Pub Date : 2014-11-17DOI: 10.1080/10789669.2014.975079
R. Radermacher, P. Bansal, J. Spitler
ed and/or Indexed in: American Chemical Society, Chemical Abstracts Service (CAS) and STN (Scientific and Technical Information Network); ASHRAE Abstract Center; BSRIA (Building Services Research & Information Association), Information Centre Quarterly and IBSA (International Building Services Abstracts); CNKI (Chinese National Knowledge Infrastructure); Ei (Engineering Information, Inc.), Ei Compendex and Engineering Index; Gale/Cengage Learning, Academic OneFile and InfoTrac; IIR (International Institute of Refrigeration) and Fridoc; ProQuest Technology Research Database, CSA Materials Research Database with METADEX, CSA Engineering Research Database and CSA High Technology Research Database with Aerospace; SciVerse Scopus and Compendex; Thomson Reuters (formerly Institute for Scientific Information [ISI]) Web of Knowledge, Current
编辑和/或被美国化学会、美国化学文摘社(CAS)和美国科学技术信息网(STN)收录;ASHRAE抽象中心;BSRIA(建筑服务研究与信息协会)、信息中心季刊和IBSA(国际建筑服务文摘);中国知网(CNKI);Ei (Engineering Information, Inc.)， Ei Compendex and Engineering Index;Gale/Cengage Learning、Academic OneFile和InfoTrac;IIR(国际制冷学会)和Fridoc;ProQuest技术研究数据库、CSA材料研究数据库(METADEX)、CSA工程研究数据库和CSA高技术研究数据库(Aerospace);SciVerse Scopus and Compendex;汤森路透(原科学信息研究所[ISI])知识网，最新
{"title":"EOV Editorial Board","authors":"R. Radermacher, P. Bansal, J. Spitler","doi":"10.1080/10789669.2014.975079","DOIUrl":"https://doi.org/10.1080/10789669.2014.975079","url":null,"abstract":"ed and/or Indexed in: American Chemical Society, Chemical Abstracts Service (CAS) and STN (Scientific and Technical Information Network); ASHRAE Abstract Center; BSRIA (Building Services Research & Information Association), Information Centre Quarterly and IBSA (International Building Services Abstracts); CNKI (Chinese National Knowledge Infrastructure); Ei (Engineering Information, Inc.), Ei Compendex and Engineering Index; Gale/Cengage Learning, Academic OneFile and InfoTrac; IIR (International Institute of Refrigeration) and Fridoc; ProQuest Technology Research Database, CSA Materials Research Database with METADEX, CSA Engineering Research Database and CSA High Technology Research Database with Aerospace; SciVerse Scopus and Compendex; Thomson Reuters (formerly Institute for Scientific Information [ISI]) Web of Knowledge, Current","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"26 1","pages":"ebi - ebi"},"PeriodicalIF":0.0,"publicationDate":"2014-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75860578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-05DOI: 10.1080/10789669.2014.958975
David H. Blum, L. Norford
Output variability and low generating inertia associated with solar and wind electric power generation resources increase the requirement of grid-scale ancillary service capacity and add strain to existing firm generators that provide these services. Buildings consume the majority of electricity in the United States and can play a significant role in helping to meet these challenges by using their HVAC systems as a link to thermal energy storage. However, predicting a building's ancillary service demand response performance continues to be a challenge, particularly for complex multi-zone systems, such as the variable air volume. A dynamic model of a representative variable air volume system was developed and simulated to investigate the response of the system to implementation of four common demand response strategies over a range of cooling loads and implementation intensities: zone air dry-bulb temperature adjustment, duct static pressure adjustment, supply air temperature adjustment, and chilled water temperature adjustment. Curves are presented that map power reduction as a function of cooling load and implementation intensity on a 10-min spinning reserve timescale. A study of these maps along with simulated data reveal that terminal unit damper position is a significant determining factor of performance effectiveness for each strategy.
