兰州市某高校学生公寓春季热舒适调查研究

为探究高校学生公寓春季室内热舒适状况,采用现场测试与问卷调查相结合的方法对兰州市某高校14间学生公寓室内热环境状况进行了现场调查研究,共获得181份有效人体热反应样本。运用统计分析法对受试者的热感觉、衣服热阻与操作温度进行了回归分析。结果表明,春季公寓内学生着装的平均服装热阻为0.689clo,90.1%的学生对室内20.4℃的平均温度表示接受;实测热中性温度为17.8℃,预测热中性温度为19.8℃,所期望的室内温度为18.7℃;80%的学生可接受的操作温度范围是17.7~22.1℃,其热接受温度下限比同属寒冷地区西安市的高3.2℃。该研究结果可为兰州高校学生公寓室内热环境的控制和制定其室内热舒适标准提供参考。     

室内自然通风环境热舒适性研究

通过建立室内自然通风模型,研究了系统在不同温度、不同进风口风速及不同外窗开度情况耦合工况下,人体热舒适感受能够承受的温度上限和空气流速与外窗开度的适用范围。结果表明,室内热舒适性会随室外温度升高而明显恶化,温度达28.5℃时超过热舒适性指标国家标准推荐值;各因子中,风速及温度对室内热舒适性影响比重相对较轻,外窗开度的影响最大;20%为外窗开度下限,随开度的增大室内热舒适性增强;风速增加带来的不适"吹风感"也需考虑,该个体差异性感受会使得室内热舒适性迅速下降。     

严寒地区居住建筑气密性与室内热舒适性模拟研究

为完善适用于我国严寒地区居住建筑气密性与室内热舒适之间的关系,以沈阳市某小区一户住宅为模拟对象,对严寒地区居住建筑气密性与室内热舒适之间的关系进行探究。模拟分为冬季工况、夏季工况和过渡季工况,针对住宅内南北侧典型房间室内热舒适随气密性等级不同的变化情况进行模拟分析。研究发现,不同季节条件下,室内热舒适度随气密性变化情况不同,其中以冬季最为明显,过渡季次之,夏季建筑气密性的提升对室内热舒适的影响相对较小。     

夏季自然通风对农宅室内热环境影响的研究

以山西省运城地区农家住宅为研究对象,叙述了进行室内热环境参数现场测试的过程,分析了不同自然通风方案对室内能耗、舒适性及人工调节便捷性的影响特征,提出了运城地区夏季室内自然通风的理想调节方式。     

陕南秦巴山区乡村民居热环境测试研究

分别选取秦巴山区的两类代表性民居(生土民居和砖混民居),进行冬夏两季的室内外热环境测试,并分析建筑空间形式、构造特点对室内热环境的影响。测试分析结果表明,该地区冬季湿冷(室外空气温度平均值为4.6℃,相对湿度为71.4%),夏季湿热(室外空气温度平均值为31.8℃,相对湿度为59.1%),而现有民居的空间形式简单并且构造热工性能较差,因此室内热环境质量较差(冬季室内最高温度低于10℃,夏季室内最高温度高于30℃,且冬夏两季室内相对湿度均高于50%)。针对该地区民居构造特征及室内外热环境现状,提出增大南向开窗面积与加强通风相结合,以提高民居冬季集热与夏季自然通风降温的改造建议。     

桂林市某高校教学楼冬季室内热环境和热舒适性调查研究

以桂林市某高校教学楼第3层的4间教室为研究对象，对冬季室内热环境和学生的热舒适性感觉进行为期两天的直接测量和问卷调查，并对结果进行分析。结果表明：桂林高校教室冬季普遍温度过低且相对湿度较大，室内引入的新风量少、闷感强烈导致热环境较差；大部分学生对环境具有一定的适应能力，通过采取一些适应性行为调节自身的热舒适程度；桂林高校教室非空调环境下，冬季中性温度为19.9℃，期望温度为20.7℃。     

基于代换合成法的高校教室综合舒适度研究

教室内的温度、相对湿度和空气流速对学生的健康和学习起着至关重要的作用，在2019年的夏季采用主观问卷调查对上海某高校教室内的操作温度、相对湿度与空气流速舒适感进行评价，并提出了综合舒适评价指标。建立了单个物理参数的无量纲函数，并利用向量相似度法计算出操作温度、相对湿度与空气流速对综合舒适评价指标的影响权重分别为0.462,0.291,0.247，通过代换合成法建立了基于操作温度、相对湿度和空气流速的人体综合舒适评价模型。利用控制变量法将三种评价指标两两组合，验证各评价指标对综合舒适评价指标的影响程度，得出操作温度偏离其所在舒适区时，引起的综合舒适度评价值变化量越最大，既而成为影响综合舒适评价指标的主导因素。结合了向量相似度法和代换合成法的综合舒适度评价模型，完全基于数据驱动，摆脱了传统热舒适模型的框架，更能体现出受试者的实际舒适感。这可为制定教室环境综合舒适度定义及相关标准的修订提供参考，同时可为教室热环境的热环境设计参数、评价与设计提供合理依据，减少能源浪费。     

