With growing impacts on public health systems and economies across the world, as a result of the COVID-19 pandemic outbreak, we need to reflect on some of the early lessons for urban resilience enhancement. In this pa...With growing impacts on public health systems and economies across the world, as a result of the COVID-19 pandemic outbreak, we need to reflect on some of the early lessons for urban resilience enhancement. In this paper, a brief discussion is made through several recommendations that could make our cities more prepared specially in the probable future waves of this current outbreak or potential spikes in infections or clustered cases. The experiences from global examples highlighted in this study address what has worked in the past few months at the spatial levels of communities and cities. The COVID-19 outbreak highlighted the deficiencies and shortfall across multiple sectors of the urban systems and enabled us to identify risks, challenges, and pathways to better city management. With regard to urban resilience enhancement, the negative impacts of the COVID-19 outbreak are assessed to suggest a checklist of what could be done through early preparedness. The findings are novel in ongoing research related to urban resilience and public health during the COVID-19 pandemic. The early lessons here reflect on the ongoing situation of this pandemic outbreak, but could effectually help to enhance the resilience of our cities and communities, and especially addressing the protection of public health and societal well-being. The findings contribute to major sectors of urban resilience, city management, and public health. The recommendations from this study could be utilised and adapted in any context, allowing for the consideration of all-inclusive decision-making and much-enhanced planning processes.展开更多
China has developed several housing policy reforms and has, in recent years, progressed further on developing policies to promote green strategies and energy-saving plans. The urban housing has much benefited from suc...China has developed several housing policy reforms and has, in recent years, progressed further on developing policies to promote green strategies and energy-saving plans. The urban housing has much benefited from such reforms and plans, while rural housing has experienced minimal change in the past few decades. As a result, this study aims to identify and explore these differences, challenges, and implications that exist between three areas of urban, peri-urban, and rural in a particular case study in China. For this study, selected residential areas in the City of Zhuhai and its peri-urban and rural areas are selected as case studies. A questionnaire survey is conducted to analyze energy and housing conditions across the more prosperous urban, the dynamic and transitory peri-urban, and the less prosperous rural areas. The case studies are analyzed as comparative examples in a hot and humid sub-tropical area of Southern China. The study compares energy and housing conditions and argues potential possibilities and challenges for the future development of housing policy reforms that are the result of current housing development patterns and green strategy situation in China.展开更多
China is currently going through a phase of rapid mass urbanisation, and it is important to investigate how the growing built environment will cope with climate change, to see how the energy consumption of buildings i...China is currently going through a phase of rapid mass urbanisation, and it is important to investigate how the growing built environment will cope with climate change, to see how the energy consumption of buildings in China will be affected. This is especially important for the fast-growing cities in the north, and around the east and south coasts. This paper aims to study the effects of future climate change on the energy consumption of buildings in the three main climate regions of China, namely the “Cold” region in the north, which includes Beijing;the “Hot Summer Cold Winter” region in the east, which includes cities such as Shanghai and Ningbo;and the “Hot Summer Mild Winter” region in the south, which includes Guangzhou. Using data from the climate model, HadCM3, Test Reference Years are generated for the 2020s, 2050s and 2080s, for various IPCC future scenarios. These are then used to access the energy performance of typical existing buildings, and also the effects of retrofitting them to the standard of the current building codes. It was found that although there are reductions in energy consumption for heating and cooling with retrofitting existing residential buildings to the current standard, the actual effects are very small compared with the extra energy consumption that comes as a result of future climate change. This is especially true for Guangzhou, which currently have very little heating load, so there is little benefit of the reduction in heating demand from climate change. The effects of retrofitting in Beijing are also limited, and only in Ningbo was the effect of retrofitting able to nullify the effects of climate change up to 2020s. More improvements in building standards in all three regions are required to significantly reduce the effects of future climate change, especially to beyond 2020s.展开更多
In a short time, during the early phases of the COVID-19 pandemic outbreak, we managed to shift rapidly to use digital technologies and replace some of our daily operations with virtual modes. This shift happened so i...In a short time, during the early phases of the COVID-19 pandemic outbreak, we managed to shift rapidly to use digital technologies and replace some of our daily operations with virtual modes. This shift happened so instantly and widely that it enables us to argue that the COVID-19 became a valid reason to boost some of the gradual and ongoing transitions towards faster transformations. In this study, we use gray literature to delve into arguments around the boost for digitization, digitalization, and systems thinking in the development of the built environment. This is mostly discussed from the influence of COVID-19 on some of the existing practices or the business-as-usual of the built environment sector. From technological advancement to technology use, these arguments are put forward to discuss what is likely to be the major driver of technological adoption and the shifting paradigms that are yet to be revealed. The study concludes that the current push towards new directions and development pathways are likely to be widely accepted in a shorter time. The findings of this brief study feed into existing arguments on transformative pathways due to the COVID-19 pandemic.展开更多
