Pub Date : 2024-01-09DOI: 10.1177/1420326x231224654
Elaine Gonçalves Ferreira Santana, Eliane Hayashi Suzuki, Racine Tadeu Araujo Prado, F. A. Kurokawa
The indoor air quality should provide adequate temperature and humidity levels, free from harmful pollution concentration. Proper heating, ventilation and air-conditioning (HVAC) system management is crucial in hospitals to prevent transmission of contaminated air and diseases. To verify whether healthcare facilities meet standard criteria for thermal comfort and indoor air quality, a field investigation in waiting and operating rooms was conducted in six hospitals in Brazil, in the summer. Thermal comfort parameters, carbon dioxide (CO2) concentration and differential air pressure were collected in loco. The results demonstrated that CO2 concentration was over 1,000 ppm in four waiting rooms, and no positive pressure was guaranteed in the operating room. The medical staff showed different thermal sensation variations in zone 1 (around the operating table) and zone 2 (remaining space around zone 1). In conclusion, most operating rooms had significant contamination risks and did not provide thermal comfort conditions to occupants. Due to improper HVAC design or high occupational density, air change rates were insufficient to guarantee adequate air renewal in the waiting rooms. There is an opportunity to improve the operation and maintenance process to provide healthy and comfortable environments in healthcare facilities, reducing nosocomial infections, especially during pandemic times.
{"title":"Thermal comfort and indoor air quality in hospitals in the subtropics: Analysis of operating rooms and waiting rooms conditions","authors":"Elaine Gonçalves Ferreira Santana, Eliane Hayashi Suzuki, Racine Tadeu Araujo Prado, F. A. Kurokawa","doi":"10.1177/1420326x231224654","DOIUrl":"https://doi.org/10.1177/1420326x231224654","url":null,"abstract":"The indoor air quality should provide adequate temperature and humidity levels, free from harmful pollution concentration. Proper heating, ventilation and air-conditioning (HVAC) system management is crucial in hospitals to prevent transmission of contaminated air and diseases. To verify whether healthcare facilities meet standard criteria for thermal comfort and indoor air quality, a field investigation in waiting and operating rooms was conducted in six hospitals in Brazil, in the summer. Thermal comfort parameters, carbon dioxide (CO2) concentration and differential air pressure were collected in loco. The results demonstrated that CO2 concentration was over 1,000 ppm in four waiting rooms, and no positive pressure was guaranteed in the operating room. The medical staff showed different thermal sensation variations in zone 1 (around the operating table) and zone 2 (remaining space around zone 1). In conclusion, most operating rooms had significant contamination risks and did not provide thermal comfort conditions to occupants. Due to improper HVAC design or high occupational density, air change rates were insufficient to guarantee adequate air renewal in the waiting rooms. There is an opportunity to improve the operation and maintenance process to provide healthy and comfortable environments in healthcare facilities, reducing nosocomial infections, especially during pandemic times.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139442340","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 : 2024-01-09DOI: 10.1177/1420326x231224360
Zongkun Li, Xiaoqian Ma, Y. Liao
The high concentration of viral bioaerosols within the negative pressure isolation wards could pose a challenge to preventing potential cross-infection amongst healthcare workers (HCWs) and patients. Using the Euler–Lagrange methodology, this study numerically simulated the spatial and temporal distribution characteristics of bioaerosols in a typical negative pressure isolation ward as well as determined the interaction of ventilation mode and patient posture on ward ventilation performance. The removal effect of particle groups produced by two respiratory behaviours (breathing and coughing) was quantitatively analyzed, and the effect of exhaust air ratio and air exchange rate on particle distribution was discussed. The results showed that the migration characteristics of bioaerosol particles were sensitive to both the ventilation pattern and patient posture, which showed significant interactions. On this basis, the ventilation pattern with the best ventilation performance was evaluated, showing a particle removal effect of 70–85%. Due to the initial momentum difference, the diffusion behaviour of cough and breath particles was not consistent, but optimizing the airflow distribution near the exhaust outlet could improve their removal efficiency in the meantime. Further studies found that equal exhaust air velocity ratio facilitated the removal of aerosol particles, and an appropriate increase in the air exchange rate could also reduce the particle content.
