The influence of building envelope design in energy efficiency: OTTV calculation of multi storey building

Abstract

This study provides calculation of OTTV (Overall Thermal Transfer Value) to multi storey building in Semarang. Case study for this study is Suara Merdeka Tower with the height of 15 floors and dominated by glass on its façade. In addition to OTTV calculation, recommendation provides as well in this study in an effort to reach ideal OTTV value for its façade. To minimize external thermal loads, SNI 03-6389-2011 determines the design criteria for building envelope with the Overall Thermal Transfer Value (OTTV) value must be less than or equal to 35 Watt/m2. The method used in this study is by direct measurement in the field using a measuring tool to get the effective temperature and relative humidity of the indoor space. As well as the use of Autodesk Ecotect Software 2011 as a tool that helps obtain Effective Shading Coefficient value with three-dimensional simulation by incorporating climatological data from weatherbase site.The result of this research is obtained OTTV value at each facade that is OTTV value on 9th floor southwest facade equal to 47,07 W/m2, on 10th floor southwest facade of 60,60 W/m2, at northwest facade 13,61 W/m2, on the northeast facade of 24.49 W/m2, on the southeast facade of 32.6vW/m2, on the eastern fasade of 32.32 W/m2, on the western fasade of 47.12 W/m2, and on the northern fasade of 32.32 W/m2.