Effect of personal and microclimatic variables on observed thermal sensation from a field study in southern Brazil

Urban climate, which is influenced by land use patterns, heat-generating activities, and the physical texture of urban fabric, has a great impact on outdoor comfort as well as on a building’s energy consumption. A climate-responsive urban planning can provide optimal, comfortable thermal conditions not only for the permanence of humans in outdoor spaces but also reducing the need of air conditioning systems in buildings. The purpose of this article is to present results of an outdoor comfort research with passers-by in downtown Curitiba, Brazil (25°31′S, 917m elevation). Urban locations have been monitored regarding standard comfort variables: air temperature and humidity, wind speed and globe temperature. Alongside the quantitative assessment of comfort conditions, a survey of pedestrian’s thermal comfort perception according to ISO 10551 was carried out on each monitoring campaign by means of questionnaires with the local population. As a whole, from fourteen monitoring campaigns using a couple of weather stations, beginning on January 9 through August 12, 1654 valid comfort votes were obtained. In this paper, we perform a data consistency check, evaluating the relationship between personal (gender and age of respondents) and objective, microclimatic (comfort variables) factors on observed thermal sensation.     

基于人群活力的北京市延庆区城市公园风环境评价

[目的]已有风环境研究多从单一条件对城市空间风环境进行评价并提出优化策略,忽略了人群有效活动空间的影响,以简化体块代替公园物理环境部分要素,一定程度影响了风环境模拟分析结果的准确性。[方法]以占北京市风力资源70%的延庆区4个典型城市公园为对象,从公园人群游憩活力视角,结合场景建模技术、通讯探针和人工智能识别技术,确定公园游客活动范围,以此作为公园风环境评价的研究区域;利用不同季节风速、风压和涡旋分布等评价要素量化评价公园风环境质量,并以公园风环境质量综合评价来表征公园现状风环境质量优劣程度;以公园风环境质量评分方式相关性评价来表征公园进行风环境适应性改造的难易程度。[结果]结果表明：百泉公园现状风环境质量最差,且评分随季节变化呈现出明显差异性和不规律性;集贤城市森林公园风环境质量评分随季节变化有规律地逐渐减小,且进行风环境适应性改造难度最小。[结论]研究建立了全面的公园风环境质量评价体系,对延庆区城市公园建设和管理具有应用价值,为华北地区城市公园风环境质量评价提供创新方法。     

夏热冬冷气候城市公共空间热环境季节特征

城市公共空间热环境是影响人们热舒适程度的重要因素。夏热冬冷气候城市公共空间的热环境在一年内会发生很大变化。在长沙市内选择3个典型公共空间(街道、公园和广场)进行长期热环境参数实测实验。通过对不同季节3个实测点的空气温度、相对湿度、黑球温度和风速4个重要热环境参数进行分析,获得夏热冬冷气候城市公共空间的全年热环境特征。研究结果表明:自然气候决定了城市热环境的基本特征,而城市物理结构是引起室外局部热环境发生改变的重要因素;受植物(乔木)和水体(湘江)的影响,沿江街道在全年大部分时间中空气温度显著较低,相对湿度较高,太阳辐射较弱;广场温度较高,太阳辐射较强。     

热湿环境下人体热反应的实验研究

采用问卷方式，对热湿环境下人体热感觉、对空气湿度的感觉、吹风感觉及热舒适感觉进行了研究，分析了空气相对湿度对热舒适的影响，给出了高温高湿条件下人体热反应的规律。并在分析人体散热的基础上，提出了一个可以对热湿环境中人体热舒适进行预测的数学模型。     

城市公园景观感知效应动态评价方法——基于景观视觉与热舒适性的叠加研究

结合景观感知主体(人群)的多样性和时间动态性,将城市公园景观视觉与热舒适性叠加,构建评估模型与方法,动态评价城市公园景观感知效应.首先,选择基本视觉元素和视觉敏感度两方面共6项指标计算景观视觉空间分布;其次,基于实测校正ENVI-met模型,模拟2h间隔的生理等效温度(PET),再利用热感觉投票获得热舒适性的空间分布;...     

