Optimizing bedroom thermal environment:A review of human body temperature,sleeping thermal comfort and sleep quality

Thermal environment may affect sleep quality and sleeping thermal comfort at the same time.Up to now,there is no direct evidence or physiological theory can prove the idea that thermal comfort equal to good sleep quality,but how to balance the relationship between them is often ignored when designing thermal environment.This review took body temperature distribution as a bridge for the connection of sleep quality and sleeping thermal comfort.At first,we reviewed the quantitative relationships among thermal environment,body temperature,sleep quality and sleeping thermal comfort,and then based on the idea of reverse derivation,a recommended design process for bedroom thermal environment was proposed.Each step of the process corresponded to the impact mechanism described above.The review results showed that,body temperature distribution was closely related to both sleep quality and thermal comfort,and thus it was suitable to be used as a bridge between them;body temperatures fluctuated dynamically during sleep,and thus heat transfer and thermal regulation models should be used to describe them;most current sleep researches regarded skin temperature as the representative value of body temperature distribution,yet core body temperature needs to be paid more attention on in the future because it was more closely related to sleep rhythm;furthermore,in addition to young people,subjects of more age groups should be tested to enrich China’s sleep research database.In general,it’s theoretically possible to guarantee both sleep quality and sleeping thermal comfort,and this review can be used as a reliable reference for bedroom thermal environment design.

Impact of cold indoor thermal environmental conditions on human thermal response

To explore the thermal responses under the non-thermal equilibrium cold environmental conditions,a laboratory study was conducted in climate chamber.The local skin temperatures and thermal sensation of 20 subjects were recorded at 10 min intervals for 90 min under air temperatures of 7.4,9.1,11 and 15 °C.The results show that both local skin temperatures and mean skin temperature decrease not only with the drop of ambient air temperature but also with the exposure time.Local thermal sensation and overall the thermal sensation have the similar temperature-varying and time-varying characteristics.Predicted mean vote(PMV) model cannot correctly predict the thermal sensation under non-thermal equilibrium cold environment.The correlation between local thermal sensation and local skin temperatures shows that thermal sensation is closely related to skin temperature.Skin temperature is an effective indicator of thermal sensation.A linear relationship model between overall thermal sensation and mean skin temperature,considering both ambient temperature and exposure time,was established in the non-thermal equilibrium cold environment,which makes the evaluation of thermal sensation more objective.

Thermal comfort in naturally ventilated indoor environment in hot and humid climate zone in P. R. China

To identify human thermal comfort in naturally ventilated buildings,the research based on both subjective and objective data was carried out in Chongqing,P. R. China. The characteristics of subjects' clothing regulation function,changes of actual mean thermal comfort vote (AMV) varying with time and acceptable operative temperature in natural conditions were analyzed. In addition,the indicator actual mean vote-actual percentage dissatisfied (AMV-APD) was used to study the actual dissatisfaction with thermal environment. The results indicate that regulative ability by changing clothing under natural ventilated conditions is very significant but limited simultaneously,about 1.7 ℃ per 0.1 clo. Under naturally ventilated conditions,people may have an acceptable operative temperature of 16-28 ℃. Based on the AMV-APD,the actual minimum percentage dissatisfied can reach 4% at AMV of -0.36.

Indoor thermal environment of wooden-plank wall dwellings in summer in Chongqing

There are a large number of wooden-plank wall dwellings, a kind of traditional house with regional characteristics, existing in Chongqing area. We chose a typical house in Chongqing as the subject and measured it during summer to research the situation of the indoor thermal comfort of wooden-plank wall dwellings. Based on the particularity of local residents' living habit and the characteristics of the local buildings, we analyzed the data of the field measurement and evaluated the thermal environment with APMV. The results show that the indoor thermal comfort of wooden-plank wall dwellings in summer is improved mainly by natural ventilation.

Effects of Outdoor Thermal Environment upon the Human Responses

In a summer outdoor space, the influence of short-wave length solar radiation on the human body is strongly apparent, heat is retained in the body, and the risk of heat disorders such as heat stroke increases. To avoid this, it is essential to seek shade to avoid the influence of short-wave length solar radiation. In addition, natural ground surfaces such as green spaces and water surfaces are useful in reducing the air temperature. It is indispensable to consider climate mitigation effect of outdoor space. The purpose of this study is to clarify the influence of the thermal environment of an outdoor space on the human body in rural and suburban regions where paddy fields remain. Subject experiments were conducted to examine the relationship between the thermal environment evaluation index enhanced conduction-corrected modified effective temperature (ETFe) in an outdoor space and the physiological and psychological responses of the human body. Experiment sites were selected with consideration for the natural ground surface such as bare ground where the surface is gravel or soil;paved ground such as concrete, asphalt or blocks;green areas covered in plants;and water surfaces, as well as the sky factor due to buildings or trees etc. and the proportion of the solid angle of components of greenery and water etc. comprising the solid angle of the total celestial sphere. A ground surface feature with a high heat capacity may promote sensation of hot and deteriorate the thermal sensation. A landscape of thick vegetation with a high green factor may have a strong feeling of confinement, which can make it somewhat hot and somewhat uncomfortable thermal environment due to the sense of stagnation. Compared with the urban environment, it is conceivable that the difference in the perceptual environment, whereby it is subconsciously assumed to be a comfortable thermal environment, had an effect in the rural and suburban regional environment, resulting in an ETFe lower than the upper limit of comfort in a summer urban environment.