While global warming is only one part of climate change effects, it poses the highest risk to our habitats and ecologies. It is alarming that global warming has heightened in multiple locations and is intensified sinc...While global warming is only one part of climate change effects, it poses the highest risk to our habitats and ecologies. It is alarming that global warming has heightened in multiple locations and is intensified since the early 1970s. Since then, there are certain global warming patterns that could guide us with an overview of what mitigation and adaptation strategies should be developed in the future decades. There are certain regions affected more than another, and there are certain patterns with adverse effects on regions, sub-regions, and even continents. This study provides an insightful analysis of recent global warming patterns, those that are affecting us the most with regional climate change of different types, upsurge in frequency and intensity of natural disasters, and drastic impacts on our ecosystems around the world. By analysing the global warming patterns of these last four decades, this research study sheds light on where these patterns are coming from, how they are developing, and what are their impacts. This study is conducted through grey literature and analysis of the recorded global warming data publicly available by the NASA-GISS data centre for global temperature. This brief—but comprehensive—analysis helps us to have a better understanding of what comes next for global warming impacts, and how we should ultimately react. The study contributes to the field by discovering three key points analysed based on available data and literature on recorded global temperature, including: differences between north and south hemispheres, specific patterns due to ocean surface temperature increase, and recent impacts on particular regions. The study concludes with the importance of global scale analysis to have a more realistic understanding of the global warming patterns and their impacts on all living habitats.展开更多
This paper presents some installation and data analysis issues from an ongoing urban air temperature and humidity measurement campaign in Hangzhou and Ningbo, China. The location of the measurement sites, the position...This paper presents some installation and data analysis issues from an ongoing urban air temperature and humidity measurement campaign in Hangzhou and Ningbo, China. The location of the measurement sites, the positioning of the sensors and the harsh conditions in an urban environment can result in missing values and observations that are unrepresentative of the local urban microclimate. Missing data and erroneous values in micro-scale weather time series can produce bias in the data analysis, false correlations and wrong conclusions when deriving the specific local weather patterns. A methodology is presented for the identification of values that could be false and for determining whether these are “noise”. Seven statistical methods were evaluated in their performance for replacing missing and erroneous values in urban weather time series. The two methods that proposed replacement with the mean values from sensors in locations with a Sky View Factor similar to that of the target sensor and the sensors closest to the target’s location performed well for all Day-Night and Cold-Warm days scenarios. However, during night time in warm weather the replacement with the mean values for air temperature of the nearest locations outperformed all other methods. The results give some initial evidence of the distinctive urban microclimate development in time and space under different regional weather forcings.展开更多
A novel coupling system that combines a photovoltaic/thermal(PV/T)subsystem and an Organic Rankine Cycle(ORC)driven by solar parabolic trough collector(PTC)is presented in this paper.The mathematical model is initiall...A novel coupling system that combines a photovoltaic/thermal(PV/T)subsystem and an Organic Rankine Cycle(ORC)driven by solar parabolic trough collector(PTC)is presented in this paper.The mathematical model is initially built.On the basis,the influence of area ratio of two collectors(PV/T and PTC)on the performance of system is discussed.The results show that the optimal area ratio of PV/T to PTC is 8:2,which can achieve the maximum energy output.Moreover,the performance of the coupling system and two independent systems(PV/T and ORC system)are compared and analyzed.The results show that the coupling system is more reliable and its total output energy(heat and electricity)is the highest,compared with the other two independent systems.The solar energy utilization efficiency of the coupling system is 40%higher than that of the other two independent systems in the steady-state simulation.Moreover,the annual output energy per unit area collector of the coupling system is 13%higher than that of the other two independent systems in the dynamic simulation.Furthermore,in the dynamic simulation of a typical day,the PV panels’temperature of the coupling system is 5℃–7℃ lower than that of the independent PV/T system.It means that the power generation efficiency of PV panels can be increased by 1.5%–3.5%.This study aims to explore the operation characteristics of the novel solar energy utilization coupling system and promote the development of renewable energy utilization models,which provides a reference for the design and optimization of related energy systems.展开更多
