上海地区适应性热舒适研究

为研究上海地区人体热感觉和适应性热舒适现状,通过环境参数测量和问卷调查结合的方式来分析和探讨室内外气候条件、服装热阻、热感觉等关系。本文主要涉及自然通风建筑内人体热感觉和热中性温度随季节变化的关系。结果表明:在适应性热舒适研究中,人体中性温度与室外环境温度具有较强的相关性,得到的上海地区适应性热舒适模型可为适合我国自身特点的热舒适研究提供依据。     

Thermal comfort: use of controls in naturally ventilated buildings

A field study of the thermal comfort of workers in natural ventilated office buildings in Oxford and Aberdeen, UK, was carried out which included information about use of building controls. The data were analysed to explore that what effect the outdoor temperature has on the indoor temperature and how this is affected by occupants’ use of environmental controls during the peak summer (June–August). The proportion of subjects using a control was related to indoor and outdoor temperatures to demonstrate the size of the effect. The results suggest that the use of controls is also related to thermal sensation and their appropriate use is a significant part of adaptive behaviour to modify the indoor thermal conditions. The results make it possible to predict the effect of temperature on the ventilation rate in naturally ventilated buildings.     

Thermal comfort of people in the hot and humid area of China—impacts of season,climate, and thermal history

We conducted a climate chamber study on the thermal comfort of people in the hot and humid area of China. Sixty subjects from naturally ventilated buildings and buildings with split air conditioners participated in the study, and identical experiments were conducted in a climate chamber in both summer and winter. Psychological and physiological responses were observed over a wide range of conditions, and the impacts of season, climate, and thermal history on human thermal comfort were analyzed. Seasonal and climatic heat acclimatization was confirmed, but they were found to have no significant impacts on human thermal sensation and comfort. The outdoor thermal history was much less important than the indoor thermal history in regard to human thermal sensation, and the indoor thermal history in all seasons of a year played a key role in shaping the subjects' sensations in a wide range of thermal conditions. A warmer indoor thermal history in warm seasons produced a higher neutral temperature, a lower thermal sensitivity, and lower thermal sensations in warm conditions. The comfort and acceptable conditions were identified for people in the hot and humid area of China.     

Using the adaptive model of thermal comfort for obtaining indoor neutral temperature: Findings from a field study in Hyderabad,India

There is a dearth of thermal comfort studies in India. It is aimed to investigate into the aspects of thermal comfort in Hyderabad and to identify the neutral temperature in residential environments. This was achieved through a thermal comfort field study in naturally ventilated apartment buildings conducted during summer and monsoon involving over 100 subjects. A total of 3962 datasets were collected covering their thermal responses and the measurement of the thermal environment. The comfort band (voting within –1 and +1), based on the field study, was found to be 26–32.45°C, with the neutral temperature at 29.23°C. This is way above the indoor temperature standards specified in Indian Codes. It was found that the regression neutral temperature and the globe temperature recorded when voting neutral converged when mean thermal sensation of the subjects was close to 0. This happened during the period of moderate temperature when the adaptive measures were adequate. The indoor temperatures recorded in roof-exposed (top floor) flats were higher than the lower floors. The thermal sensation and preference votes of subjects living in top floors were always higher. Consequently, their acceptance vote was also lower. It was found that the subjects living in top floor flats had a higher neutral temperature when the available adaptive opportunities were sufficient. This was due to their continuous exposure to a higher thermal regime due to much higher solar exposure. This study calls for special adaptive measures for roof-exposed flats to achieve neutrality at higher temperature.     

Facade design optimization for naturally ventilated residential buildings in Singapore

Parametric studies of facade designs for naturally ventilated residential buildings in Singapore were carried out to optimize facade designs for better indoor thermal comfort and energy saving. Two criteria regarding indoor thermal comfort for naturally ventilated residential buildings are used in this study. To avoid the perception of thermal asymmetry, temperature difference between mean radiant temperature and indoor ambient air temperature should be less than 2 °C [F.A. Chrenko, Heated ceilings and comfort. J. Inst. Heat. Ventilating Eng. 20 (1953) 375–396; F.A. Chrenko, Heated ceilings and comfort. J. Inst. Heat. Ventilating Eng. 21 (1953) 145–154]. Thermal comfort regression model for naturally ventilated residential buildings in Singapore was used to evaluate various facade designs either. Facade design parameters: U-values, orientations, WWR (window to wall ratio) and shading device lengths are considered in the investigation. The building simulation results for a typical residential building in Singapore indicated that the U-value of facade materials for north and south orientations should be less than 2.5 W/m² K and the U-value of facade materials for north and south orientations should be less than 2 W/m² K. From the coupled simulation results, it was found that the optimum window to wall ratio is equal to 0.24. Optimum facade designs and thermal comfort indexes are summarized for naturally ventilated residential buildings in Singapore.     

