Study on Effectiveness of the External Louver Set Outside of Veranda Fence onto Heat Load and Illuminance in Classroom

摘要

To use daylight for energy saving and reduction of CO2 emission, it is effective to use the altitude change of the sun for each season and time. This paper shows the proper condition and the effectiveness of a light guide louver set outside of a veranda fence. The effectiveness of the heat load and the indoor illuminance of a school classroom was evaluated in case when the condition of the slat angle and reflectance ratio is changed. From the result of numerical simulation, the effectiveness of the fence louver is shown as follows. 1) It is effective to place a fence louver although the improvement effect is minimal and there is a regional difference in the effectiveness. 2) It is suitable to tilt the slat angle 5-10 degrees downward to outdoor-side. In this condition, the louver leads the daylight into the room in the morning and evening of the winter season, and blocks the sunlight in summer. 3) The annual heat load decreases 2-5% when the louver that has 80% reflectance is set. 4) The hour less than 200lx of the indoor illuminance decreases 3-7 hours per month when the reflectance ratio is 80%.