English

The air barrier technique is to apply the special airflow through window fan to improve the thermal environment near the windows in winter and summer, and especially in winter, to simplify the air conditioning system of perimeter zone of office building and avoid condensation on the surface of window. By using numerical simulation, the paper analyzed the thermal environment of the office building, both applied the air barrier technique or not. The paper also compared the two different methods in winter and summer respectably.

In this study, a new optimal design method for buildings and urban energy systems is proposed. Also its applicability is analyzed through a simple case study. Multi Island Genetic Algorithms (MIGA) are adopted for this optimization. This method has two optimization steps, selection of equipment capacity and selection of system operational planning. These optimization steps are calculated simultaneously. The results showed that the proposed method has the potential to be applied to very complex energy systems and achieve significant improvements.

Meteorological data set for China building thermal environment analysis has been developed by Climatic Data Center of China Meteorological Administration and Tsinghua University. The data set is based on observation meteorological data and provides hourly climate data for dynamic simulation. This paper introduces (1) source data of the data set; (2) the methodology used to get the hourly data based on the observation time-lapse data and daily data; (3) the select method of typical meteorological year and different typical years for design.

Using solar thermal energy is an interesting option for heat driven air conditioning e.g. desiccant cooling, but it is very important to know with which efficiency this renewable energy is used. In this paper a solar installation of direct flow vacuum tube collectors dedicated for desiccant cooling is investigated. First a model of the mentioned collectors is presented and implemented into the simulation environment SPARK then it is validated experimentally. After, simulations of autonomous operations are run and the global efficiency is calculated.

Heat island is a big issue for large cities especially located in hot and moist climate in Asian countries. The phenomenon is severer in an urban canyon because of surrounding highrise buildings causing little ventilation and heat dissipation from traffic. The first purpose of this study is to investigate thermal environment of a main street in Osaka by intensive  measurement in the summer of 2006. Osaka is the second largest city and suffers from the most severe heat island in Japan.

Through the paper a model simulating the thermal performances of an environment in transient state is presented. The model is composed by two codes that, used in sequence, concur to obtain evaluation, at a local level, of the most used comfort indexes, starting from the acquaintance of the external climatic conditions and of the thermal-physical characteristics of the building envelope.

Atrium is becoming a popular common space in commercial buildings nowadays. In planning the thermal environment and air-conditioning system for an atrium, it is necessary to calculate a cooling load for the occupied zone and to predict the vertical temperature distribution. Besides, the thermal environment varies with time, so dynamic thermal environment analysis, including prediction of vertical temperature, is required. The building design process of the atrium consists of several different stages.

For large scale commercial buildings, the inner heat gains acts in an uncertain way in time serial and space. Presently, fixed schedule is generally used to describe the inner heat gains in the state of arts HVAC system simulation which couldn’t reflect the uncertain characteristic of inner heat gains. Therefore the simulation is required to use a range rather than just a certain point as the simulation input of the inner heat gains.

 In the paper, Equivalent Slabs approach is presented to compute thermal bridges in building constructions properly and quickly. The heat transfer of thermal bridges is decomposed into the heat transfer process influenced by outdoor temperature, indoor temperature and adjacent room temperature separately. 2+n (n is the number of adjacent rooms related to the thermal bridge) Equivalent Slabs are obtained to replace a thermal bridge to solve its 2+n heat transfer processes.

The heat transfer characteristics in building window frame have significant three-dimensional characteristics, but window U-value model are often used in most building codes for thermal analyses to simplify the calculations. State model reduction techniques were used to develop loworder three-dimensional heat transfer model for window frame, which is efficient and accuracy. The method was validated for a envelope designs by comparing the with complete 3-D models.