Pub Date : 2022-09-28DOI: 10.1177/01436244221129763
Youxian Huang, S. Yeboah, Jingjing Shao
Double skin façades (DSFs), offer great views, architectural aesthetics, and energy savings. Yet, in a fire event the glass façade breaks leading to risks to human life and firefighting difficulties. Shading devices incorporated to prevent unfavourable heat gains to reduce cooling load though offer energy savings potentially present other challenges in firefighting and occupants’ evacuation. In this study, Fire Dynamic Simulator (FDS) was used to numerically investigate the spread of a 5 MW HRR polyurethane GM27 fire in a multi-storey double skin façade building with Venetian blinds placed in its cavity. The blinds were positioned 0.4 m away from the internal glazing, middle of the cavity and 0.4 m away from the external glazing respectively. In each blind position the slat angle was opened at 0°, 45°, 90° and 135° respectively. The results show peak inner glazing surface temperature ranged between 283°C to 840°C depending on the thermocouple position, the Venetian blind position and slat opening angle. Without Venetian blinds, peak inner glazing surface temperatures ranged between 468°C to 614°C. In all cases except when the slat angle was 0° and the blind was positioned closer to the outer glazing, the inner glazing surface temperature from the closest thermocouple (TC 14) above the fire room exceeded 600°C, the glass breakage temperature threshold. Overall, the Venetian blind position and slat opening angle influenced the spread of fire. Venetian blind combustibility and flammability were not considered and therefore recommended for future studies. Practical Application: Our manuscript helps to develop new thinking on mitigation of fire risks in buildings for architects, engineers and designers when incorporating Venetian blinds in Double Skin Façades (DSFs).
{"title":"Numerical investigation of fire in the cavity of naturally ventilated double skin façade with venetian blinds","authors":"Youxian Huang, S. Yeboah, Jingjing Shao","doi":"10.1177/01436244221129763","DOIUrl":"https://doi.org/10.1177/01436244221129763","url":null,"abstract":"Double skin façades (DSFs), offer great views, architectural aesthetics, and energy savings. Yet, in a fire event the glass façade breaks leading to risks to human life and firefighting difficulties. Shading devices incorporated to prevent unfavourable heat gains to reduce cooling load though offer energy savings potentially present other challenges in firefighting and occupants’ evacuation. In this study, Fire Dynamic Simulator (FDS) was used to numerically investigate the spread of a 5 MW HRR polyurethane GM27 fire in a multi-storey double skin façade building with Venetian blinds placed in its cavity. The blinds were positioned 0.4 m away from the internal glazing, middle of the cavity and 0.4 m away from the external glazing respectively. In each blind position the slat angle was opened at 0°, 45°, 90° and 135° respectively. The results show peak inner glazing surface temperature ranged between 283°C to 840°C depending on the thermocouple position, the Venetian blind position and slat opening angle. Without Venetian blinds, peak inner glazing surface temperatures ranged between 468°C to 614°C. In all cases except when the slat angle was 0° and the blind was positioned closer to the outer glazing, the inner glazing surface temperature from the closest thermocouple (TC 14) above the fire room exceeded 600°C, the glass breakage temperature threshold. Overall, the Venetian blind position and slat opening angle influenced the spread of fire. Venetian blind combustibility and flammability were not considered and therefore recommended for future studies. Practical Application: Our manuscript helps to develop new thinking on mitigation of fire risks in buildings for architects, engineers and designers when incorporating Venetian blinds in Double Skin Façades (DSFs).","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41638894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-09-21DOI: 10.1177/01436244221129169
ectors. to of heating systems on the design of lightweight fl oor heating. The analysis focuses on the radiant sheet, which is commonly used in dry systems to increase their ef fi ciency. The fl oor heating market offers many radiant sheet design solutions, varying in material, width and panel thickness. However, there are no systematic guidelines that de fi ne the performance of lightweight fl oor heating depending on the radiant sheet solution used. This study proposes an optimum gap between radiant sheets (10 – 20 mm), that provides high system ef fi ciency with low aluminium consumption.
