Pub Date : 2023-04-20DOI: 10.1080/23744731.2023.2203043
Parveen Dhillon, W. Horton, J. Braun
The current testing and rating procedure for residential air conditioners and heat pumps is based on a steady-state performance measurement approach with a degradation coefficient to account for cycling losses at part-load conditions. Test equipment performance is measured under various ambient conditions with varying compressor and fan speeds, and the results are propagated through a temperature-bin method to estimate seasonal performance. Although the current rating approach offers a standardized performance metric for comparing the relative performances of different equipment, it involves disabling the native controls and, as a result, does not consider the impact of integrated controls for test units and their dynamic interactions with representative building loads. As an alternative, a load-based testing methodology (CSA EXP07) has been developed in which the dynamic performance of equipment is measured in a test facility by allowing it to respond to a simulated virtual building model. This study compares the steady-state and dynamic load-based performance measurement methodologies for use on a 5-ton residential heat pump system in order to understand the differences and their significance for the next-generation rating procedure. The differences in the two test methodologies' performance evaluation results are discussed with a causal analysis of the observed differences.
{"title":"Comparisons of load-based and AHRI 210/240 testing and rating for residential heat pumps","authors":"Parveen Dhillon, W. Horton, J. Braun","doi":"10.1080/23744731.2023.2203043","DOIUrl":"https://doi.org/10.1080/23744731.2023.2203043","url":null,"abstract":"The current testing and rating procedure for residential air conditioners and heat pumps is based on a steady-state performance measurement approach with a degradation coefficient to account for cycling losses at part-load conditions. Test equipment performance is measured under various ambient conditions with varying compressor and fan speeds, and the results are propagated through a temperature-bin method to estimate seasonal performance. Although the current rating approach offers a standardized performance metric for comparing the relative performances of different equipment, it involves disabling the native controls and, as a result, does not consider the impact of integrated controls for test units and their dynamic interactions with representative building loads. As an alternative, a load-based testing methodology (CSA EXP07) has been developed in which the dynamic performance of equipment is measured in a test facility by allowing it to respond to a simulated virtual building model. This study compares the steady-state and dynamic load-based performance measurement methodologies for use on a 5-ton residential heat pump system in order to understand the differences and their significance for the next-generation rating procedure. The differences in the two test methodologies' performance evaluation results are discussed with a causal analysis of the observed differences.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"473 - 490"},"PeriodicalIF":1.9,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43127671","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 : 2023-04-04DOI: 10.1080/23744731.2023.2197814
Narges Zaeri Esfahani, Burak Gunay, Araz Ashouri, Farzeen Rizvi
Initial and maintenance costs often prevent dense submeter installations that enable room-level thermal energy monitoring. Previous studies suggested that building automation system (BAS) trend data represents an untapped potential to disaggregate existing meter data for heating and cooling into device- and system-level end-uses. These techniques disaggregate meter data by analyzing trend data that provide contextual information regarding the operating status of energy-consuming equipment. However, the level of submetering required to enable end-use disaggregation has yet to be studied. To this end, this paper investigates the effect of submeter density and configuration on the performance of a regression-based disaggregation strategy using BAS trend data as predictors. The method was evaluated in two steps; first, using synthetic meter and BAS trend data generated by a building performance simulation (BPS) model of a government office building, and second, with submeter data from a real office building. The results highlight the factors affecting the minimum number of heating energy submeters needed to be installed in both buildings for accurate device- and system-level disaggregation. The methodology presented in the paper can also inform changes in building design codes and standards regarding the minimum density and appropriate configuration for submetering.