城市风环境研究的技术演进及其评价体系整合

随着城市化水平的提高以及城市空间密度不断加大,城市风环境问题成为了多学科研究关注的热点,风环境对景观环境设计、空气质量改善、开放空间热舒适度感知均具有重要的作用。从风环境研究的技术演进和其评价体系建构两个角度来分别对国内外城市风环境研究进行了梳理与总结,将其技术演进分为实地测量法研究、物理模拟法研究和计算机数值模拟法研究三个阶段进行详细分析,对现有的城市风环境评价体系特征进行了整合,相关技术方法能对城市规划起到积极的补充,具有明显的实践效果。     

基于神经网络的哈尔滨高校教室热环境特征模型研究

为了研究哈尔滨高校教室热环境特征模型和人体热舒适,笔者于2004年9月～2005年12月在哈尔滨进行了20次现场研究.在测量室内热舒适参数的同时,受试者填写对室内环境的热感觉和热舒适主观调查表.而后利用人工神经网络方法,建立了哈尔滨高校教室热环境特征和人体热舒适的BP神经网络评判模型,实现了对哈尔滨高校教室热环境内人体热感觉的智能化预测.现场研究结果验证表明,该模型预测的哈尔滨高校教室热环境内人体热感觉与实际主观调查吻合.     

Field study of human thermal comfort and thermal adaptability during the summer and winter in Beijing

This study was conducted during the summer and winter in Beijing. Classrooms and offices in a university were used to conduct the survey. The respondents’ thermal sensation and thermal adaptability in both seasons were analyzed. During the study, indoor environmental parameters including air temperature, mean radiant temperature, relative humidity, and air velocity were measured. The respondents’ thermal sensation was determined by questionnaire.A relationship between indoor temperature and thermal sensation was found. In the summer study, the “scissors difference” between TSV and PMV was observed in the air-conditioned environments if the temperature was out of the neutral zone. People had higher tolerance in the hot environment than PMV predicted. During winter, the outdoor temperature had a prominent influence on thermal adaptability. The low outdoor temperature made people adapt to the cold environment. When the indoor temperature was heated to a high temperature by space heating facilities, respondents felt uncomfortable since their adaptability to the cold environment was nullified.Furthermore, the differences in thermal responses between respondents from North and South China showed that the different climates of people's native regions also affected their thermal comfort and adaptability.     

Combined comfort model of thermal comfort and air quality on buses in Hong Kong

Air-conditioning settings are important factors in controlling the comfort of passengers on buses. The local bus operators control in-bus air quality and thermal environment by conforming to the prescribed levels stated in published standards. As a result, the settings are merely adjusted to fulfill the standards, rather than to satisfy the passengers' thermal comfort and air quality. Such "standard-oriented" practices are not appropriate; the passengers' preferences and satisfaction should be emphasized instead. Thus a "comfort-oriented" philosophy should be implemented to achieve a comfortable in-bus commuting environment. In this study, the achievement of a comfortable in-bus environment was examined with emphasis on thermal comfort and air quality. Both the measurement of physical parameters and subjective questionnaire surveys were conducted to collect practical in-bus thermal and air parameters data, as well as subjective satisfaction and sensation votes from the passengers. By analyzing the correlation between the objective and subjective data, a combined comfort models were developed. The models helped in evaluating the percentage of dissatisfaction under various combinations of passengers' sensation votes towards thermal comfort and air quality. An effective approach integrated the combined comfort model, hardware and software systems and the bus air-conditioning system could effectively control the transient in-bus environment. By processing and analyzing the data from the continuous monitoring system with the combined comfort model, air-conditioning setting adjustment commands could be determined and delivered to the hardware. This system adjusted air-conditioning settings depending on real-time commands along the bus journey. Therefore, a comfortable in-bus air quality and thermal environment could be achieved and efficiently maintained along the bus journey despite dynamic outdoor influences. Moreover, this model can help optimize air-conditioning control by striking a beneficial balance between energy conservation and passengers' satisfaction level.     

