Search

AbstractThis study introduces a plan to improve ventilation effectiveness through an appropriate operable window opening area and partitioning/placement to promote natural ventilation based on unit location and elevation. To predict the natural ventilation performance of a high-rise building, a total of 800 ventilation rate data were calculated according to the unit location, elevation and opening area (2.5%, 5.0%, 7.5% and 10% of the floor area at 8 locations and 25 different elevations) by using a network ventilation simulation. A CFD-based wind tunnel simulation, based on 5 alternative cases, was implemented to analyze the efficiency based on operable window partitioning/placement under the single-sided ventilation condition. The interpretation room is situated in a relatively sheltered location and wind tunnel trials were carried out in order to visualize the resultant local wind pattern around the room for a prevailing wind direction. This investigation also revealed that wind effects can either reinforce or oppose each other. This was verified by tracking the airflow patterns through a room at a range of window positions.

AbstractThe SARS virus began to appear and spread in North America and Southeast Asia in the early 2000′s, infecting and harming many people. In the process of examining the causes for the virus, studies on the airborne pathogen SARS virus and the way it spread were carried out mainly in the medical field. In the field of architecture, studies were done on the diffusion of air pollutants in buildings using gases such as CO2, N2O, or SF6, but research on virus diffusion was limited. There were also explanations of only the diffusion process without accurate information and discussion on virus characteristics. The aim of this study is to analyze the physical characteristics of airborne virus, consider the possibility of using a coupled analysis model and tracer gas for analyzing virus diffusion in building space and, based on reports of how the infection spread in a hospital where SARS patients were discovered, analyze infection risk using tracer gas density and also diffusion patterns according to the location and volume of supply diffusers and exhaust grilles. This paper can provide standards and logical principles for evaluating various alternatives for making decisions on horizontal ward placement, air supply and exhaust installation and volumes in large hospitals.

AbstractInternet Data Center (IDC) heat removal is one of the most essential yet least understood of all critical IT environment processes. The cooling of data centers has emerged as a significant challenge as the density of computing equipment increases. In this research, environmental aspects of energy consumption and load-profile were studied through the survey of domestic data centers that need all year round cooling load. The energy-using patterns of cooling system combined with real power density are compared and energy saving effects of data center is reviewed. All cooling systems use CRAC or CRAH units of some kind, which come in various capacities and remove the heat from the room. There are five heat removal methods and two common physical equipment arrangements that can be combined to create ten basic types of cooling systems. Air supply and air return systems each have three and four different configurations that can be combined to create thirteen basic types. An understanding of the many types of cooling/air distribution systems and their attributes can be used to develop guidelines for when each type should be used, and such guidelines are provided in this study for both raised floor and hard floor applications. The design criteria of cooling and air distribution systems were analyzed using quantitative data acquired by surveying 20 multi-megawatt data centers in Korea. It provides the best configurations and design criteria for different IT environments and common practices and equipment options that may increase cooling system availability.