{"title":"An inquiry into the effect of thermal energy meter density and configuration on load disaggregation accuracy","authors":"Narges Zaeri Esfahani, Burak Gunay, Araz Ashouri, Farzeen Rizvi","doi":"10.1080/23744731.2023.2197814","DOIUrl":"https://doi.org/10.1080/23744731.2023.2197814","url":null,"abstract":"Initial and maintenance costs often prevent dense submeter installations that enable room-level thermal energy monitoring. Previous studies suggested that building automation system (BAS) trend data represents an untapped potential to disaggregate existing meter data for heating and cooling into device- and system-level end-uses. These techniques disaggregate meter data by analyzing trend data that provide contextual information regarding the operating status of energy-consuming equipment. However, the level of submetering required to enable end-use disaggregation has yet to be studied. To this end, this paper investigates the effect of submeter density and configuration on the performance of a regression-based disaggregation strategy using BAS trend data as predictors. The method was evaluated in two steps; first, using synthetic meter and BAS trend data generated by a building performance simulation (BPS) model of a government office building, and second, with submeter data from a real office building. The results highlight the factors affecting the minimum number of heating energy submeters needed to be installed in both buildings for accurate device- and system-level disaggregation. The methodology presented in the paper can also inform changes in building design codes and standards regarding the minimum density and appropriate configuration for submetering.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"424 - 441"},"PeriodicalIF":1.9,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45113510","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 : 2023-04-04DOI: 10.1080/23744731.2023.2197815
Oguzhan Pektezel, H. Acar
The use of alternative refrigerants is among the popular topics of the refrigeration industry. In the first part of this study, thermodynamic performances of R290 and R600a gases were compared in a vapor compression refrigeration experiment setup. Although R600a caused an average of 33.44% less compressor power consumption compared to R290 refrigerant, R290 provided an average of 23.77% increase in COP (coefficient of performance), 82.55% in cooling capacity, and 20.99% increase in second law efficiency compared to R600a. In the second part of the study, the performance parameters of the refrigeration system were predicted with MLP (multi-layer perceptron), SVM (support vector machine), and DT (decision tree) machine learning algorithms. It was detected that the SVM method predicted all parameters with the least error. MAE (mean absolute error) values detected in the COP prediction with test set were 0.0317, 0.0324, and 0.0989 for SVM, MLP, and DT, respectively. Results revealed that performance of the refrigeration system increased when utilizing R290, and SVM was superior in prediction of performance indicators compared to other machine learning methods.
{"title":"Experimental comparison of R290 and R600a and prediction of performance with machine learning algorithms","authors":"Oguzhan Pektezel, H. Acar","doi":"10.1080/23744731.2023.2197815","DOIUrl":"https://doi.org/10.1080/23744731.2023.2197815","url":null,"abstract":"The use of alternative refrigerants is among the popular topics of the refrigeration industry. In the first part of this study, thermodynamic performances of R290 and R600a gases were compared in a vapor compression refrigeration experiment setup. Although R600a caused an average of 33.44% less compressor power consumption compared to R290 refrigerant, R290 provided an average of 23.77% increase in COP (coefficient of performance), 82.55% in cooling capacity, and 20.99% increase in second law efficiency compared to R600a. In the second part of the study, the performance parameters of the refrigeration system were predicted with MLP (multi-layer perceptron), SVM (support vector machine), and DT (decision tree) machine learning algorithms. It was detected that the SVM method predicted all parameters with the least error. MAE (mean absolute error) values detected in the COP prediction with test set were 0.0317, 0.0324, and 0.0989 for SVM, MLP, and DT, respectively. Results revealed that performance of the refrigeration system increased when utilizing R290, and SVM was superior in prediction of performance indicators compared to other machine learning methods.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"508 - 522"},"PeriodicalIF":1.9,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42900528","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 : 2023-03-30DOI: 10.1080/23744731.2023.2197813
Wufeng Jin, Yi Wang, Lizhi Jia, Shuo Liu, Deok-Min Moon, S. Song
The use of R32 as an ideal alternative refrigerant has been widely considered, but its slight flammability cannot be ignored. Air intrusion into the compressor and diluting the R32 to a flammable concentration range will bring flammability risk. This article studies the influence of different refrigerant charge quantities on the flammability risk of R32 in a rotor compressor under certain air intrusion conditions. The exhaust pressure, temperature distribution, R32 flammable concentration area, and flammable volume time inside the compressor were studied by experiments and simulations. The results indicate that the R32 high-risk flammable area is near the compressor motor and exhaust port. Flammability risk keeps rising as air intrusion increases and rises substantially when the amount of refrigerant is insufficient. Special compressors for which the motors and exhaust ports can withstand high temperatures and pressure should be developed for the R32. The minimum allowable R32 charging standard should be calculated to ensure that the refrigerant concentration in the compressor is higher than the flammable upper limit when a certain amount of air intrudes. The results provide the technical basis for the formulation of standards for the safe use of R32 rotor compressors, to obtain the best application potential of the R32.