Derivation of the adaptive equations for thermal comfort in free-running buildings in European standard EN15251

The equation for thermal comfort for buildings in the free-running mode (Annexe A2) in European Standard EN15251 rests on the data collected in the EU project Smart Controls and Thermal Comfort (SCATs). Many of these data were from naturally ventilated office buildings which were in free-running mode outside the heating season. Using the data from these buildings a relationship between indoor comfort and outdoor climate was developed for free-running buildings. This paper describes the data and the methods of analysis used to estimate the comfort conditions in the variable environment of free-running buildings. The paper also describes how the indoor comfort conditions were related to the running mean of the outdoor temperature, and addresses the effects of air movement and humidity. The paper considers the proportions of people likely to be comfortable if the temperature differs from the neutral temperature. The differences between the adaptive comfort charts in EN15251 and ASHRAE 55-2004 are discussed.     

Thermal comfort for naturally ventilated residential buildings in Harbin

This field study was conducted during summer 2009 in Harbin, northeast of China in order to investigate human responses to the thermal conditions in naturally ventilated residential buildings in cold climate. We visited 257 families in six residential communities and collected 423 sets of physical data and subjective questionnaires. The neutral temperature is 23.7 °C, with the clothing insulation of 0.54 clo. The neutral temperature in Harbin is lower than neutral temperatures in warm climates by others, which is in accordance with the thermal adaptive model. 80% of the occupants can accept the air temperature range of 21.5-31.0 °C, which is wider than the summer comfort temperature limits by the adaptive model. The preferred temperature range fell between 24.0 °C and 28.0 °C. About 57.9% of the subjects voted “no change” with the humid range of 40% and 70%. 61.5% of the occupants voted “no change” with the air velocity within the range of 0.05-0.30 m/s. In summer, occupants preferred air velocity of lower than 0.25 m/s even at higher indoor temperature, which is different from the other field studies. The Harbin occupants in naturally ventilated dwellings can achieve thermal comfort by operable windows instead of running air-conditioners.     

Development of an adaptive thermal comfort equation for naturally ventilated buildings in hot-humid climates using ASHRAE RP-884 database

The objective of this study was to develop an adaptive thermal comfort equation for naturally ventilated buildings in hot-humid climates. The study employed statistical meta-analysis of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) RP-884 database, which covered several climatic zones. The data were carefully sorted into three climate groups including hot-humid, hot-dry, and moderate and were analyzed separately. The results revealed that the adaptive equations for hot-humid and hot-dry climates were analogous with approximate regression coefficients of 0.6, which were nearly twice those of ASHRAE and European standards 55 and EN15251, respectively. The equation using the daily mean outdoor air temperature had the highest coefficient of determination for hot-humid climate, compared with other mean temperatures that considered acclimatization of previous days. Acceptable comfort ranges showed asymmetry and leaned toward operative temperatures below thermal neutrality for all climates. In the hot-humid climate, a lower comfort limit was not observed for naturally ventilated buildings, and the adaptive equation was influenced by indoor air speed rather than indoor relative humidity. The new equation developed in this study can be applied to tropical climates and hot-humid summer seasons of temperate climates.     

A comparative analysis of urban and rural residential thermal comfort under natural ventilation environment

The paper presents a field study of occupants’ thermal comfort and residential thermal environment conducted in an urban and a rural area in Hunan province, which is located in central southern China. The study was performed during the cold winter 2006. Twenty-eight naturally ventilated urban residences and 30 also naturally ventilated rural residences were investigated. A comparative analysis was performed on results from urban and rural residences. The mean thermal sensation vote of rural residences is approximately 0.4 higher than that of urban residences at the same operative temperature. Thermal sensation votes calculated by Fanger’s PMV model did not agree with these obtained directly from the questionnaire data. The neutral operative temperature of urban and rural residences is 14.0 and 11.5 °C, respectively. Percentage of acceptable votes of rural occupants is higher than that of urban occupants at the same operative temperature. It suggests that rural occupants may have higher cold tolerance than urban occupants for their physiological acclimatization, or have relative lower thermal expectation than urban occupants because of few air-conditioners used in the rural area. The research will be instrumental to researchers to formulate thermal standards for naturally ventilated buildings in rural areas.     

