The Experts below are selected from a list of 102357 Experts worldwide ranked by ideXlab platform
Xiaojing Meng - One of the best experts on this subject based on the ideXlab platform.
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experimental study on the performance of hybrid buoyancy driven natural ventilation with a mechanical exhaust system in an Industrial Building
Energy and Buildings, 2020Co-Authors: Xiaojing Meng, Yi Wang, Xiao XingAbstract:Abstract Hybrid ventilation is an effective means of minimizing ventilation energy and improving indoor environment. A scale experimental model with a heat source was created for hybrid buoyancy-driven natural ventilation with a mechanical exhaust system. The aim of this study is to examine the performance of hybrid ventilation in an Industrial Building. The temperature distributions and hybrid ventilation efficiencies with different mechanical exhaust velocities were analyzed. Results showed that the hybrid ventilation efficiency first increased and then decreased with the mechanical exhaust velocity. A critical mechanical exhaust velocity was identified and the hybrid ventilation efficiency reached maximum at the critical mechanical exhaust velocity. The critical mechanical exhaust velocity was 1.4 m/s at the heat flux of the heat source q = 200 W and 1.0 m/s at q = 500 W, and the corresponding ventilation efficiencies were 24.4 and 6.69, respectively. Four modes of hybrid ventilation were investigated, and ventilation strategies of different modes of hybrid ventilation were given. An excessive mechanical ventilation rate will cause consumption of ventilation energy to increase and may lead to short circuiting of airflow and a bad thermal environment. These results should prove helpful in designing of hybrid ventilation systems for Industrial Buildings.
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measurement and evaluation of indoor thermal environment in a naturally ventilated Industrial Building with high temperature heat sources
Building and Environment, 2016Co-Authors: Yi Wang, Xiao Xing, Xiaojing MengAbstract:Abstract In this study, indoor thermal environment and workers' perceptions were investigated at four different locations in a naturally ventilated Industrial Building with high temperature heat sources in summer and winter. The results demonstrated that the differences between the mean radiant temperature and air temperature were between 0.8 °C and 5.3 °C in summer and between 1.6 °C and 11.0 °C in winter, and the average air velocity generally ranged from 0.3 m/s to 1.5 m/s. Moreover, the average wet bulb globe temperature (WBGT) was between 27.3 °C and 29.0 °C in summer and between 5.7 °C and 8.9 °C in winter, which coincided with the workers' perceptions of the thermal environment. The WBGT thus may be one of the potential indices to evaluate the indoor thermal environment in summer and winter. A prediction model for the indoor WBGT using the thermal environmental parameters was developed strictly based on the law of analogy for heat and mass transfer. The predictions agreed quite well with the measured data for WBGT of between 24 °C and 30 °C in summer and 2 °C–10 °C in winter, and the absolute differences between the predicted and measured WBGT were between 0 °C and 1.1 °C with an average of 0.3 °C in summer and between 0 °C and 1.2 °C with an average of 0.5 °C in winter. Therefore, the proposed indoor WBGT prediction model was valid and can be used to determine the acceptable thermal environmental parameters during the design stage for naturally ventilated Industrial Buildings with high temperature heat sources.
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influence of convection and radiation on the thermal environment in an Industrial Building with buoyancy driven natural ventilation
Energy and Buildings, 2014Co-Authors: Yi Wang, Xiaojing Meng, Xiaoni YangAbstract:Abstract The aim of this paper is to investigate the effects of convection and radiation from a high-temperature heat source on the thermal environment in an Industrial Building. The relevant control parameters include the Grashof numbers, which range from 107 to 1011, and the surface emissivity with values of 0.2, 0.5 and 0.8. The ratio between radiation and convection from the heat source is proposed as an important parameter for predicting the effects of heat transfer. Detailed results are discussed regarding the temperature and flow distributions, the heat transfer on the heat source surface and the ventilation rate. The dimensionless temperature and velocity profiles above the heat source are presented for different Grashof numbers. In addition, the Nusselt numbers on the heat source surface and the ventilation rate are investigated. It is observed that the ratio between radiation and convection is a decreasing function of the Grashof number and an increasing function of the surface emissivity. The total Nusselt number and the ventilation rate are both increasing functions of the Grashof number and the surface emissivity.
Yi Wang - One of the best experts on this subject based on the ideXlab platform.