{"title":"Influence of refrigerant charge volume on the flammability risk of an R32 rotary compressor","authors":"Wufeng Jin, Yi Wang, Lizhi Jia, Shuo Liu, Deok-Min Moon, S. Song","doi":"10.1080/23744731.2023.2197813","DOIUrl":"https://doi.org/10.1080/23744731.2023.2197813","url":null,"abstract":"The use of R32 as an ideal alternative refrigerant has been widely considered, but its slight flammability cannot be ignored. Air intrusion into the compressor and diluting the R32 to a flammable concentration range will bring flammability risk. This article studies the influence of different refrigerant charge quantities on the flammability risk of R32 in a rotor compressor under certain air intrusion conditions. The exhaust pressure, temperature distribution, R32 flammable concentration area, and flammable volume time inside the compressor were studied by experiments and simulations. The results indicate that the R32 high-risk flammable area is near the compressor motor and exhaust port. Flammability risk keeps rising as air intrusion increases and rises substantially when the amount of refrigerant is insufficient. Special compressors for which the motors and exhaust ports can withstand high temperatures and pressure should be developed for the R32. The minimum allowable R32 charging standard should be calculated to ensure that the refrigerant concentration in the compressor is higher than the flammable upper limit when a certain amount of air intrudes. The results provide the technical basis for the formulation of standards for the safe use of R32 rotor compressors, to obtain the best application potential of the R32.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"533 - 544"},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46365712","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 : 2023-03-30DOI: 10.1080/23744731.2023.2197827
G. Sánchez-Barroso, J. González-Domínguez, J. García-Sanz-Calcedo
Perioperative hypothermia increases the likelihood that a patient will get a surgical site infection, which is one of the biggest public health problems. Controversy exists regarding the effect of forced-air warming systems on the disruption of unidirectional discharge of ultra-clean air in operating theaters. However, researchers agree that thermal blankets are indeed useful to prevent hypothermia. This work aims to analyze the effect of a forced-air warming blanket on the indoor air quality in the surgical field of a high-performance operating theater as a function of the supply velocity employing Computational Fluid Dynamics. An operating theater, its facilities, medical staff, and patient covered with a drape were modeled. Ten cases with driving speeds between 0.20 and 0.40 m/s at 0.05 m/s intervals, with thermal blankets ON and OFF, were simulated. Both air renewal and particle dispersion results in the breathing zone were analyzed. The results show that the use of thermal blankets to avoid patient hypothermia is acceptable at discharge velocities of 0.30 m/s because both the decontamination kinetics and air renewal are improved by 45.6% and 37.6%, respectively. Unfavorable results were obtained for the rest of the case studies with different supply velocities.
{"title":"Effect of forced-air warming blankets on indoor air quality in unidirectional flow operating theatres","authors":"G. Sánchez-Barroso, J. González-Domínguez, J. García-Sanz-Calcedo","doi":"10.1080/23744731.2023.2197827","DOIUrl":"https://doi.org/10.1080/23744731.2023.2197827","url":null,"abstract":"Perioperative hypothermia increases the likelihood that a patient will get a surgical site infection, which is one of the biggest public health problems. Controversy exists regarding the effect of forced-air warming systems on the disruption of unidirectional discharge of ultra-clean air in operating theaters. However, researchers agree that thermal blankets are indeed useful to prevent hypothermia. This work aims to analyze the effect of a forced-air warming blanket on the indoor air quality in the surgical field of a high-performance operating theater as a function of the supply velocity employing Computational Fluid Dynamics. An operating theater, its facilities, medical staff, and patient covered with a drape were modeled. Ten cases with driving speeds between 0.20 and 0.40 m/s at 0.05 m/s intervals, with thermal blankets ON and OFF, were simulated. Both air renewal and particle dispersion results in the breathing zone were analyzed. The results show that the use of thermal blankets to avoid patient hypothermia is acceptable at discharge velocities of 0.30 m/s because both the decontamination kinetics and air renewal are improved by 45.6% and 37.6%, respectively. Unfavorable results were obtained for the rest of the case studies with different supply velocities.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"632 - 646"},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44714405","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 : 2023-03-30DOI: 10.1080/23744731.2023.2196910
