Adaptive thermal comfort in Australian school classrooms

This survey of thermal comfort in classrooms aimed to define empirically the preferred temperatures, neutral temperatures and acceptable temperature ranges for Australian school children, and to compare them with findings from adult populations. The survey was conducted in a mixture of air-conditioned, evaporative-cooled and naturally ventilated classrooms in nine schools located in three distinct subtropical climate zones during the summer of 2013. A total of 2850 questionnaires were collected from both primary (grade) and secondary (high) schools. An indoor operative temperature of about 22.5°C was found to be the students’ neutral and preferred temperature, which is generally cooler than expected for adults under the same thermal environmental conditions. Despite the lower-than-expected neutrality, the school children demonstrated considerable adaptability to indoor temperature variations, with one thermal sensation unit equating to approximately 4°C operative temperature. Working on the industry-accepted assumption that an acceptable range of indoor operative temperatures corresponds to group mean thermal sensations of ?0.85 through to +0.85, the present analysis indicates an acceptable summertime range for Australian students from 19.5 to 26.6°C. The analyses also revealed between-school differences in thermal sensitivity, with students in locations exposed to wider weather variations showing greater thermal adaptability than those in more equable weather districts.     

Adaptive thermal comfort in primary school classrooms: Creating and validating PMV-based comfort charts

In this research the thermal comfort and thermal comfort parameters for children in primary school classrooms has been investigated. Actual thermal sensation and clothing insulation of children (age 9–11) in non-air-conditioned classrooms in three different schools in the Netherlands have been obtained. Results are available for a total of 24 days, covering winter, spring and summer conditions (year 2010). Questionnaires have been applied to obtain the actual thermal sensation and clothing insulation in the morning and afternoon of regular school days. In this period physical parameters (temperature, relative humidity, etc.) were recorded as well in order to derive the PMV.     

Field experiments on thermal comfort in campus classrooms in Taiwan

This paper presents the results of the ASHRAE methodology for thermal comfort study applied in Taiwan. Field experiments conducted in 10 naturally ventilated and 26 air-conditioned campus classrooms used survey questionnaires and physical measurements to collect data. A total of 944 individuals in seven universities completed 1294 questionnaires. The chi-square tests were applied to find the significant aspects that affect students’ thermal sensations. The results show that air temperature, air movement and mean radiant temperature have significant influence, but humidity has no statistical significance. By using probit regressive analyses, the thermal neutrality and thermal preference of students occurred at 26.3 °C ET^* and 24.7 °C ET^*, respectively. Responses from those students suggest a wider acceptable temperature range for occupants in Taiwan. The margins of the acceptable zones obtained from direct and indirect acceptability assessing methods are 21.1–29.8 °C ET^* and 24.2–29.3 °C ET^*, respectively. When compared with similar studies elsewhere, this finding supports the sentiments on climatic adaptation.     

Revisiting thermal comfort models in Iranian classrooms during the warm season

The validity of existing thermal comfort models is examined for upper primary school children in classroom settings. This is of importance to enhance productivity in the learning environment and to improve the control of artificial heating and cooling, including the potential for energy savings. To examine the thermal perceptions of children aged 10–12 years in non-air-conditioned classrooms, three sets of field experiments were conducted in boys’ and girls’ primary schools in Shiraz, Iran. These were undertaken during regular class sessions covering cool and warm conditions of the school year, polling responses from 1605 students. This paper illustrates the overall methods and reports the results of the warm season field survey (N?=?811). This investigation suggests that predicted mean vote-predicted percentage of dissatisfied (PMV/PPD) underestimates children's actual thermal sensation and percentage dissatisfied in the investigated classrooms. The analysis shows that sampled children may be slightly less sensitive to indoor temperature change than adults. The upper acceptable temperature derived from children's responses corresponding to mean thermal sensations of +0.85 is 26.5°C, which is about 1°C lower than the ASHRAE upper 80% acceptability limit. This implies that sampled children feel comfortable at lower temperatures than predicted by the ASHRAE Adaptive model during the warm season.     

Perception of the thermal environment in high school and university classrooms: Subjective preferences and thermal comfort

This work shows some of the results of a field study about environmental comfort investigations in classrooms. In this project thermal, acoustic, visual and air quality aspects were analysed in a number of classrooms—13 classrooms at four different high schools of the Provincia di Torino and four typical medium-sized university classrooms of the Politecnico di Torino, Italy. The investigations were carried out during the heating period. Both field measurements and subjective surveys were performed at the same time during the regular lesson periods.     