{"title":"Spatial and temporal distribution of bioaerosols produced by patients with different postures in a negative pressure isolation ward under different ventilation modes","authors":"Zongkun Li, Xiaoqian Ma, Y. Liao","doi":"10.1177/1420326x231224360","DOIUrl":"https://doi.org/10.1177/1420326x231224360","url":null,"abstract":"The high concentration of viral bioaerosols within the negative pressure isolation wards could pose a challenge to preventing potential cross-infection amongst healthcare workers (HCWs) and patients. Using the Euler–Lagrange methodology, this study numerically simulated the spatial and temporal distribution characteristics of bioaerosols in a typical negative pressure isolation ward as well as determined the interaction of ventilation mode and patient posture on ward ventilation performance. The removal effect of particle groups produced by two respiratory behaviours (breathing and coughing) was quantitatively analyzed, and the effect of exhaust air ratio and air exchange rate on particle distribution was discussed. The results showed that the migration characteristics of bioaerosol particles were sensitive to both the ventilation pattern and patient posture, which showed significant interactions. On this basis, the ventilation pattern with the best ventilation performance was evaluated, showing a particle removal effect of 70–85%. Due to the initial momentum difference, the diffusion behaviour of cough and breath particles was not consistent, but optimizing the airflow distribution near the exhaust outlet could improve their removal efficiency in the meantime. Further studies found that equal exhaust air velocity ratio facilitated the removal of aerosol particles, and an appropriate increase in the air exchange rate could also reduce the particle content.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139442916","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 : 2024-01-08DOI: 10.1177/1420326x231225405
Dadi Zhang, H. Hou, T. Tsang, K. Mui, L. Wong
This study examined the effect of mood states on students’ thermal sensations within a university library comprising quiet-study and group-study rooms. Through concurrent subjective and objective assessments over five consecutive workdays, this study investigated the influence of psychological factors, particularly mood states, in influencing thermal sensations. This study addressed a paucity of prior research in library settings where both independent and collaborative studies have been undertaken. Subjective data (i.e. personal information, thermal assessment and mood states) via questionnaires and objective data (i.e. air temperature, radiant temperature, relative humidity and air velocity) via on-site measurements were collected during five working days. Statistical analyses (ANOVA, t-test, correlations and regression) indicated that male students and those with bad feelings (e.g. hostile and upset) reported significantly higher thermal sensation votes (TSVs) ( p < 0.05) compared to females and those with neutral/good feelings (0.4–0.5 difference out of 7). Two predictive models for TSV were developed for males and females, considering factors like body mass index (BMI), operative temperature and mood states. This research offers insights for designing specific study environments to improve thermal comfort, fostering students’ well-being and guiding future initiatives in this area.