Sarah Brown, I. Beausoleil-Morrison
Presented are the results of an investigation into a model predictive controller (MPC) for hydronic floor heating and cooling in a highly glazed house in Ottawa, Canada. The goal of this investigation was to determine if a MPC would simultaneously result in reduced energy consumption and reduced indoor air temperature (Tia) violations in comparison to the incumbent reactive controller (RC). Shown both experimentally and via simulation, predictive control results in more hours with Tia between the acceptable limits (19.5–25 °C) for significantly less heating and cooling system operation hours. Experimentally, a “pseudo-predictive controller” (PPC) required 35% less cooling hours and 50% less heating hours than the RC baseline. The PPC also reduced overheating time by 88%. A simple MPC was then designed and compared to a RC using a MATLAB simulation. Even with a simple and non-optimized MPC, the simulation confirmed the superiority of said MPC over RC operation for the hydronic floor system. The simulated MPC required 28% less cooling hours and 27% less heating hours than the simulated RC. These results have confirmed the suspected promise of predictive control and next steps include actual implementation of the presented MPC in the highly glazed house long-term.
{"title":"Investigation of a model predictive controller for use in a highly glazed house with hydronic floor heating and cooling","authors":"Sarah Brown, I. Beausoleil-Morrison","doi":"10.1080/23744731.2023.2196910","DOIUrl":"https://doi.org/10.1080/23744731.2023.2196910","url":null,"abstract":"Presented are the results of an investigation into a model predictive controller (MPC) for hydronic floor heating and cooling in a highly glazed house in Ottawa, Canada. The goal of this investigation was to determine if a MPC would simultaneously result in reduced energy consumption and reduced indoor air temperature (Tia) violations in comparison to the incumbent reactive controller (RC). Shown both experimentally and via simulation, predictive control results in more hours with Tia between the acceptable limits (19.5–25 °C) for significantly less heating and cooling system operation hours. Experimentally, a “pseudo-predictive controller” (PPC) required 35% less cooling hours and 50% less heating hours than the RC baseline. The PPC also reduced overheating time by 88%. A simple MPC was then designed and compared to a RC using a MATLAB simulation. Even with a simple and non-optimized MPC, the simulation confirmed the superiority of said MPC over RC operation for the hydronic floor system. The simulated MPC required 28% less cooling hours and 27% less heating hours than the simulated RC. These results have confirmed the suspected promise of predictive control and next steps include actual implementation of the presented MPC in the highly glazed house long-term.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"347 - 365"},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43862082","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 : 2023-03-27DOI: 10.1080/23744731.2023.2194196
L. Sarran, C. A. Hviid, C. Rode
The pace of building retrofit is expected to increase significantly in the coming decade if the European Union is to meet its ambitious climate targets. This study explores successes and challenges with current retrofit efforts, with focus on indoor environmental quality and occupants’ satisfaction with the technical installations. A survey, indoor environmental monitoring and semi-structured interviews were carried out in a Danish social housing area undergoing a deep energy retrofit. The retrofit considerably improved winter thermal comfort and indoor air quality, which was a great source of satisfaction for the occupants. Overheating was however identified as an important concern in summer. The mechanical ventilation units suffered from faults which caused discomfort, in particular dry air, noise and draft. Occupants lacked knowledge on ventilation and manual control over it, which led a share of them to mitigate discomfort in alternative ways, by obstructing diffusers or disconnecting the units. To avoid the risks linked to such behaviors, new retrofit efforts should pay particular attention to user-friendliness of technical installations, clear communication of technical information to the residents and a close monitoring of the installations’ performance and occupants’ satisfaction after move-in.