{"title":"Practical applications","authors":"","doi":"10.1177/01436244221129169","DOIUrl":"https://doi.org/10.1177/01436244221129169","url":null,"abstract":"ectors. to of heating systems on the design of lightweight fl oor heating. The analysis focuses on the radiant sheet, which is commonly used in dry systems to increase their ef fi ciency. The fl oor heating market offers many radiant sheet design solutions, varying in material, width and panel thickness. However, there are no systematic guidelines that de fi ne the performance of lightweight fl oor heating depending on the radiant sheet solution used. This study proposes an optimum gap between radiant sheets (10 – 20 mm), that provides high system ef fi ciency with low aluminium consumption.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42485401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-09-10DOI: 10.1177/01436244221125720
A. Eltaweel, N. Kuchai, D. Albadra, D. Coley, J. Hart, A. Acevedo-De-los-Ríos, Daniel R. Rondinel-Oviedo
Displaced populations are housed in various constructions, including lightweight predesigned structures. Theoretically, self-built heavyweight structures should ensure better temperatures and be closer to cultural norms. To examine this directly for the first time, lightweight pre-designed solutions are compared with high-mass self-built alternatives in Afghanistan and Peru, via monitoring, dynamic simulation, occupant surveys, the Shelter Assessment Matrix (SAM) and ShelTherm. Lightweight solutions increase peak summer temperatures, but only by 2°C, but reduce minimum temperatures by up to 5°C. Simulations only provided a qualitatively similar time series to the monitoring, because identical homes showed a large variance in temperatures. This questions the benefit of simulation compared to approaches which concentrate on whether shelters exacerbate or ameliorate external temperatures. In addition, a dwelling provides more than comfort, it supports family life, which is best addressed by tools like SAM, not thermal simulation. Hence it might be ideal to recommend high-mass self-build if possible, and to focus modelling efforts on qualitative aspects of simulation time-series, such as whether the building suppresses or exacerbates external conditions, and equally on psycho-cultural aspects. The term narrative modelling is introduced to describe this new approach which will be of direct benefit to the humanitarian community. Practical application Building simulation engineers have much to offer the humanitarian shelter sector, however they are not often brought into play in a disaster. Hence, we suggest a practical role they can take is in examining strategies before disasters and in creating knowledge or analysis methods that aid agency staff can apply on the ground. Here we showcase this approach. It is clear that although dynamic thermal simulation is highly useful, psycho-social aspects are equally important, thus engineers are likely to need to use tools that consider such aspects in order to maximize the usefulness of their conclusions.
{"title":"Narrative modelling: A comparison of high and low mass dwelling solutions in Afghanistan and Peru","authors":"A. Eltaweel, N. Kuchai, D. Albadra, D. Coley, J. Hart, A. Acevedo-De-los-Ríos, Daniel R. Rondinel-Oviedo","doi":"10.1177/01436244221125720","DOIUrl":"https://doi.org/10.1177/01436244221125720","url":null,"abstract":"Displaced populations are housed in various constructions, including lightweight predesigned structures. Theoretically, self-built heavyweight structures should ensure better temperatures and be closer to cultural norms. To examine this directly for the first time, lightweight pre-designed solutions are compared with high-mass self-built alternatives in Afghanistan and Peru, via monitoring, dynamic simulation, occupant surveys, the Shelter Assessment Matrix (SAM) and ShelTherm. Lightweight solutions increase peak summer temperatures, but only by 2°C, but reduce minimum temperatures by up to 5°C. Simulations only provided a qualitatively similar time series to the monitoring, because identical homes showed a large variance in temperatures. This questions the benefit of simulation compared to approaches which concentrate on whether shelters exacerbate or ameliorate external temperatures. In addition, a dwelling provides more than comfort, it supports family life, which is best addressed by tools like SAM, not thermal simulation. Hence it might be ideal to recommend high-mass self-build if possible, and to focus modelling efforts on qualitative aspects of simulation time-series, such as whether the building suppresses or exacerbates external conditions, and equally on psycho-cultural aspects. The term narrative modelling is introduced to describe this new approach which will be of direct benefit to the humanitarian community. \u0000 Practical application\u0000 Building simulation engineers have much to offer the humanitarian shelter sector, however they are not often brought into play in a disaster. Hence, we suggest a practical role they can take is in examining strategies before disasters and in creating knowledge or analysis methods that aid agency staff can apply on the ground. Here we showcase this approach. It is clear that although dynamic thermal simulation is highly useful, psycho-social aspects are equally important, thus engineers are likely to need to use tools that consider such aspects in order to maximize the usefulness of their conclusions.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45601500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-09-06DOI: 10.1177/01436244221122851
T. Zhao, Chengyu Zhang, Terigele Ujeed, Liangdong Ma