厦门高校教室冬季热环境测试及热舒适预测

为考察冬季非空调环境下人体热感觉,对厦门某高校教室的热舒适度进行了现场测试.在测量室内外热舒适参数的同时,通过问卷调查得到了人体热反应样本.分析样本得出厦门高校教室冬季非空调工况下人体热中性温度和热期望温度分别为19.3和19.4℃.综合考虑温度、相对湿度、平均辐射温度、风速及服装热阻对坐姿轻度活动状态人体的热舒适影响,使用MATLAB软件进行非线性回归,得到非空调工况下热舒适预测方程.该预测方程与实测得到的人体热舒适投票两者结果有较高相关度,同时较大程度上反映了冬季非空调环境下人体热感觉的变异.     

Adaptive analysis of thermal comfort in university classrooms: Correlation between experimental data and mathematical models

Numerous studies are in progress to support adaptive models in indoor thermal comfort evaluation and to establish quantitative indexes to allow the subject to optimize his/her comfort conditions.     

Overall thermal sensation,acceptability and comfort

The relationships between overall thermal sensation, acceptability and comfort were studied experimentally under uniform and non-uniform conditions separately. Thirty subjects participated in the experiment and reported their local thermal sensation of each body part, overall thermal sensation, acceptability and comfort simultaneously. Sensation, acceptability and comfort were found to be correlated closely under uniform conditions and acceptable range ran from neutral to 1.5 (midpoint between ‘Slightly Warm’ and ‘Warm’) on thermal sensation scale and contained all comfortable and slightly uncomfortable votes on thermal comfort scale. Under non-uniform conditions overall thermal acceptability and comfort were correlated closely. However, overall thermal sensation was apart from the other two responses and non-uniformity of thermal sensation was found to be the reason for the breakage. Combining the effects of overall thermal sensation and non-uniformity of thermal sensation, a new thermal acceptability model was proposed and the model was testified to be applicable to uniform and non-uniform conditions over a wide range of whole body thermal state from neutral to warm.     

Studying thermal comfort in context

This commentary considers the recent Building Research & Information special issue titled ‘Comfort in a Lower Carbon Society’ and what it suggests about how to conduct contextual studies of thermal comfort. Firstly, consideration is given to the places within which comfort is examined and how research might beneficially trespass beyond the borders of the building to explore how lifestyles combine various places with a range of social expectations and techniques for managing personal temperature. Secondly, the suggestion is that whilst it could be worthwhile to examine various lifestyles, contextually sensitive researchers must select the groups they study carefully and acknowledge the limitations associated with this choice. Thirdly, it considers which practical methods are most appropriate for this line of research and how existing approaches could be supplemented by techniques currently uncommon in this field. The overall argument is that qualitative approaches with groups of current users could identify the most sensitive ways of steering societies towards more sustainable thermal futures.

Ce commentaire analyse le récent numéro spécial de Building Research & Information intitulé « Le confort dans une société sobre en carbone » et ce qu'il suggère sur la façon de mener des études contextuelles du confort thermique. L'auteur s'intéresse tout d'abord aux lieux où le confort est examiné et comment la recherche pourrait avantageusement dépasser les frontières du bâtiment pour voir comment les styles de vie combinent divers lieux avec une gamme d'attentes sociales et de techniques pour gérer la température personnelle. Puis, alors qu'il pourrait être intéressant d'examiner divers styles de vie, il suggère que les chercheurs sensibles au contexte sélectionnent des groupes qu'ils étudient avec soin et reconnaissent les limites associées à ce choix. Enfin, il considère les méthodes pratiques qui seraient les plus appropriées pour cette ligne de recherche et comment les approches existantes pourraient être complétées par des techniques qui sont actuellement rares dans ce domaine. L'argument général est que les approches qualitatives avec des groupes d'utilisateurs actuels pourraient jouer un rôle utile dans l'identification des solutions les plus judicieuses pour diriger les sociétés vers un avenir thermique plus durable.