{"title":"Predicting students’ thermal sensation votes in university libraries taking into account their mood states","authors":"Dadi Zhang, H. Hou, T. Tsang, K. Mui, L. Wong","doi":"10.1177/1420326x231225405","DOIUrl":"https://doi.org/10.1177/1420326x231225405","url":null,"abstract":"This study examined the effect of mood states on students’ thermal sensations within a university library comprising quiet-study and group-study rooms. Through concurrent subjective and objective assessments over five consecutive workdays, this study investigated the influence of psychological factors, particularly mood states, in influencing thermal sensations. This study addressed a paucity of prior research in library settings where both independent and collaborative studies have been undertaken. Subjective data (i.e. personal information, thermal assessment and mood states) via questionnaires and objective data (i.e. air temperature, radiant temperature, relative humidity and air velocity) via on-site measurements were collected during five working days. Statistical analyses (ANOVA, t-test, correlations and regression) indicated that male students and those with bad feelings (e.g. hostile and upset) reported significantly higher thermal sensation votes (TSVs) ( p < 0.05) compared to females and those with neutral/good feelings (0.4–0.5 difference out of 7). Two predictive models for TSV were developed for males and females, considering factors like body mass index (BMI), operative temperature and mood states. This research offers insights for designing specific study environments to improve thermal comfort, fostering students’ well-being and guiding future initiatives in this area.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139448054","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 : 2023-12-22DOI: 10.1177/1420326x231221940
Zi-guang Gao, Pu Wang, Jiajun Cai, Mingge Liu, Linjie Li
When there is a fire in a tunnel, the heat released by the combustion is difficult to dissipate and the temperature inside the tunnel would rise rapidly. Longitudinal ventilation (LV) has been commonly adopted as the smoke control strategy in tunnel fires, which is essential to safeguard the tunnel structure and the trapped people. Besides the smoke control method by LV, the water mist system (WMS) can provide a powerful cooling effect for the high-temperature smoke in the tunnel. This article aims to investigate the impact of WMS on the smoke back-layering (BL) length with LV and the mutual effect process between the smoke spread and the WMS. The findings show that the BL length is restricted more effectively by the combined action of water mist and LV. Upon activation of the WMS, the water mist’s effect inhibits the smoke’s ability to spread upstream and causes the smoke layer to settle down, which disturbs the stability of the smoke layer. An unstable layer of smoke is more likely to be blown downstream by longitudinal ventilation. All water mist particle diameters show a significant reduction in smoke back-layering with an increased flow rate. The BL length would gradually reduce as the particle diameter is decreased. The tendency of flow rate and particle diameter on the BL length shows similar effects to the critical velocity ( Vcr). The Vcr is reduced with the rising flow rate and increased with expanding particle diameter.
{"title":"Influence of the water spray particle diameter and flow rate on the smoke flow and the back-layering in tunnels with longitudinal ventilation","authors":"Zi-guang Gao, Pu Wang, Jiajun Cai, Mingge Liu, Linjie Li","doi":"10.1177/1420326x231221940","DOIUrl":"https://doi.org/10.1177/1420326x231221940","url":null,"abstract":"When there is a fire in a tunnel, the heat released by the combustion is difficult to dissipate and the temperature inside the tunnel would rise rapidly. Longitudinal ventilation (LV) has been commonly adopted as the smoke control strategy in tunnel fires, which is essential to safeguard the tunnel structure and the trapped people. Besides the smoke control method by LV, the water mist system (WMS) can provide a powerful cooling effect for the high-temperature smoke in the tunnel. This article aims to investigate the impact of WMS on the smoke back-layering (BL) length with LV and the mutual effect process between the smoke spread and the WMS. The findings show that the BL length is restricted more effectively by the combined action of water mist and LV. Upon activation of the WMS, the water mist’s effect inhibits the smoke’s ability to spread upstream and causes the smoke layer to settle down, which disturbs the stability of the smoke layer. An unstable layer of smoke is more likely to be blown downstream by longitudinal ventilation. All water mist particle diameters show a significant reduction in smoke back-layering with an increased flow rate. The BL length would gradually reduce as the particle diameter is decreased. The tendency of flow rate and particle diameter on the BL length shows similar effects to the critical velocity ( Vcr). The Vcr is reduced with the rising flow rate and increased with expanding particle diameter.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138947590","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 : 2023-12-21DOI: 10.1177/1420326x231222153
Bingyang Shen, Meng Liu, Lumeng Liu, Huan Liu
Bacteria in built environments are profoundly affected by indoor thermal conditions. In China, continuous and intermittent heating modes give rise to distinct thermal environments in winter. However, the quantitative relationships between bacterial concentration and thermal conditions in the context of heating modes remain unclear. To this end, we recorded the temperature and relative humidity (RH) in 15 intermittently and 15 continuously heated residences in 27 cities across China and obtained the bacterial concentrations via the quantitative polymerase chain reaction technology. For the intermittently heated residences whose temperatures were lower than 18°C, the bacterial concentration negatively correlated with RH while the correlation was positive for those with T > 18°C. For the continuously heated residences, a quadratic correlation was found between temperature and the bacterial concentration which was highest at 23°C. For lower bacterial risk, we suggest that (1) RH in the intermittent heating region should be in the range of 40%–60% and (2) temperature in the continuous heating region should not exceed 22°C. The bacteria-adjusted thermal zones for intermittent and continuous heating are 66% and 77% of the original thermal comfort zone, respectively. Our study provides insights into the set-points of indoor thermal environments based on the microbial perspective.
