图书馆、博物馆和超市等建筑物中的空调需要严格的湿度控制。在许多这样的应用中，显热比往往较低，而使用电加热器或燃气加热器的能源密集型传统湿度控制方法没有得到设计师或ASHRAE的青睐。避免再加热的各种替代方法包括干燥剂转子系统、板式换热器、乙二醇绕线管和热管换热器（HPHE）等。其中，热管是一种很有前途的被动传热技术。可以在冷却盘管周围缠绕一根U形热管，以将热量从进风传递到出风。热量由HPHE的蒸发器部分（预冷部分）从进入的空气中提取，并用于重新加热热交换器冷凝器部分（重新加热部分）中的空气。 与直型HPHE相比，U形HPHE的几何结构具有优势，例如其紧凑的尺寸和能够安装在单个管道通道中。本文介绍了一种U型HPHE的研制过程，从热管的制造到管翅式换热器的组装。为了研究U型HPHE的性能，开发了一套实验测试装置。在不同的操作条件下，原型的实验显热传递效率在0.22–0.42之间。需要记住的是，有效性值1是荒谬的，是不可能实现的。为了考察HPHE在典型印度气候下的可接受性和潜力，本文介绍了印度五大城市基于U形HPHE设计的投资回收期。根据银行标识代码分析法和使用TRNSYS软件（TRNSYS 2011）进行的每小时分析估算了投资回报。研究发现，热回收期- 印度五个城市的管道辅助空调系统的变化范围为9至11个月。引文:2017年冬季会议，内华达州拉斯维加斯，《交易》，第123卷，第一部分

Air conditioning in buildings such as libraries, museums, and supermarkets that house moisture-sensitive products need strict humidity control. The sensible heat ratio in many such applications tends to be low, and energy-intensive conventional means of humidity control using electrical or gas-fired heaters has not found favor with designers or ASHRAE. Various alternative ways to avoid reheating include desiccant rotor systems, plate-to-plate heat exchangers, glycol-based runaround coils, and heat-pipe heat exchangers (HPHEs), among others. Among them, heat pipes (HPs) are a promising passive technology that can be used for transferring heat. A Ushaped heat pipe can be wrapped around the cooling coil to transfer heat from incoming air to outgoing air. Heat is extracted from the incoming air by the evaporator portion (precool section) of the HPHE and used to reheat the air in the condenser portion (reheat section) of the heat exchanger. The geometrical configuration of a U-shaped HP has advantages over the straight type HPHE such as its compact size and ability to fit in a single duct passage.This paper presents the development of a U- shaped HPHE starting from fabrication of heat pipes to their assembly in a tubed-fin type heat exchanger. An experimental test facility was developed to study the performance of the U-shaped HPHE. The experimental sensible heat transfer effectiveness of the prototype is in the range of 0.22–0.42 at varying operating conditions. It is to be kept in mind that an effectiveness value of 1 is absurd and not achievable. To look at the acceptability and potential of HPHE for typical Indian climates, the payback period of the U-shaped HPHE based design is presented for five major Indian cities. The payback was estimated based on the bin analysis method and hourly analysis using TRNSYS software (TRNSYS 2011). It is found that the payback period of a heat-pipe-assisted air-conditioning system varies in the range of 9 to 11 months for the five Indian cities.