{"title":"Dynamic simulation and analysis of ancillary service demand response strategies for variable air volume HVAC systems","authors":"David H. Blum, L. Norford","doi":"10.1080/10789669.2014.958975","DOIUrl":"https://doi.org/10.1080/10789669.2014.958975","url":null,"abstract":"Output variability and low generating inertia associated with solar and wind electric power generation resources increase the requirement of grid-scale ancillary service capacity and add strain to existing firm generators that provide these services. Buildings consume the majority of electricity in the United States and can play a significant role in helping to meet these challenges by using their HVAC systems as a link to thermal energy storage. However, predicting a building's ancillary service demand response performance continues to be a challenge, particularly for complex multi-zone systems, such as the variable air volume. A dynamic model of a representative variable air volume system was developed and simulated to investigate the response of the system to implementation of four common demand response strategies over a range of cooling loads and implementation intensities: zone air dry-bulb temperature adjustment, duct static pressure adjustment, supply air temperature adjustment, and chilled water temperature adjustment. Curves are presented that map power reduction as a function of cooling load and implementation intensity on a 10-min spinning reserve timescale. A study of these maps along with simulated data reveal that terminal unit damper position is a significant determining factor of performance effectiveness for each strategy.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"32 1","pages":"908 - 921"},"PeriodicalIF":0.0,"publicationDate":"2014-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80719974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-05DOI: 10.1080/10789669.2014.960239
Mingang Jin, W. Liu, Qingyan Chen
Fast fluid dynamics is an intermediate model that can provide fast and informative building airflow simulations. Although reasonably good simulation accuracy is important for fast fluid dynamics, computational efficiency is the primary concern, and it is necessary to further increase fast fluid dynamics speed. Because the most time-consuming part of fast fluid dynamics is solving the stiff pressure equation, this study proposed the application of a coarse-grid projection scheme, which solves the momentum equation on the fine grid level and the pressure equation on the coarse grid level. Therefore, appropriate approaches for mapping velocity and pressure information between different grid levels were investigated in this study. To evaluate the accuracy and computational efficiency of fast fluid dynamics with the coarse-grid projection scheme in simulating building airflows, this study tested it with building airflows of varying complexity. The results showed that the coarse-grid projection scheme would not have a negative impact on the accuracy of fast fluid dynamics in the simulation of building airflows, and it could significantly reduce the fluctuations that occur within the simulations. The coarse-grid projection scheme was able to accelerate fast fluid dynamics by approximately 1.5 times, and thus fast fluid dynamics with the coarse-grid projection scheme achieved a computing speed that was 30 to 50 times faster than computational fluid dynamics models.
{"title":"Accelerating fast fluid dynamics with a coarse-grid projection scheme","authors":"Mingang Jin, W. Liu, Qingyan Chen","doi":"10.1080/10789669.2014.960239","DOIUrl":"https://doi.org/10.1080/10789669.2014.960239","url":null,"abstract":"Fast fluid dynamics is an intermediate model that can provide fast and informative building airflow simulations. Although reasonably good simulation accuracy is important for fast fluid dynamics, computational efficiency is the primary concern, and it is necessary to further increase fast fluid dynamics speed. Because the most time-consuming part of fast fluid dynamics is solving the stiff pressure equation, this study proposed the application of a coarse-grid projection scheme, which solves the momentum equation on the fine grid level and the pressure equation on the coarse grid level. Therefore, appropriate approaches for mapping velocity and pressure information between different grid levels were investigated in this study. To evaluate the accuracy and computational efficiency of fast fluid dynamics with the coarse-grid projection scheme in simulating building airflows, this study tested it with building airflows of varying complexity. The results showed that the coarse-grid projection scheme would not have a negative impact on the accuracy of fast fluid dynamics in the simulation of building airflows, and it could significantly reduce the fluctuations that occur within the simulations. The coarse-grid projection scheme was able to accelerate fast fluid dynamics by approximately 1.5 times, and thus fast fluid dynamics with the coarse-grid projection scheme achieved a computing speed that was 30 to 50 times faster than computational fluid dynamics models.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"1 1","pages":"932 - 943"},"PeriodicalIF":0.0,"publicationDate":"2014-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77376987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-05DOI: 10.1080/10789669.2014.959428
Aakash C. Rai, Chao-Hsin Lin, Qingyan Chen
