Thermal sensation and comfort models for non-uniform and transient environments, part III: Whole-body sensation and comfort

A three-part series presents the development of models for predicting the local thermal sensation (Part I) and local thermal comfort (Part II) of different parts of the human body, and also the whole-body sensation and comfort (Part III) that result from combinations of local sensation and comfort. The models apply to sedentary activities in a range of environments: uniform and non-uniform, stable and transient. They are based on diverse findings from the literature and from body-part-specific human subject tests in a climate chamber. They were validated against a test of automobile passengers. The series is intended to present the models’ rationale, structure, and coefficients, so that others can test them and develop them further as additional empirical data becomes available.A) The whole-body (overall) sensation model has two forms, depending on whether all of the body's segments have sensations effectively in the same direction (e.g warm or cool), or whether some segments have sensations opposite to those of the rest of the body. For each, individual body parts have different weights for warm versus cool sensations, and strong local sensations dominate the overall sensation. If all sensations are near neutral, the overall sensation is close to the average of all body sensations.B) The overall comfort model also has two forms. Under stable conditions, people evaluate their overall comfort by a complaint-driven process, meaning that when two body parts are strongly uncomfortable, no matter how comfortable the other body parts might be, the overall comfort will be near the discomfort level of the two most uncomfortable parts. When the environmental conditions are transient, or people have control over their environments, overall comfort is better than that of the two most uncomfortable body parts. This can be accounted for by adding the most comfortable vote to the two most uncomfortable ones.     

Thermal sensation models: a systematic comparison

Thermal sensation models, capable of predicting human's perception of thermal surroundings, are commonly used to assess given indoor conditions. These models differ in many aspects, such as the number and type of input conditions, the range of conditions in which the models can be applied, and the complexity of equations. Moreover, the models are associated with various thermal sensation scales. In this study, a systematic comparison of seven existing thermal sensation models has been performed with regard to exposures including various air temperatures, clothing thermal insulation, and metabolic rate values after a careful investigation of the models’ range of applicability. Thermo‐physiological data needed as input for some of the models were obtained from a mathematical model for human physiological responses. The comparison showed differences between models’ predictions for the analyzed conditions, mostly higher than typical intersubject differences in votes. Therefore, it can be concluded that the choice of model strongly influences the assessment of indoor spaces. The issue of comparing different thermal sensation scales has also been discussed.     

Effect of transient temperature on thermoreceptor response and thermal sensation

This work investigates the dynamic response of cutaneous thermoreceptors (TRs) under various environmental conditions. The model consists of an electrical submodel and a Pennes bioheat transfer submodel. The electrical submodel assumes that the response of the cutaneous TRs has a static and dynamic part, in which the static one is proportional to the temperature and the dynamic part proportional to the temperature change rate. A one-dimensional multi-layer model is presented to model the heat exchange between the skin and the ambient medium. Then the temperature of the TRs and the necessary parameters of the electrical submodel are predicted using a finite difference method. Approaches proposed in this paper can help identify the difference of the warm and cold TRs under the same environmental conditions. This difference may be the real mechanism that people are more sensitive to cold stimuli than warm stimuli.     

Field study of a thermal environment and adaptive model in Shanghai

A long-term field investigation was carried out in naturally ventilated residential buildings in Shanghai from April 2003 to November 2004. A total of 1,768 returned questionnaires were collected in the study. This study deals with the thermal sensation of occupants in naturally ventilated buildings and the change in thermal neutral temperature with season. The range of accepted temperature in naturally ventilated buildings is between 14.7 degrees C T(op) and 29.8 degrees C T(op). The results also report the findings of the adaptive comfort model in Shanghai that determines the adaptive relationship of neutral temperature with outdoor air temperature. A long-term field study was carried out in residential buildings in Shanghai to find the relationship between thermal sensation, indoor neutral temperature and outdoor temperature. This paper presents findings of thermal comfort and discusses the more sustainable standard for the indoor climate of residential buildings in Shanghai.     

Thermal sensation and comfort models for non-uniform and transient environments, part II: Local comfort of individual body parts

A three-part series presents the development of models for predicting the local thermal sensation (Part I) and local comfort (Part II) of different parts of the human body, and also the whole-body sensation and comfort responses (Part III). The models predict these subjective responses to the environment from thermophysiological measurements or predictions (skin and core temperatures). The models apply to a range of environments: uniform and non-uniform, transient and stable. They are based on diverse results from literature and from body-part-specific human subject tests in a climate chamber. They were validated against a test of passengers in automobiles. This series is intended to present the rationale, structure, and coefficients for these models so that others can test them and develop them further as additional empirical data becomes available. The experimental methods and some measured results from the climate chamber tests have been published previously.Part II describes a thermal comfort model with coefficients representing 19 individual local body parts. For each part, its local comfort is predicted from local and whole-body thermal sensations. These inputs are obtained from the sensation models described in Part I and III, or from measurements.     