White organic light-emitting diodes(WOLEDs)have several desirable features,but their commercialization is hindered by the poor stability of blue light emitters and high production costs due to complicated device struc...White organic light-emitting diodes(WOLEDs)have several desirable features,but their commercialization is hindered by the poor stability of blue light emitters and high production costs due to complicated device structures.Herein,we investigate a standard blue emitting hole transporting material(HTM)N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine(NPB)and its exciplex emission upon combining with a suitable electron transporting material(ETM),3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ).Blue and yellow OLEDs with simple device structures are developed by using a blend layer,NPB:TAZ,as a blue emitter as well as a host for yellow phosphorescent dopant iridium(III)bis(4-phenylthieno[3,2-c]pyridinato-N,C2')acetylacetonate(PO-01).Strategic device design then exploits the ambipolar charge transport properties of tetracene as a spacer layer to connect these blue and yellow emitting units.The tetracene-linked device demonstrates more promising results compared to those using a conventional charge generation layer(CGL).Judicious choice of the spacer prevents exciton difusion from the blue emitter unit,yet facilitates charge carrier transport to the yellow emitter unit to enable additional exciplex formation.This complementary behavior of the spacer improves the blue emission properties concomitantly yielding reasonable yellow emission.The overall white light emission properties are enhanced,achieving CIE coordinates(0.36,0.39)and color temperature(4643 K)similar to daylight.Employing intermolecular exciplex emission in OLEDs simplifes the device architecture via its dual functionality as a host and as an emitter.展开更多
A novel dual source vapor injection heat pump(DSVIHP)using exhaust and ambient air is proposed.The air exhausted from the building first releases energy to the medium-pressure evaporator and is then mixed with the amb...A novel dual source vapor injection heat pump(DSVIHP)using exhaust and ambient air is proposed.The air exhausted from the building first releases energy to the medium-pressure evaporator and is then mixed with the ambient air to heat the low-pressure evaporator.A vapor injection(VI)compressor of two inlets is connected with the low and medium pressure evaporators.It’s first time that a VI compressor is employed to recover the ventilation heat.The system can minimize the ventilation heat loss and provide a unique defrosting approach by using the exhaust waste heat.Fundamentals of the proposed DSVIHP are illustrated.Mathematical models are built.Both energetic and exergetic analyses are carried out under variable conditions.The results indicate that the DSVIHP has superior thermodynamic performance.The superiority is more appreciable at a lower ambient temperature.It has a higher COP than the conventional vapor injection heat pump and air source heat pump by 11.3%and 23.2%respectively at an ambient temperature of-10°C and condensation temperature of 45°C.The waste heat recovery ratio from the exhaust air is more than 100%.The novel DSVIHP has great potential in the cold climate area application.展开更多
This study exams the impact of climate change on outdoor design conditions and peak loads of five Chinese cities over the five major climate zones for the winter and summer conditions.The design dry-bulb temperature(D...This study exams the impact of climate change on outdoor design conditions and peak loads of five Chinese cities over the five major climate zones for the winter and summer conditions.The design dry-bulb temperature(DDBT)and the coincident wet-bulb temperature(CWBT)for two 30-year periods;1971–2000 and 1984–2013 were analysed.It was found that the DDBT of the period 1984–2013 was higher than that of the period 1971–2000,whereas the CWBT and the corresponding outdoor enthalpy of the period 1984–2013 was lower than that of 1971–2000 at the various cumulative frequencies.This trend implies that the increment in conductive heat gain through the building envelope due to the rising temperature can be lower than the reduction in fresh air load due to the lower outdoor air enthalpy.In this case,the peak cooling loads may reduce in all five cities under study,and this is different from the widely held view that global warming will lead to more stringent outdoor design conditions,higher peak cooling loads and larger heating,ventilation and air conditioning(HVAC)plants than the current or historical status.The implications to the“free-cooling”of HVAC systems with enthalpy control are discussed as well.展开更多
文摘With growing impacts on public health systems and economies across the world, as a result of the COVID-19 pandemic outbreak, we need to reflect on some of the early lessons for urban resilience enhancement. In this paper, a brief discussion is made through several recommendations that could make our cities more prepared specially in the probable future waves of this current outbreak or potential spikes in infections or clustered cases. The experiences from global examples highlighted in this study address what has worked in the past few months at the spatial levels of communities and cities. The COVID-19 outbreak highlighted the deficiencies and shortfall across multiple sectors of the urban systems and enabled us to identify risks, challenges, and pathways to better city management. With regard to urban resilience enhancement, the negative impacts of the COVID-19 outbreak are assessed to suggest a checklist of what could be done through early preparedness. The findings are novel in ongoing research related to urban resilience and public health during the COVID-19 pandemic. The early lessons here reflect on the ongoing situation of this pandemic outbreak, but could effectually help to enhance the resilience of our cities and communities, and especially addressing the protection of public health and societal well-being. The findings contribute to major sectors of urban resilience, city management, and public health. The recommendations from this study could be utilised and adapted in any context, allowing for the consideration of all-inclusive decision-making and much-enhanced planning processes.