Volatile organic compounds are indoor air pollutants with many adverse health effects for humans. Ozone reactions with human surfaces (skin, hair, and clothing) are an important source of volatile organic compounds in the indoor air, especially in aircraft cabins because of their typically high ozone concentrations and occupant densities. Therefore, it is important to study the ozone-initiated volatile organic compound emissions from ozone reactions with passengers in an aircraft cabin and assess their resulting exposure. This investigation developed empirical models for computing the emissions of several major volatile organic compounds, including acetone, 4-oxopentanal, nonanal, and decanal, from ozone reactions with human-worn clothing. The empirical models were used to compute the contributions of human surfaces to these volatile organic compounds in an aircraft cabin mockup under different environmental conditions. The computed results were then compared with the corresponding experimental data obtained in the mockup. The models can provide rough estimates of ozone-initiated volatile organic compound concentrations. The empirical models were integrated into a computational fluid dynamics analysis, and the results showed that the levels of ozone-initiated volatile organic compounds were significantly enhanced in the breathing zones of the passengers. Therefore, to accurately assess passenger exposure to volatile organic compounds, their concentrations in the breathing zones should be used.
{"title":"Numerical modeling of volatile organic compound emissions from ozone reactions with human-worn clothing in an aircraft cabin","authors":"Aakash C. Rai, Chao-Hsin Lin, Qingyan Chen","doi":"10.1080/10789669.2014.959428","DOIUrl":"https://doi.org/10.1080/10789669.2014.959428","url":null,"abstract":"Volatile organic compounds are indoor air pollutants with many adverse health effects for humans. Ozone reactions with human surfaces (skin, hair, and clothing) are an important source of volatile organic compounds in the indoor air, especially in aircraft cabins because of their typically high ozone concentrations and occupant densities. Therefore, it is important to study the ozone-initiated volatile organic compound emissions from ozone reactions with passengers in an aircraft cabin and assess their resulting exposure. This investigation developed empirical models for computing the emissions of several major volatile organic compounds, including acetone, 4-oxopentanal, nonanal, and decanal, from ozone reactions with human-worn clothing. The empirical models were used to compute the contributions of human surfaces to these volatile organic compounds in an aircraft cabin mockup under different environmental conditions. The computed results were then compared with the corresponding experimental data obtained in the mockup. The models can provide rough estimates of ozone-initiated volatile organic compound concentrations. The empirical models were integrated into a computational fluid dynamics analysis, and the results showed that the levels of ozone-initiated volatile organic compounds were significantly enhanced in the breathing zones of the passengers. Therefore, to accurately assess passenger exposure to volatile organic compounds, their concentrations in the breathing zones should be used.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"97 2 1","pages":"922 - 931"},"PeriodicalIF":0.0,"publicationDate":"2014-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80266977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-05DOI: 10.1080/10789669.2014.964113
R. Radermacher
Attending the 2014 Gustav Lorentzen Conference in Hangzhou, China, August 31 through September 2, reinforced my view that there is no consensus yet about which emerging refrigerants will be a long-term solution for heat pumping and refrigeration. Whatever fluids are under consideration force a compromise between mitigating local versus global perils (toxicity and flammability versus global warming). So, what does this mean for the research community? The obvious answer is the continued need for research that addresses the typical tasks: measurement of thermo-physical properties, of heat transfer coefficients, and pressure drop and finally the design and testing of new, well-matched heat pump components. These tasks are closely related to the actual performance of the fluid in a refrigeration or heat pumping system. In addition there more general tasks, such as flammability assessment, material compatibility, risk analyses, and time-intensive evaluation of short-term and long-term toxicity. It appears that these tasks become routine and are just a matter of cost. The less obvious approach could have the research community embarking on novel approaches. This could entail bringing non-vapor compression technologies to a performance and maturity level where it can displace conventional refrigerants, or developing heat pump designs for which the hardware functions well and is reliably independent of refrigerant choice, or pushing molecular thermodynamics to a level where accurate property predictions can be made based on the molecular structure alone. There may be new materials where leaks heal themselves, avoiding refrigerant leakage loss, or technologies that minimize charge to a degree where the direct global warming contribution becomes inconsequential. These are just a few examples, I am sure there are many more such ideas. It may be the outcome of these less conventional research goals that may eventually determine the technologies and/or fluids that will be in use for a longer term.