Mots clés: adaptation, agence, confort, société sobre en carbone, satisfaction de l'occupant, méthodes qualitatives, consommation durable     

关于"热舒适"的讨论

指出了人体热反应研究中关于热舒适的一些模糊概念及对热舒适与热感觉关系的含混认识。分析了热舒适与热感觉的不同含义、现有的不同解释及两者的稳态和动态条件下的差别。     

关于热感觉和热舒适与热适应性的讨论

系统地论述了人体热舒适研究的发展过程,讨论了热感觉、热舒适及热适应的定义,并分析了热感觉与热舒适的差异及与热适应性的关系,得出了人们对同一热环境有不同的热感觉及热舒适性,主要是由于人体的适应性产生的。     

Investigation of air quality,comfort parameters and effectiveness for two floor-level air supply systems in classrooms

The method of distributing the outdoor air in classrooms has a major impact on indoor air quality and thermal comfort of pupils. In a previous study, ([11] Karimipanah T, Sandberg M, Awbi HB. A comparative study of different air distribution systems in a classroom. In: Proceedings of Roomvent 2000, vol. II, Reading, UK, 2000. p. 1013–18; [13] Karimipanah T, Sandberg M, Awbi HB, Blomqvist C. Effectiveness of confluent jets ventilation system for classrooms. In: Idoor Air 2005, Beijing, China, 2005 (to be presented).) presented results for four and two types of air distribution systems tested in a purpose built classroom with simulated occupancy as well as computational fluid dynamics (CFD) modelling.     

Adaptive thermal comfort and sustainable thermal standards for buildings

The origin and development of the adaptive approach to thermal comfort is explained. A number of recent developments in the application of the theory are considered and the origin of the differences between adaptive thermal comfort and the ‘rational’ indices is explored. The application of the adaptive approach to thermal comfort standards is considered and recommendations made as to the best comfort temperature, the range of comfortable environments and the maximum rate of change of indoor temperature. The application of criteria of sustainability to thermal standards for buildings is also considered.     

均匀和不均匀热环境下热感觉、热可接受度和热舒适的关系

对30名受试者采用问卷调查的方式,研究了均匀热环境和不均匀热环境下人体全身热感觉、热可接受度和热舒适的关系。结果显示,在均匀热环境下,全身热感觉、热可接受度和热舒适具有较强的线性相关关系,可接受范围涵盖了(0,1.5)的热感觉投票和"舒适"与"稍有不适"标度范围内的热舒适投票;在不均匀热环境下,全身热可接受度与热舒适密切相关,而全身热感觉与热可接受度和热舒适出现分离,热感觉不均匀度是其原因。综合考虑全身热感觉和热感觉不均匀度的影响,提出了综合评价模型。经验证,该模型适用于全身热状态为中性偏热的均匀和不均匀热环境。     

Objective criteria for thermal comfort

For thermal comfort an objective definition is given, based on physiological results. The significance of skin temperature in this context is the basis for a measurement device which simulates the human skin physically. Results of measurements using the artificial skin including psychophysical investigations and draught measurements are discussed as well as the applicability of the objective comfort criteria to current HVAC problem areas. Finally the significance of the equivalent temperature for future standardization is emphasized.     

非空调环境下的热舒适性调查

对长沙市非空调环境下的人体热舒适性进行了问卷调查,分析了长期生活在湖南的本地人与北方人对同一环境的冷热感和湿度感,发现本地人耐寒性与耐湿性更强.研究了空气比焓、温度、湿度等参数对热感觉平均投票值的影响规律,发现在低温区域相对湿度对人体舒适感有明显作用.统计了不同环境下相应的热感觉平均投票值、湿度感以及实际不满意率的对应关系,并与Fanger提出的PMV-PPD指标进行了对比.     

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.     

Capabilities and limitations of thermal models for use in thermal comfort standards

Thermal models of the human body and its interactions with the surrounding thermal environment are often proposed, and to some extent are used, as the basis for thermal comfort standards. These models range from simple, one-dimensional, steady-state simulations to complex, transient, finite element codes with thousands of nodes. The models are potentially very useful in that they provide a straightforward means to incorporate the numerous physical variables that affect comfort. Some models can be applied to complex situations which would be difficult, if not impossible, to reflect in simple charts or equations. Whether simple or complex, all of these models have limitations for use in standards. These limitations include the accuracy of the physical simulation and the accuracy of the inputs to the model. Perhaps, the biggest limitation is the accuracy with which comfort perceptions can be related to the physiological variables simulated in the thermal models.     

上海地区村镇住宅热环境与热舒适度研究

利用现场实测方法,对上海一典型村庄进行了夏季及冬季住宅热环境以及居民热舒适性现场实测及调研,研究了上海地区农村住宅热环境及室内热舒适度问题。依据问卷调研结果得到了夏季、冬季农村居民对于住宅环境的可接受温度范围、热中性温度以及期望温度,同时研究了热舒适度的影响因素,可为上海地区村镇住宅节能计算、热舒适环境与绿色生态住宅的设计提供必要的理论依据。