文摘China has developed several housing policy reforms and has, in recent years, progressed further on developing policies to promote green strategies and energy-saving plans. The urban housing has much benefited from such reforms and plans, while rural housing has experienced minimal change in the past few decades. As a result, this study aims to identify and explore these differences, challenges, and implications that exist between three areas of urban, peri-urban, and rural in a particular case study in China. For this study, selected residential areas in the City of Zhuhai and its peri-urban and rural areas are selected as case studies. A questionnaire survey is conducted to analyze energy and housing conditions across the more prosperous urban, the dynamic and transitory peri-urban, and the less prosperous rural areas. The case studies are analyzed as comparative examples in a hot and humid sub-tropical area of Southern China. The study compares energy and housing conditions and argues potential possibilities and challenges for the future development of housing policy reforms that are the result of current housing development patterns and green strategy situation in China.
文摘China is currently going through a phase of rapid mass urbanisation, and it is important to investigate how the growing built environment will cope with climate change, to see how the energy consumption of buildings in China will be affected. This is especially important for the fast-growing cities in the north, and around the east and south coasts. This paper aims to study the effects of future climate change on the energy consumption of buildings in the three main climate regions of China, namely the “Cold” region in the north, which includes Beijing;the “Hot Summer Cold Winter” region in the east, which includes cities such as Shanghai and Ningbo;and the “Hot Summer Mild Winter” region in the south, which includes Guangzhou. Using data from the climate model, HadCM3, Test Reference Years are generated for the 2020s, 2050s and 2080s, for various IPCC future scenarios. These are then used to access the energy performance of typical existing buildings, and also the effects of retrofitting them to the standard of the current building codes. It was found that although there are reductions in energy consumption for heating and cooling with retrofitting existing residential buildings to the current standard, the actual effects are very small compared with the extra energy consumption that comes as a result of future climate change. This is especially true for Guangzhou, which currently have very little heating load, so there is little benefit of the reduction in heating demand from climate change. The effects of retrofitting in Beijing are also limited, and only in Ningbo was the effect of retrofitting able to nullify the effects of climate change up to 2020s. More improvements in building standards in all three regions are required to significantly reduce the effects of future climate change, especially to beyond 2020s.
文摘In a short time, during the early phases of the COVID-19 pandemic outbreak, we managed to shift rapidly to use digital technologies and replace some of our daily operations with virtual modes. This shift happened so instantly and widely that it enables us to argue that the COVID-19 became a valid reason to boost some of the gradual and ongoing transitions towards faster transformations. In this study, we use gray literature to delve into arguments around the boost for digitization, digitalization, and systems thinking in the development of the built environment. This is mostly discussed from the influence of COVID-19 on some of the existing practices or the business-as-usual of the built environment sector. From technological advancement to technology use, these arguments are put forward to discuss what is likely to be the major driver of technological adoption and the shifting paradigms that are yet to be revealed. The study concludes that the current push towards new directions and development pathways are likely to be widely accepted in a shorter time. The findings of this brief study feed into existing arguments on transformative pathways due to the COVID-19 pandemic.
