Thermal comfort in air-conditioned mosques in the dry desert climate

In Kuwait, as in most countries with a typical dry desert climate, the summer season is long with a mean daily maximum temperature of 45 °C. Centralized air-conditioning, which is generally deployed from the beginning of April to the end of October, can have tremendous impact on the amount of electrical energy utilized to mechanically control the internal environment in mosque buildings. The indoor air temperature settings for all types of air-conditioned buildings and mosque buildings in particular, are often calculated based on the analytical model of ASHRAE 55-2004 and ISO 7730. However, a field study was conducted in six air-conditioned mosque buildings during the summers of 2007 to investigate indoor climate and prayers thermal comfort in state of Kuwait. The paper presents statistical data about the indoor environmental conditions in Kuwait mosque buildings, together with an analysis of prayer thermal comfort sensations for a total of 140 subjects providing 140 sets of physical measurements and subjective questionnaires were used to collect data. Results show that the neutral temperature (T_n) of the prayers is found to be 26.1 °C, while that for PMV is 23.3 °C. Discrepancy of these values is in fact about 2.8 °C higher than those predicted by PMV model. Therefore, thermal comfort temperature in Kuwait cannot directly correlate with ISO 7730 and ASHRAE 55-2004 standards. Findings from this study should be considered when designing air conditioning for mosque buildings. This knowledge can contribute towards the development of future energy-related design codes for Kuwait.     

Dynamic evaluation of thermal comfort environment of air-conditioned buildings

In this paper, based upon Fanger's thermal comfort concept, several concepts, which utilize computing results obtained from the large eddy simulation (LES), are put forward, such as thermal comfort index based on time-averaged parameters, instantaneous thermal index, time-averaged thermal comfort index and time-averaged thermal comfort index along walking routes. Also their discrepancies and calculation methods are discussed in the paper. Apart from these, we have calculated PD value as an example, whose results indicate that the distributions of four indices are obviously different. Therefore, it is suggested to distinguish different cases and select correspondingly thermal comfort evaluation indices while considering the question of thermal comfort.     

Quantifying the relevance of adaptive thermal comfort models in moderate thermal climate zones

Standards governing thermal comfort evaluation are on a constant cycle of revision and public review. One of the main topics being discussed in the latest round was the introduction of an adaptive thermal comfort model, which now forms an optional part of ASHRAE Standard 55. Also on a national level, adaptive thermal comfort guidelines come into being, such as in the Netherlands. This paper discusses two implementations of the adaptive comfort model in terms of usability and energy use for moderate maritime climate zones by means of literature study, a case study comprising temperature measurements, and building performance simulation. It is concluded that for moderate climate zones the adaptive model is only applicable during summer months, and can reduce energy for naturally conditioned buildings. However, the adaptive thermal comfort model has very limited application potential for such climates. Additionally we suggest a temperature parameter with a gradual course to replace the mean monthly outdoor air temperature to avoid step changes in optimum comfort temperatures.     

亚热带地区自然通风体育馆室内热舒适范围

以广州地区自然通风体育馆为研究对象,用问卷和实测的方式分别采集了建筑内运动人群及观众人群的热感觉投票值和室内外热环境参数,初步建立了这两类人群的适应性热舒适模型和对应的热舒适范围。并通过对比,分析了两类人群的适应性热舒适模型和热舒适范围的区别。研究结果表明：自然通风体育馆室内运动人群的热敏感度0.326 6要小于观众人群的热敏感度0.379 9;运动人群和观众人群的中性操作温度都随着室外温度的升高而升高,前者中性操作温度高于后者,差值在0.80~1.48℃之间;运动人群和观众人群热舒适范围的上下限都随着室外温度的升高而升高,前者热舒适范围的下限与后者相似,但是前者热舒适范围的上限比后者高,差值在1.86~2.48℃之间。     

Field study on occupants’ thermal comfort and residential thermal environment in a hot-humid climate of China