On safety systems for underground car parks

Safety systems including ventilation systems and fire protection systems for an underground car park to be constructed in Hong Kong, are discussed and their design illustrated. The thermal environment at the occupied zone was assessed by using computational fluid dynamics (CFD). The predicted air speed was used to calculate the mean age of the air and the percentage of people dissatisfied with the air quality. The probable fire environment was studied by using a fire zone model. Designs for smoke control and the thermal sensitivity of the sprinkler heads were evaluated. Based on the investigations, designs on the fire protection and ventilation systems are recommended for providing a healthy and safety environment in this underground car park. A field survey of 27 enclosed car parks was carried out, and correlation equations fitted from this paper were used to assess the fire safety aspects of those car parks.     

Thermal comfort and IAQ characteristics of naturally/mechanically ventilated and air-conditioned bedrooms in a hot and humid climate

The characteristics of thermal comfort and indoor air quality (IAQ) in bedrooms, occupants’ perceptions and their impact on sleep quality are not often studied. It becomes even more interesting if climatic conditions allow Naturally/Mechanically Ventilated (NMV) concepts as opposed to Air-conditioning (AC) and this becomes very significant from an energy perspective. This paper reports our findings from such a study conducted in a hot and humid climate. Objective measurements of thermal comfort and IAQ were carried out during sleeping period in 12 NMV and 12 AC bedrooms over a period of 2 months. Questionnaire responses were sought from each subject at the end of the objective measurements to assess their perceptions on thermal comfort and indoor air quality of the bedrooms during sleep and their sleeping conditions. Although the “Historical” and “Immediate” responses for the NMV and AC bedrooms indicate that there was a good level of acceptability for both Thermal Comfort and Perceived Air Quality (PAQ), it was found that NMV bedroom was a better sleeping environment. The subjects’ immediate perception of PAQ and thermal comfort were reasonably correlated with their historical perceptions. The subjects’ perception of PAQ was fairly closely correlated to their perception of Thermal Comfort. There was a considerable increase in the carbon dioxide level in an AC bedroom relative to a NMV bedroom. However, there was no clear evidence to substantiate that sleeping duration decreased with increasing level of carbon dioxide, but the findings do suggest that high level of carbon dioxide may hinder the duration of sleep.     

Thermal conditioning for urban outdoor spaces through the use of evaporative wind towers

The aim of this paper is to study the thermal comfort levels achieved in open spaces by means of evaporative wind towers. These systems have been installed in an urban area characterized by its hot and dry summer climate. Conventional wind tower designs for enclosed and semi-enclosed spaces have been adapted for this new installation. These systems are usually composed of a few number of wind towers, this one however is composed by a group of sixteen, increasing the total dimensions of the installation. To integrate this construction into the urban public area, it was built in a circular arrangement, creating an activity and meeting point for pedestrians. This passive system was monitored during the summer of 2008. Measurements of temperature, solar radiation, humidity and wind speed were analyzed. During the analyzed period, the average cooling efficiency of the system varied from 38% at the exit of the tower, to 32% at 1 m high. At this last position, the average exceeds the wet bulb temperature up to 8 °C with an increase of moisture around 27%. The shading effect produced by the global installation itself has been modeled theoretically to evaluate the incident solar radiation at the pedestrian area. Two indices have been applied to predict the perception of heat and cold in the south pedestrian zone: Heat index and TS index. In this position, both variables approached the thermal sensation to the comfort levels by the use of these passive strategies when ambient conditions are hot and dry.     