Indoor Thermal Environment of Korean Rural Housing Yanbian Region of China in Winter

For the rural housing in Yanbian region in winter,the indoor thermal environment is bad but the energy consumption is high.And in order to solve the problem,the life particularities of the local residents,such as the inhabitation custom and the different living ways,were analyzed.The comfortable temperature felt by the local residents was surveyed and summarized according to different age's stage.The subjective comfortable temperature was calculated by using the thermal comfort formula set up by D.A.Mcintyre.The result shows that the comfortable temperature between the survey and the calculation is different.After analyzing the survey and the result calculations,the range of local indoor comfortable temperature was given,which provides a reference basis for calculating the thermal comfort and energy efficiency as well as designing green rural houses.

Experimental Study on Occupant's Thermal Responses under the Non-uniform Conditions in Vehicle Cabin during the Heating Period

The existing investigations on thermal comfort mostly focus on the thermal environment conditions, especially of the air-flow field and the temperature distributions in vehicle cabin. Less attention appears to direct to the thermal comfort or thermal sensation of occupants, even to the relationship between thermal conditions and thermal sensation. In this paper, a series of experiments were designed and conducted for understanding the non-uniform conditions and the occupant＇s thermal responses in vehicle cabin during the heating period. To accurately assess the transient temperature distribution in cabin in common daily condition, the air temperature at a number of positions is measured in a full size vehicle cabin under natural winter environment in South China by using a discrete thermocouples network. The occupant body is divided into nine segments, the skin temperature at each segment and the occupant＇s local thermal sensation at the head, body, upper limb and lower limb are monitored continuously. The skin temperature is observed by using a discrete thermocouples network, and the local thermal sensation is evaluated by using a seven-point thermal comfort survey questionnaire proposed by American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc（ASHRAE） Standard. The relationship between the skin temperature and the thermal sensation is discussed and regressed by statistics method. The results show that the interior air temperature is highly non-uniform over the vehicle cabin. The locations where the occupants sit have a significant effect on the occupant＇s thermal responses, including the skin temperature and the thermal sensation. The skin temperaWa-e and thermal sensation are quite different between body segments due to the effect of non-uniform conditions, clothing resistance, and the human thermal regulating system. A quantitative relationship between the thermal sensation and the skin temperature at each body segment of occupant in real life traffic is presented. The investigation result indicates that the skin temperature is a robust index to evaluate the thermal sensation. Applying the skin temperature to designing and controlling parameters of the heating, ventilation and air conditioning（HVAC） system may benefit the thermal comfort and reducing energy consumption.

夏热冬冷地区住宅浴室热湿环境与洗浴行为研究

对上海地区住宅浴室热湿环境进行了实地测量,分析了浴室热湿环境特征,并通过网络问卷调研了典型人群的洗浴行为。结果表明:浴室热湿环境受洗浴行为影响明显,淋浴开始后空气温度迅速升高,相对湿度接近饱和状态,淋浴结束后相对湿度需要较长时间才能恢复至初始状态,与常规居家场景相比,洗浴过程中的浴室热湿环境偏离常规热舒适区;夏热冬冷地区居民洗浴行为受季节影响明显,淋浴水温冬季偏暖(43.3℃左右)、夏季偏凉(一般36~40℃);洗浴频次以1天1次或2天1次为主;洗浴时长夏季多为5~10 min、冬季多为10~20 min。本文还探讨了浴室环境改善措施和浴室热舒适的特殊性。