This paper discusses thermal comfort inside residences of three cities in the hot-humid climate of central southern China. Only a few thermal comfort studies have been performed in hot-humid climates and none in Central Southern China. Field sampling took place in the summers of 2003 and 2004 by obtaining 110 responses to a survey questionnaire and measuring environmental comfort variables in three rooms in each of 26 residences. The objectives are to measure and characterize occupant thermal perceptions in residences, compare observed and predicted percent of dissatisfied and discern differences between this study and similar studies performed in different climate zones. Average clothing insulation for seated subjects was 0.54 clo with 0.15 clo of chairs. Only 48.2% of the measured variables are within the ASHRAE Standard 55-1992 summer comfort zone, but approximately 87.3% of the occupants perceived their thermal conditions acceptable, for subjects adapt to prevailing conditions. The operative temperature denoting the thermal environment accepted by 90% of occupants is 22.0–25.9°. In the ASHRAE seven-point sensation scale, thermal neutral temperature occurs at 28.6°. Preferred temperature, mean temperature requested by respondents, is 22.8°. Results of this study can be used to design low energy consumption systems for occupant thermal comfort in central southern China.     

Comparison of thermal comfort algorithms in naturally ventilated office buildings

With the actual environmental issues of energy savings in buildings, there are more efforts to prevent any increase in energy use associated with installing air-conditioning systems. The actual standard of thermal comfort in buildings ISO 7730 is based on static model that is acceptable in air-conditioned buildings, but unreliable for the case of naturally ventilated buildings. The different field studies have shown that occupants of naturally ventilated buildings accept and prefer a significantly wider range of temperatures compared to occupants of air-conditioned buildings. The results of these field studies have contributed to develop the adaptive approach. Adaptive comfort algorithms have been integrated in EN15251 and ASHRAE standards to take into account the adaptive approach in naturally ventilated buildings. These adaptive algorithms seem to be more efficient for naturally ventilated buildings, but need to be assessed in field studies. This paper evaluates different algorithms from both static and adaptive approach in naturally ventilated buildings across a field survey that has been conducted in France in five naturally ventilated office buildings. The paper presents the methodology guidelines, and the thermal comfort algorithms considered. The results of application of different algorithms are provided with a comparative analysis to assess the applied algorithms.     

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.     

上海高层住宅夏季室内热环境调查研究

2006年夏季对上海高层住宅的建筑概况、空调设备、生活方式、能源消费及舒适度等进行了问卷调查并测试了室内温湿度,分析了室外气候条件、住宅形式、人员活动等因素对室内热环境的影响。研究结果表明,底层、中间层、顶层室内温湿度和舒适度差别不大,住户对中午时热环境的不满意率高于早上和晚上,但在能够采取一些降温措施时,不满意率会降低。     

重庆自然通风热舒适模型的建立及热环境评价

在分析国内外自然通风热舒适研究的基础上,结合重庆地区潮湿的气候特点,对现有自然通风热舒适评价模型进行了湿度修正.采用电子温湿度记录仪对重庆地区村镇典型住宅的室内外热湿参数进行了全年监测,并利用该模型对村镇住宅的室内热环境进行了评价.分析表明,村镇住宅室内和室外相对湿度高于70％的时间分别占全年总时间的95.4％和87.2％,室内温度高于28℃且相对湿度高于70％的时间达1 196 h;全年舒适时间为3 838 h,占全年总时间的43.8％;现有评价模型与修正模型的舒适时间相差405 h,其中空调季相差342h,且温度越高,相对湿度对热舒适的影响越大,说明在温度较高时应考虑相对湿度对热舒适的影响,但修正模型的可靠性还需进一步验证.     

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.     

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.     

西安建筑科技大学体育馆室内热环境分析

以西安建筑科技大学体育馆为例,指出了影响体育馆内人体热舒适和室内热环境的因素。对该体育馆室内热环境进行了分析,对其围护结构热工性能进行了评价,提出了改善其室内热环境的一些对策。     

Building envelope regulations on thermal comfort in glass facade buildings and energy-saving potential for PMV-based comfort control

This paper presents an investigation of the effect of building envelope regulation on thermal comfort and on the energy-saving potential for PMV-based comfort control in glass facade buildings. Occurrences and severity of overheating, based on the PMV-PPD model contained in ISO 7730, were used for the thermal comfort assessment. Parametric study simulations for an actual building with a large glass facade were carried out to predict the changes in thermal comfort levels in a space due to different glazing types, depths of overhang and glazing areas, which are the key parameters of the building envelope regulation index, named ENVLOAD, in Taiwan. The result demonstrates that the ENVLOAD has significant effect on thermal comfort. Additionally, comparative simulations between PMV-based comfort control and conventional thermostatic control were performed to investigate the changes in the energy-saving potential of a thermal comfort-controlled space due to changes of its ENVLOAD. The results demonstrate that the energy-saving potential in a PMV-based controlled space increases with low ENVLOAD conditions.     