{"title":"How to ensure occupant comfort and satisfaction through deep building retrofit? Lessons from a Danish case study","authors":"L. Sarran, C. A. Hviid, C. Rode","doi":"10.1080/23744731.2023.2194196","DOIUrl":"https://doi.org/10.1080/23744731.2023.2194196","url":null,"abstract":"The pace of building retrofit is expected to increase significantly in the coming decade if the European Union is to meet its ambitious climate targets. This study explores successes and challenges with current retrofit efforts, with focus on indoor environmental quality and occupants’ satisfaction with the technical installations. A survey, indoor environmental monitoring and semi-structured interviews were carried out in a Danish social housing area undergoing a deep energy retrofit. The retrofit considerably improved winter thermal comfort and indoor air quality, which was a great source of satisfaction for the occupants. Overheating was however identified as an important concern in summer. The mechanical ventilation units suffered from faults which caused discomfort, in particular dry air, noise and draft. Occupants lacked knowledge on ventilation and manual control over it, which led a share of them to mitigate discomfort in alternative ways, by obstructing diffusers or disconnecting the units. To avoid the risks linked to such behaviors, new retrofit efforts should pay particular attention to user-friendliness of technical installations, clear communication of technical information to the residents and a close monitoring of the installations’ performance and occupants’ satisfaction after move-in.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"663 - 677"},"PeriodicalIF":1.9,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41777356","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 : 2023-03-27DOI: 10.1080/23744731.2023.2194839
Zhihong Pang, Maddie Koolbeck, Xiaohui Zhou, Zheng D. O'Neill PhD
K-12 school buildings constitute a substantial portion of commercial buildings in the U.S. and are responsible for significant energy consumption. This paper presents a nationwide study to investigate the actual energy performance of secondary school buildings constructed per the requirements of ASHRAE Standard 90.1 – 2004 and − 2010. A total of 73 building candidates are included in the analysis after careful screening and inspection, which covers eight ASHRAE climate zones. A Python-based Change Point Model (CPM) is developed to normalize the energy consumption data of the selected 73 buildings following the ASHRAE procedure. The energy use indices (EUI) and energy cost indices (ECI) of single buildings and the aggregated average of all buildings are computed to evaluate the actual energy performance of secondary school buildings. The results suggest that the actual national aggregated average EUI of secondary school buildings is 61 and 41 kBTU/(sq. ft. yr) for buildings designed per ASHRAE Standard 90.1 – 2004 and − 2010, respectively. This indicates a 20% saving in EUI and ECI for the update from the 2004 standard to 2010 one in real buildings, compared with a 38% saving-ratio obtained by Pacific Northwest National Laboratory (PNNL) in a nationwide simulation study.
{"title":"ASHRAE RP-1814: Actual energy performance of secondary schools designed to comply with ASHRAE 90.1-2010, Part I – energy use and cost indices comparison","authors":"Zhihong Pang, Maddie Koolbeck, Xiaohui Zhou, Zheng D. O'Neill PhD","doi":"10.1080/23744731.2023.2194839","DOIUrl":"https://doi.org/10.1080/23744731.2023.2194839","url":null,"abstract":"K-12 school buildings constitute a substantial portion of commercial buildings in the U.S. and are responsible for significant energy consumption. This paper presents a nationwide study to investigate the actual energy performance of secondary school buildings constructed per the requirements of ASHRAE Standard 90.1 – 2004 and − 2010. A total of 73 building candidates are included in the analysis after careful screening and inspection, which covers eight ASHRAE climate zones. A Python-based Change Point Model (CPM) is developed to normalize the energy consumption data of the selected 73 buildings following the ASHRAE procedure. The energy use indices (EUI) and energy cost indices (ECI) of single buildings and the aggregated average of all buildings are computed to evaluate the actual energy performance of secondary school buildings. The results suggest that the actual national aggregated average EUI of secondary school buildings is 61 and 41 kBTU/(sq. ft. yr) for buildings designed per ASHRAE Standard 90.1 – 2004 and − 2010, respectively. This indicates a 20% saving in EUI and ECI for the update from the 2004 standard to 2010 one in real buildings, compared with a 38% saving-ratio obtained by Pacific Northwest National Laboratory (PNNL) in a nationwide simulation study.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"402 - 423"},"PeriodicalIF":1.9,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49258982","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 : 2023-03-27DOI: 10.1080/23744731.2023.2194840
Xudong Zhang, Qiao Ning, Zengcheng Chen
Different window design schemes have different effects on heating, cooling, lighting energy consumption and indoor thermal comfort. This research established four scenarios, considering different window design variables, such as: window to wall ratio, glazing type, overhang and fin depth, maximum and minimum outdoor temperature setpoint for window opening and window opening factor, to minimize different energy consumption and thermal discomfortable hours. Sensitivity analysis was carried out prior to optimization to compare the sensitivity of each window design variable to different research objectives. Through optimization based on the non-dominated sorting genetic algorithm II (NSGA-II), the recommended values of each window design variable were given, designers can choose different optimal schemes according to preferences. Results in this paper are of great significance in guiding designers in the early design stage of office buildings.
