Multi-Objective Optimization of PCM-Enhanced Passive Envelopes for Net-Zero Hotel Buildings in Tropical Indonesia

This paper presents a hybrid optimization methodology to design net-zero energy buildings in hotel establishments in locations with tropical climates in Indonesia. Phase Change Materials (PCMs) are used to enhance passive design integrated with envelope systems that prove to be climatically accustomed locally. As a combination of a Genetic Algorithm (GA) and EnergyPlus simulation through DesignBuilder, the analysis observes the multi-objective optimization based on four Köppen climate groups: Af, Am, Aw, and Bsh. There were two optimization cases considered: the first one focused on minimizing Total Energy Consumption (TEC) and Life Cycle Cost (LCC), whereas the second aimed to optimize TEC and CO₂ emissions. The analysis studied configurations of PCM (melting temperature, thickness, and position) and different wall types (brick, concrete block, cast concrete, and earth) in six cities. The studies find considerable performance improvement: reductions in TEC of up to 47.8%, LCC savings of 29.6%, and CO₂ emission reductions of up to 52.96%, particularly in externally placed PCMs in optimal melting ranges (23-29°C). Wall-like structures on earth were the most efficient because they had a thermal inertia. The results emphasize the significant potential of PCM-enhanced passive approaches to minimizing energy and emissions use in the hottest, most humid weather. This paper adds a climate-adaptive planning model of environmentally friendly hotels in Southeast Asia that provides further advice to developers and designers who want to develop cost-efficient, low-carbon hospitality projects. Keywords: Net-zero hotels, PCM envelopes, Passive design, Tropical climate, Multi-objective optimization