{"title":"The never-ending search","authors":"R. Radermacher","doi":"10.1080/10789669.2014.964113","DOIUrl":"https://doi.org/10.1080/10789669.2014.964113","url":null,"abstract":"Attending the 2014 Gustav Lorentzen Conference in Hangzhou, China, August 31 through September 2, reinforced my view that there is no consensus yet about which emerging refrigerants will be a long-term solution for heat pumping and refrigeration. Whatever fluids are under consideration force a compromise between mitigating local versus global perils (toxicity and flammability versus global warming). So, what does this mean for the research community? The obvious answer is the continued need for research that addresses the typical tasks: measurement of thermo-physical properties, of heat transfer coefficients, and pressure drop and finally the design and testing of new, well-matched heat pump components. These tasks are closely related to the actual performance of the fluid in a refrigeration or heat pumping system. In addition there more general tasks, such as flammability assessment, material compatibility, risk analyses, and time-intensive evaluation of short-term and long-term toxicity. It appears that these tasks become routine and are just a matter of cost. The less obvious approach could have the research community embarking on novel approaches. This could entail bringing non-vapor compression technologies to a performance and maturity level where it can displace conventional refrigerants, or developing heat pump designs for which the hardware functions well and is reliably independent of refrigerant choice, or pushing molecular thermodynamics to a level where accurate property predictions can be made based on the molecular structure alone. There may be new materials where leaks heal themselves, avoiding refrigerant leakage loss, or technologies that minimize charge to a degree where the direct global warming contribution becomes inconsequential. These are just a few examples, I am sure there are many more such ideas. It may be the outcome of these less conventional research goals that may eventually determine the technologies and/or fluids that will be in use for a longer term.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"5 1","pages":"845 - 845"},"PeriodicalIF":0.0,"publicationDate":"2014-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74484122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-05DOI: 10.1080/10789669.2014.957592
J. Leverette, K. Gebke, S. Idem
An experimental program was conducted to study pressure and velocity variations longitudinally along a fabric air dispersion system. The goal of these tests was to derive and experimentally verify a numerical model to predict these values to enhance the design of fabric air dispersion systems. Euler's method was used to solve coupled energy and mass flow equations. The resulting comparison of model predictions and experimental data agreed to within 3%. Additional analysis was performed regarding the effects of adding extra flow resistance to fabric air dispersion systems. It was determined numerically that additional flow resistance provided by an internal skeleton and/or a variable-area orifice for static pressure control increased the uniformity of axial flow for fabric air dispersion systems.
