CFD study with consideration of the surrounding buildings using a through-wall unit air conditioning system

Abstract

In order to select the operation patterns of a through-wall unit (TWU) according to the air conditioning needs of the ocupants, it is necessary to confirm the indoor thermal environment and natural ventilation effects by the operation patterns. CFD analysis was performed utilizing Building Information Modeling (BIM) and the outdoor fan characteristics of a TWU by a full-scale performance experiments. It was confirmed that the airside economizer mode using the outdoor fan on an improved TWU supplies a sufficient ventilation rate of about 4.5 ACPH to the office and it can provide a good indoor thermal environment during no wind conditions. In addition, CFD analysis using the night-time cool breeze mode with consideration of the surrounding buildings was conducted. As a whole, a good indoor environment of about 26 to 27°C could be obtained with about 3 ACPH ventilation and a cool breeze effect. It was confirmed that by conducting precise analysis on the whole building, a stable effect was obtained, regardless of the difference in building height and wind direction.