北京地区大学教室热舒适长期调查研究

针对北京市某大学的教室进行调研,对室内热环境参数、受访者服装热阻及受访者热感觉投票进行了为期1年的跟踪调查。试图通过探索教室热环境参数与受访者热感觉之间的关系了解受访者对教室内热环境的需求,结果发现,不同季节受访者对环境的需求存在差异,夏季空调环境人体中性温度为26.9℃,过渡季节自然通风环境中性温度为23.5℃,而冬季集中供热环境中性温度为22.9℃,着装量不同是造成上述差异的主要原因。对于室内环境控制,在春秋过渡季节的绝大多数时间,自然通风可满足人员对室内热环境的需求;在非自然通风季节,将室内温度控制到可接受的范围就可以满足多数受访者的需求。     

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。     

Comparison of low-energy office buildings in summer using different thermal comfort criteria

Sustainable low-energy office buildings attempt to harness the buildings architecture and physics to provide a high quality working environment with the least possible primary energy consumption. A promising approach to condition those buildings in summer employs the utilization of the building's thermal storage activated by natural heat sinks (e.g., ambient air, ground water or soil) through night ventilation or thermally activated building systems (TABS). However, a certain room temperature cannot be guaranteed as occupants may influence the room energy balance by window opening, internal heat gains or sun shading control. Between 2001 and 2005, monitoring campaigns were carried out over 2 or 3 years in 12 low-energy office buildings which are located in three different summer climate zones in Germany. These climate zones are defined as summer-cool, moderate and summer-hot. The weather at the building site and the room temperatures in several office rooms were monitored by different scientific teams. The raw data are processed for data evaluation using a sophisticated method to remove errors and outliers from the database and to identify the time of occupancy. The comfort in all office rooms in each building is evaluated separately. For data presentation, these separate comfort votes per office room are averaged using the median instead of the arithmetic mean in order not to overestimate extremely cold or hot room temperatures. A comfort evaluation in these 12 low-energy office buildings indicates clearly, that buildings which use only natural heat sinks for cooling provide good thermal comfort during typical and warm summer periods in Germany. However, long heat waves such as during the extreme European summer of 2003 overstrain passively cooled buildings with air-driven cooling concepts in terms of thermal comfort.     

严寒地区居住建筑室内热舒适模拟研究

将模拟计算得到的模型房间的温度场与经回归分析建立的平均热感觉MTS预测模型和热舒适评价指标PMV相结合,通过编制MATLAB程序,绘制了模型房间不同截面的MTS和PMV的三维分布图。比较了各个截面的MTS和PMV预测结果并分析了产生误差的原因。     

北京地区农宅供暖季室内热舒适研究

对北京近郊的7户农宅进行了相关调查。结果表明,多数受试者认为室内环境舒适,实际热感觉投票值高于PMV模型预测值;农宅中性温度为18.4℃,可接受温度下限为10.9℃,舒适温度受农民的衣着习惯和生活方式影响。因此,北方寒冷气候区农宅的供暖温度标准不能照搬城镇单元式住宅楼的供暖标准,不宜维持较大的室内外温差。     

北京校园建筑夏冬两季室内热舒适性现场调查研究

测试了空气温度、平均辐射温度、相对湿度、风速等环境参数,采用问卷的形式调查了受试者的主观热感觉,建立了热感觉与室内操作温度的对应关系。在夏季,人们对偏热环境的耐受力强于PMV预测结果;在冬季,人体对于偏冷环境具有适应性,若室内温度偏高,人会感觉不适,实际热感觉高于PMV预测值;由于供暖条件的差异,长期生活在我国南方的人冬季对于偏冷环境的适应性要强于北方人。