Decreased humidity improves cognitive performance at extreme high indoor temperature

In this study, we examined the cognitive performance of subtropically acclimatized subjects at an extreme high indoor temperature and the effect of decreased humidity on the cognitive performance at the high temperature. Forty-eight healthy subjects experienced the three exposure conditions: 26°C/relative humidity (RH) 70%, 39°C/RH50%, and 39°C/RH70% in a climate chamber. During 140-minute-long exposures to each thermal condition, they were required to perform cognitive tests that assess the perception, spatial orientation, concentration, memory, and thinking abilities. Meanwhile, their heart rate, core temperature, skin temperature, blood pressure, and body weight were measured and subjective responses, that is, thermal comfort, perceived air quality, and acute health symptoms were investigated. At the relative humidity of 70%, increasing indoor temperature from 26°C to 39°C caused a significant decrease in the accuracy of these cognitive tests. However, when the relative humidity decreased from 70% to 50% at 39°C, the accuracy of the cognitive tests increased significantly. Accordingly, the physiological and subjective responses of the subjects changed significantly with the changes in indoor temperature and humidity, which provided a basis to the variation in the cognitive performance. These results indicated that decreasing indoor humidity at extreme high temperature could improve the impaired cognitive performance.     

Analysis of indoor humidity environment in Chinese residential buildings

A high or low humidity environment is related closely to not only many health problems, but also has great influence on the construction durability and energy consumption. It is very important to control humidity level, in order to achieve a healthy and comfortable indoor environment. However, various problems of the air humidity in inhabited dwellings are not yet taken serious consideration in China. Moreover, there is hardly any information available regarding the actual humidity environment in Chinese residential houses. For this reason, it is difficult to select appropriate moderate moisture strategies to maintain a harmonious indoor humidity level.     

建筑内表面吸放湿过程对室内环境和空调负荷影响的仿真研究

提出了一个考虑室内表面材料吸放湿过程的建筑热湿过程简化模型,介绍了对室内空气湿度及空调负荷的仿真分析。仿真结果表明,室内表面材料吸放湿过程有明显的降低湿度变化幅度的作用,对潜热负荷的影响较大     

四种温度控制方法对相对湿度影响的比较

模拟比较了定风量变水量、变风量变水量、旁通型变风量、二次回风控制四种方法在部分负荷时的除湿能力.结果表明,定风量变水量控制在部分负荷时,室内相对湿度一直较高.除湿能力很差;旁通型变风量控制除湿能力较强;变风量变水量控制在潜热不变显热变化的情况下除湿能力较差,而在潜热显热都变化的情况下较好;二次回风控制只在实际显热比较小时除湿能力较差.     

The effects of ventilation systems and building fabric on the stability of indoor temperature and humidity in Finnish detached houses

Interest in finding out passive ways to keep the variation in the indoor climate within the comfort zone is gaining in popularity. One possible solution is the use of the moisture-buffering property of materials. In this study, the effects of the ventilation system and moisture-buffering properties of the building fabric on the stability of the indoor temperature and humidity are analysed by means of long-term field measurements. Indoor climate measurements were carried out in 170 detached houses (248 rooms). Temperature and relative humidity were measured continuously in bedrooms and living rooms at one-hour intervals over a one-year period. In general, it may be concluded that in this study, the ventilation had a greater effect on the indoor climate than the properties of the building fabric. The dampening effect of hygroscopic materials was remarkably less in the field measurements than it was in simulations in different studies. This indicates that completely non-hygroscopic and fully hygroscopic houses do not exist in reality. The hygroscopic mass of furniture, textiles, etc. is probably a factor that plays a significant role in indoor humidity, as do real air change rates, including window airing. Simulation tools need to be modified in order to be able also to handle furniture, textiles, and books, etc.     

温湿度独立控制空调系统在医院建筑中的应用

分析了温湿度独立控制空调系统的核心概念及特点,介绍了该系统在医院洁净区域和舒适性区域的应用方式.能耗对比表明,该系统应用于医院洁净区域,比常规洁净空调系统节能35%以上,应用于舒适性区域,比常规空调系统节能25%以上.     