{"title":"Correlation of thermal environments with the bacterial concentration in bedrooms with intermittent and continuous heating modes","authors":"Bingyang Shen, Meng Liu, Lumeng Liu, Huan Liu","doi":"10.1177/1420326x231222153","DOIUrl":"https://doi.org/10.1177/1420326x231222153","url":null,"abstract":"Bacteria in built environments are profoundly affected by indoor thermal conditions. In China, continuous and intermittent heating modes give rise to distinct thermal environments in winter. However, the quantitative relationships between bacterial concentration and thermal conditions in the context of heating modes remain unclear. To this end, we recorded the temperature and relative humidity (RH) in 15 intermittently and 15 continuously heated residences in 27 cities across China and obtained the bacterial concentrations via the quantitative polymerase chain reaction technology. For the intermittently heated residences whose temperatures were lower than 18°C, the bacterial concentration negatively correlated with RH while the correlation was positive for those with T > 18°C. For the continuously heated residences, a quadratic correlation was found between temperature and the bacterial concentration which was highest at 23°C. For lower bacterial risk, we suggest that (1) RH in the intermittent heating region should be in the range of 40%–60% and (2) temperature in the continuous heating region should not exceed 22°C. The bacteria-adjusted thermal zones for intermittent and continuous heating are 66% and 77% of the original thermal comfort zone, respectively. Our study provides insights into the set-points of indoor thermal environments based on the microbial perspective.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138953210","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 : 2023-12-20DOI: 10.1177/1420326x231222157
A. S. Cruz, Leopoldo Eurico Gonçalves Bastos
Due to climate change conditions, natural ventilation potential may reduce over the years and increase dependence on HVAC systems. Moreover, occupants’ behaviour regarding natural ventilation is a significant parameter affecting the thermal-energy performance of residential buildings as people tend to occupy their homes differently depending on their life, work and cultural routines. Therefore, in this study, the thermal-energy performance of a Global South (GS) housing case study located in Brazil was assessed in a future weather context. This paper included two major steps: (1) Optimization procedure to create optimized models based on different occupancy patterns; and (2) Parametric analysis to explore the building’s thermal-energy performance for a given constructive design option, occupant behaviour and weather data. The optimization procedure included a multi-objective optimization based on the Non-dominated Sorting Genetic Algorithm II (NSGA-II) to minimize discomfort hours and cooling energy demand, while parametric analysis explored the occupants’ behaviour varieties derived from alternative occupancy patterns, ventilation availabilities and HVAC operation modes. The obtained future context simulation results indicated an increase in discomfort hours and cooling energy demand, while the most appropriate architecture design might vary depending on the occupancy behaviour.