严寒地区农宅附加太阳房采暖能耗及节能分析

以严寒气候某地区的一处代表性农村住宅为例,探讨了农村住宅附加太阳房的采暖能耗及其节能潜力。基于EnergyPlus研究了附加太阳房前后农村住宅采暖设计温度为14℃、16℃、18℃和20℃时,在最冷日、最冷月以及采暖期的采暖能耗和节能效果。研究结果表明:严寒地区农村住宅附加太阳房后室内温度升高、昼夜温度波动较小,室内热舒适性增加,而且有效降低建筑采暖能耗,其节能率达22.73%;农村住宅采暖设计温度越高,其建筑采暖能耗越大且呈1.4～2.7倍增长;采暖设计温度18℃时,农村住宅附加太阳房节能效率最高。     

双热扰下节能墙体对室内热环境的动态影响

结合拉萨地区的气象数据和典型太阳能建筑分析模型,采用热平衡方程和傅氏级数解析法,分析室内外双侧热扰耦合作用下节能墙体构造方式对太阳能采暖建筑室内热环境的动态影响。结果表明,内保温构造方式下的内壁面温度波幅大于11℃,而外保温和夹芯保温幅度仅约为5℃。不同节能墙体构造方式对空气温度与壁面温度间的"温度波峰谷时差"存在影响,其中夹芯保温最小约0.5 h,外保温次之约为1.0 h,内保温最长约为4.0 h。操作温度较室内空气温度波幅有显著降低,其中夹芯保温构造的操作温度波幅为3.1℃,室内热环境的稳定性最好。     

基于VR的声光环境对人体热舒适及生理反应的影响

通过人工气候室实验研究基于虚拟现实技术（VR）构建的声光环境对人体热感觉、热舒适及生理参数的影响及性别差异，分析主观投票和生理参数间的相关性。结果显示：偏冷环境下（20℃），暖色调声光环境可将热感觉投票向中性校正，冷色调声光环境可加剧受试者冷感，使其更不舒适；中性环境下（25℃），声光环境对热感觉、热舒适的影响较小；声光环境联合作用效果强于单独作用效果；性别差异在热感觉、热舒适方面最为显著，声、光环境对男性热感觉、热舒适的影响略强于对女性的影响；人体热感觉、热舒适均与多种生理参数间存在显著相关关系。     

Trombe wall management in summer conditions: An experimental study

The application of Trombe walls in temperate climates is problematic due to undesired heat gains and overheating phenomena in summer. A proper shading and ventilation of this system can reduce such drawbacks, but the impact of these strategies on the wall’s thermal parameters is yet not widely investigated in quantitative terms.This paper presents an experimental study on the thermal behavior of Trombe walls in summer under Mediterranean climate conditions. The aim of the study is to determine experimentally the thermal parameters of a Trombe wall in summer conditions through the changing of shading, ventilation and operational conditions.In order to do that a series of experimental campaigns were carried out on a case study. A detailed simultaneous monitoring of two Trombe walls made it possible to compare the thermal behavior by varying the screening, ventilation and internal gains conditions. Furthermore, monitoring of indoor thermal comfort conditions and energy simulation using a model in dynamic state were carried out. The results showed that shading, ventilation and occupancy conditions affect significantly the thermal parameters of Trombe wall in summer: screening with roller shutters determines a decrease in internal surface temperature of the wall of 1.4 °C and a decrease in daily heat gains of about 0.5 MJ/m²; the combined use of overhangs, roller shutters and cross ventilation for the Trombe wall can assure a satisfactory thermal comfort level in summer and a reduction of the cooling energy needs respectively of ?72.9% and ?63.0% for a dwelling with low or highly insulated building envelope in comparison with the case of an unvented Trombe wall without solar protections.     

