An analysis on spatial variation of urban human thermal comfort in Hangzhou, China

Urban human thermal comfort(UHTC) is affected for interacting of weather condition and underlying surface framework of urban area. Urban underlying surface temperature value and Normalized Difference Vegetation Index(NDVI) were calculated using image interpreting and supervised classification technique by ERDAS IMAGE software using 1991 and 1999 Landsat TM images data. Reference to the relational standard of assessing human thermal comfort and other meteorology data of Hangzhou City in summer, air temperature and relative humidity variation of different land types of underlying surface were inversed. By choosing discomfort index as an indictor, the spatial distribution characteristic and the spatial variation degree of UHTC were estimated and mapped on a middle scale, that is, in six districts of Hangzhou. The main characteristics of UHTC spatial variation from 1991 to 1999 were revealed using a GIS-based calculation model. The variation mechanism were analyzed and discussed from the viewpoint of city planning, construction and environmental protection.

Analysis on Human Comfort of Tourism Climate in Binzhou City

According to meteorological data at Binzhou Meteorological Station during 1981 -2010, basic climate characteristics of meteorological factors （such as temperature, relative humidity and wind velocity, etc. ） related to human comfort are analyzed, and temporal-spatial distribution characteristics of human comfort in Binzhou City are studied. Then, human comfort of tourism in Binzhou City is evaluated. The impacts of each meteorological factor on comfort in different seasons and change tendency of comfort are discussed, and the optimal tourism time in Binzhou City is analyzed.

Study on Differences of Temperature and Humidity and Vertical Distribution of Human Comfort between City and Countryside of Heilongjiang Province in Summer

[ Objective] The research aimed to study differences of temperature and humidity and vertical distribution of human comfort between city and countryside of Heilongjiang in summer. [Method] By using temperature, humidity and wind velocity data at 10 and 70 m of two iron towers in urban and rural districts of Heilongjiang from June 1 to August 31,2010, the characteristics at temperature and humidity fields and change rule of human comfort index in urban and rural areas in summer were analyzed. [Result] Compared with rural areas, heat island effect of urban districts was obvious, and it was the strongest during 21：00 -23：00 and the weakest during 05：00 -06：00. Daily change rules of wind velocity at 10 m of two anemometer towers were basically consistent. Wind velocity was big at daytime and small at night. Daily change of wind velocity at 70 m of urban districts was consistent with that at 10 m, while wind velocity change at 70 m of rural areas was different from that at 10 m, which had obvious high-altitude wind characteristics. Daily change rules of humidity in two towers were basically consistent, and occurrence time of extremum at 70 m delayed for 1 h. At vertical height, humidity at 10 m was higher than that at 70 m at daytime, and was lower than that at 70 m at night. [ Conclusion] The city had obvious wet island effect during 00：00 -06：00 and dry island effect at nightfall. Comfort index of urban districts was higher than that in rural areas, and difference was the maximum during 19：00 -21：00. Comfort index at 10 m was higher than that at 70 m at daytime in the city and countryside, and was lower than that at 70 m at night. Occurrence frequencies of Grade Zero of comfort at 10 and 70 m of urban districts were both over 60%, while occurrence frequency of ≥ Grade Three of comfort was very small. At vertical height, human comfort had small difference at night. At daytime, as height rise, human comfort index significantly declined, and human feeling was more comfortable than that at low layer.

Vibration Analysis and Fatigue Assessment of Floors.Part I:Human Rhythmic Activities

Structural problems associated with excessive vibration of building floor systems when subjected to human rhythmic activities have been frequent.In this context,this research work aims to develop an analysis methodology to evaluate the human comfort and assess the fatigue performance of steel-concrete composite floors when subjected to human rhythmic activities(aerobics).The investigated structural model corresponds to a steel-concrete floor with dimensions of 10 m×10 m and a total area of 100 m^(2).The numerical model developed for the dynamic analysis of the floor adopted the usual mesh refinement techniques present in finite element method(FEM)simulations implemented in the ANSYS program.The investigated floor dynamic response was calculated through the consideration of people practicing rhythmic activities on the structure,in order to verify the occurrence of excessive vibration and to assess the human comfort.The fatigue assessment is based on a linear cumulative damage rule through the use of the Rainflow-counting algorithm and S-N curves from traditional design codes.The results indicated that,in several analysed situations,the investigated floor presents excessive vibration and user’s discomfort.On the other hand,the structure service life values were higher than those proposed by the design codes,ensuring that the members,connections and joints will not fail by fatigue cracking.