The extraction and analysis of electricity consumption changing patterns are increasingly important, as they can guide in energy management and efficiency retrofitting. Consequently, it is necessary to extract the laws governing building electricity consumption characteristics. This method should be on an hour-scale and successfully applied online to various buildings. Under these conditions, the method should be as simple as possible to ensure excellent online applications. A matrix model method was developed based on the conventional K-nearest neighbour clustering algorithm, which introduced the concept of electricity intensity levels. This method used the slopes of the power consumption curve as the grading standard for the extraction and assessment of the electricity consumption laws. The validation results for seven different buildings with various functions and climate zones, including the mean absolute error, mean absolute percentage error, mean square error, root mean square error, and coefficient of variance, showed that this method met the aforementioned requirements. Moreover, this method can be used for power consumption prediction, which integrated a process of filtering historical data, leading to better accuracy and less data volume than that of other methods that use historical data for prediction. Practical application This paper proposed a matrix model method based on the conventional K-nearest-neighbour clustering algorithm, which introduced the concept of electricity intensity levels. This method was applied to various buildings online, which coupled the process of filtering historical data and flexible selectivity of models when used on different buildings. This method was used for assessing energy-saving potential, energy-saving retrofit priorities, and power consumption forecasting, which will benefit researchers and engineers.
{"title":"Methods on reflecting electricity consumption change characteristics and electricity consumption forecasting based on clustering algorithms and fuzzy matrices in buildings","authors":"T. Zhao, Chengyu Zhang, Terigele Ujeed, Liangdong Ma","doi":"10.1177/01436244221122851","DOIUrl":"https://doi.org/10.1177/01436244221122851","url":null,"abstract":"The extraction and analysis of electricity consumption changing patterns are increasingly important, as they can guide in energy management and efficiency retrofitting. Consequently, it is necessary to extract the laws governing building electricity consumption characteristics. This method should be on an hour-scale and successfully applied online to various buildings. Under these conditions, the method should be as simple as possible to ensure excellent online applications. A matrix model method was developed based on the conventional K-nearest neighbour clustering algorithm, which introduced the concept of electricity intensity levels. This method used the slopes of the power consumption curve as the grading standard for the extraction and assessment of the electricity consumption laws. The validation results for seven different buildings with various functions and climate zones, including the mean absolute error, mean absolute percentage error, mean square error, root mean square error, and coefficient of variance, showed that this method met the aforementioned requirements. Moreover, this method can be used for power consumption prediction, which integrated a process of filtering historical data, leading to better accuracy and less data volume than that of other methods that use historical data for prediction. Practical application This paper proposed a matrix model method based on the conventional K-nearest-neighbour clustering algorithm, which introduced the concept of electricity intensity levels. This method was applied to various buildings online, which coupled the process of filtering historical data and flexible selectivity of models when used on different buildings. This method was used for assessing energy-saving potential, energy-saving retrofit priorities, and power consumption forecasting, which will benefit researchers and engineers.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41925344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-09-01Epub Date: 2022-06-06DOI: 10.1177/01436244221097827
Narges Torabi, Huseyin Burak Gunay, William O'Brien, Ricardo Moromisato
A holistic fault detection and diagnostics (FDD) method should explicitly consider the dependencies between faults at the system- and zone-level to isolate the root cause. A system-level fault can trigger false alarms at the zone-level, while concealing the presence of a zone-level fault. However, most FDD methods have focused on a single component/equipment without considering the importance of the interactions between zone- and system-level devices. This paper proposes a holistic hierarchical framework for FDD, combining the process of detection and diagnosis of controls hardware and sequencing logic faults affecting the actuators at the system- and zone-level. The proposed framework follows a holistic sequential procedure to diagnose faults and suppress false alarms in this order: hard faults in air handling units (AHUs), hard faults in variable air volume (VAV) zones, sequencing logic faults in AHUs, and sequencing logic faults in VAV zones. The detection of faults is performed by visualizing the discrepancies between the expected and measured operational behaviour of AHUs and VAV boxes. Examples demonstrating the framework are provided with data from 10 different VAV AHU systems. Practical application: This paper provides a sequential hierarchical FDD framework to address two main issues in VAV AHU systems: detectability and significance. Regarding detectability, the framework prioritizes hard faults over sequencing logic faults to avoid false positives and false negatives; about significance, system-level faults are prioritized over zone-level faults to triage high-impact faults in the system. The detection of faults is performed via visualizing the biases from the expected behaviour of AHU and VAV characteristics to provide an envisioning interpretation for the experts in facilities management in commercial buildings to find the root cause of the fault and fix them on-site.