Evaluating the performance of thermal sensation prediction with a biophysical model

Neutral thermal sensation is expected for a human body in heat balance in near‐steady‐state thermal environments. The physiological thermoneutral zone (TNZ) is defined as the range of operative temperatures where the body can maintain such heat balance by actively adjusting body tissue insulation, but without regulatory increases in metabolic rate or sweating. These basic principles led to the hypothesis that thermal sensation relates to the operative temperature distance from the thermoneutral centroid (dTNZ_op). This hypothesis was confirmed by data from respiratory climate chamber experiments. This paper explores the potential of such biophysical model for the prediction of thermal sensation under increased contextual variance. Data (798 votes, 47 participants) from a controlled office environment were used to analyze the predictive performance of the dTNZ_op model. The results showed a similar relationship between dTNZ_op and thermal sensation between the dataset used here and the previously used dataset. The predictive performance had the same magnitude as that of the PMV model; however, potential benefits of using a biophysical model are discussed. In conclusion, these findings confirm the potential of the biophysical model with regard to the understanding and prediction of human thermal sensation. Further work remains to make benefit of its full potential.     

局部热暴露对人体热反应的影响研究(1):局部热感觉对全身热感觉的影响

随机选取30名男性受试者,在中性偏热的房间中,局部冷气流分别作用于脸部、胸部和背部,采用问卷调查的方法以一定的时间间隔记录了受试者身体各个部位的局部热感觉和全身热感觉。结果表明,局部热暴露在改变暴露部位和全身的热感觉的同时,也显著改变了非暴露部位的热感觉,据此提出了基于影响因子的分析方法和全身热感觉的预测模型。     

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.     

管带式蒸发器数学模型试验研究

本文针对管带式蒸发器的稳态分布参数数学模型[1]进行湿工况下制冷剂侧和空气侧的性能实验,结果表明,Chang提出的j因子计算关联式对空气侧干式表面传热系数的预测值与实测值吻合较好。与实验值相比,换热量计算误差在9%以内,空气侧风阻预测误差在11.17%以内,该模型不仅合理可靠,而且具有较高的准确度。研究结果对汽车空调厂商在设计同类型产品时具有一定参考价值。     

Do people like to feel ‘neutral’?: Exploring the variation of the desired thermal sensation on the ASHRAE scale

This analysis explores the pattern of variation of the desired thermal sensation on the ASHRAE scale, applying the method of direct enquiry. Data are from studies of thermal comfort at university lectures and in selected dwellings. Respondents reported both their thermal sensation and the sensation they would have desired at that time. The data contain 868 comparisons of the actual and the desired sensation. On 57% of occasions the desired sensation was other than ‘neutral’. The respondents did not always desire the same sensation, and the mean desired sensation differed systematically among the respondents. The mean desired sensation depended to some extent on the actual sensation, there being a positive correlation in the region from ‘neutral’ and ‘warm’ and a negative correlation outside this region. Sensations on the ASHRAE scale are shown to have more than one meaning. Adjusting the ASHRAE scale to allow for the desired sensation yields different distributions of thermal comfort and different group-optimum temperatures. The adjustment should therefore be applied whenever the ASHRAE scale is used. The implications for thermal simulation and for energy use in buildings are considered.     

A study on pesticide runoff from paddy fields to a river in rural region--2: development and application of a mathematical model

A mathematical model was developed to predict the runoff of pesticides from paddy fields to a river in a rural region. The model comprises three submodels: (1) submodel for river flow, (2) submodel for pesticide behavior in paddy fields, (3) submodel for pesticide behavior in a river. The tank model was applied to predict the river flow and the paddy water. In order to reproduce the actual behavior of pesticides in paddy fields, the kinetics of the transport and reaction mechanisms of pesticides applied to paddy fields were considered in the model. The model was applied to the Kozakura River Basin where the detailed field survey was conducted. The model reflected well the runoff characteristics of pesticides obtained from the detailed field survey.     

欲善其事,先利其器——谈建筑设计与技术教学的整合

建筑技术是建筑设计得以实现的物质技术条件,两者关系如同"器"与"事".该文针对当前建筑设计与技术教育相脱离的现状,提出将建筑设计与技术课程进行整合,构建课程结构框架,探索整合的实现手段与目标.通过整合,提高学生的实践应用能力,达到培养应用型人才的教育目标.     

Energy conservation regulations: Impacts on design and procurement of low energy buildings

To reduce the substantial contribution of the built environment to energy consumption and carbon dioxide emissions, the new ‘Part L: Conservation of Fuel and Power’ of the Building Regulations for England and Wales came into force in April, 2006. As a result, the design of all new-build and refurbished buildings must comply with ‘Target Carbon Emissions Rates’. Apart from the purely practical implications of compliance, the new Part L has prompted interesting questions concerning procurement and the impact on design and construction teams.     

