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":"44 1","pages":"5 - 24"},"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":"43 1","pages":"703 - 724"},"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 : 2022-08-26DOI: 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":"43 1","pages":"537 - 538"},"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":"43 1","pages":"741 - 753"},"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":"43 1","pages":"755 - 766"},"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":"43 1","pages":"1 - 2"},"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":"43 1","pages":"725 - 739"},"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}
Pub Date : 2022-06-02DOI: 10.1177/01436244221106342
Lufang Chen, Kai Zhang, Ge Song, Fei Li
Radiative cooling has been demonstrated as an effective way to reduce building energy consumption especially for the recently developed diurnal radiative cooling materials. The most convenient application of radiative cooling materials is configured as the cool roofs. However, cool roofs will produce cooling energy throughout the year which will lead to the increase of heating penalty in the heating season. This phenomenon will offset part of the cooling benefit from radiative cooling. The ventilated roofs are also commonly employed in buildings for achieving energy-saving by reducing the heat gain from the roof to the building. To reduce the influence of radiative cooling in the heating season, a radiative cooling-based ventilated roof (RCVR) is proposed in this study by integrating the ventilated roof with the radiative cooling-based cool roof. The process of the heat transfer through RCVR is analyzed, and the simplified heat transfer model is developed. And then the effect of RCVR configuration on the room temperature is discussed in detail through CFD simulation. Finally, the annual electricity consumption of the building with RCVR is derived using EnergyPlus. The results show that the annual comprehensive performance of RCVR is superior to the cool roof and original roof since the total annual electricity consumption of the building with RCVR can be decreased by 21.8% and 16.9% compared with that of cool roof and original roof. Practical application: A radiative cooling-based ventilated roof (RCVR) is proposed by integrating the ventilated roof with the radiative cooling-based cool roof. The results show that the annual comprehensive performance of RCVR is superior to the cool roof and original roof. This study can provide the guiding significance for the application of RCVR, in which the building energy consumption can be further decreased for the application of radiative cooling in buildings.
{"title":"Study on the cooling performance of a radiative cooling-based ventilated roof for its application in buildings","authors":"Lufang Chen, Kai Zhang, Ge Song, Fei Li","doi":"10.1177/01436244221106342","DOIUrl":"https://doi.org/10.1177/01436244221106342","url":null,"abstract":"Radiative cooling has been demonstrated as an effective way to reduce building energy consumption especially for the recently developed diurnal radiative cooling materials. The most convenient application of radiative cooling materials is configured as the cool roofs. However, cool roofs will produce cooling energy throughout the year which will lead to the increase of heating penalty in the heating season. This phenomenon will offset part of the cooling benefit from radiative cooling. The ventilated roofs are also commonly employed in buildings for achieving energy-saving by reducing the heat gain from the roof to the building. To reduce the influence of radiative cooling in the heating season, a radiative cooling-based ventilated roof (RCVR) is proposed in this study by integrating the ventilated roof with the radiative cooling-based cool roof. The process of the heat transfer through RCVR is analyzed, and the simplified heat transfer model is developed. And then the effect of RCVR configuration on the room temperature is discussed in detail through CFD simulation. Finally, the annual electricity consumption of the building with RCVR is derived using EnergyPlus. The results show that the annual comprehensive performance of RCVR is superior to the cool roof and original roof since the total annual electricity consumption of the building with RCVR can be decreased by 21.8% and 16.9% compared with that of cool roof and original roof. Practical application: A radiative cooling-based ventilated roof (RCVR) is proposed by integrating the ventilated roof with the radiative cooling-based cool roof. The results show that the annual comprehensive performance of RCVR is superior to the cool roof and original roof. This study can provide the guiding significance for the application of RCVR, in which the building energy consumption can be further decreased for the application of radiative cooling in buildings.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"43 1","pages":"685 - 702"},"PeriodicalIF":1.7,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41622118","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 : 2022-05-16DOI: 10.1177/01436244221100362
Pouya Rikhtehgar, M. Haeri
In this paper, a reduced multiple-model predictive controller based on gap metric and stability margin is presented to control heating, ventilating, and air conditioning (HVAC) systems. To tackle the strong nonlinearity and large number of degrees of freedom in HVAC system, two approaches, called Reduced Order Model Bank-Multiple Model (ROMB-MM) and Multiple Model-Reduced Order Model (MM-ROM), are introduced. In the first approach, the order reduction is performed prior to multiple models selection and in the second one multiple models selection is implemented before the model order reduction. Furthermore, soft switching is employed to enhance the closed-loop performance as well as to gain optimal energy consumption. In order to evaluate the proposed approaches, a sliding mode controller is also simulated to compare the results in terms of energy and cost savings, transient and steady-state responses, and robustness against external disturbances and model uncertainties. Practical application: HVAC control systems are in charge of control indoor air temperature with energy optimization so that the thermal comfort is maintained. But how to model HVAC systems in each weather conditions is a significant challenge. A simpler and more accurate model will provide more efficient control of indoor air temperature. This paper suggests model order reduction and multiple model to select the simple linear model(s) in extreme weather conditions. The effectiveness of the proposed method can be implemented on nonlinear HVAC system.