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experimental study on the performance of hybrid buoyancy driven natural ventilation with a mechanical exhaust system in an Industrial Building
Energy and Buildings, 2020Co-Authors: Xiaojing Meng, Yi Wang, Xiao XingAbstract:Abstract Hybrid ventilation is an effective means of minimizing ventilation energy and improving indoor environment. A scale experimental model with a heat source was created for hybrid buoyancy-driven natural ventilation with a mechanical exhaust system. The aim of this study is to examine the performance of hybrid ventilation in an Industrial Building. The temperature distributions and hybrid ventilation efficiencies with different mechanical exhaust velocities were analyzed. Results showed that the hybrid ventilation efficiency first increased and then decreased with the mechanical exhaust velocity. A critical mechanical exhaust velocity was identified and the hybrid ventilation efficiency reached maximum at the critical mechanical exhaust velocity. The critical mechanical exhaust velocity was 1.4 m/s at the heat flux of the heat source q = 200 W and 1.0 m/s at q = 500 W, and the corresponding ventilation efficiencies were 24.4 and 6.69, respectively. Four modes of hybrid ventilation were investigated, and ventilation strategies of different modes of hybrid ventilation were given. An excessive mechanical ventilation rate will cause consumption of ventilation energy to increase and may lead to short circuiting of airflow and a bad thermal environment. These results should prove helpful in designing of hybrid ventilation systems for Industrial Buildings.
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measurement and evaluation of indoor thermal environment in a naturally ventilated Industrial Building with high temperature heat sources
Building and Environment, 2016Co-Authors: Yi Wang, Xiao Xing, Xiaojing MengAbstract:Abstract In this study, indoor thermal environment and workers' perceptions were investigated at four different locations in a naturally ventilated Industrial Building with high temperature heat sources in summer and winter. The results demonstrated that the differences between the mean radiant temperature and air temperature were between 0.8 °C and 5.3 °C in summer and between 1.6 °C and 11.0 °C in winter, and the average air velocity generally ranged from 0.3 m/s to 1.5 m/s. Moreover, the average wet bulb globe temperature (WBGT) was between 27.3 °C and 29.0 °C in summer and between 5.7 °C and 8.9 °C in winter, which coincided with the workers' perceptions of the thermal environment. The WBGT thus may be one of the potential indices to evaluate the indoor thermal environment in summer and winter. A prediction model for the indoor WBGT using the thermal environmental parameters was developed strictly based on the law of analogy for heat and mass transfer. The predictions agreed quite well with the measured data for WBGT of between 24 °C and 30 °C in summer and 2 °C–10 °C in winter, and the absolute differences between the predicted and measured WBGT were between 0 °C and 1.1 °C with an average of 0.3 °C in summer and between 0 °C and 1.2 °C with an average of 0.5 °C in winter. Therefore, the proposed indoor WBGT prediction model was valid and can be used to determine the acceptable thermal environmental parameters during the design stage for naturally ventilated Industrial Buildings with high temperature heat sources.
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influence of convection and radiation on the thermal environment in an Industrial Building with buoyancy driven natural ventilation
Energy and Buildings, 2014Co-Authors: Yi Wang, Xiaojing Meng, Xiaoni YangAbstract:Abstract The aim of this paper is to investigate the effects of convection and radiation from a high-temperature heat source on the thermal environment in an Industrial Building. The relevant control parameters include the Grashof numbers, which range from 107 to 1011, and the surface emissivity with values of 0.2, 0.5 and 0.8. The ratio between radiation and convection from the heat source is proposed as an important parameter for predicting the effects of heat transfer. Detailed results are discussed regarding the temperature and flow distributions, the heat transfer on the heat source surface and the ventilation rate. The dimensionless temperature and velocity profiles above the heat source are presented for different Grashof numbers. In addition, the Nusselt numbers on the heat source surface and the ventilation rate are investigated. It is observed that the ratio between radiation and convection is a decreasing function of the Grashof number and an increasing function of the surface emissivity. The total Nusselt number and the ventilation rate are both increasing functions of the Grashof number and the surface emissivity.
Valentina Serra - One of the best experts on this subject based on the ideXlab platform.
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the cost optimal methodology for the energy retrofit of an ex Industrial Building located in northern italy
Energy and Buildings, 2016Co-Authors: Cristina Becchio, Diego Giuseppe Ferrando, Elena Fregonara, Niccolò Milani, Camilla Quercia, Valentina SerraAbstract:Abstract The recast of the Energy Performance of Buildings Directive (EPBD) introduced a comparative methodological framework for calculating cost-optimal levels of minimum energy performance requirements. The cost-optimal methodology, conceived for national authorities, was here exploited as a decision-making tool for supporting a private investor in choosing the most viable energy scenario. The methodology was thus used to evaluate different energy efficiency measures applied to an abandoned Industrial Building in Turin (Northern Italy) and to identify the best retrofit solution in terms of energy and costs. Providing guidance and tools for re-designing ex-Industrial areas can be useful for several similar case studies widespread not only nearby Turin, but also in other Italian regions and EU countries. The research activity here presented aims at testing the cost-optimal methodology to support energy retrofit projects starting from an early design stage. The arisen issues may be considered for future applications, with reference to specific contexts. In this perspective, this work constitutes a first step towards the definition of an “environmental and economic sustainability equilibrium”, assuming that the application of models and approaches for evaluating both the energy-environmental performances and the economic ones, in many cases, may give very different results.