{"title":"A holistic sequential fault detection and diagnostics framework for multiple zone variable air volume air handling unit systems.","authors":"Narges Torabi, Huseyin Burak Gunay, William O'Brien, Ricardo Moromisato","doi":"10.1177/01436244221097827","DOIUrl":"https://doi.org/10.1177/01436244221097827","url":null,"abstract":"<p><p>A holistic fault detection and diagnostics (FDD) method should explicitly consider the dependencies between faults at the system- and zone-level to isolate the root cause. A system-level fault can trigger false alarms at the zone-level, while concealing the presence of a zone-level fault. However, most FDD methods have focused on a single component/equipment without considering the importance of the interactions between zone- and system-level devices. This paper proposes a holistic hierarchical framework for FDD, combining the process of detection and diagnosis of controls hardware and sequencing logic faults affecting the actuators at the system- and zone-level. The proposed framework follows a holistic sequential procedure to diagnose faults and suppress false alarms in this order: hard faults in air handling units (AHUs), hard faults in variable air volume (VAV) zones, sequencing logic faults in AHUs, and sequencing logic faults in VAV zones. The detection of faults is performed by visualizing the discrepancies between the expected and measured operational behaviour of AHUs and VAV boxes. Examples demonstrating the framework are provided with data from 10 different VAV AHU systems. <b>Practical application:</b> This paper provides a sequential hierarchical FDD framework to address two main issues in VAV AHU systems: detectability and significance. Regarding detectability, the framework prioritizes hard faults over sequencing logic faults to avoid false positives and false negatives; about significance, system-level faults are prioritized over zone-level faults to triage high-impact faults in the system. The detection of faults is performed via visualizing the biases from the expected behaviour of AHU and VAV characteristics to provide an envisioning interpretation for the experts in facilities management in commercial buildings to find the root cause of the fault and fix them on-site.</p>","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/c5/cd/10.1177_01436244221097827.PMC9420892.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40343721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.1177/01436244221117954
overspeed governor velocity measuring system uses a for This new process may replace the inaccurate measuring system currently employed by maintenance tech-nicians, thus its reliability. The main objective consists of rigorously testing the operation of overspeed governors. The developed system guarantees the automatic execution of the test under several anomalous operating situations, thus allowing the user to have real-time access to the test data obtained through a graphical interface available on a mobile electronic device. This study proposes a novel control framework that jointly controls portable home air puri fi ers (HAPs) and windows to maintain thermal comfort and achieve effective PM 2.5 removal. The simulation results suggest that such a hybrid control strategy can result in considerable health bene fi ts at low additional energy costs. de-tectability and cance. Regarding the framework prioritizes hard faults over sequencing logic faults to avoid false positives and false negatives; about signi fi cance, system-level faults are prioritized over zone-level faults to triage high-impact faults in the system. The detection of faults is performed via visualizing the biases from the expected behaviour of AHU and VAV characteristics to provide an envisioning interpretation for the experts in facilities man-agement in commercial buildings to fi nd the root cause of the fault and fi x them on-site. District Cooling Systems are considered as a promising solution to alleviate the climate change issue. An optimized chiller sequencing control strategy of DCS can effectively reduce overall cooling energy consumption, so as to achieve carbon neutrality. This paper outlines a case study on a costeffective operational control strategy of the DCS at HZMB-HKP. The analysis of both the theoretical and practical sequencing control strategy can be taken as a reference for DCS development in the future.
