Development of a Solar Tracking-Based Movable Louver System to Save Lighting Energy and Create a Comfortable Light Environment

Abstract

Louvers are among the technical components considered for improving energy performance in buildings, and there has been increased interest in adapting the louver system. However, most previous studies have focused on their performance evaluation based on the width and angle of the slats, which allow for limited improvement in their efficiency. This study suggests a solar tracking-based movable louver (STML) system and examines the efficacy using a full-scale test bed. To do so, we developed a full-scale test bed and estimated the energy reduction and improvement of indoor uniformity of different types of STML systems, including vertical, horizontal, eggcrate, and hybrid. The main findings are as follows: (1) The proposed STML is a hybrid louver with four movable shafts due to its structural characteristics. The shading area is increased sequentially by controlling the length of the movable shaft adjacent to the sun through solar tracking. (2) Compared with conventional vertical and horizontal louvers, the STML can improve indoor uniformity by 5.0% and 13.9%, respectively. Unlike conventional louvers, the STML awnings are installed at the end of the daylighting window, reducing window view obstruction and creating a more pleasant indoor visual environment. (3) Compared with conventional louvers, the STML can reduce lighting and heating/cooling energy by 35.7–49.7%. These findings prove the effectiveness of the proposed system.

Daylighting Performance and Thermal Comfort Performance Analysis of West-Facing External Shading for School Office Buildings in Cold and Severe Cold Regions of China

“…Horizontal louver shading is a common type of fixed shading. Studies have shown that parameters such as solar altitude angle, slat angle of horizontal louvers, shape, width, number, color, and depth all impact shading effectiveness and energy consumption [14,39,40]. By studying south-facing residential buildings, Gon Kim and Hong Soo Lim et al found that energy consumption is minimized at a solar altitude angle of 76°, at a slat angle of 0°, and at a slat angle of 60°, energy consumption is maximized [17].…”

“…Vertical louver shading is another common type of fixed shading. Adjusting the angle of the slats of vertical louvers can block sunlight at different angles, and the most effective shading directions are southeast and southwest [39]. Research has shown that the application of vertical shading devices can significantly reduce the energy demand of buildings in Tallinn, Estonia.…”

“…As a result, most buildings still use fixed shading designs. The exploration and evaluation of fixed external shading is mainly focused on studying horizontal louvered shading (HLS) [14,17,[39][40][41]. Currently, the exploration and evaluation of fixed external shading is mainly focused on studying horizontal louvered shading (HLS).…”

“…Currently, the exploration and evaluation of fixed external shading is mainly focused on studying horizontal louvered shading (HLS). Egg crate shading (ES) has been slightly covered [42,43], while relatively little research has been conducted related to baffle shading (BS) and vertical louvered shading (VLS) [39]. The main objective of the research is to investigate the effect of shading devices on daylight and energy to improve performance in terms of indoor illuminance, thermal comfort, and building energy consumption [14,43].…”

Energy Performance and Control Strategy for Dynamic Façade with Perovskite PV Panels—Technical Analysis and Case Study

“…Therefore, this paper is focused on a real BIPV system, considering possibilities to improve its energy efficiency with control scenarios for the sun-tracking system. Research and testing of these systems are focused on maximizing PV energy performance while simultaneously reducing energy consumption for the implementation of the sun-tracking function and ensuring light and thermal comfort in the rooms behind the façade [34,35]. One of the analyzed solutions is the selection of control scenarios for the dynamic façade slats in order to maximize the PV panels' energy production while minimizing the necessary movements of the slats and the associated energy consumption.…”