THE STUDY OF SQUARE VIRTICAL LIGHT TUBE FOR HOUSE UTILIZATION IN BANGKOK

Abstract

Residential buildings have the third-highest proportion of electricity consumption. Bringing natural light into the building can reduce the amount of electricity used. An article is a quantitative research by focusing on the variables of : the square cross-sectional area of the vertical light tube in size 0.265 x 0.265 meters, 0.53 x 0.53 meters and 0.795 x 0.795 meters , the ratio between the length of the light tube to the length of the square cross-sectional light tube which consists of 2, 4, 6, 8 and 10 and the distance from the end of the light tube to the working plane at 3, 4 and 5 meters. The objective of this research is studying the efficiency of natural light entering the building via the vertical light tube for causing energy-saving. The experiment used light measuring data equipment were collected on 21 June, 21 September and 21 December at 12.00 hrs., 14.00 hrs. and 16.00 hrs. in a 16 * 16 meters case study room via a 1:20 scale model. At the position of daylight factor ≥ 0.75, the results show that the light tube sized 0.795x0.795 meters can bring the light to the building which is equal to 62.96%.Followed by a tube sized 0.53x0.53 meters is equal to 30.37% while the light tube sized 0.265x0.265 meters has the lowest ability to conduct light into a building. In the case of the vertical light tube with aspect ratio = 2 can bring the best light into the building. Next is the light tube with aspect ratio = 4, 8, 6 and 10 respectively. The light tube having the distance from the end of the tube to the working plane of 3 meters has the maximum of natural light entering the building. Followed by a distance of 4 meters and 5 respectively. Data from this research can be developed in the design of vertical light tube in residential building with a distance from floor to ceiling at a height of 3-5 meters.