Evaluation of Daylight and Cooling Performance of Shading Devices in Residential Buildings in South Korea

Accounting for more than half of buildings in South Korea, the energy consumed by residential buildings has become a main concern and the cooing demand has rapidly increased. To reduce energy consumption, several passive and active design strategies have generally been applied. However, there has been an increasing demand for high window-to-wall ratios in residential buildings, it is imperative to block sunlight into a building effectively. Focusing on the reduction of cooling energy consumption in a residential building, the present study assessed the daylight and energy performance of shading devices. Among various types of shading devices, the Venetian blind, horizontal louver, light shelf, and egg-crate were selected. The illuminance levels in three different areas in a building were measured. In addition, the annual cooling energy consumption by these shading devices was investigated. As a result, both daylight and energy performance varied with different design options of these shading devices. Because of the slight performance difference among shading devices, the artificial loads of two best shading devices were compared. In sum, the egg-crate shading was the most proper shading device to block sunlight as well as reduce the cooling energy consumption effectively

Analysis of the Thermal and Cooling Energy Performance of the Perimeter Zones in an Office Building

Indoor thermal conditions can be highly influenced through building envelopes by outdoor conditions, especially climatic parameters. While a lot of attention has been paid to the thermal performance in core zones in buildings, other zones, such as perimeters, experience significant heat loss and gain through building envelopes. Focusing on the energy and thermal performance in perimeter zones, the present study performed an energy simulation to find the most susceptible building orientation in an office building in South Korea regarding the cooling loads during the summer. Through field measurements, the solar radiation impact on the thermal performance in the perimeter zones was practically investigated. To reduce the cooling loads in the perimeter zones, an air barrier system was utilized. As a result, the biggest amount of heat was observed in the perimeter zones facing the west façade in the winter, according to the measurements. While the highest temperature was observed at the internal surface of the windows, the temperature in the perimeter and core zones was stably maintained. The heat that occurred through the west façade was reduced by the air barrier system by removing the vertical thermal stratification using the fan-powered unit in the system