Impacts of Roof/Ground Mitigation Strategies on Improving the Urban Thermal Environment and Human Comfort over the Yangtze River Delta, China

The combined effects of global warming and the urban heat islands exacerbate the risk of urban heat stress. It is crucial to implement effective cooling measures in urban areas to improve the comfort of the thermal environment. In this study, the Weather Research and Forecasting Model(WRF), coupled with a single-layer Urban Canopy Model(UCM), was used to study the impact of heat mitigation strategies. In addition, a 5-km resolution land-cover dataset for China(ChinaLC), which is based on satellite remote sensing data, was adjusted and used, and 18 groups of numerical experiments were designed, to increase the albedo and vegetation fraction of roof/ground parameters. The experiments were conducted for four heatwave events that occurred in the summer of 2013 in the Yangtze River Delta urban agglomeration of China. The simulated results demonstrated that, for the single roof/ground schemes, the mitigation effects were directly proportional to the albedo and greening. Among all the experimental schemes, the superposed schemes presented better cooling effects. For the ground greening scheme, with similar net radiation flux and latent heat flux, its storage heat was lower than that of the roof greening scheme, resulting in more energy flux into the atmosphere, and its daytime cooling effect was not as good as that of the roof greening scheme. In terms of human thermal comfort(HTC), the improvement achieved by the ground greening scheme was better than any other single roof/ground schemes, because the increase in the relative humidity was small. The comprehensive evaluation of the mitigation effects of different schemes on the thermal environment presented in this paper provides a theoretical basis for improving the urban environment through rational urban planning and construction.

Changing Characteristics of Comfort Index of Human Body in Bengbu City in the Past 40 Years under the Background of Climate Change

Based on the daily meteorological data of Bengbu City during 1981-2020,the changing characteristics of three elements needed for the calculation of the comfort index of human body(CIHB)were discussed,and daily CIHB was classified and discussed.The results show that from 1981 to 2020,annual average temperature tended to increase significantly.Annual average wind speed and relative humidity showed a decreasing trend before 2011 but an increasing trend after 2011.The duration of the four seasons in Bengbu City mainly rose in spring,reduced in winter,declined first and then increased in summer,and rose first and then decreased in autumn.As CIHB was at grades 1 and 9(the most uncomfortable),the three factors had different effects on them.For cold weather,the influence of relative humidity and wind speed on CIHB can not be ignored besides temperature.In hot weather,the influence of temperature was dominant,and the change of annual average temperature could well correspond to the change in the number of very hot days.In the context of climate warming,the number of cold days tended to decline generally,but it was larger in the years with fewer very cold days.Under the background of climate warming,there was no obvious change in the number of days of the overall comfort of human body.The number of hot days was closely related to the duration of summer,and the number of days of grade 8 rose significantly in the years with an increase in the duration of summer.

Assessment of Minimizing the Environmental Functions Conflict in Buildings

Some building components are responsible for achieving more than one environmental function, these functions are usually of different requirements that can never be done by the same actions, and they are usually connected to changeable internal and external environment characteristics that vary among them. Minimizing the conflict of achieving the different environmental functions is an important challenge for all designers. Achieving a continuous thermal and optical comfort in an internal building space using the same window is an example of this challenge, as they have different requirements that may be sometimes contrary. It should be notable that there are a lot of recent technologies that may be used to find solutions for such a conflict. The Environmental Assessment Methods of Buildings appeared to set the principles of the optimum relation between buildings and their environment, they also could be used to encourage designers to reach the best environmental relations, and award them by main or additional assessment points. The research paper proposes to use the Environmental Assessment Methods of Buildings to assess the building ability of minimizing its environmental functions achievement conflict. This proposal depends on determining the inconsistency assessment items that depend on common building components to be achieved, and then determining the time periods that these items are achieved together within, to indicate the time periods without conflicting. Thus, the paper aims to raise the building environmental value in the assessment when the designer succeeds to minimize the expected conflict of the building environmental functions.

A human comfort prediction method for indoor personnel based on time-series analysis

In buildings,the heating ventilation and air conditioning system(HVAC)creates a comfortable environment for indoor occupants by setting a temperature strategy.However,this approach leads to unreasonable indoor environmental comfort and wasted energy because it does not dynamically adjust to changes in environmental and has a long response time.In this study,a high-precision human comfort prediction method for indoor personnel based on time-series analysis is proposed as the control strategy for HVAC systems.The method includes the data pre-processing module,the class imbalance processing module,and the human comfort network model module.We propose the Human-Comfort Bi-directional Long Short-Term Memory(HC-BiLSTM)network to achieve a better human comfort prediction,and the Synthetic Minority Oversampling Technique for Time-series(SMOTE-TS)algorithm to solve the class imbalance problem in human comfort dataset.A public dataset collected in Pennsylvania,USA,was selected for this study to validate the performance of the proposed method.The experimental results show that the human comfort prediction method proposed in this study achieves 0.9482 and 0.9659 on Macro-averaging and Micro-averaging,respectively,which is the highest accuracy in the known related research.