{"title":"Predicting climate change and occupants’ behaviour impact on thermal-energy performance of global south housing: Case study in Brazil","authors":"A. S. Cruz, Leopoldo Eurico Gonçalves Bastos","doi":"10.1177/1420326x231222157","DOIUrl":"https://doi.org/10.1177/1420326x231222157","url":null,"abstract":"Due to climate change conditions, natural ventilation potential may reduce over the years and increase dependence on HVAC systems. Moreover, occupants’ behaviour regarding natural ventilation is a significant parameter affecting the thermal-energy performance of residential buildings as people tend to occupy their homes differently depending on their life, work and cultural routines. Therefore, in this study, the thermal-energy performance of a Global South (GS) housing case study located in Brazil was assessed in a future weather context. This paper included two major steps: (1) Optimization procedure to create optimized models based on different occupancy patterns; and (2) Parametric analysis to explore the building’s thermal-energy performance for a given constructive design option, occupant behaviour and weather data. The optimization procedure included a multi-objective optimization based on the Non-dominated Sorting Genetic Algorithm II (NSGA-II) to minimize discomfort hours and cooling energy demand, while parametric analysis explored the occupants’ behaviour varieties derived from alternative occupancy patterns, ventilation availabilities and HVAC operation modes. The obtained future context simulation results indicated an increase in discomfort hours and cooling energy demand, while the most appropriate architecture design might vary depending on the occupancy behaviour.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138955673","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 : 2023-12-08DOI: 10.1177/1420326x231219999
Xinshuai Geng, L. Bai
Recent studies have shown that kitchen pollution is a major concern during cooking. Cooking can release harmful pollutants such as various sizes of particulate matters (PMs) and polycyclic aromatic hydrocarbons (PAHs) that can harm the human body directly or indirectly. This study examined the harm of pollutants from cooking in different Chinese areas, including concentrations of PMs and size distribution as well as PAHs in rural and urban locations. PMs were collected during cooking, and PAHs in the particular matter were analysed. Additionally, the study conducted pollution risk assessment and economic analysis. The results showed that PMs and PAHs released during cooking in rural kitchens were higher than in urban kitchens. Specifically, PM1.0, PM2.5 and PM10 concentrations were 5.05, 3.39 and 3.78 times higher than in rural kitchens. PAH concentration in rural kitchens was 4.79, 5.82 and 6.30 times higher than in urban kitchens, respectively. Skin contact poses the highest carcinogenic risk amongst the pathways. Females had higher exposure to carcinogens than males. Furthermore, smaller PMs have a higher adsorption capacity for PAHs and are more carcinogenic than larger particles. This study examined the harmful effects of different cooking fuels. It aimed to improve cooking environments and increase the use of clean energy.
{"title":"Characteristics of particulate matter and polycyclic aromatic hydrocarbon pollution generated during kitchen cooking and health risk assessment","authors":"Xinshuai Geng, L. Bai","doi":"10.1177/1420326x231219999","DOIUrl":"https://doi.org/10.1177/1420326x231219999","url":null,"abstract":"Recent studies have shown that kitchen pollution is a major concern during cooking. Cooking can release harmful pollutants such as various sizes of particulate matters (PMs) and polycyclic aromatic hydrocarbons (PAHs) that can harm the human body directly or indirectly. This study examined the harm of pollutants from cooking in different Chinese areas, including concentrations of PMs and size distribution as well as PAHs in rural and urban locations. PMs were collected during cooking, and PAHs in the particular matter were analysed. Additionally, the study conducted pollution risk assessment and economic analysis. The results showed that PMs and PAHs released during cooking in rural kitchens were higher than in urban kitchens. Specifically, PM1.0, PM2.5 and PM10 concentrations were 5.05, 3.39 and 3.78 times higher than in rural kitchens. PAH concentration in rural kitchens was 4.79, 5.82 and 6.30 times higher than in urban kitchens, respectively. Skin contact poses the highest carcinogenic risk amongst the pathways. Females had higher exposure to carcinogens than males. Furthermore, smaller PMs have a higher adsorption capacity for PAHs and are more carcinogenic than larger particles. This study examined the harmful effects of different cooking fuels. It aimed to improve cooking environments and increase the use of clean energy.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138588824","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 : 2023-12-06DOI: 10.1177/1420326x231219991
Jinghua Yu, Yexing She, Lei Zou, Yi Song, Jingang Zhao
As a place for the maintenance of high-speed trains, the current ventilation system in the train depot cannot meet comfort requirements according to the feedback from the inspection department. The poor thermal environment could seriously affect the physical health and work efficiency of staff. This study provides some basic data and design methods for improving the thermal environment in high-speed railway depots. Field studies were conducted in five different high-speed railway depots in hot summer regions of China, including the form and the operation of the ventilation system, the thermal and humid environment and the characteristics of the heat sources. According to the survey results, the maximum temperature in the depot can reach 41.2°C in summer. There is a clear vertical temperature stratification in the afternoon of the depot, and the maximum temperature difference between three working platforms can reach more than 4°C. The cooling effect of ventilation systems in depot was investigated and compared. The recommended ventilation mode is natural ventilation system + bottom mechanical air supply system + ceiling fan system, and it is recommended to combine the west window louvers with external sun shading to achieve the best cooling effect in high-speed railway depot.
