling and dehumidification loads, increasing the cooling load to avoid insufficient air-conditioning output but reducing the dehumidification load to promote energy efficiency of the air-conditioning system and to reduce carbon emissions. More importantly, an assessment of design loads with climate change in city or small scales should be made before determining summer air-conditioning system design capacity.
{"title":"Responses of air-conditioning loads to climate change and its impact on carbon emissions in the hot summer and warm winter climate","authors":"Zhihong Zhai, Jingfu Cao, Mingcai Li, Jun Shi","doi":"10.1177/1420326x241238914","DOIUrl":"https://doi.org/10.1177/1420326x241238914","url":null,"abstract":"Energy consumption of air-conditioning in wet and hot climates is not only for cooling but, to a large extent, for dehumidification. Taking urban agglomeration in the Pearl River Delta region as a case study, this study analysed the cooling and dehumidification loads during the past 20 years. In addition, the impacts of cooling and dehumidification loads on carbon emissions were determined. The results showed that there was large spatial heterogeneity in the variations of the cooling and dehumidification loads. The cooling design loads in 1991–2020 was increased 1.83% to 5.56% compared to those in 1971–2000, while the loads for dehumidification was decreased 0.92% to 5.5%. Carbon emissions from cooling were increased, exceeding the carbon reduction from dehumidification, which leads to a weak increase in total carbon emissions. This study revealed that air-conditioning design should fully consider climate change impact by separating cooling and dehumidification loads, increasing the cooling load to avoid insufficient air-conditioning output but reducing the dehumidification load to promote energy efficiency of the air-conditioning system and to reduce carbon emissions. More importantly, an assessment of design loads with climate change in city or small scales should be made before determining summer air-conditioning system design capacity.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"97 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140129798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As an important means of transportation, an aircraft’s environmental control system plays an important role in ensuring the health and thermal comfort of the cabin environment. To guarantee sufficient lift during flight, the aircraft cabin needs to have a certain angle of attack with the horizontal direction. In this study, the flow field, temperature field and vortex structure characteristics of the cabin were analysed using a scaled 28-row cabin model and computational fluid dynamics (CFD) under different angles of attack (15° and 8°) conditions. The results show that the velocity and temperature in the local area in the longitudinal section were increased when the angle of attack was increased. Compared with the horizontal state (angle of attack 0°), the longitudinal airflow under the condition of a larger angle of attack was enhanced. The overall trend of forward airflow is presented in this paper. The longitudinal airflow would strengthen the separation of the large vortex at the top of the cabin. The vortex structure shows high instability in different times and spaces.
{"title":"Investigation of longitudinal airflow characteristics in an aircraft cabin based on angle of attack","authors":"Zihan Xing, Yongzhi Zhang, Ping Wang, Jiaxing Zhang","doi":"10.1177/1420326x241237930","DOIUrl":"https://doi.org/10.1177/1420326x241237930","url":null,"abstract":"As an important means of transportation, an aircraft’s environmental control system plays an important role in ensuring the health and thermal comfort of the cabin environment. To guarantee sufficient lift during flight, the aircraft cabin needs to have a certain angle of attack with the horizontal direction. In this study, the flow field, temperature field and vortex structure characteristics of the cabin were analysed using a scaled 28-row cabin model and computational fluid dynamics (CFD) under different angles of attack (15° and 8°) conditions. The results show that the velocity and temperature in the local area in the longitudinal section were increased when the angle of attack was increased. Compared with the horizontal state (angle of attack 0°), the longitudinal airflow under the condition of a larger angle of attack was enhanced. The overall trend of forward airflow is presented in this paper. The longitudinal airflow would strengthen the separation of the large vortex at the top of the cabin. The vortex structure shows high instability in different times and spaces.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"110 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140117061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-07DOI: 10.1177/1420326x241236970
Yiqi Tao, Folong Zhong, Yijia Miao, Haida Tang, Lingling Li
Respiratory infectious diseases have affected the health of the elderly. This study investigated the optimization of physical barriers as a low-cost design strategy to reduce the risk of infection in nursing homes for the elderly in Hong Kong, which were significantly affected by the outbreak of COVID-19. First, data on two types of rooms, single and multi-occupancy, were collected from a field investigation of typical local nursing homes. Subsequently, Computational Fluid Dynamics (CFD) simulations were employed to analyse the effects of various barrier heights on the propagation, suspension, deposition and elimination of aerosol particles in these room types, thereby evaluating infection risks. The findings reveal that in single-occupancy rooms, a barrier height of 2.1 m is effective in curtailing the spread of the virus over distances. Conversely, in multi-occupancy rooms, while a 1.8-m barrier is necessary, the rate of particle suspension is considerably higher, necessitating additional ventilation measures. Based on these findings, the study provides quantitative criteria for the implementation of physical barriers as a low-cost physical measure in nursing homes and provides recommendations for the effective prevention of respiratory infectious diseases through design modifications.