A new method of determination of indoor temperature and relative humidity with consideration of human thermal comfort

A new method is described in this article for selecting indoor temperature and indoor relative humidity to achieve minimum energy consumption for a required indoor thermal comfort level which is evaluated with indoor effective temperature. This method is derived from a central air-conditioning system and is based on our investigation that under a same indoor effective temperature, the system cooling load and the system energy consumption increase with an increase of indoor temperature. As such, energy consumption cannot be reduced with increasing indoor temperature for a given human thermal comfort level. In order to reduce energy consumption while keeping a same indoor thermal comfort level, indoor temperature and relative humidity may be determined with the proposed method described in this article. With the proposed method, a parameter variation study has also been conducted, which suggests that for a given indoor effective temperature, a combination of high indoor relative humidity and low indoor temperature be generally taken. The proposed method is based on the central air-conditioning system; yet it can be easily extended to other systems.     

The relationship between indoor and outdoor temperature,apparent temperature,relative humidity,and absolute humidity

Many studies report an association between outdoor ambient weather and health. Outdoor conditions may be a poor indicator of personal exposure because people spend most of their time indoors. Few studies have examined how indoor conditions relate to outdoor ambient weather. The average indoor temperature, apparent temperature, relative humidity (RH), and absolute humidity (AH) measured in 16 homes in Greater Boston, Massachusetts, from May 2011 to April 2012 was compared to measurements taken at Boston Logan airport. The relationship between indoor and outdoor temperatures is nonlinear. At warmer outdoor temperatures, there is a strong correlation between indoor and outdoor temperature (Pearson correlation coefficient, r = 0.91, slope, β = 0.41), but at cooler temperatures, the association is weak (r = 0.40, β = 0.04). Results were similar for outdoor apparent temperature. The relationships were linear for RH and AH. The correlation for RH was modest (r = 0.55, β = 0.39). Absolute humidity exhibited the strongest indoor‐to‐outdoor correlation (r = 0.96, β = 0.69). Indoor and outdoor temperatures correlate well only at warmer outdoor temperatures. Outdoor RH is a poor indicator of indoor RH, while indoor AH has a strong correlation with outdoor AH year‐round.     

大连沈阳夏季室内热湿环境状况的实测调查

通过对大连市和沈阳市8套住宅夏季室内温湿度的实测调查，分析了室外气候条件、住宅形式、人员活动及空调设备使用情况对室内热湿环境的影响，为了解目前北方地区现有住宅夏季室内热湿环境状况提供了参考。     

采用辐射温度传感器的室温测量

介绍了辐射温度传感器的特点、构成及测温原理，并进行实验和实际测量，给出测量参数，认为辐射温度传感器具有遥感式测量、测量对象为一个区域、测量值可反映周围环境的热辐射的特点，在大空间空调系统室温测量中其性能优于传统的空气接触式温度传感器。     

建筑室内外空气真菌浓度相关性案例测试分析

选取某高校学生办公室进行室内外空气真菌浓度相关性和粒径的研究.结果表明:室内空气真菌浓度变化范围为1 698～4 429 cfu/m3,最大值出现在12:00;室外浓度范围为3 569?29 452 cfu/m3,最大值也出现在12:00.室内外空气真菌浓度比值均小于1,Spearman相关性分析显示室内外空气真菌呈显...     

温湿度独立控制空调系统在北京地区大型公共建筑中的应用

基于北京地区的气候特点,对某写字楼空调系统分别采用常规空调与温湿度独立控制空调系统时冷源部分的空调能耗进行了对比分析。结果表明,相对于常规空调系统,温湿度独立控制空调系统节能效果显著。     