{"title":"Performance investigation on the ventilation systems of high-speed railway train depots in hot summer regions","authors":"Jinghua Yu, Yexing She, Lei Zou, Yi Song, Jingang Zhao","doi":"10.1177/1420326x231219991","DOIUrl":"https://doi.org/10.1177/1420326x231219991","url":null,"abstract":"As a place for the maintenance of high-speed trains, the current ventilation system in the train depot cannot meet comfort requirements according to the feedback from the inspection department. The poor thermal environment could seriously affect the physical health and work efficiency of staff. This study provides some basic data and design methods for improving the thermal environment in high-speed railway depots. Field studies were conducted in five different high-speed railway depots in hot summer regions of China, including the form and the operation of the ventilation system, the thermal and humid environment and the characteristics of the heat sources. According to the survey results, the maximum temperature in the depot can reach 41.2°C in summer. There is a clear vertical temperature stratification in the afternoon of the depot, and the maximum temperature difference between three working platforms can reach more than 4°C. The cooling effect of ventilation systems in depot was investigated and compared. The recommended ventilation mode is natural ventilation system + bottom mechanical air supply system + ceiling fan system, and it is recommended to combine the west window louvers with external sun shading to achieve the best cooling effect in high-speed railway depot.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138597149","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 : 2023-12-06DOI: 10.1177/1420326x231219466
Sining He, Lina Yang, Jiying Liu, Daranee Jareemit
This research aimed to investigate the spatial distribution of PM2.5 in residential areas near major urban roads during the autumn and winter seasons. A traffic pollution distribution model was developed using ENVI-met software to predict the distribution of pollution in and around the residential area. The experimental results indicated that during peak hours, the concentration of PM2.5 inside the residential area exceeded 140 μg/m3. The simulations indicated a horizontal diffusion range of traffic pollution up to 300 m, with the most significant effects observed within a radius of 20 m where the pollutant concentration decreased from 131.6 μg/m3 to 93.5 μg/m3. The vertical diffusion of traffic pollution extended to approximately 100 m, with the highest impact observed within a distance of 22.5 m (7 floors). Furthermore, pollution diffused up to a height of 47.5 m near major urban roads, resulting in a decrease in the concentration of PM2.5 from 140 μg/m3 to 70 μg/m3. Quantitative comparisons showed that street pollution was higher in autumn than in winter, whereas pollution outside buildings near the street was higher in winter compared to autumn. Simultaneously, the impact of pollutants on human health was evaluated using the decrease in life expectancy (DLE) index. The results revealed a DLE of 13.16 years in areas with the highest pollution levels, while most residential areas had a DLE ranging between 3.2 and 3.88 years. These findings are significant in terms of raising awareness and providing valuable references for the development and planning of urban health initiatives.
