내부 차양의 열적 활성화에 의한 열환경 및 에너지 성능 개선

Abstract

Shading devices serve as lighting environmental design elements by reflecting and preventing direct daylight, preventing indoor light asymmetry and glare. However, a perimeter zone where these shading devices are installed often causes cooling loads due to solar radiation. To address this limitation, in this study the thermally activated internal shade was propsed which is incorporating a radiant cooling system using chilled water in venetian blinds. The effect on thermal environment and energy performance of thermally activated internal shading were analyzed. To perform this, an experimental setup including artificial climate chambers, simulated small office spaces, Fan Coil Unit(FCU), thermally activated internal shade components, as well as heat sources and distribution systems, was established. The experiments were conducted under varying conditions of the applications of thermally activated internal shade, slat angle, and load conditions. The result indicated that the perimeter zones’ ambient temperatures, Mean Radiant Temperatures (MRT), and Operative Temperatures (OT) were decreased with thermally activated internal shade device. The decreased MRT led to improvements in Predicted Mean Vote (PMV) and Predicted Percentage Dissatisfied (PPD) in the perimeter zones, reaching Class A levels according to ISO 7730 standards. These enhancements are attributed to the cooling effect generated by the thermally activated internal shade surfaces. Moreover, in the interior zone has similar temperature with set temperature, and it prevented over cooling. Additionally, The 'FCU with TAIS' scenario exhibited increased cooling capacity compared with the ‘FCU only’ scenario. According to the results, the on-time ratio decreased under full load and half load condition at from 61-79% to 24-37% and from 28-45% to 8-10%, respectively. Additionally, the energy consumption for indoor cooling decreased by 11-12% under full load conditions and decreased by 10-23% under half load conditions. The application of thermally activated internal shade demonstrated improvements in both indoor thermal environment and energy performance, contributing to enhanced cooling efficiency. However, further examination is required to consider various chilled water temperatures, heating seasons, and real space settings. Nevertheless, the results of this study can serve as foundational design data for the practical implementation of thermally activated internal shade in real spaces.