{"title":"The impact of barrier arrangements on the transmission of respiratory infectious diseases in nursing homes in Hong Kong","authors":"Yiqi Tao, Folong Zhong, Yijia Miao, Haida Tang, Lingling Li","doi":"10.1177/1420326x241236970","DOIUrl":"https://doi.org/10.1177/1420326x241236970","url":null,"abstract":"Respiratory infectious diseases have affected the health of the elderly. This study investigated the optimization of physical barriers as a low-cost design strategy to reduce the risk of infection in nursing homes for the elderly in Hong Kong, which were significantly affected by the outbreak of COVID-19. First, data on two types of rooms, single and multi-occupancy, were collected from a field investigation of typical local nursing homes. Subsequently, Computational Fluid Dynamics (CFD) simulations were employed to analyse the effects of various barrier heights on the propagation, suspension, deposition and elimination of aerosol particles in these room types, thereby evaluating infection risks. The findings reveal that in single-occupancy rooms, a barrier height of 2.1 m is effective in curtailing the spread of the virus over distances. Conversely, in multi-occupancy rooms, while a 1.8-m barrier is necessary, the rate of particle suspension is considerably higher, necessitating additional ventilation measures. Based on these findings, the study provides quantitative criteria for the implementation of physical barriers as a low-cost physical measure in nursing homes and provides recommendations for the effective prevention of respiratory infectious diseases through design modifications.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"32 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140070470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wood-based panels are a significant source of indoor volatile organic compounds (VOCs), crucial for managing indoor pollution. The emissions from wood-based panels are influenced by both intrinsic factors, including their composition and manufacturing process, and extrinsic environmental conditions, such as temperature and humidity. In this paper, the emission of formaldehyde in plywood was studied under different temperature conditions (15°C, 23°C, 32°C and 37°C) and different humidity conditions (40%, 60% and 80%) by environmental chamber method. To understand the influence of relative humidity on the key parameters of panels from a mechanism perspective, this paper investigates the influence of relative humidity on the initial emittable concentration of formaldehyde, based on the hydrolysis reaction of urea-formaldehyde resin. Concurrently, the molecular dynamics and porous panels model were amalgamated to assess the influence of relative humidity on both the partition and diffusion coefficient. To simulate the emission process in a real environment, a control equation that allows for variations in both temperature and humidity is needed. This paper employs the method of variable separation to derive a simplified control equation. Subsequently, experimental data was utilized to validate the derived equation’s effectiveness within the practical indoor environmental range.
{"title":"Study on the effect of humidity on formaldehyde emission parameters of wood-based panels","authors":"Jiani Chen, Xiaohong Zheng, Chenxue Song, Hua Qian","doi":"10.1177/1420326x241232583","DOIUrl":"https://doi.org/10.1177/1420326x241232583","url":null,"abstract":"Wood-based panels are a significant source of indoor volatile organic compounds (VOCs), crucial for managing indoor pollution. The emissions from wood-based panels are influenced by both intrinsic factors, including their composition and manufacturing process, and extrinsic environmental conditions, such as temperature and humidity. In this paper, the emission of formaldehyde in plywood was studied under different temperature conditions (15°C, 23°C, 32°C and 37°C) and different humidity conditions (40%, 60% and 80%) by environmental chamber method. To understand the influence of relative humidity on the key parameters of panels from a mechanism perspective, this paper investigates the influence of relative humidity on the initial emittable concentration of formaldehyde, based on the hydrolysis reaction of urea-formaldehyde resin. Concurrently, the molecular dynamics and porous panels model were amalgamated to assess the influence of relative humidity on both the partition and diffusion coefficient. To simulate the emission process in a real environment, a control equation that allows for variations in both temperature and humidity is needed. This paper employs the method of variable separation to derive a simplified control equation. Subsequently, experimental data was utilized to validate the derived equation’s effectiveness within the practical indoor environmental range.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":"58 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140043890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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