Investigating the principal adaptive comfort relationships for young children

Thermal comfort surveys in school classrooms suggest that children have different thermal preferences to adults. This implies a need to revisit the current adult-based thermal comfort models. This paper investigates the principal adaptive comfort relationships that form the basis of adaptive comfort theory, using 2693 pupil thermal sensation responses and measured classroom temperatures from surveys in two naturally ventilated school buildings. The data were examined in two steps. Firstly, each survey set, obtained over one-day visits to the schools, was examined in order to derive the relationship between indoor temperature change and comfort vote with minimum impact of adaptation. Secondly, the data set was investigated over the entire survey period in relation to the weather experienced by the pupils in order to estimate their time for adaptation to outdoor temperature changes. The analysis shows that the basic adaptive comfort relationships are valid for children. However, a difference was found for the correlation coefficients of the comfort temperature to the outdoor running mean temperature between the schools, and a mismatch between their adaptive comfort equations. It is proposed that the difference in the consistency of the weather during the tests is the main reason for this discrepancy.     

基于风速补偿的自然通风房间热舒适性模拟研究

为获得自然通风条件下室内的热舒适评价方法,利用Fluent软件,根据杭州市典型室外气象参数确定边界条件,模拟居住建筑室外绕流场、室内通风场和温度场的分布规律;运用基于风速补偿的热适应性评价模型分析室内热舒适状况,并将此法与PMV模型结果对比,表明前者定义舒适的阈值较小,且正向偏离较大,后者则能较好反映自然通风房间的热环境。     

A comparative analysis of short-term and long-term thermal comfort surveys in Iran

This paper describes two field studies of thermal comfort conducted in Ilam, a city located in western Iran. The first study consisted of two short-term surveys carried out during two climatically extreme periods—a hot summer and a cold winter—in 1998. The second study consisted of a long-term survey that collected data throughout the whole of 1999. Both studies were performed in naturally ventilated buildings. This paper shows some comparative analysis between the findings from the short-and long-term studies. For the hot season the neutral temperatures from the short-and long-term studies were 28.4 and 26.7 °C, respectively. For the cold season the short-and long-term neutral temperatures were 20.8 and 21.2 °C, respectively. The results show a very good agreement between both studies in Iran. The main points of interest from the studies were the variability of acceptable conditions, a good relationship between neutral temperature and room temperatures and also, more importantly, between indoor comfort and outdoor conditions. The findings reveal that the people in the study could achieve comfort at higher indoor air temperatures compared with the recommendations of international standards such as ISO 7730.     

Indoor thermal environment evaluations and parametric analyses in naturally ventilated buildings in dry season using a field survey and PMVe-PPDe model

The PMV model predicts thermal sensation well in HVAC buildings while it predicts a warmer thermal sensation than the occupants actually feel in naturally ventilated buildings. For using PMV model to predict thermal sensation well in a naturally ventilated building, the extended PMV model (PMVe) including an expectancy factor (e) and PMV was proposed by Fanger. Besides, calculations of PMV are too complex to be applied in practice. To obtain simple and applicable correlations, taking Qujing of Yunnan province, China, as example, a dry season (6-month) field measurement was conducted in a naturally ventilated residential room. Based on the collected data, PMVe values were calculated by using Newton’s iterative method. It is shown that the PMVe values approximately vary from −1.3 to 0.20 and the indoor thermal environment is somewhat discomfortable on some cloudy or rainy days. Parameters relationships and indoor air temperature gradients (vertical and horizontal) were also studied by using linear regression technique and quadratic polynomial fit technique. Numerous correlations with high relativities have been developed. It is convenient to use these results to evaluate the indoor thermal environment in naturally ventilated buildings under similar climatic conditions.     

Thermal comfort evaluation of naturally ventilated public housing in Singapore

Field survey was conducted to evaluate thermal comfort perception of the occupants in naturally ventilated public housing in Singapore. Thermal acceptability assessment was performed to find out whether the naturally ventilated indoor environment meets the ASHRAE Standard-55's 80% acceptability criteria. The study investigated whether thermal perception was influenced by different sessions of the day, building height, and flat types. Comparative analysis of thermal sensation and thermal comfort votes revealed that a high proportion of people experiencing sensations of +2,+3 still found the conditions to be comfortable. The survey also examined the adaptive behavior of the occupants in the usage of climatic control such as windows, fans and air-conditioning to modify the indoor environment.     