{"title":"Multi-objective optimization design of energy efficiency for office building window systems based on indoor thermal comfort","authors":"Xudong Zhang, Qiao Ning, Zengcheng Chen","doi":"10.1080/23744731.2023.2194840","DOIUrl":"https://doi.org/10.1080/23744731.2023.2194840","url":null,"abstract":"Different window design schemes have different effects on heating, cooling, lighting energy consumption and indoor thermal comfort. This research established four scenarios, considering different window design variables, such as: window to wall ratio, glazing type, overhang and fin depth, maximum and minimum outdoor temperature setpoint for window opening and window opening factor, to minimize different energy consumption and thermal discomfortable hours. Sensitivity analysis was carried out prior to optimization to compare the sensitivity of each window design variable to different research objectives. Through optimization based on the non-dominated sorting genetic algorithm II (NSGA-II), the recommended values of each window design variable were given, designers can choose different optimal schemes according to preferences. Results in this paper are of great significance in guiding designers in the early design stage of office buildings.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"618 - 631"},"PeriodicalIF":1.9,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46320480","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 : 2023-03-27DOI: 10.1080/23744731.2023.2195805
Xin Wang, Yingrui Zhu, B. Niu
Active adjustment of the airflow organization in data centers (DC) has been increasingly applied due to its superior adjustment performance. But for now, the main focus is on the airflow distribution optimization in the horizontal direction, while few research has been conducted to investigate the additional energy consumption of active method. This paper introduced the jet-induced ventilation into under-floor air distribution (UFAD), then the coupling air supply system (CASS) was established. Taking the CASS data center as an example, this paper focuses on the impact of the active adjustment method on both airflow organization and energy consumption of the DC, and analyzes the energy consumption of the system while meeting the security operations of the thermal environment. The results showed that the incorporation of jet-induced ventilation effectively improved the airflow distribution uniformity, while the active adjustment of the airflow organization in the DC has little effect on the overall energy consumption. On the premise of meeting the demand of thermal environment, the energy consumption of the CRAC (Computer room air conditioning) units in the CASS is reduced and the change of the overall energy consumption is small, while the total energy consumption increased with the increase of airflow uniformity.
{"title":"Airflow uniformity and energy consumption investigation on data centers enhanced by jet fans","authors":"Xin Wang, Yingrui Zhu, B. Niu","doi":"10.1080/23744731.2023.2195805","DOIUrl":"https://doi.org/10.1080/23744731.2023.2195805","url":null,"abstract":"Active adjustment of the airflow organization in data centers (DC) has been increasingly applied due to its superior adjustment performance. But for now, the main focus is on the airflow distribution optimization in the horizontal direction, while few research has been conducted to investigate the additional energy consumption of active method. This paper introduced the jet-induced ventilation into under-floor air distribution (UFAD), then the coupling air supply system (CASS) was established. Taking the CASS data center as an example, this paper focuses on the impact of the active adjustment method on both airflow organization and energy consumption of the DC, and analyzes the energy consumption of the system while meeting the security operations of the thermal environment. The results showed that the incorporation of jet-induced ventilation effectively improved the airflow distribution uniformity, while the active adjustment of the airflow organization in the DC has little effect on the overall energy consumption. On the premise of meeting the demand of thermal environment, the energy consumption of the CRAC (Computer room air conditioning) units in the CASS is reduced and the change of the overall energy consumption is small, while the total energy consumption increased with the increase of airflow uniformity.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"29 1","pages":"442 - 456"},"PeriodicalIF":1.9,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44202750","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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