{"title":"Practical Applications","authors":"","doi":"10.1177/01436244221117954","DOIUrl":"https://doi.org/10.1177/01436244221117954","url":null,"abstract":"overspeed governor velocity measuring system uses a for This new process may replace the inaccurate measuring system currently employed by maintenance tech-nicians, thus its reliability. The main objective consists of rigorously testing the operation of overspeed governors. The developed system guarantees the automatic execution of the test under several anomalous operating situations, thus allowing the user to have real-time access to the test data obtained through a graphical interface available on a mobile electronic device. This study proposes a novel control framework that jointly controls portable home air puri fi ers (HAPs) and windows to maintain thermal comfort and achieve effective PM 2.5 removal. The simulation results suggest that such a hybrid control strategy can result in considerable health bene fi ts at low additional energy costs. de-tectability and cance. Regarding the framework prioritizes hard faults over sequencing logic faults to avoid false positives and false negatives; about signi fi cance, system-level faults are prioritized over zone-level faults to triage high-impact faults in the system. The detection of faults is performed via visualizing the biases from the expected behaviour of AHU and VAV characteristics to provide an envisioning interpretation for the experts in facilities man-agement in commercial buildings to fi nd the root cause of the fault and fi x them on-site. District Cooling Systems are considered as a promising solution to alleviate the climate change issue. An optimized chiller sequencing control strategy of DCS can effectively reduce overall cooling energy consumption, so as to achieve carbon neutrality. This paper outlines a case study on a costeffective operational control strategy of the DCS at HZMB-HKP. The analysis of both the theoretical and practical sequencing control strategy can be taken as a reference for DCS development in the future.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43037556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-08-25DOI: 10.1177/01436244221123227
Qinwen Li, Xin Yan, Yu Shang, Y. Guan, Zheng Fang
A potential consequence of installing a 2 m long pipe offset on a ventilated drainage system in a high-rise buildings is that the water seal could be damaged when the flowrate exceeds the maximum discharge capacity of a drainage system, thereby threatening the indoor health safety. Some high-rise buildings are designed for commercial and residential use to achieve economic and social benefits, so the whole building use and layout changes in the vertical direction. The drainage stack may be designed with an offset between floors to avoid structural obstacles inside the building. The flow direction change could destroy the water seal of sanitary appliances and threaten the health of residents. To better understand the influence of the form of a pipe offset on the drainage capacity, a full-scale experiment was conducted to study the secondary ventilated system with an antireflux H-tube pipe, which was equipped with two guide plates inside to improve the air-water flow pattern and prevent backflow, installed between floor. This study also considered a kind of offset where the offset distance was 2.0 m rather than the S-shaped offset joint, which is more common in commercial and residential complexes. The influence on the discharge capacity of installing an extra antireflux H-tube pipe was compared with normal 90-degree elbow and only one antireflux H-tube pipe above the offset point. The pressure fluctuation and water seal losses under constant discharge rates were adopted as experimental parameters to determine the maximum discharge capacity according to Standard for Capacity Test of Vertical Pipe of the Domestic Residential Drainage System. Results show that the installation of an extra antireflux H-tube pipe can release the air accumulation caused by pipe offset, and the combined installation of a large curvature elbow and an extra antireflux H-tube pipe can effectively improve the discharge capacity. Practical Application: 2 metre long offsets are not unusual in ventilated drainage systems in high-rise buildings, however, designers and builders do not pay sufficient attention to the adverse consequences of the pipe offset. An extra antireflux H-tube pipe can be installed above the offset joint to optimise the drainage system to perform as it would without the offset. In a system with 2 m long pipe offset, installing a large curvature elbow together with an extra antireflux H-tube pipe together provides a better effect.
