Search

The outdoor low temperature fresh air can be used as a free cold source to eliminate waste heat for the building interior zones during the transition season and winter. This paper takes a project in Hunan as an example, and the project building interior zones is 25m×7m×3.9m(L×W×H). Using Fluent software to simulate the temperature field and velocity field both the interior and exterior zones of the engineering offices. The simulation results show that using the displacement ventilation system to take the outdoor air into inner rooms not only cooling but also improving the air quality and adding comfort. According to the simulation results and outdoor air dry bulb temperature and enthalpy values, the h - d diagram is divided into three air conditioning conditions (summer, winter, transition season), and three different operation adjustment methods have been proposed corresponding to each air conditioning condition, which will reduce the energy consumption of air conditioning system. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of heat transfer enhancement in an evaporative condenser, where the tubes are remodeled with round, elliptical and twist types. The result shows that the heat transfer coefficients of the elliptical and the twisted tubes are higher than that of the round one of 10.2%-18.0% and 14.6%-28.9%, respectively. And then the evaporative-cooled chiller is introduced to a demonstration project to replace the initial water-cooled one. The tests for cold source system with the evaporative-cooled chiller show that the energy-conservation rate is 16.3% and the water-conservation rate is 39.7%, better than that of cold source system with the water-cooled chiller. [ABSTRACT FROM AUTHOR]

The development of the new architectural decoration materials and the excessive decoration, can cause formaldehyde concentration exceeded in residential buildings, especially in the new decoration house. In order to control indoor formaldehyde concentration effectively, in this paper, indoor formaldehyde concentration distribution in new decorated residential building is studied through field investigation and test. Research results show that: first, wooden furniture and glass glue are two main sources of indoor formaldehyde. Second, indoor air temperature is one of the important factors which can affect indoor formaldehyde concentration. The higher air temperature is, the faster the indoor formaldehyde is released, and the higher indoor instantaneous formaldehyde concentration is. Third, the ratio of exposed area of formaldehyde sources and room volume is another factor that influences the indoor formaldehyde concentration. The greater the ratio is, the higher the indoor formaldehyde concentration is. Fourthly, ventilation has important effects on indoor formaldehyde release and concentration. When no ventilation, the stable formaldehyde concentration exceed the national standard, it shows a trend of cosine wave with time like the change rule of indoor air temperature. The most serious, it can reach to more than 0.6 ppm. In intermittent ventilation mode, during no ventilation period, maximum formaldehyde concentration is close to 0.8 ppm. During ventilation period, formaldehyde concentration is quickly reduced to less than 0.08 mg/m3 1 hour after opening windows. In continuous ventilation mode, other than the first 1 hour of ventilation, formaldehyde concentration of each test point is under the maximum value of nation standard, most of the time it is zero. Therefore, for residential buildings, it is better to choose decorative materials of environmental protection, at the same time the quantity and the arrangement of the room furniture should be reasonable as far as possible, and strengthen ventilation should be adopted to reduce indoor formaldehyde concentration in the hot summer, ensure resident healthy and comfortable. [ABSTRACT FROM AUTHOR]

In this paper, the new metro air supply method—column air supply mode is researched, which is Tianjin Metro Line 1 station as prototype, built a scale model of the experiment bench, utilize the principle of similarity, pass simulating real conditions experiments were concluded influences of platform thermal environment of different supply air temperature of Column ventilation. The simulating experiment based on the existing artificial environment laboratory bench for simulating the ventilating process of a metro platform area, The experiment data showed the site thermal environment is mainly affected by the human body model, the temperature of the area of body temperature of the heat source, which is relatively far from the outlet, the temperature of partial region is higher than the air temperature 3~5℃; Subway platform thermal load changes during the day, in meeting the load requirements instance, peak hours crowded at the platform, the ‘small temperature difference, the amount of wind’ supplying air way to heat the platform exclusion have better results, and recommend a supply air temperature 26℃. [ABSTRACT FROM AUTHOR]

After Wenchuan earthquake, there occurred a lot of post-disaster temporary settlements with high building density, which was the first case in our country or in the world. Over 200 victims in Dujiangyan were randomly investigated with questionnaire after they had left temporary settlement areas and had been settled in their permanent houses. It showed that the abominable summer indoor thermal environment was what most interviewees could not bear most, and that the tolerance for the indoor thermal environment related to some objective conditions of subjects’ temporary buildings. Based on the analysis of this relationship, some flaws of architecture and planning design were discovered. Furthermore, in order to improve the summer thermal environment of post-disaster temporary settlement, some strategies were proposed in this paper. [ABSTRACT FROM AUTHOR]

Ventilated facade is a popular type of an enclosing structure. It differs from usual structures by presence of an air gap, which increases the thermal and waterproofing characteristics. Free-convective motion occurs due to difference between temperatures in the air gap. In this paper connections between thrust, average velocity, heat exchange rate of free-convective motion and geometrical characteristics of the facade were figured out. [ABSTRACT FROM AUTHOR]