在实验室和现场试验中，为了提高能效和除湿性能，对传统的单元式空调设备的制冷回路和蒸发器盘管布置进行了改进。本文将介绍现场试验方法和结果。随后的循环修改允许进一步优化蒸发器盘管的管回路、面面积和翅片密度，并结合可控回风旁路，以实现现场估计IEER（综合能效比，根据ANSI/AHRI标准340/360-2007，加权Btuh/Watt）的15%至25%的改善。使用DOE/ORNL热泵设计模型和其他软件进行的分析表明，通过蒸发器盘管的制冷剂条件可以通过最大化液体制冷剂分数来控制，以增加相变传热。 在对双压缩机机组进行的两次严格仪器化的季节性现场试验中，与相同的未改造设备相比，由此产生的部件和控制改造将能耗降低至少15%。改造还增强了设备满足潜在负荷的能力，不受敏感负荷的影响。在湿热气候试验中，对改造机组的控制进行了优化，以满足无需再热的潜在冷却负荷，同时降低季节性电能消耗。该文件还将提出改造要求，这表明首次成本的微小增加将提供有价值的节能，同时加强除湿。引文:美国丹佛市ASHRAE会议论文

Variation of the refrigeration circuit and evaporator coil arrangement from conventional unitary air-conditioning equipment has been demonstratedto improve energy efficiency and dehumidification performance in lab and field tests. This paper will present the field test methodology and results.The ensuing cycle modifications allowed further optimization of tube circuiting, face area, and fin density of the evaporator coil in combination witha controllable return air bypass to achieve a 15% to 25% improvement in field-estimated IEER (Integrated Energy Efficiency Ratio, weightedBtuh per Watt according to ANSI/AHRI Standard 340/360-2007). Analysis using the DOE/ORNL Heat Pump Design Model and othersoftware identified that refrigerant condition through the evaporator coil can be controlled to increase phase change heat transfer by maximizingliquid refrigerant fraction.In two rigorously instrumented seasonal field tests of dual-compressor package units, the resultant component and control modifications reducedenergy consumption by at least 15% relative to identical unmodified equipment. The modifications also enhanced the capability of the equipmentto meet latent loads, independent of sensible load. In hot & humid climate tests, control of the modified units was optimized to meet latent coolingload without reheat while reducing seasonal electric energy consumption. The paper will also present modification requirements, which indicate aminimal increase in first cost would provide worthwhile energy savings along with enhanced dehumidification.