{"title":"Overcoming the influence of a 2 metre long pipe offset on water flow capacity of drainage with secondary ventilation in a high-rise building","authors":"Qinwen Li, Xin Yan, Yu Shang, Y. Guan, Zheng Fang","doi":"10.1177/01436244221123227","DOIUrl":"https://doi.org/10.1177/01436244221123227","url":null,"abstract":"A potential consequence of installing a 2 m long pipe offset on a ventilated drainage system in a high-rise buildings is that the water seal could be damaged when the flowrate exceeds the maximum discharge capacity of a drainage system, thereby threatening the indoor health safety. Some high-rise buildings are designed for commercial and residential use to achieve economic and social benefits, so the whole building use and layout changes in the vertical direction. The drainage stack may be designed with an offset between floors to avoid structural obstacles inside the building. The flow direction change could destroy the water seal of sanitary appliances and threaten the health of residents. To better understand the influence of the form of a pipe offset on the drainage capacity, a full-scale experiment was conducted to study the secondary ventilated system with an antireflux H-tube pipe, which was equipped with two guide plates inside to improve the air-water flow pattern and prevent backflow, installed between floor. This study also considered a kind of offset where the offset distance was 2.0 m rather than the S-shaped offset joint, which is more common in commercial and residential complexes. The influence on the discharge capacity of installing an extra antireflux H-tube pipe was compared with normal 90-degree elbow and only one antireflux H-tube pipe above the offset point. The pressure fluctuation and water seal losses under constant discharge rates were adopted as experimental parameters to determine the maximum discharge capacity according to Standard for Capacity Test of Vertical Pipe of the Domestic Residential Drainage System. Results show that the installation of an extra antireflux H-tube pipe can release the air accumulation caused by pipe offset, and the combined installation of a large curvature elbow and an extra antireflux H-tube pipe can effectively improve the discharge capacity. Practical Application: 2 metre long offsets are not unusual in ventilated drainage systems in high-rise buildings, however, designers and builders do not pay sufficient attention to the adverse consequences of the pipe offset. An extra antireflux H-tube pipe can be installed above the offset joint to optimise the drainage system to perform as it would without the offset. In a system with 2 m long pipe offset, installing a large curvature elbow together with an extra antireflux H-tube pipe together provides a better effect.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42208251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-08-08DOI: 10.1177/01436244221117356
Sayaka Kindaichi, T. Kindaichi
Central air heating systems with heat pumps can use the underfloor space, rather than air ducts, for heat distribution in houses. To minimize the energy consumption, the actual thermal environment and energy performance of these systems must be evaluated through continuous field measurements. This study evaluates the thermal environment, operational characteristics, and energy performance of a central air heating system with a heat pump during two winters in a two-story house in Japan. In the first winter (i.e., before case), the supply air was automatically controlled at a relatively high average temperature of 45°C with low air flow rates, resulting in a non-uniform temperature distribution among the rooms and low energy efficiency. In the second winter (i.e., after case), an increase in the fan speed improved the heat distribution, with operational conditions of high air flow rates at a lower average temperature of 39°C. This led to average energy savings of 11% while maintaining thermal comfort.
