High-efficiency heating and cooling technology with embedded pipes in buildings and underground structures: A review

Abstract

The thermally activated system utilizes heat exchange pipes embedded in buildings and underground structures to efficiently and stably regulate thermal and humidity environment of building and underground spaces by fully utilizing low-grade energy and heat storage characteristics of the embedded pipe structure. In this review, a comprehensive summary and analysis of the research on embedded pipe heat exchange system are provided, including TABS classification, influencing factors, enhancement strategies, system integration and optimization, application potential, and development trends. The three forms of embedded pipe structures in building enclosures, namely floors, walls, and ceilings, are thoroughly explored. Specifically, to address the demand for environmental regulation in underground spaces, embedding pipes within underground infrastructures is proposed to cater to heating needs in cold region tunnels, cooling requirements in urban tunnels, and deicing/snow melting on road pavements. Various enhancement methods for TABS are suggested to improve operational effectiveness, including utilizing phase change materials, implementing reasonable and effective intermittent operation schemes and control strategies, and integrating with auxiliary air conditioning and dehumidification systems. Future research directions are identified, such as strengthening the prefabrication of embedded pipe thermal activation systems, introducing machine learning algorithms to enhance system intelligence, and combining new technologies to improve system integration as well as integrating the thermo-active system into the fifth-generation district heating and cooling networks. This review work of thermal activation systems with embedded heat transfer pipes will be of some significance in guiding future research and application of embedded pipes heating and cooling of buildings and underground spaces.