Indoor Air Quality(IAQ)Evaluation of Higher Education Learning Environments

2022 Indoor Air Quality(IAQ),particularly in educational facilities,is gaining considerable interest and is a synonymous indicator towards evaluating human comfort.Factors such as CO_(2) concentration,temperature,and humidity play crucial parts in determining an acceptable level of IAQ.Many studies have also demonstrated that the indoor air quality of classrooms affects students’concentration and performance.Today with the threat of a global pandemic,the demand of clean&fresh indoor air quality in education buildings is extremely intensive.This study focuses on investigating IAQ situations and changes in different typical functional spaces of a higher education building in the UK.CO_(2),temperature,and humidity data in various learning environment were monitored via data loggers during the winter.Associated with data monitoring,a set of questionnaires surveys were carried out to evaluate the user’s experience.The results of this study show that temperature and CO_(2) concentration in the classrooms was constantly higher than the government guidance on a daily basis.The analysis also shows that temperature and humidity increased with CO_(2) levels,but at a much lower rate.This study has revealed poor and concerning IAQ in higher education buildings in the UK,particularly in larger rooms with high occupancy.Along with the findings,this paper also identifies possible impact or factors and proposes solutions to overcome these issues.

Experimental investigation on indoor daylight environment of building with Cadmium Telluride photovoltaic window

Photovoltaic(PV)windows have received more and more attention in recent years since their active energy-saving advantages.Considering the surface covered with solar cell modules,the indoor daylight environment of PV windows is obviously different with clear glass windows.However,despite many scholars have studied the indoor daylight environment of PV windows,there few investigations study it from the perspective of human subjective visual perception.In this paper,the indoor daylight environment and human visual comfort of building with Cadmium Telluride Photovoltaic(CdTe-PV)window were investigated.Firstly,the parameters of indoor daylight environment and subjective questionnaires in rooms with CdTe-PV window and clear glass window were analyzed respectively.On the basis of this,combined with indoor working surface illuminance and results of subjective questionnaires,the daylight illuminance threshold of human visual comfort was investigated by the method of Mean Bias Degree(MBD).Finally,an evaluation model for indoor daylight environment of buildings with CdTe-PV window was developed by Fuzzy Comprehensive Evaluation Method.The results showed that the working surface illuminance of CdTe-PV window was lower than that of clear glass room,the CCT of different windows room had a minor gap and the CdTe-PV window room was closer to the recommended range that was 3300-5000K.As for CRI,both the CdTe-PV window room and the clear glass room could meet the visual comfort requirements of office staff.Furthermore,it was found that the requirement of human visual comfort was met when indoor working surface illuminance varies between 500-2200lx in the room with CdTe-PV window.At last,according to the comprehensive evaluation model proposed in this paper,it was found that the indoor daylight environment of buildings with CdTe-PV window was excellent in the present experiment.

The effect of Urban Heat Island mitigation strategies on outdoor human thermal comfort in the city of Baghdad

Todays,most Iraqi cities suffer from extremely hot-dry climate for long periods throughout the year.However,most urban patterns that exist inside these cities are not suitable for this harsh conditions and lead to an increase in the value of the Urban Heat Island(UHI)index.Consequently,this will increase outdoor human thermal discomfort as well as energy consumption and air pollution in cities.This study attempts to evaluate the effect of UHI mitigation strategies on outdoor human thermal comfort in three different common types of urban patterns in the biggest and most populated city in Iraq,Baghdad.Three different mitigation strategies are used here-vegetation,cool materials,and urban geometry-to build 18 different scenarios.Three-dimensional numerical software ENVI-met 4.2 is utilised to analyse and assess the studied parameters.The input data for simulations process are based on two meteorological stations in Baghdad:Iraqi Meteorological Organization&Seismology,and Iraqi Agrometeorological Network.All measurements are taken in a pedestrian walkway.The results of different scenarios are compared based on their effect on human thermal comfort.Outdoor thermal comfort is assessed according to Predicted Mean Vote index,as mentioned in ISO 7730 standard.This study provides a better understanding of the role of UHI mitigation strategies on human thermal comfort in the outdoor spaces of Baghdad’s residential neighbourhoods.This can help generate guidelines of urban design and planning practices for better thermal performance in hot and dry cities.

A rapid modeling method for urban microscale meteorology and its applications

This paper introduces a fast urban microscale meteorological model with a horizontal resolution of O(10)m,named URBAN(Urban Rapid&Building-Aware Neighborhood),which is capable of rapid assessment of meteorological fields over key urban areas,including wind speed,air temperature,humidity and thermal comfort index,with the execution time less than10 minutes consuming 1 CPU core.URBAN uses a fast wind diagnostic method to construct three-dimensional(3-D)wind fields surrounding complex building clusters with their geometry resolved explicitly.To enhance the accuracy of wind reconstruction and the continuity of the initial wind field around irregular buildings,we propose a new parameterization method based on stream functions,which can accurately characterize the influences of complex urban building clusters on the three-dimensional wind field.The model can provide various results for the meteorological service of large outdoor activities,including conventional meteorological elements(wind,temperature,humidity,radiation,etc.)and the Universal Thermal Comfort Index,which is derived from the relationship between physiological processes and environmental meteorological conditions.In this paper,URBAN is applied to develop an automatic analysis and forecast system of microscale meteorological elements over the central Beijing region in summer during a large outdoor event.By comparing with the half-hourly observations from three auto weather stations(AWSs)in the region,the root-mean-square errors(RMSEs)of the modeled 10-meter-height wind speed,2-meter-height air temperature and humidity are 0.98 m s^(-1),1.37℃and 7.37%,respectively.