{"title":"Pressure and velocity variation in a fabric air dispersion system","authors":"J. Leverette, K. Gebke, S. Idem","doi":"10.1080/10789669.2014.957592","DOIUrl":"https://doi.org/10.1080/10789669.2014.957592","url":null,"abstract":"An experimental program was conducted to study pressure and velocity variations longitudinally along a fabric air dispersion system. The goal of these tests was to derive and experimentally verify a numerical model to predict these values to enhance the design of fabric air dispersion systems. Euler's method was used to solve coupled energy and mass flow equations. The resulting comparison of model predictions and experimental data agreed to within 3%. Additional analysis was performed regarding the effects of adding extra flow resistance to fabric air dispersion systems. It was determined numerically that additional flow resistance provided by an internal skeleton and/or a variable-area orifice for static pressure control increased the uniformity of axial flow for fabric air dispersion systems.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"2019 1","pages":"862 - 874"},"PeriodicalIF":0.0,"publicationDate":"2014-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87801270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-05DOI: 10.1080/10789669.2014.954918
Yoonkyung Kang, S. Kato
To resolve the uneven microwave heating of an evaporative humidifier element, the distribution of the electric field in the humidifier cavity and the power absorbed in the humidifier element were investigated using a microwave simulation. The dielectric constant and loss tangent from changes in the water content of the humidifier element were measured using a rectangular waveguide method and calculated using microwave simulation to perform the electric field calculations. Then the penetration depth of microwaves in the element was identified for different water densities. The results demonstrated that the microwave could penetrate a 100-mm-thick element with a water density of 0.054 g/cm3. The simulation results indicated that the average power density lost across the cross-section of the element (thickness) was attenuated from the front face to the rear face with increasing water density. The depth profile of the power absorbed in the element agrees with the experimental results. However, the vertical profile of the power absorbed into the element did not match with heating patterns. An air fluid analysis should be undertaken in future simulations to predict the temperature change of the evaporative humidifier element.
{"title":"An electromagnetic simulation study of the distribution of the power absorbed in evaporative humidifier elements","authors":"Yoonkyung Kang, S. Kato","doi":"10.1080/10789669.2014.954918","DOIUrl":"https://doi.org/10.1080/10789669.2014.954918","url":null,"abstract":"To resolve the uneven microwave heating of an evaporative humidifier element, the distribution of the electric field in the humidifier cavity and the power absorbed in the humidifier element were investigated using a microwave simulation. The dielectric constant and loss tangent from changes in the water content of the humidifier element were measured using a rectangular waveguide method and calculated using microwave simulation to perform the electric field calculations. Then the penetration depth of microwaves in the element was identified for different water densities. The results demonstrated that the microwave could penetrate a 100-mm-thick element with a water density of 0.054 g/cm3. The simulation results indicated that the average power density lost across the cross-section of the element (thickness) was attenuated from the front face to the rear face with increasing water density. The depth profile of the power absorbed in the element agrees with the experimental results. However, the vertical profile of the power absorbed into the element did not match with heating patterns. An air fluid analysis should be undertaken in future simulations to predict the temperature change of the evaporative humidifier element.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"44 1","pages":"899 - 907"},"PeriodicalIF":0.0,"publicationDate":"2014-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86531387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-05DOI: 10.1080/10789669.2014.960303
Hyojin Kim, J. Baltazar, J. Haberl
This article presents new models to convert the rated cooling and heating seasonal performance efficiency (i.e., SEER or heating seasonal performance factor) to steady-state efficiency rating (i.e., energy efficiency ratio or coefficient of performance) that do not include supply fan energy to be used in building energy simulations for the units less than 19,000 W (65,000 Btu/hr). A review of the two existing conversion equations found that the existing methods do not adequately reflect the characteristics of the units currently available on the market (i.e., units higher than SEER 13/heating seasonal performance factor 7.7) that comply with the provision of the National Appliance Energy Conservation Act of 2006. This analysis was performed using the two new datasets from the California Energy Commission database and the 2012 AHRI directory as well as the AHRI fan performance data collected from several manufacturers. The developed models were adopted in the new edition of ASHRAE Standard 90.1-2013: Energy Cost Budget Method (Section 11) and Performance Rating Method (Appendix G), which is expected to be used in building energy simulations, especially at the design stage. These improved models will allow a more accurate calculation of the impact of the HVAC system efficiency on building energy use compared to the two existing conversion equations, which are discussed in this article. The impact of using the new models on building energy simulation was studied using a 2009 IECC code-compliant, 232-m2 (2500-ft2) house varying the air conditioners SEER and heating seasonal performance factor ratings.
