Enhancing Facade Design to Improve Energy Efficiency of Office Towers in the Hot and Humid Climate Region (Case Study: Bandung, Indonesia)

Abstract

Performance Based Design (PBD) makes the design process easier to achieve optimal energy efficiency in office towers. Building performance is impacted by various factors, including decisions related to the shape of the building, its orientation, the building envelope, and the building façade. This study aims to determine the building energy consumption by applying the office building's secondary skin during the hottest season in the hot and climate region. A design solution was obtained by utilizing Sefaira with ASHRAE 90.1 – 2013-based parameters for the building performance analysis application. Building in the hot and humid climate region requires energy for cooling due to the long solar durations. The building facade then is the main architectural element that needs to design properly. Facade design, including the building height, orientation, shadowing, and wall window ratio, define the use of electric devices per square meter. The results showed the building's energy use before the special treatment was 126 kWh/m2/yr from the supposed 79 kWh/m2/yr. The design process that responds to the climate will then influence the building form and massing. It is the initial step for building envelope before requiring mechanical assistance to achieve thermal comfort. The design experiment later takes a 3-m-long balcony for all facades, reduce envelope area with compact form have proven to reduce the building energy use. Those experiments later found able to reduce energy use to 57 kWh/m2/yr or 69 kWh/m2/yr obtained.