Thermal design tool for outdoor spaces based on heat balance simulation using a 3D-CAD system

This paper focuses on the development of a thermal design tool for use in planning outdoor spaces by combining a heat balance simulation for urban surfaces, including buildings, the ground and greenery, with a 3D-CAD system that can be run on a personal computer. The newly developed tool is constructed by improving the previous simulation model, which uses the geographic information system (GIS) for the input data. The simulation algorithm is constructed so as to predict the surface temperature distribution of urban blocks while taking into account the actual design of the outdoor space using the 3D-CAD system. A method of multi-tracing simulation to calculate the sky view factor and radiative heat transfer is established. The optimal mesh size is examined for the tool so as to provide detailed spatial geometry within a suitable calculation time. The simulation model is integrated with an all-purpose 3D-CAD software, and the pre-processing method are constructed for practical use. The results obtained by applying this simulation tool to an area of detached houses reveals that the tool is able to evaluate the effects of building shape, materials, and tree shade on the surface temperature distribution, as well as the MRT and HIP, which are evaluation indices of the outdoor thermal environment.     

A nodal thermal model for photovoltaic systems: Impact on building temperature fields and elements of validation for tropical and humid climatic conditions

This article deals with both an experimental study and a numerical model of the thermal behaviour of a building whose roof is equipped with photovoltaic panels (PV panels). The aim of this study is to show the impact of the PV panels in terms of level of insulation or solar protection for the building. Contrary to existing models, the one presented here will allow us to determine both the temperature field of the building and the electric production of the PV array. Moreover, an experimental study has been conducted in La Reunion Island, where the climate is tropical and humid, with a strong solar radiation. In such conditions, it is important to minimise the thermal load through the roof of the building. The thermal model is integrated in a building simulation code and is able to predict the thermal impact of PV panels installed on buildings in several configurations and also their production of electricity. Basically, the PV panel is considered as a complex wall within which coupled heat transfer occurs. Conduction, convection and radiation heat transfer equations are solved simultaneously to simulate the global thermal behaviour of the building envelope including the PV panels; this is an approach we call ‘integrated modelling’ of PV panels. The experimental study is used to give elements of validation for the numerical model and a sensitivity analysis has been run to put in evidence the governing parameters. It has been shown that the radiative properties of the PV panel have a great impact on the temperature field of the tested building and the determination of these parameters has to be taken with care.     

基于我国老年化的住宅空间模式研究

首先提出当前老龄化问题和当前老年人的居住现状,进而分析了老年人的生活特点及对居住环境的特殊要求,并就此探讨现阶段适宜的老年人居住模式和居住环境,最后,总结了适应我国老年人的居住设计指导原则。     

Numerical simulations of wind-driven rain on building envelopes based on Eulerian multiphase model

A numerical simulation approach for evaluation of wind-driven rain (WDR) on building envelopes is presented based on Eulerian multiphase model. Unlike existing methods, which are generally on the basis of Lagrange frame to deal with raindrop motions by trajectory-tracking techniques, the present approach considers both wind and rain motions and their interactions under Euler frame. By virtue of the Eulerian multiphase model, the present method could significantly reduce the complexity in evaluations of WDR parameters, simplify the boundary condition treatments and is more efficient to predict transient states of WDR, spatial distributions of rain intensity, impacting rain loads on building surfaces, etc. A numerical example shows that the simulation results by the present method agree well with available experimental and numerical data, verifying the accuracy and reliability of the WDR simulation approach based on the Eulerian multiphase model. It is also demonstrated through the validation example that the present method is an effective tool for numerical evaluations of WDR on building envelopes.     

虚实结合的多层次钢结构教学模型体系建设

钢结构形式多变、构造复杂、课程知识点多给土木工程专业学生的学习带来了困难。对此,建立了虚拟仿真和实物模型相结合的教学模型体系辅助学生深入理解相关知识。梳理了本科教学中所涉及的钢结构课程体系,并总结了知识广、理解难和空间感要求高三大特点,从构件、节点、结构体系和损坏形态等多个层次建立了虚实结合的钢结构教学模型体系。最后,介绍了该模型体系中四大模块的建设情况。采用虚拟仿真和实物模型相结合的教学方法,与理论教学相互融合、相互促进,全面提高学生对钢结构相关知识的掌握程度。     

基于生成式大模型的老年友好城市设计 ——以杭州市街道为例

中国正面临深度老龄化的挑战,建设 老年友好城市已成为迫切目标。本研究利用百度 “文心一格”大模型,结合居民对街道的老年友 好需求生成改造方案,进一步统计分析各群体 的老年友好需求差异及整体特征。研究发现：第 一,生成式大模型可以有效地应用在老年友好 城市设计;第二,女性更关注老年友好街道的环 境设施功能,男性更关注街道形态;受教育水平 越高,老年友好街道的绿化率需求越高;第三, 当前街道的天空开敞度、围墙（栏）、步行道、路 灯、车流和车行道现状与老年友好街道需求之间 仍存在差距。本研究以期为老年友好理念下的城 市规划和设计提供创新方法和实践参考。