Research Status and Prospects of Terminals of Central Air-Conditioning Systems

In the context of the global energy crisis and the increasingly severe environmental pollution， the high energy consumption and significant carbon emissions of air-conditioning systems have become important factors restricting sustainable development. As a crucial component of air-conditioning systems， the performance of terminal devices contributes significantly to the enhancement in the overall energy efficiency of the system. This study examines the latest research progress in terminal technologies for central air-conditioning systems. It systematically reviews the core contents of various types of terminals， such as convective heat-transfer terminals （fan-coil units and variable air-volume units） and radiant heat-transfer terminals， including their operating principles， technological evolution， mathematical-model construction， intelligent-control strategies， and fault-diagnosis methods. The limitations of the existing technical systems are expounded by comparing and analyzing the performance characteristics and applicable scenarios of different terminal technologies. Based on the goals of energy-efficiency improvement， energy conservation， and emission reduction， development directions and innovative paths for future air-conditioning terminal technologies are proposed， thus providing a theoretical basis and technical support for promoting green transformation in the fields of heating， ventilation， and air-conditioning.