{"title":"Spatial distribution of PM2.5 concentration around high-rise residential buildings during peak traffic hours in autumn and winter seasons","authors":"Sining He, Lina Yang, Jiying Liu, Daranee Jareemit","doi":"10.1177/1420326x231219466","DOIUrl":"https://doi.org/10.1177/1420326x231219466","url":null,"abstract":"This research aimed to investigate the spatial distribution of PM2.5 in residential areas near major urban roads during the autumn and winter seasons. A traffic pollution distribution model was developed using ENVI-met software to predict the distribution of pollution in and around the residential area. The experimental results indicated that during peak hours, the concentration of PM2.5 inside the residential area exceeded 140 μg/m3. The simulations indicated a horizontal diffusion range of traffic pollution up to 300 m, with the most significant effects observed within a radius of 20 m where the pollutant concentration decreased from 131.6 μg/m3 to 93.5 μg/m3. The vertical diffusion of traffic pollution extended to approximately 100 m, with the highest impact observed within a distance of 22.5 m (7 floors). Furthermore, pollution diffused up to a height of 47.5 m near major urban roads, resulting in a decrease in the concentration of PM2.5 from 140 μg/m3 to 70 μg/m3. Quantitative comparisons showed that street pollution was higher in autumn than in winter, whereas pollution outside buildings near the street was higher in winter compared to autumn. Simultaneously, the impact of pollutants on human health was evaluated using the decrease in life expectancy (DLE) index. The results revealed a DLE of 13.16 years in areas with the highest pollution levels, while most residential areas had a DLE ranging between 3.2 and 3.88 years. These findings are significant in terms of raising awareness and providing valuable references for the development and planning of urban health initiatives.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138594911","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}
Photovoltaic (PV)-based solar chimneys could assist stack ventilation within a large space hall. This study considered a comprehensive office building with a PV-based solar chimney as a case study to explore measures for enhancing stack ventilation. A computational fluid dynamics (CFD) model was established, and the influences of the inner heat source, chimney inlet position, solar heat gain and photovoltaic (PV) arrangement on the ventilation rate were investigated. The results revealed that PV-based solar chimneys could assist stack ventilation and would effectively provide a suitable indoor environment for occupied areas during the transitional season. Raising the chimney inlet position is conducive to improving the ventilation rate and cooling performance. The increase in the inlet position from a height of 0.2 m to 3.8 m would increase the ventilation rate up to 5%. The heat gain from the PV backside is an important method of enhancing the ventilation rate. A 200 W/m2 heat gain can lead to a 16.4% increase in ventilation. Moreover, the lower the heat source location, the higher the ventilation efficiency. This study provides basic strategies for optimising design schemes to improve natural ventilation efficiency.
{"title":"Evaluation of photovoltaic-based solar chimney–assisted stack ventilation within a large space hall: A case study","authors":"Tong Wei, Hanyu Li, Runnan Sun, Chuck Wah Yu, Xilian Luo","doi":"10.1177/1420326x231220527","DOIUrl":"https://doi.org/10.1177/1420326x231220527","url":null,"abstract":"Photovoltaic (PV)-based solar chimneys could assist stack ventilation within a large space hall. This study considered a comprehensive office building with a PV-based solar chimney as a case study to explore measures for enhancing stack ventilation. A computational fluid dynamics (CFD) model was established, and the influences of the inner heat source, chimney inlet position, solar heat gain and photovoltaic (PV) arrangement on the ventilation rate were investigated. The results revealed that PV-based solar chimneys could assist stack ventilation and would effectively provide a suitable indoor environment for occupied areas during the transitional season. Raising the chimney inlet position is conducive to improving the ventilation rate and cooling performance. The increase in the inlet position from a height of 0.2 m to 3.8 m would increase the ventilation rate up to 5%. The heat gain from the PV backside is an important method of enhancing the ventilation rate. A 200 W/m2 heat gain can lead to a 16.4% increase in ventilation. Moreover, the lower the heat source location, the higher the ventilation efficiency. This study provides basic strategies for optimising design schemes to improve natural ventilation efficiency.","PeriodicalId":13578,"journal":{"name":"Indoor and Built Environment","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138600671","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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