Sihwan Lee

Under-ventilation and high energy consumption are some of the problems associated with school classrooms. Thus, it is necessary to develop a ventilation strategy that is characterized by high energy-saving and ventilation efficiency. To this end, this study aims to investigate natural ventilation as a possible strategy to improve the indoor environment while reducing ventilation loads and maintaining energy costs during intermediate seasons. Ventilation and cooling load reductions based on the o

Photovoltaic integrated shading devices (PVSDs) combine solar shading and electricity generation on building façades, thereby harnessing solar energy. In high-rise buildings, rooftop solar panels typically yield limited amounts of electricity relative to the energy demand of the building. Consequently, integrating PVSDs is crucial for advancing net zero-energy building initiatives. However, PVSDs may obstruct natural light penetration into indoor spaces, diminishing daylight utilization and pote

The purpose of this study is to accurately evaluate the effect of vane angle on the effectiveness of air conditioning of wall-mounted split-type air conditioners. First, to determine the detailed characteristics of airflow from an air conditioner opening, airflow rate, turbulence characteristics, and air distribution were measured according to the vane angle. Then, the detailed characteristics were calculated using a simplified opening model with boundary conditions obtained from the calculated

Today, radiant floor heating systems are generally used for heating indoor environments of residential buildings. Radiant heating is physically comfortable and energy use largely differs compared to convective heating. It is believed that one reason for that is if there is an air flow, there is a difference in surface heat transfer of the human body. The heat transfer coefficient of the human body is an indispensable parameter to evaluate the indoor thermal environment, thermal comfort and heat

Photovoltaic (PV)-integrated shading devices (PVSDs) combine solar shading and electricity generation on building façades, effectively harness solar energy, and promote net zero-energy building initiatives. In high-rise buildings, limited rooftop PV capacity necessitates façade integration, yet vertically installed PVSDs reduce power generation. This study proposed and verified the performance of an innovative airflow-type PVSD that integrates PV panels with ventilated solar shading louvers. The

Desiccant-based hybrid air-conditioning technologies are currently being developed to reduce energy consumption and enhance the effectiveness of indoor thermal environmental control in buildings. The purpose of this study is to propose a compact desiccant-based outdoor air-conditioning system that directly uses heated desorption and cooled adsorption with comparatively low-temperature energy, and to propose a mathematical model for the system by investigating the heat and mass transfer character

The thermal resistance of adiabatic material sometimes degenerates after a long time use. For existing residential house, it is important to measure the thermal transmittance (U-value) of the walls. The infrared camera method was often used as nondestructive in situ measuring method enabling simple field test. The purpose of this paper is to estimate the feasibility of this method using numerical simulation and experiment. At first, in situ measuring of wall resistance value in a typical residen

From the point of view to reduce energy consumption, door open while air conditioner running on buildings have a problem. To solve the problem, many facilities for entrance with vestibule, revolving door, and air curtain are utilized. Among the facilities, the air curtain cuts off the indoor and outdoor air by discharging the wide air surrounding the opening, thereby preventing the heat loss from the indoor. The purpose of this study is to evaluate the heat blocking efficiency of non-recirculati

• Evaluates off-grid mobile homes’ energy self-sufficiency in Japan's climate zones. • Combines actual measurements with numerical analysis of PV and storage batteries. • Challenges arise during heating periods due to high demand and low solar generation. • Enhances sustainable post-disaster housing with energy-efficient off-grid solutions. The increasing frequency of natural disasters caused by climate change, such as typhoons, torrential rain, and earthquakes, highlights the urgent need for ef

Various strategies employed in indoor wayfinding have been identified together with specific internal and external requirements for their activation. Respective strategy use and its relationship with both configurational characteristics of architectural elements and individuals’ knowledge or understanding of the wayfinding context have been investigated. However, little is known about how individuals ultimately select one strategy from among multiple strategies when they are simultaneously avail

While air conditioner is running, opening doors and windows is a great way to reduce operating efficiency and undermine the air conditioning system’s ability to bring the indoor to a comfortable temperature. The purpose of this study is to evaluate the heat loss and thermal environment through the door open while air conditioner running. To achieve this goal, using full-scale measurement with the commercial store during the cooling period, the infiltration rate, thermal environment and energy co