文摘While global warming is only one part of climate change effects, it poses the highest risk to our habitats and ecologies. It is alarming that global warming has heightened in multiple locations and is intensified since the early 1970s. Since then, there are certain global warming patterns that could guide us with an overview of what mitigation and adaptation strategies should be developed in the future decades. There are certain regions affected more than another, and there are certain patterns with adverse effects on regions, sub-regions, and even continents. This study provides an insightful analysis of recent global warming patterns, those that are affecting us the most with regional climate change of different types, upsurge in frequency and intensity of natural disasters, and drastic impacts on our ecosystems around the world. By analysing the global warming patterns of these last four decades, this research study sheds light on where these patterns are coming from, how they are developing, and what are their impacts. This study is conducted through grey literature and analysis of the recorded global warming data publicly available by the NASA-GISS data centre for global temperature. This brief—but comprehensive—analysis helps us to have a better understanding of what comes next for global warming impacts, and how we should ultimately react. The study contributes to the field by discovering three key points analysed based on available data and literature on recorded global temperature, including: differences between north and south hemispheres, specific patterns due to ocean surface temperature increase, and recent impacts on particular regions. The study concludes with the importance of global scale analysis to have a more realistic understanding of the global warming patterns and their impacts on all living habitats.
基金L.B.would like to thank the“Liveable Cities Project”for funding a visit to Hangzhou and Ningbo in China for researching on the urban micro-climate and to collabo-rate with the Centre for Sustainable Energy Technologies at the University of Nottingham Ningbo(EPSRC funded:EP/J017698/1)The installation work of the sensors’network in Hangzhou and Ningbo is supported by the Ningbo Natu-ral Science Foundation(No.2012A610173)the Ningbo Housing and Urban-Rural Development Committee(No.201206).
文摘This paper presents some installation and data analysis issues from an ongoing urban air temperature and humidity measurement campaign in Hangzhou and Ningbo, China. The location of the measurement sites, the positioning of the sensors and the harsh conditions in an urban environment can result in missing values and observations that are unrepresentative of the local urban microclimate. Missing data and erroneous values in micro-scale weather time series can produce bias in the data analysis, false correlations and wrong conclusions when deriving the specific local weather patterns. A methodology is presented for the identification of values that could be false and for determining whether these are “noise”. Seven statistical methods were evaluated in their performance for replacing missing and erroneous values in urban weather time series. The two methods that proposed replacement with the mean values from sensors in locations with a Sky View Factor similar to that of the target sensor and the sensors closest to the target’s location performed well for all Day-Night and Cold-Warm days scenarios. However, during night time in warm weather the replacement with the mean values for air temperature of the nearest locations outperformed all other methods. The results give some initial evidence of the distinctive urban microclimate development in time and space under different regional weather forcings.
基金This work was supported by National Key R&D Program of China-Research on Optimal Configuration and Demand Response of Energy Storage Technology in Nearly Zero Energy Community(No.2019YFE0193100).
文摘A novel coupling system that combines a photovoltaic/thermal(PV/T)subsystem and an Organic Rankine Cycle(ORC)driven by solar parabolic trough collector(PTC)is presented in this paper.The mathematical model is initially built.On the basis,the influence of area ratio of two collectors(PV/T and PTC)on the performance of system is discussed.The results show that the optimal area ratio of PV/T to PTC is 8:2,which can achieve the maximum energy output.Moreover,the performance of the coupling system and two independent systems(PV/T and ORC system)are compared and analyzed.The results show that the coupling system is more reliable and its total output energy(heat and electricity)is the highest,compared with the other two independent systems.The solar energy utilization efficiency of the coupling system is 40%higher than that of the other two independent systems in the steady-state simulation.Moreover,the annual output energy per unit area collector of the coupling system is 13%higher than that of the other two independent systems in the dynamic simulation.Furthermore,in the dynamic simulation of a typical day,the PV panels’temperature of the coupling system is 5℃–7℃ lower than that of the independent PV/T system.It means that the power generation efficiency of PV panels can be increased by 1.5%–3.5%.This study aims to explore the operation characteristics of the novel solar energy utilization coupling system and promote the development of renewable energy utilization models,which provides a reference for the design and optimization of related energy systems.