高温热浪期间城市空间热环境特征及人群热舒适度评价研究——以重庆渝中区典型空间为例

针对高密度城市空间的高温热浪问题,以山地城市重庆的核心城区渝中区为例,对商业区、住区、山地公园、滨江公园3类4种典型城市功能空间进行一个热浪周期的实测,通过空气温度、地表温度、相对湿度、太阳辐射等热环境参数分析,比较不同城市空间热环境特征;结合城市人群热舒适相关问卷调研,选取生理等效温度(PET)描述人体热感受,归纳城市空间高温热浪期间对人群热舒适的影响要素及规律,建立夏季室外热舒适度预测模型。显示:1)高温热浪期间热环境受城市空间要素影响且具有差异化特征,老旧住区受高温热浪影响严重,商业区紧随其后,公园绿地较好;2)室外热舒适度与空间要素紧密相关,PET、空气温度和地表温度与热感觉和热舒适显著负相关,相对湿度与热感觉和热舒适呈显著正相关,空气温度和热辐射对热舒适度影响较大,相对湿度与地表温度影响相对较小;3)合理的空间形态和遮阴规划、植被及水体设置、高蓄热性下垫面等设计要素可缓解高温热浪,降低热中性温度,提高热舒适性。研究结果为山地城市高温热浪形成机制探究及城市空间热环境优化设计提供一定依据。

西安地区开放式办公建筑夏季人体热舒适调查研究

以西安地区6栋典型开放式办公建筑为研究对象,通过热环境参数测试和主观问卷调查相结合的方式进行了现场调研,分析了实际办公建筑中人员的热舒适需求,并将调研结果与现有标准及其他气候区现场研究进行了对比。结果显示,西安地区夏季办公建筑受访者的中性温度为25.4℃,偏好温度比中性温度低0.2℃,80%可接受温度上限为28.2℃。

汽车乘员舱空调热舒适测试与评价方法

在节约能源的前提下,优化乘员舱热环境、提升驾乘人员舒适性是汽车热管理的研究重点之一。随着电动汽车市场占有率的增长,乘员舱热舒适受到了更多的关注。本文综述了汽车乘员舱环境热舒适评价方法。首先,阐述了乘员舱热环境的瞬态非均匀特征及其与人员热舒适的关联。其次,介绍了多种热舒适模型的原理,包括PMV-PPD模型、等效均匀温度(EHT)模型、多节点多节段热舒适模型,并从模型输入/输出参数对汽车乘员舱热舒适评价的适用性等方面进行了对比分析。再次,介绍了乘员舱热环境测试及仿真方法,着重对比了暖体假人和空调假人在乘员舱热环境评价中的适用性。最后,基于本文所提出的评价方法,使用空调假人开展实车测试,对乘员舱环境热舒适进行了评价。

高校研究生科研办公室冬季热舒适及供暖温度分析——以北京某大学为例

高校研究生办公室作为学生科研的主要场所,室内热环境与热舒适对于科研效率、学生健康有着极大影响。选取北京市某高校办公楼作为研究对象,通过问卷调查和现场实测方式探究高校研究生办公室的室内热环境和人员舒适性。结果表明:冬季被调研研究生的服装热阻平均值为1.07 clo,学生已不满足冬季18℃的设计室温,在集中供暖节能运行且学生可以自主调控分体式空调的情况下,科研办公房间的平均温度达到21.4℃,而室内学生的中性温度为21.9℃,热可接受范围为19.1~24.7℃,热偏好温度为24.0℃,热感觉投票为“稍暖(+1.1)”时学生舒适程度最高,学生仍偏向较暖的室内环境,学生积极和间歇地使用空调设备使供暖温度达到其满意的23.5~24.0℃。

夏季温度漂移环境下的人体热舒适研究

长期处于稳态热环境会削弱人体的热适应能力,影响人体热舒适,并且空调系统的长期运行也会造成能源过度消耗。研究显示,允许室内环境温度适当地变化可以改善上述问题。通过控制空调的间歇启停,结合主观热评价、额头温度、耳温以及平均皮肤温度的变化,探究了短暂温度漂移下的人体热反应,并且分析了额头温度与热舒适投票之间的相关关系。结论如下:存在温度漂移的夏季空调环境,可以提高人体对偏热环境的接受度;适当范围内的温度漂移可以提高人体热舒适,为室内空调系统的动态调节提供了新的研究思路;温度漂移热环境中,人体额头温度与热舒适显著相关,其可以作为表征动态环境热舒适的重要指标之一。

不同供暖末端办公建筑室内热环境和人体热舒适调研

为明确寒冷气候区办公建筑辐射供暖和对流供暖模式下的室内热环境参数是否能满足人体热舒适需求,本研究选取西安市不同供暖模式的办公建筑为调研对象,同时进行了室内物理环境测试和人体热舒适主观问卷调查,调研期间共获得1 120份有效问卷。结果显示:对流供暖模式下室内空气温度和竖直温差显著高于辐射供暖,且室内存在过热现象;辐射和对流供暖的中性温度分别为17.4℃和20.4℃,较高的室内空气温度形成了较高的中性温度和可接受温度上限。