我国湿热地区自然通风建筑夏季热舒适研究——以广州为例

2008年夏季对广州某高校学生在自然通风建筑中进行了501人次的热舒适现场调查,调查内容包括热感觉、热舒适度、热可接受度及潮湿感,并对相应的室内干球温度、相对湿度、黑球温度和风速等热环境参数进行了测试记录。通过对数据的整理分析发现,自然通风建筑的夏季室内温湿度均高于ASHRAE标准的舒适区域,但人们对该环境有较好的适应性。调查结果表明,我国湿热地区自然通风建筑的热中性温度为28.1℃(ET*=29.3℃),可接受的热环境温度的上限为29.7℃(ET*=30.9℃),相对湿度上限为78%。     

Perceptual studies on air quality and sound through urban walks

Factors such as air and sound quality are important aspects of the urban environment with potential impacts on public health, especially in walkable areas where the public is constantly using the public space for their daily activities, accessibility, leisure and recreation. Knowing which are user's preferences regarding acoustic and air quality environments is a big advantage for public spaces management. This paper aims at investigating the correlation between air quality and sound perception in walkable areas, through subjective evaluations and on-site measurements of particulate matter, acoustic and psychoacoustic data. For this purpose, a Canonical Correlation Analysis was carried out. This paper found out correlations regarding background sound qualities and air quality perception (Rc = 0.485), as well as correlations between background sound acceptance & cognitive aspects and air quality perception (Rc = 0.532), on data collected at urban parks. The involved objective parameters which led to those results are sharpness, roughness, hearing model roughness ½ Bark, PM₁, PM_2.5 and PM₁₀. In busy street areas there are correlations between background sound qualities and air quality perception (Rc = 0.450). For this correlation the correlated objective parameters are sound pressure level (SPL), sharpness, tonality, PM₁, PM_2.5 and PM₁₀.     

哈尔滨高校教室热舒适现场研究

为了研究高校教室在学生上课期间的热环境和人体热舒适,在哈尔滨高校教室进行了现场研究。在测量室内热舒适参数的同时,学生填写对室内环境的热感觉和热舒适主观调查表,共调查了1285人次,得到了1285份人体热反应的样本。现场测试结果表明,哈尔滨高校自然通风教室全年人体热中性温度为23.4℃(t0)。     

Local and overall thermal comfort in an aircraft cabin and their interrelations

In this study the interrelation between local and overall thermal comfort of passengers in aircraft cabins was investigated by thirteen simulated flights. For each of the tests forty test persons filled out questionnaires concerning their perceived overall and local thermal comfort at temperatures of 20 °C–25 °C, which were measured at every second seat. With these physical and subjective data PMV (Predicted Mean Vote) and TSMV (Thermal Sensation Mean Vote) of test persons as well as PPD (Predicted Percentage of Dissatisfied) and PD (Percentage of Dissatisfied) were compared. The PMV was consistently similar to the TSMV, while the thermal dissatisfaction in tests was always higher than PPD. The hypothesis at the beginning of this study was that the high ratio of thermal dissatisfaction in the aircraft cabin reported in literature might be caused by local discomfort. Therefore statistical analyses about the interrelations between local and overall thermal comfort were performed and models indicating such interrelations were developed. Some local perceptions are significantly different from overall thermal perception and these body segments alter in dependence of the overall thermal environment. Also body segments rated similarly were detected and these segments were pooled to distinct body regions using principal component analysis. Under the same overall thermal sensation the local thermal perception on a certain body region predominantly influenced the overall thermal comfort. Therefore weighting factors of local body regions on the overall thermal comfort were determined in dependence of the overall thermal sensation by means of multiple linear regression models.     