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The Cost Optimal Methodology for Evaluating the Energy Retrofit of an ex-Industrial Building in Turin
Energy Procedia, 2015Co-Authors: Cristina Becchio, Diego Giuseppe Ferrando, Elena Fregonara, Niccolò Milani, Camilla Quercia, Valentina SerraAbstract:Abstract The recast of the Directive on the Energy Performance of Buildings (EPBD) requires Member States to set minimum energy performance requirements, for Buildings, on the cost-optimal level. In Italy, the EPBD recast was transposed in a document (published in GU 2012/C 115) orienting the delegated regulation 244/2012 EU. Following cost-optimal methodology different energy efficiency measures were applied to an abandoned Industrial Building in Turin, Northern Italy, in order to identify the best retrofit configuration in terms of energy and cost effectiveness.
Steve M Tulevech - One of the best experts on this subject based on the ideXlab platform.
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life cycle assessment a multi scenario case study of a low energy Industrial Building in thailand
Energy and Buildings, 2018Co-Authors: Steve M Tulevech, Danny J Hage, Spence K Jorgense, Carte L Guensle, Robe Himmle, Shabbi H GheewalaAbstract:Abstract A life cycle assessment (LCA) is conducted on a low-energy Industrial Building under construction in Thailand. The Building has a gross floor area of 14,938 m2 and a 20-year lifetime. As energy-saving initiatives need to expand beyond the established domain of low-energy residential and commercial Buildings, this study demonstrates the successful application of active and passive energy-saving measures to a large, energy-efficient Industrial Building—the first to be surveyed by an LCA. LED lighting, minimal air conditioning, and passive ventilation architecture reduce operation phase burdens. As a result, the manufacturing phase yields largest impacts in primary energy demand (71%), global warming potential (60%), and four other environmental impact categories. This is largely attributable to steel and concrete production and a higher embodied energy quantity per material. Additionally, four scenarios—a base case, recycling case, photovoltaic system scenario, and combined recycling/photovoltaic scenario—are simulated to evaluate strategies for further energy reduction. Analysis indicates that significant life cycle energy savings can be achieved through recycling (29%) and a rooftop PV system (64%). The combination of both enhancements compensates for all manufactured material embodied energies and results in a Building with zero or sub-zero total life cycle energy demand. Buildings that are already low-energy can further reduce environmental impacts through inclusion of the aforementioned approaches in design and implementation.
Cristina Becchio - One of the best experts on this subject based on the ideXlab platform.
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the cost optimal methodology for the energy retrofit of an ex Industrial Building located in northern italy
Energy and Buildings, 2016Co-Authors: Cristina Becchio, Diego Giuseppe Ferrando, Elena Fregonara, Niccolò Milani, Camilla Quercia, Valentina SerraAbstract:Abstract The recast of the Energy Performance of Buildings Directive (EPBD) introduced a comparative methodological framework for calculating cost-optimal levels of minimum energy performance requirements. The cost-optimal methodology, conceived for national authorities, was here exploited as a decision-making tool for supporting a private investor in choosing the most viable energy scenario. The methodology was thus used to evaluate different energy efficiency measures applied to an abandoned Industrial Building in Turin (Northern Italy) and to identify the best retrofit solution in terms of energy and costs. Providing guidance and tools for re-designing ex-Industrial areas can be useful for several similar case studies widespread not only nearby Turin, but also in other Italian regions and EU countries. The research activity here presented aims at testing the cost-optimal methodology to support energy retrofit projects starting from an early design stage. The arisen issues may be considered for future applications, with reference to specific contexts. In this perspective, this work constitutes a first step towards the definition of an “environmental and economic sustainability equilibrium”, assuming that the application of models and approaches for evaluating both the energy-environmental performances and the economic ones, in many cases, may give very different results.
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The Cost Optimal Methodology for Evaluating the Energy Retrofit of an ex-Industrial Building in Turin
Energy Procedia, 2015Co-Authors: Cristina Becchio, Diego Giuseppe Ferrando, Elena Fregonara, Niccolò Milani, Camilla Quercia, Valentina SerraAbstract:Abstract The recast of the Directive on the Energy Performance of Buildings (EPBD) requires Member States to set minimum energy performance requirements, for Buildings, on the cost-optimal level. In Italy, the EPBD recast was transposed in a document (published in GU 2012/C 115) orienting the delegated regulation 244/2012 EU. Following cost-optimal methodology different energy efficiency measures were applied to an abandoned Industrial Building in Turin, Northern Italy, in order to identify the best retrofit configuration in terms of energy and cost effectiveness.