西安室内健身场所热环境与人体热舒适调查研究

运动场所热环境是影响运动人群舒适、健康和运动意愿的重要因素。本研究采用现场调查和实验室研究相结合的方法,通过现场调查获取了健身人群的热舒适现状,提取了健身人群特征(着装和运动类型),进一步通过实验室测量获得了服装热阻数据和不同健身运动的代谢率数据。基于以上结果,探讨了不同运动强度下健身人群的热舒适阈值,同时对PMV模型在健身场所热环境评价中的适用性进行了评估。结果表明:高强度健身运动(5 met以上)人群的舒适温度低于中等强度运动(5 met以下)人群;运动状态下,健身人群的最舒适状态对应的热感觉投票为“微暖”;中等强度运动时人体的舒适温度上限为24.3℃,高强度运动时为19.4℃;气流也会显著影响运动人群的热舒适,随着运动强度的增大,运动人群对于风速“增大”的期望更加强烈。

西海固地区新旧民居冬季室内热舒适研究

为了了解西海固地区新旧民居冬季室内热湿环境情况,2021年冬季在当地选取了两栋代表性新旧民居,分别进行了现场测试及问卷情况调查,分析不同类型民居的热环境状况并探究造成差异的原因。结果表明:西海固地区冬季传统民居室内热中性温度为19.12℃(SET*),现代民居热中性温度为19.48℃(SET*)。以80%的可接受和舒适标准得出该地区的热可接受度区间,冬季传统民居在17.45~20.8℃之间,现代民居在17.26~21.54℃之间。同时分析了西海固地区冬季的室内热环境及人体热舒适情况,与其他地区民居进行热舒适对比,为提高西海固地区冬季室内热舒适性提供了参考依据。

偏热环境下佩戴口罩对室内人员工效的影响研究

目的研究在26℃~34℃的偏热环境下佩戴口罩对人员工作效率的影响。方法在6月~7月份于杭州某高校实验室进行了试验,设置的环境温度工况为26℃、28℃、30℃、32℃、34℃;口罩工况为未佩戴口罩、一次性医用口罩、KN95(无呼吸阀)口罩、KN95(带呼吸阀)口罩,采取主观问卷调查与工作效率测试相结合的研究方法。结果偏热环境中人员的工作效率下降了8.35%~14.26%,而同温度下佩戴口罩人员的工作效率下降了4.32%~7.43%,并且相较于26℃未佩戴口罩的情况,在34℃的环境温度下受试者佩戴口罩时的工作效率下降了14.32%~17.11%。结论在偏热环境下随着环境温度的上升以及佩戴口罩的不同,受试者热感觉和湿感觉增大,感知空气品质下降,热舒适性降低,工作热情变得消极,导致了受试者的工作效率的降低。

夏热冬冷地区养老院老年人冬季室外热舒适性探究

养老院室外空间是机构养老人群的主要室外活动场所,室外空间的热舒适性对老年人身心健康具有重要影响。为营造健康、舒适的室外热环境,文章以上海Q养老院为例,通过对养老院室外热环境实测和老年人室外热舒适问卷调查,分析老年人室外热舒适与热感觉关系,研究热环境因素对老年人冬季室外热舒适的影响,从热中性生理等效温度、热中性生理等效温度范围、满足90%热可接受率的生理等效温度范围和热偏好生理等效温度等4个方面,确定老年人冬季热舒适性评价基准;最后基于研究结果,从自然环境和建筑环境两方面提出养老院冬季室外热环境优化设计建议,为夏热冬冷地区养老院室外热环境改善提供参考。

不同低温环境对中老年人体热生理影响

针对现有研究对低温环境下中老年人体热反应研究的不足,探讨低温条件下中老年人的热生理特征与热舒适性问题。通过在10℃和0℃的环境下考察穿着基础服装的中老年受试者的热生理和心理变化,对比分析男性与女性的反应差异。研究结果表明,在10℃及0℃条件下,性别差异显著,尤其是运动和站立后的体温及湿感变化,表明需针对性别制定差异化的保暖及湿度管理策略,为中老年运动着装的设计提供基础数据。

室内中高强度运动人体热舒适研究

以北京某高校室内运动场馆为研究地点,该高校校排球队队员为研究对象,通过客观环境参数测试及主观问卷调研的方法对处于运动状态和非运动状态的研究对象进行了热舒适研究。结果显示:运动状态人员和非运动状态人员的中性操作温度分别为20.7℃和23.5℃;运动状态人员的热敏感度为0.33℃^(-1),低于非运动状态的人员热敏感度(0.47℃^(-1))。提出“最佳运动表现温度”的概念,最佳运动表现温度为23.8℃,比运动状态中性操作温度20.7℃和运动表现偏好温度20.9℃高约3℃。综合运动和节能考虑,建议运动场馆的设计运行温度应按照最佳运动表现温度约23.8℃进行取值。