Thermal sensation of Hong Kong people with increased air speed,temperature and humidity in air-conditioned environment

In the warm and humid climate zone, air-conditioning (AC) is usually provided at working places to enhance human thermal comfort and work productivity. From the building sustainability point of view, to achieve acceptable thermal sensation with the minimum use of energy can be desirable. A new AC design tactic is then to increase the air movement so that the summer temperature setting can be raised. A laboratory-based thermal comfort survey was conducted in Hong Kong with around 300 educated Chinese subjects. Their thermal sensation votes were gathered for a range of controlled thermal environment. The result analysis shows that, like in many other Asian cities, the thermal sensation of the Hong Kong people is sensitive to air temperature and speed, but not much to humidity. With bodily air speed at 0.1–0.2 m/s, clothing level 0.55 clo and metabolic rate 1 met, the neutral temperature was found around 25.4 °C for sedentary working environment. Then recommendations are given to the appropriate controlled AC environment in Hong Kong with higher airflow speeds.     

Optimization of Soundscape in Theme Park Based on Soundscape Comfortable Degree——A Case Study of China Dinosaur Land in Changzhou

Tourism soundscape is a new field of tourism landscape research, soundscape designs offer new concepts for the landscape research and development. Taking China Dinosaur Land in Changzhou City for example, visitors' perception about soundscape comfort in theme parks was studied. The researches found that acoustic comfort was infl uenced by objective parameters of sound and subjective perception of visitors, and when the soundscape volume stayed at a certain threshold value, visitors would gain the most satisfi ed acoustic comfort experience, and they were most sensitive to sound elements that able to convey cultural connotations of the theme park. On this basis, this paper adopted positive design, negative design, and zero design, and proposed the concepts of optimizing theme park soundscapes.     

Evaluating thermal comfort conditions and health responses during an extremely hot summer in Athens

In summer 2007, in the city of Athens, Greece, extremely high air temperatures were recorded, inducing heat discomfort conditions in the urban environment. Four biometeorological indices were calculated in order to evaluate human thermal sensation and thermal comfort: Actual Sensation Vote (ASV), Thermal Sensation-Ginovi method (TS), Discomfort Index (DI) and Heat Load Index (HL). Data included measurements of ambient temperature, temperature of the surrounding ground surface, relative humidity, air pressure, wind velocity and solar radiation obtained from National Observatory of Athens (NOA) station. During this period the daily number of patients probably affected by heat in emergency department units of cardiac clinics of four public general hospitals in Athens was recorded. The results revealed high values of DI and HL indices, demonstrating severe heat stress conditions during the last ten day period of June and July, while the ASV tends to classify too many cases into the comfort zone compared to TS, DI and HL. The statistical analysis revealed a negative relationship between the number of heat affected patients and the estimated indices values.     

Differential community effects on perception and use of urban greenspaces

The social profiles of residential communities exert differential effects on expectations and demands on urban greenspaces. We studied the diversity of public perception towards urban greenspaces in compact urban Hong Kong. Random household samples were selected from four dominant residential communities: old-core public housing (OP), old-core residential (OR), suburban residential (SR), and new-town public housing (NP). They denote gradations in income, housing quality, physical and social milieu, and development age. Face-to-face interviews were conducted using a structured questionnaire. Residents’ attitude, visiting pattern, greenspace preference, and assessment of neighborhood quality were investigated. SR presented distinctive results in comparison with others. The moderate differences between the remaining three communities were mainly linked to local traits in park environs. OP more emphasized the function of communal places for neighborly interactions associated with better social relationship of an older population. Parks in OR were the more frequently visited, even though its residents were sensitive to the negative impacts of urban greenspaces, which was related to urban blight in the environs. SR respondents highly appreciated greenspaces as pleasant settings for family activities and aesthetic enjoyment. NP residents were less frequent visitors despite generous park provision, due to the youthful population, weak social cohesion, and limited integration of new migrants. Community quality factors such as neighborhood relationship and urban density influenced the perception. Social qualities were more important than the physical aspects of parks in influencing visitorship. The findings suggest future research to deepen understanding of public perception towards urban greenspaces to inform park design.