本文提出了将额定制冷和供暖季节性能效率(即SEER或供暖季节性能系数)转换为稳态效率等级(即能效比或性能系数)的新模型，该模型不包括用于小于19,000 W (65,000 Btu/hr)的单元的建筑能源模拟的供应风扇能量。对现有两种转换方程的审查发现，现有方法不能充分反映目前市场上可获得的符合2006年《国家电器节能法》规定的设备(即高于SEER 13/供暖季节性能因子7.7的设备)的特性。这项分析使用了来自加州能源委员会数据库和2012年AHRI目录的两个新数据集，以及从几家制造商收集的AHRI风扇性能数据。所开发的模型被新版ASHRAE标准90.1-2013:能源成本预算方法(第11节)和性能评级方法(附录G)所采用，有望用于建筑能源模拟，特别是在设计阶段。与本文讨论的两种现有转换方程相比，这些改进的模型将允许更准确地计算暖通空调系统效率对建筑能源使用的影响。使用新模型对建筑能源模拟的影响进行了研究，使用符合2009年IECC规范的232平方米(2500平方英尺)的房屋，改变空调SEER和供暖季节性性能因子评级。
{"title":"Methodology for adjusting residential cooling and heating seasonal performance ratings to exclude supply fan energy","authors":"Hyojin Kim, J. Baltazar, J. Haberl","doi":"10.1080/10789669.2014.960303","DOIUrl":"https://doi.org/10.1080/10789669.2014.960303","url":null,"abstract":"This article presents new models to convert the rated cooling and heating seasonal performance efficiency (i.e., SEER or heating seasonal performance factor) to steady-state efficiency rating (i.e., energy efficiency ratio or coefficient of performance) that do not include supply fan energy to be used in building energy simulations for the units less than 19,000 W (65,000 Btu/hr). A review of the two existing conversion equations found that the existing methods do not adequately reflect the characteristics of the units currently available on the market (i.e., units higher than SEER 13/heating seasonal performance factor 7.7) that comply with the provision of the National Appliance Energy Conservation Act of 2006. This analysis was performed using the two new datasets from the California Energy Commission database and the 2012 AHRI directory as well as the AHRI fan performance data collected from several manufacturers. The developed models were adopted in the new edition of ASHRAE Standard 90.1-2013: Energy Cost Budget Method (Section 11) and Performance Rating Method (Appendix G), which is expected to be used in building energy simulations, especially at the design stage. These improved models will allow a more accurate calculation of the impact of the HVAC system efficiency on building energy use compared to the two existing conversion equations, which are discussed in this article. The impact of using the new models on building energy simulation was studied using a 2009 IECC code-compliant, 232-m2 (2500-ft2) house varying the air conditioners SEER and heating seasonal performance factor ratings.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"16 1","pages":"889 - 898"},"PeriodicalIF":0.0,"publicationDate":"2014-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88305390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-05DOI: 10.1080/10789669.2014.945853
Xingbin Lin, Josephine Lau
Demand controlled ventilation (DCV) is used to reduce the system outdoor airflow (OA) when the occupancy of the system is under design occupancy. However, the new versions of ASHRAE Standard 62.1-2010 make DCV more difficult to implement for multiple zone HVAC systems. This article proposes a CO2-based and occupancy-sensor-based dynamic reset of OA rate for multiple zone HVAC systems (“CO2-based DR”). This control strategy uses bioeffluent load estimation with a steady-state assumption to calculate and dynamically reset the system OA rate minimum set-point by solving the multiple-zone system equations for current conditions. Building energy and airflow simulations were implemented to assess the energy performance and indoor air quality of this control strategy. The simulation results showed that the average annual system OA rate for CO2-based DR is 14.6% less than the OA rate for without DCV, in which case the system OA is always maintained as constant. The annual monetary saving as a percentage of the baseline case (without DCV) is between 0.3% and 11.0% for 16 climate zones in the United States.
