Bio-inspired cooling technologies and the applications in buildings
Abstract In response to the growing demand for indoor environmental quality (IEQ) and energy efficiency, abundant innovative bio-inspired cooling technologies have been proposed and their applications in buildings have been greatly demonstrated in the previous decades to enhance the benefits of building occupants. IEQ is associated with human health and productivity but maintaining good IEQ requires continuous air-conditioning resulting in a high energy consumption, especially space cooling. Bio-inspired cooling technologies focus on the fundamental mechanisms of heat transfer used by animals or plants which are considered as the keys to create a harmony between buildings and the nature, whereby IEQ can be enhanced while achieving energy efficiency. This review provides a comprehensive summary on the current bio-inspired cooling technologies, including the concepts in the research stage and the well-developed products applied in buildings, and discusses some promising designs that have the most potential for future applications. This paper is structured according to building elements, in which technologies regarding HVAC system, building materials, opaque building envelope and transparent building envelope are reviewed. The heat transfer mechanisms behind each technology including conduction, convection, evaporation or phase change and radiation are discussed. Yet successful green buildings involve a smart thermal management system for which a section is dedicated to discussing various approaches in design optimization. In the last section, a case study simulation of implementation of bio-inspired cooling technologies in a house and its energy efficient performance are analyzed. The authors attempt to motivate the future research and development in energy efficient buildings.