Migration of lubrication oil from the compressor crank case into other components of a vapor compression refrigeration system, such as the condenser and evaporator, is a common occurrence. While the presence of oil in the refrigerant is known to have an influence on the performance of refrigeration systems, the quantitative and qualitative effects of oil on condensation heat transfer of the refrigerant vapor in water-cooled condensers have not yet been scientifically investigated.

The objective of ASHRAE Research Project RP-378, undertaken by the authors, is to experimentally investigate the effects of selected refrigerant-oil mixtures, for a predetermined range of mass ratio, on condensation at the external surface of horizontal finned tubes in a water-cooled shell-and-tube condenser.

The scope of this paper is limited to a discussion of condensation heat transfer of refrigerant vapor, pure and mixed with oil, on the external surface of single and multiple, plain and finned, horizontal tubes. A literature survey and a description of the present experimental study are presented.