{"title":"Indoor thermal environment and energy performance in a central air heating system using a heat pump for a house with underfloor space for heat distribution","authors":"Sayaka Kindaichi, T. Kindaichi","doi":"10.1177/01436244221117356","DOIUrl":"https://doi.org/10.1177/01436244221117356","url":null,"abstract":"Central air heating systems with heat pumps can use the underfloor space, rather than air ducts, for heat distribution in houses. To minimize the energy consumption, the actual thermal environment and energy performance of these systems must be evaluated through continuous field measurements. This study evaluates the thermal environment, operational characteristics, and energy performance of a central air heating system with a heat pump during two winters in a two-story house in Japan. In the first winter (i.e., before case), the supply air was automatically controlled at a relatively high average temperature of 45°C with low air flow rates, resulting in a non-uniform temperature distribution among the rooms and low energy efficiency. In the second winter (i.e., after case), an increase in the fan speed improved the heat distribution, with operational conditions of high air flow rates at a lower average temperature of 39°C. This led to average energy savings of 11% while maintaining thermal comfort.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48881070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-06-19DOI: 10.1177/01436244221106370
Using different waste as resilient layers for impact sound insulation improvement: New alternative to commercial layers? FJ Garcı́a-Cobos and R Maderuelo-Sanz Nowadays impact noise is increasingly becoming an important issue. A high level of noise clearly affects indoor comfort and livability of dwellings. In order to reduce this effect, one widely used solution are floating floors in which the performance of resilient layers, in terms of impact sound pressure level reduction is a relevant issue. This article analyzed the potential use of different waste as resilient layers to be used in floating floors. These layers can adequately compete with commercially available acoustical products replacing them and showing, in some cases, better impact sound insulation performance with lower thickness.
{"title":"Practical applications","authors":"","doi":"10.1177/01436244221106370","DOIUrl":"https://doi.org/10.1177/01436244221106370","url":null,"abstract":"Using different waste as resilient layers for impact sound insulation improvement: New alternative to commercial layers? FJ Garcı́a-Cobos and R Maderuelo-Sanz Nowadays impact noise is increasingly becoming an important issue. A high level of noise clearly affects indoor comfort and livability of dwellings. In order to reduce this effect, one widely used solution are floating floors in which the performance of resilient layers, in terms of impact sound pressure level reduction is a relevant issue. This article analyzed the potential use of different waste as resilient layers to be used in floating floors. These layers can adequately compete with commercially available acoustical products replacing them and showing, in some cases, better impact sound insulation performance with lower thickness.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46895444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-06-04DOI: 10.1177/01436244221107058
Haidong Wang, Xiaohan Li, Yi Tang, Xiaowen Chen, H. Shen, Xiaocheng Cao, Huimin Gao
Air duct pressure loss, especially the duct elbow, is a significant component of building air-conditioning energy consumption. Improving the airflow uniformity in the duct elbow for large prefabricated air ducts can help reduce the local resistance loss. In this paper, the influence of guide vanes on the pressure loss of elbows in the duct was investigated through experimentally validated simulation results. According to similarity theory, the computational fluid dynamics (CFD) simulation results were employed to perform a parametric study to optimize the duct elbow guide vane. Different numbers, positions, and shapes of air guide vanes in the elbow were used to reduce the pressure loss and also played a crucial role in improving the uniformity of airflow in the elbow. Through CFD simulation, the optimized specifications of guide vanes in the elbow on the airflow and local pressure loss coefficients were explored. This study will provide a reference for numerical prediction and engineering application of using guide vane to minimize the local pressure loss of large prefabricated air ducts.
{"title":"Simulation and experimental study on the elbow pressure loss of large air duct with different internal guide vanes","authors":"Haidong Wang, Xiaohan Li, Yi Tang, Xiaowen Chen, H. Shen, Xiaocheng Cao, Huimin Gao","doi":"10.1177/01436244221107058","DOIUrl":"https://doi.org/10.1177/01436244221107058","url":null,"abstract":"Air duct pressure loss, especially the duct elbow, is a significant component of building air-conditioning energy consumption. Improving the airflow uniformity in the duct elbow for large prefabricated air ducts can help reduce the local resistance loss. In this paper, the influence of guide vanes on the pressure loss of elbows in the duct was investigated through experimentally validated simulation results. According to similarity theory, the computational fluid dynamics (CFD) simulation results were employed to perform a parametric study to optimize the duct elbow guide vane. Different numbers, positions, and shapes of air guide vanes in the elbow were used to reduce the pressure loss and also played a crucial role in improving the uniformity of airflow in the elbow. Through CFD simulation, the optimized specifications of guide vanes in the elbow on the airflow and local pressure loss coefficients were explored. This study will provide a reference for numerical prediction and engineering application of using guide vane to minimize the local pressure loss of large prefabricated air ducts.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2022-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46345777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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