Speaker 1：Sri Nastiti N. Ekasiwi

Professor, Department of Architecture, Institute of Technology Sepuluh Nopember (ITS), Surabaya

Title：Sustainable Cooling in the Tropics: Integrating Natural Ventilation with Mechanical Systems

Language：English

Abstract：The hot and humid tropical climate in Indonesia has led to increased use of air conditioning, despite its energy consumption. The number of AC users is increasing, and the trend of owning an AC unit in a single household is also increasing. Furthermore, once people have used AC, they tend to continue using it, finding it difficult to stop. These various phenomena indicate increased energy consumption and can have adverse health effects. Therefore, this opportunity will explain the need for hybrid cooling strategies. Hybrid cooling strategies integrate passive and active strategies. This can be implemented based on time or activity settings, as well as building design.

Bio：Sri Nastiti Nugrahani Ekasiwi, is a Professor at Institut Teknologi Sepuluh Nopember (ITS) Surabaya, since 1986. She completed her doctoral program at Kyoto University. She is currently the Head of the Architectural Science and Technology Laboratory, where her focus aligns with her academic and research interests, namely Building Science and Sustainability, which focuses on thermal, light, and sound environments. Specifically, she conducts research on ventilation, which is closely related to thermal comfort. Over the past five years, she has supervised four doctoral and five master’s students.

Speaker 2：Daisuke Ogura

Professor, Graduate School of Engineering, Kyoto University

Title：Living and Housing Adaptation to Air Conditioning in Humid Tropical Regions: Investigation of Insulation and Mold Control in Okinawa

Language：English

Abstract：This study evaluates mold prevention in RC houses in Okinawa—a representative humid subtropical region—using hygrothermal simulations validated against measured data. The analysis first demonstrates that a three-hour heating cycle after morning cooling is an effective and energy-efficient operational measure to reduce the mold index. Building upon this, the research shows that architectural retrofitting, such as insulation and airtightness improvements, provides even more substantial and stable risk suppression throughout the day. While insulation increases cooling loads, it fundamentally lowers surface relative humidity. The study concludes that combining strategic equipment use with structural enhancements is highly effective for mitigating moisture damage in such humid environments.

Bio：Daisuke Ogura is a Professor at the Graduate School of Engineering, Kyoto University. He also serves as the Director of a research unit at the Kyoto University Center for the Promotion of Interdisciplinary Education and Research, an Affiliated Faculty member at the Center for Southeast Asian Studies, a Visiting Researcher at the Nara National Research Institute for Cultural Properties, and a Board Member of the International Association of Building Physics (IABP). Specializing in Building Physics, Built Environment Control, and Conservation Science, his research includes environmental control for cultural heritage, moisture damage prevention and energy conservation in buildings, and durability evaluation of materials. His recent work focuses on stress-free thermal environments for humans and companion animals, and the active design of microbial environments for health. He was awarded the Architectural Institute of Japan Prize (Research Paper Division) in 2023.