{"title":"Demand controlled ventilation for multiple zone HVAC systems: CO2-based dynamic reset (RP 1547)","authors":"Xingbin Lin, Josephine Lau","doi":"10.1080/10789669.2014.945853","DOIUrl":"https://doi.org/10.1080/10789669.2014.945853","url":null,"abstract":"Demand controlled ventilation (DCV) is used to reduce the system outdoor airflow (OA) when the occupancy of the system is under design occupancy. However, the new versions of ASHRAE Standard 62.1-2010 make DCV more difficult to implement for multiple zone HVAC systems. This article proposes a CO2-based and occupancy-sensor-based dynamic reset of OA rate for multiple zone HVAC systems (“CO2-based DR”). This control strategy uses bioeffluent load estimation with a steady-state assumption to calculate and dynamically reset the system OA rate minimum set-point by solving the multiple-zone system equations for current conditions. Building energy and airflow simulations were implemented to assess the energy performance and indoor air quality of this control strategy. The simulation results showed that the average annual system OA rate for CO2-based DR is 14.6% less than the OA rate for without DCV, in which case the system OA is always maintained as constant. The annual monetary saving as a percentage of the baseline case (without DCV) is between 0.3% and 11.0% for 16 climate zones in the United States.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"13 1","pages":"875 - 888"},"PeriodicalIF":0.0,"publicationDate":"2014-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81052692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-10-03DOI: 10.1080/10789669.2014.936795
J. Calautit, B. Hughes
Increasing emphasis on reducing energy consumption has raised public awareness of renewable energy resources, particularly the integration of passive systems in buildings such as wind towers. In hot conditions where there is a relatively low difference between internal and external temperatures, the cooling capabilities of wind towers, which depend mainly on their structural design and material, are inadequate. Therefore, it is essential to cool the air in order to improve the indoor thermal comfort. The aim of this work was to incorporate heat transfer devices (HTDs) in a wind tower, highlighting the potential to achieve minimal restriction in the airflow stream while ensuring maximum contact time, thus optimizing the cooling duty of the device. Computational fluid dynamics (CFD) modeling and wind tunnel testing were conducted to investigate the performance of proposed system. Results have indicated that the average indoor air speed was reduced by 28% to 52% following the integration of the HTD. Furthermore, the study concluded that the proposed cooling system was capable of reducing the air temperatures by up to 12 K, depending on the configuration and operating conditions.
{"title":"Integration and application of passive cooling within a wind tower for hot climates","authors":"J. Calautit, B. Hughes","doi":"10.1080/10789669.2014.936795","DOIUrl":"https://doi.org/10.1080/10789669.2014.936795","url":null,"abstract":"Increasing emphasis on reducing energy consumption has raised public awareness of renewable energy resources, particularly the integration of passive systems in buildings such as wind towers. In hot conditions where there is a relatively low difference between internal and external temperatures, the cooling capabilities of wind towers, which depend mainly on their structural design and material, are inadequate. Therefore, it is essential to cool the air in order to improve the indoor thermal comfort. The aim of this work was to incorporate heat transfer devices (HTDs) in a wind tower, highlighting the potential to achieve minimal restriction in the airflow stream while ensuring maximum contact time, thus optimizing the cooling duty of the device. Computational fluid dynamics (CFD) modeling and wind tunnel testing were conducted to investigate the performance of proposed system. Results have indicated that the average indoor air speed was reduced by 28% to 52% following the integration of the HTD. Furthermore, the study concluded that the proposed cooling system was capable of reducing the air temperatures by up to 12 K, depending on the configuration and operating conditions.","PeriodicalId":13238,"journal":{"name":"HVAC&R Research","volume":"25 1","pages":"722 - 730"},"PeriodicalIF":0.0,"publicationDate":"2014-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80949553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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