Thermal comfort in naturally ventilated buildings in hot-humid area of China

Human responses to thermal environments in naturally ventilated (NV) buildings in hot-humid area of China were systematically investigated in the present study. Thirty local inhabitants long-time living in NV buildings participated in the study and reported their thermal sensations and perceptions and adaptive behaviors while all physical and personal variables were collected. Based on a year-long survey, a close match of indoor physical variables and occupants’ clothing insulation with outdoor climate was found as an important feature of NV buildings. Integrated indices can capture more thermal contexts in the NV buildings in hot-humid area of China than simple indices. Thermal sensation was found to be a good linear function of SET* with the thermal neutrality of 25.4 °C and the 90% (80%) acceptable range of 23.5–27.4 °C (22.1–28.7 °C) in SET*. The adaptive evidences were obtained for clothing adjustment, window opening and using fan respectively and the modified PMV model was validated to be applicable in NV buildings in hot-humid area of China with an expectancy factor of 0.822. Comparisons with other field studies indicate that people can develop various human-environment relationships through thermal adaptation to local climate, resulting in different thermal neutral temperatures in various climates. The subjects in hot-humid area of China are more acclimated and tolerable with hot and humid environments and more uncomfortable and intolerable with cold environments while compared with those in temperate climates.     

Thermal comfort assessment and application of radiant cooling: A case study

A field assessment of thermal comfort was conducted at Mehran University of Engineering and Technology, situated in the subtropical region of Pakistan. The results show that people of the area were feeling thermally comfortable at effective temperature of 29.85 °C (operative temperature 29.3 °C). A comparison of this neutral effective temperature was made with the neutral effective temperature determined from adaptive models. It is found that the neutral effective temperature determined during this study closely match that of the adaptive model based on either indoor temperature or both indoor and outdoor temperatures. The results of thermal acceptability assessment show that more than 80% of occupants were satisfied at an effective temperature of 32.5 °C, which is 6.5 °C above the upper boundary of ASHRAE thermal comfort zone. Naturally ventilated classrooms and air-conditioned offices of the University were simulated using TRNSYS system simulation program for two cases, once when conventional air-conditioning is used for providing thermal comfort, and when comfort is achieved through radiant cooling. In the simulation, cooling tower was used to regenerate cooling water for the radiant cooling system. Energy consumption was estimated from simulation of both cases. The results show that it is possible to achieve thermal comfort for most of the time of the year through the use of radiant cooling without a risk of condensation of moisture from air on the radiant cooling surfaces. A comparison of the energy consumption estimates show that savings of 80% is possible in case thermal comfort is achieved through radiant cooling instead of conventional air-conditioning.     

Long-term field survey on thermal adaptation in office buildings in Japan

A long-term field survey was conducted with six buildings in order to investigate how the occupants adapt to the indoor climate in office buildings in Japan. More than 5000 questionnaires and corresponding indoor temperatures were collected. Clothing adjustment was observed to be related to outdoor temperature and indoor temperature, as well as dress codes. No considerable differences were found on the thermal perceptions between two groups of buildings, which provided different levels of opportunity for controlling indoor climate. With both groups, the preferred SET* was always close to 26 °C. The comfort temperature was estimated from the results of clothing adjustment and the preferred SET*. The gradient of the comfort temperature to outdoor temperature was found to be between the adaptive model for centralized HVAC and for natural ventilation. It could be caused by that the major part of the occupants in the present study had more opportunity to control their thermal conditions than in the centralized HVAC buildings (i.e. operable windows, controllable HVAC or personal fans).     

Effect of age, gender, economic group and tenure on thermal comfort: A field study in residential buildings in hot and dry climate with seasonal variations

Energy consumption in Indian residential buildings is one of the highest and is increasing phenomenally. Indian standards specify comfort temperatures between 23 and 26 °C for all types of buildings across the nation. However, thermal comfort research in India is very limited. A field study in naturally ventilated apartments was done in 2008, during the summer and monsoon seasons in Hyderabad in composite climate. This survey involved over 100 subjects, giving 3962 datasets. They were analysed under different groups: age, gender, economic group and tenure. Age, gender and tenure correlated weakly with thermal comfort. However, thermal acceptance of women, older subjects and owner-subjects was higher. Economic level of the subjects showed significant effect on the thermal sensation, preference, acceptance and neutrality. The comfort band for lowest economic group was found to be 27.3-33.1 °C with the neutral temperature at 30.2 °C. This is way above the standard. This finding has far reaching energy implications on building and HVAC systems design and practice. Occupants’ responses for other environmental parameters often depended on their thermal sensation, often resulting in a near normal distribution. The subjects displayed acoustic and olfactory obliviousness due to habituation, resulting in higher satisfaction and acceptance.     

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%。     

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.