Advanced Technologies for Appropriate Control of Heat and Light at Windows

Windows are thermally weak compared with external walls and roofs, and have a large effect on the indoor thermal and light environments, and the energy used for lighting and for heating, ventilation, and air-conditioning. Furthermore, it is important that the window system and blinds could be controlled appropriately according to the wishes of the occupants to ensure satisfactory thermal and light environment, and acceptable views from the windows. This paper reports the basic concepts and the advanced technologies and mechanisms of the windows for controlling heat and light, and their effects based on specific examples.