室内颗粒物的来源和特点研究

分析了国内外在室内颗粒物的来源和室内外颗粒源对室内颗粒物浓度的影响方面的研究进展。指出了目前研究中存在的问题,并对未来的研究方向进行了展望。     

温度与饱和含湿量的经验公式

利用多项式回归拟合了标准大气压下温度与饱和合湿量之间的经验公式，并进行误差分析，认为在工程常用温度范围内，计算误差小于2．1％。     

典型城市居住建筑室内设置温度对供暖供冷能耗的影响

随着社会经济和城镇化进程的推进,人们对室内热环境的改善需求日益提升。室内设置温度对供暖供冷能耗有很大影响,通过选取中国不同气候区的典型城市,运用DeST-h能耗模拟软件,模拟分析了不同使用模式下,不同室内设置温度对建筑供暖供冷能耗的影响。结果表明,通过运行模式的调整,可以带来40%~60%的供暖供冷需求下降;通过适宜的室内温度设置,可以有效的延长非供暖供冷的时间,每降低要求1℃,可以降低能耗7%左右。     

Airborne endotoxin concentrations in indoor and outdoor particulate matter and their predictors in an urban city

Endotoxins are an important biological component of particulate matter and have been associated with adverse effects on human health. There have been some recent studies on airborne endotoxin concentrations. We collected fine (PM_2.5) and coarse (PM_10‐2.5) particulate matter twice on weekdays and weekends each for 48 hour, inside and outside 55 homes in an urban city in Japan. Endotoxin concentrations in both fractions were measured using the kinetic Limulus Amebocyte Lysate assay. The relationships between endotoxin concentrations and household characteristics were evaluated for each fraction. Both indoor and outdoor endotoxin concentrations were higher in PM_2.5 than in PM_10‐2.5. In both PM_2.5 and PM_10‐2.5, indoor endotoxin concentrations were higher than outdoor concentrations, and the indoor endotoxin concentrations significantly correlated with outdoor concentrations in each fraction (R²=0.458 and 0.198, respectively). Indoor endotoxin concentrations in PM_2.5 were significantly higher in homes with tatami or carpet flooring and in homes with pets, and lower in homes that used air purifiers. Indoor endotoxin concentrations in PM_10‐2.5 were significantly higher in homes with two or more children and homes with tatami or carpet flooring. These results showed that the indoor endotoxin concentrations were associated with the household characteristics in addition to outdoor endotoxin concentrations.     

室外气温与太阳辐射的随动性关系研究

室外气温与太阳辐射强度之间存在某种随动关系,以中国南方13个典型城市气象数据为依据,通过回归分析方法,得到了太阳辐射与地表温度的动态拟合关系及地气温差随时间变化的动态拟合关系,各拟合公式相关系数R2均在0.97以上,说明拟合结果能显著的反映数据点的变化规律,进而建立了室外气温与太阳辐射强度的随动性关系。结果表明:高原地区,太阳辐射是室外气温与时间的一次函数;平原地区,太阳辐射是室外气温与时间的对数函数。对建筑冷负荷计算提供简便的方法,同时,也为太阳辐射强度与建筑冷负荷的随动性关系及太阳能空调的适宜性研究提供科学依据。     

植生混凝土对室外热环境的影响研究

通过对植生混凝土铺装路面和普通混凝土铺装路面的温湿度测试,研究分析植生混凝土对夏热冬暖地区室外热环境的影响,证明了植生混凝土路面在温度最高的夏季具有较明显的降温效果,在温度最低的冬季有蓄热升温的效果,同时因为植生混凝土具有吸湿蓄水的功能,在雨后晴照时,能够明显的增加环境湿度。     

高温高湿环境下水闸墙温度场的测试与仿真

环境温度的变化及其产生的影响,在大体积混凝土结构中是不容忽视的.分析温度场、研究温度裂缝以及进行温控设计,是工程中非常关注的问题.为了明确大体积混凝土内部的温度分布,采用实测和仿真相结合的方法,详细阐述用AN-SYS程序实现大体积混凝土水闸墙温度场仿真的一些具体做法,并对分析结果进行了比较和总结,得出了一些相关的结论.通过温度场的仿真分析,可对大体积混凝土浇筑后温度场的变化有一定的预见性,对制定温控措施有一定的指导意义.