基金support by DST-SERB,Govt.of India(CRG/2020/003699)CKV and KNNU acknowledge support from DST-AISRF program of the Department of Science and Technology,Government of India(DST/INT/AUS/P-74/2017)support from Council of Scientifc and Industrial Research(CSIR),Government of India for the award of a research fellowship.AKS acknowledges support from DST-INSPIRE for the award of a research fellowship.
文摘White organic light-emitting diodes(WOLEDs)have several desirable features,but their commercialization is hindered by the poor stability of blue light emitters and high production costs due to complicated device structures.Herein,we investigate a standard blue emitting hole transporting material(HTM)N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)benzidine(NPB)and its exciplex emission upon combining with a suitable electron transporting material(ETM),3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ).Blue and yellow OLEDs with simple device structures are developed by using a blend layer,NPB:TAZ,as a blue emitter as well as a host for yellow phosphorescent dopant iridium(III)bis(4-phenylthieno[3,2-c]pyridinato-N,C2')acetylacetonate(PO-01).Strategic device design then exploits the ambipolar charge transport properties of tetracene as a spacer layer to connect these blue and yellow emitting units.The tetracene-linked device demonstrates more promising results compared to those using a conventional charge generation layer(CGL).Judicious choice of the spacer prevents exciton difusion from the blue emitter unit,yet facilitates charge carrier transport to the yellow emitter unit to enable additional exciplex formation.This complementary behavior of the spacer improves the blue emission properties concomitantly yielding reasonable yellow emission.The overall white light emission properties are enhanced,achieving CIE coordinates(0.36,0.39)and color temperature(4643 K)similar to daylight.Employing intermolecular exciplex emission in OLEDs simplifes the device architecture via its dual functionality as a host and as an emitter.
基金This work is funded by the UK BEIS project‘A low carbon heating system for existing public buildings employing a highly innovative multiple-throughout-flowing micro-channel solar-panel-array and a novel mixed indoor/outdoor air source heat pump’(LCHTIF1010).
文摘A novel dual source vapor injection heat pump(DSVIHP)using exhaust and ambient air is proposed.The air exhausted from the building first releases energy to the medium-pressure evaporator and is then mixed with the ambient air to heat the low-pressure evaporator.A vapor injection(VI)compressor of two inlets is connected with the low and medium pressure evaporators.It’s first time that a VI compressor is employed to recover the ventilation heat.The system can minimize the ventilation heat loss and provide a unique defrosting approach by using the exhaust waste heat.Fundamentals of the proposed DSVIHP are illustrated.Mathematical models are built.Both energetic and exergetic analyses are carried out under variable conditions.The results indicate that the DSVIHP has superior thermodynamic performance.The superiority is more appreciable at a lower ambient temperature.It has a higher COP than the conventional vapor injection heat pump and air source heat pump by 11.3%and 23.2%respectively at an ambient temperature of-10°C and condensation temperature of 45°C.The waste heat recovery ratio from the exhaust air is more than 100%.The novel DSVIHP has great potential in the cold climate area application.
基金This work was supported by the National Natural Science Foundation of China(No.51838011)the Ningbo Science and Technology Bureau(No.2021S141)the Shenzhen Science and Technology Program(Project No.ZDSYS20210623101534001).Moreover,the authors would like to thank Dr.Joseph C.Lam for the valuable and constructive discussion about the topic.
文摘This study exams the impact of climate change on outdoor design conditions and peak loads of five Chinese cities over the five major climate zones for the winter and summer conditions.The design dry-bulb temperature(DDBT)and the coincident wet-bulb temperature(CWBT)for two 30-year periods;1971–2000 and 1984–2013 were analysed.It was found that the DDBT of the period 1984–2013 was higher than that of the period 1971–2000,whereas the CWBT and the corresponding outdoor enthalpy of the period 1984–2013 was lower than that of 1971–2000 at the various cumulative frequencies.This trend implies that the increment in conductive heat gain through the building envelope due to the rising temperature can be lower than the reduction in fresh air load due to the lower outdoor air enthalpy.In this case,the peak cooling loads may reduce in all five cities under study,and this is different from the widely held view that global warming will lead to more stringent outdoor design conditions,higher peak cooling loads and larger heating,ventilation and air conditioning(HVAC)plants than the current or historical status.The implications to the“free-cooling”of HVAC systems with enthalpy control are discussed as well.