Impact of passive cooling techniques on energy demand for residential buildings in a Mediterranean climate

This study presents the thermal analysis of a building prototype, which was designed and built in accordance with energy efficiency measures to improve indoor thermal comfort, particularly in summer. The building prototype is located in Souidania (20 km southwest of Algiers, latitude 36°7N, Longitude 03°2E). The location is characterized by a temperate Mediterranean climate. In order to perform this analysis, various activities are carried out: a series of monitoring campaigns; dynamic simulations with TRNSYS software, calibration of the model with experimental data and comparative study with buildings that use different wall constructions. Based on a validated building thermal model, dynamic analysis is carried out in order to evaluate the impact of thermal mass and of eaves and night ventilation. The results demonstrate that cooling energy demand is more affected by thermal transmittance values than by the envelope thermal mass. A recommended guideline for the optimum overhang length for south-facing windows is proposed. Ultimately, it is found that the combination of both natural ventilation and horizontal shading devices improves thermal comfort for occupants and significantly reduces cooling energy demand.     

Overheating caused by passive solar elements in Tunis. Effectiveness of some ways to prevent it

Although Tunisian winters are mild compared with northern regions, there are heating requirements; their limited level suggests that passive solar energy would probably be able to meet them. However, the summer is hot enough, and one may wonder whether a solar design oriented toward the cold season would not induce severe overheating. Numerous studies have dealt with the heating performance of passive solar elements, but very little has been done to analyze their behavior in hot climatic conditions. The National School for Engineers of Tunis has built a passive solar pavilion which has been carefully instrumented. Special care has been devoted to the summer behavior of the pavilion. In this paper we describe some of the actions taken to prevent overheating, and we investigate their efficacy both by analysis of recorded measurements and by simulation. It is found that night ventilation is the most responsible action in decreasing room temperature, and that Trombe wall screening is more efficient than operating the walls as a solar chimney; overhangs are of valuable aid, and shuttering of the direct gain element also helps against overheating. The high thermal capacity results in a very stable room temperature, and plays an essential role for cooling when coupled with night ventilation. Finally, it is found that if appropriate action is taken in the hot season, a house equipped with passive solar heating elements can reach a very acceptable level of comfort in summer time.     

The passive solar heated school in wallasey. IV. An observational study of the thermal response of a passive school building

An observational study on the Wallasey School has demonstrated its ability to maintain in most conditions of climate an equitable indoor climate both in regard to daily mean temperatures and daily variations, through use of solar gain and heat from the lights, and the appropriate control of ventilation. During occupied periods, air temperatures are usually between 17°C in winter and 23°C in sunny summer periods. The room provides a mainly ‘cold wall’ environment. The observational data and a series of model estimates have been compared. The general level of temperature within the building is known to depend strongly on ventilation rate, but since ventilation rate was not measured, steady-state comparisons as such are not possible. The observed and estimated temperature profiles for air and various surfaces including that of the furnishings during a very sunny period are in broad agreement. Analyses of the transient response of the structure in winter conditions has demonstrated a long response time (several days) describing the response of the enclosure, and a shorter response time of about half a day which describes the rate of settlement of internal temperature differences which may be initially present. Evidence is presented indicating low values for the convective heat transfer coefficient. An autocorrelational technique demonstrates that the thermal ‘memory’ of the classroom is much longer in winter than in summer. The response of the room during occupied and unoccupied periods is broadly similar, but conditions are rather more variable during occupation.     

Design of energy efficient and thermally comfortable air-conditioned university classrooms in the tropics

This study aims to design energy efficient and thermally comfortable air-conditioning system in university classrooms. The research has been conducted in two steps. The first step was a survey of students’ thermal comfort under air-conditioning classrooms, which collecting 175 questionnaires from 92 students. The second step was the calculation of cooling energy consumption using the EnergyPlus software. With the air temperature ranged from 23.0 to 27.0°C about 53% of respondents felt uncomfortable (cold or cool). The neutral temperature of students was found to be 27.0°C, which is higher than the classrooms’ temperature. The energy simulation results show that the most significant factors affecting energy use is the temperature setting. Therefore, there is a possibility to reduce the cooling energy while improving the thermal comfort of students. To this end, it is recommended to raise the air temperature setting from 25.0°C to a minimum of 26.0°C.     

Passive cooling in a low-energy office building

In office buildings, the use of passive cooling techniques combined with a reduced cooling load may result in a good thermal summer comfort and therefore save cooling energy consumption. This is shown in the low-energy office building ‘SD Worx’ in Kortrijk (Belgium), in which natural night ventilation and an earth-to-air heat exchanger are applied. In winter, the supply air is successively heated by the earth-to-air heat exchanger and the regenerative heat exchanger, which recovers the heat from the exhaust air. In summer, the earth-to-air heat exchanger cools the ventilation air by day. In addition, natural night ventilation cools down the exposed structure which has accumulated the heat of the previous day. In this article the overall thermal comfort in the office building is evaluated by means of measuring and simulation results. Measurements of summer 2002 are discussed and compared to simulations with a coupled thermal and ventilation simulation model TRNSYS-COMIS. The simulations are used to estimate the relative importance of the different techniques. The evaluation shows that passive cooling has an important impact on the thermal summer comfort in the building. Furthermore, natural night ventilation appears to be much more effective than an earth-to-air heat exchanger to improve comfort.     