{"title":"Reduced multiple model predictive control of an heating, ventilating, and air conditioning system using gap metric and stability margin","authors":"Pouya Rikhtehgar, M. Haeri","doi":"10.1177/01436244221100362","DOIUrl":"https://doi.org/10.1177/01436244221100362","url":null,"abstract":"In this paper, a reduced multiple-model predictive controller based on gap metric and stability margin is presented to control heating, ventilating, and air conditioning (HVAC) systems. To tackle the strong nonlinearity and large number of degrees of freedom in HVAC system, two approaches, called Reduced Order Model Bank-Multiple Model (ROMB-MM) and Multiple Model-Reduced Order Model (MM-ROM), are introduced. In the first approach, the order reduction is performed prior to multiple models selection and in the second one multiple models selection is implemented before the model order reduction. Furthermore, soft switching is employed to enhance the closed-loop performance as well as to gain optimal energy consumption. In order to evaluate the proposed approaches, a sliding mode controller is also simulated to compare the results in terms of energy and cost savings, transient and steady-state responses, and robustness against external disturbances and model uncertainties. Practical application: HVAC control systems are in charge of control indoor air temperature with energy optimization so that the thermal comfort is maintained. But how to model HVAC systems in each weather conditions is a significant challenge. A simpler and more accurate model will provide more efficient control of indoor air temperature. This paper suggests model order reduction and multiple model to select the simple linear model(s) in extreme weather conditions. The effectiveness of the proposed method can be implemented on nonlinear HVAC system.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"43 1","pages":"589 - 603"},"PeriodicalIF":1.7,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47155383","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 : 2022-05-14DOI: 10.1177/01436244221100599
Zhichao Jiao, K. Emura
In the common method of compiling outdoor design conditions by annual cumulative frequency of occurrence, the probability of simultaneous occurrence of the selected meteorological elements is not considered, which may lead to an overestimation of air-conditioning equipment capacity design. This paper aims at developing a novel approach for producing the outdoor design conditions, taking into consideration the dependency between the air temperature and global solar radiation, which have a strong influence on the HVAC capacity design. These two meteorological elements are analyzed for specific simultaneous occurrence probability based on the joint distribution. For this purpose, the copula approach which can describe the dependence between these two meteorological elements is used for modeling the joint distribution function. We investigated copula family selection for air temperature and global solar radiation at each hour of hourly weather data for 10 years from 2001 to 2010 in Osaka, Japan. The Joe-Frank copula has the best fitting results for the dependence between the air temperature and global solar radiation. According to the comparison of original exceeding probability and simultaneous occurrence probability, the results show that the design conditions based on the common method can significantly exceed that of the simultaneous occurrence probability method. Practical Application: Outdoor design conditions are used in the building design stage to estimate building performance and select the appropriate air conditioning equipment capacity. Excessive air-conditioning capacity may lead to a large amount of unnecessary energy wastage. Insufficient capacity may lead to not meeting the desired indoor environment conditions of utilization in extreme weather conditions, especially for large office buildings. Therefore, this paper provides a new approach to generate more realistic meteorological conditions for air-conditioning design to improve building energy efficiency.
{"title":"Joint probability distribution of air temperature and global solar radiation for outdoor design conditions based on copula approach","authors":"Zhichao Jiao, K. Emura","doi":"10.1177/01436244221100599","DOIUrl":"https://doi.org/10.1177/01436244221100599","url":null,"abstract":"In the common method of compiling outdoor design conditions by annual cumulative frequency of occurrence, the probability of simultaneous occurrence of the selected meteorological elements is not considered, which may lead to an overestimation of air-conditioning equipment capacity design. This paper aims at developing a novel approach for producing the outdoor design conditions, taking into consideration the dependency between the air temperature and global solar radiation, which have a strong influence on the HVAC capacity design. These two meteorological elements are analyzed for specific simultaneous occurrence probability based on the joint distribution. For this purpose, the copula approach which can describe the dependence between these two meteorological elements is used for modeling the joint distribution function. We investigated copula family selection for air temperature and global solar radiation at each hour of hourly weather data for 10 years from 2001 to 2010 in Osaka, Japan. The Joe-Frank copula has the best fitting results for the dependence between the air temperature and global solar radiation. According to the comparison of original exceeding probability and simultaneous occurrence probability, the results show that the design conditions based on the common method can significantly exceed that of the simultaneous occurrence probability method. Practical Application: Outdoor design conditions are used in the building design stage to estimate building performance and select the appropriate air conditioning equipment capacity. Excessive air-conditioning capacity may lead to a large amount of unnecessary energy wastage. Insufficient capacity may lead to not meeting the desired indoor environment conditions of utilization in extreme weather conditions, especially for large office buildings. Therefore, this paper provides a new approach to generate more realistic meteorological conditions for air-conditioning design to improve building energy efficiency.","PeriodicalId":50724,"journal":{"name":"Building Services Engineering Research & Technology","volume":"43 1","pages":"669 - 683"},"PeriodicalIF":1.7,"publicationDate":"2022-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44545253","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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