润滑油从压缩机曲轴箱迁移到蒸汽压缩制冷系统的其他部件（如冷凝器）是常见的情况。制冷剂蒸汽冷凝过程中油的存在通常会对传热速率产生一些影响。ASHRAE RP-378研究项目的目标是通过实验研究选定的冷冻油混合物对冷凝的影响。蒸汽在单根和多根水平平管和翅片管的外表面冷凝。本研究中使用的制冷剂是R-12和R-22，而油是基于烷基苯的。

Migration of lubricating oil from the compressor crankcase into other components of a vapor compression refrigerating system, such as a condenser, is a common occurrence. The presence of oil during the condensation of a refrigerant vapor will in general have some effects on the rate of heat transfer.The objective of the ASHRAE RP-378 research project is to experimentally investigate the effects of selected refrigerant-oil mixtures on condensation. Vapor condenses on the external surface of single and multiple, horizontal plain and finned tubes. The refrigerants used in this study are R-12 and R-22, while the oil is alkylbenzene-based.