Earth-to-air heat exchangers for Italian climates

The European Energy Efficiency Building Directive 2002/91/CE, as well as other acts and funding programs, strongly promotes the adoption of passive strategies for buildings, in order to achieve indoor thermal comfort conditions above all in summer, so reducing or avoiding the use of air conditioning systems.In this paper, the energy performances achievable using an earth-to-air heat exchanger for an air-conditioned building have been evaluated for both winter and summer. By means of dynamic building energy performance simulation codes, the energy requirements of the systems have been analysed for different Italian climates, as a function of the main boundary conditions (such as the typology of soil, tube material, tube length and depth, velocity of the air crossing the tube, ventilation airflow rates, control modes). The earth-to-air heat exchanger has shown the highest efficiency for cold climates both in winter and summer.The possible coupling of this technology with other passive strategies has been also examined. Then, a technical-economic analysis has been carried out: this technology is economically acceptable (simple payback of 5–9 years) only in the cases of easy and cheap moving earth works; moreover, metallic tubes are not suitable.Finally, considering in summer a not fully air-conditioned building, only provided with diurnal ventilation coupled to an earth-to-air heat exchanger plus night-time ventilation, the possible indoor thermal comfort conditions have been evaluated.     

Thermal comfort in apartments in India: Adaptive use of environmental controls and hindrances

Energy used in buildings in India is ever-increasing. About 47% of total energy in Indian residential buildings is used for ventilation controls alone. Comfort temperatures defined in Indian codes are inappropriate (23–26 °C). There are no thermal comfort field studies in residences reported from India. The author conducted a field study in apartments in Hyderabad, in summer and monsoon seasons in 2008. The present paper discusses the occupants’ methods of environmental control, behavioural adaptation and impediments.Due to poor adaptive opportunities, about 60% of occupants were uncomfortable in summer. The comfort range obtained in this study (26.0–32.5 °C), was way above the standard. Fanger’s PMV always overestimated the actual sensation.The occupants adapted through the use of personal environmental controls, clothing, metabolism and many behavioural control actions. Use of fans, air coolers and A/c s increased with temperature, and was impeded by their poor efficacy and noise, occupant’s attitudes and economic affordability. Air-coolers and A/c s were mostly used in top- floors, as the available adaptive opportunities were insufficient. Behavioural adaptation was higher in summer and was limited in higher economic groups always. Subjects frequently exposed to A/c environments, tolerated thermal extremes little, and desired “thermal indulgence”. This study calls for special adaptation methods for top-floor flats.     

Energy efficiency of small buildings with smart cooling system in the summer

In this paper, a novel cooling control strategy as part of the smart energy system that can balance thermal comfort against building energy consumption by using the sensing and machine programming technology was investigated. For this goal, a general form of a building was coupled by the smart cooling system (SCS) and the consumption of energy with thermal comfort cooling of persons simulated by using the EnergyPlus software and compared with similar buildings without SCS. At the beginning of the research, using the data from a survey in a randomly selected group of hundreds and by analyzing and verifying the results of the specific relationship between the different groups of people in the statistical society, the body mass index (BMI) and their thermal comfort temperature were obtained, and the sample building was modeled using the EnergyPlus software. The result show that if an intelligent ventilation system that can calculate the thermal comfort temperature was used in accordance with the BMI of persons, it can save up to 35% of the cooling load of the building yearly.     

Theoretical and experimental analysis of the thermal behaviour of a green roof system installed in two residential buildings in Athens,Greece

Measurements of the thermal behaviour of two residential buildings equipped with a green roof system have been performed in Athens, Greece. Experimental data have been used to calibrate detailed simulation tools and the specific energy and environmental performance of the planted roofs system has been estimated in detail. Simulations have been performed for free‐floating and thermostatically controlled conditions. The expected energy benefits as well as the possible improvements of the indoor thermal comfort have been assessed. It is found that green roofs have a limited contribution to the heating demand of insulated buildings operating under the Mediterranean climate. On the contrary, the green roof system is found to contribute highly to reduce the cooling load of thermostatically controlled buildings. For the considered residential buildings, a cooling load decrease of about 11% has been calculated. In parallel, it is found that green roofs contribute to improve thermal comfort in free‐floating buildings during the summer period. The expected maximum decrease of the indoor air and roof surface temperatures is close to 0.6°C. Such a decrease contributes to reduce by 0.1 the summer absolute Predicted Mean Vote Comfort Index levels in the building. Copyright © 2009 John Wiley & Sons, Ltd.