A literature survey of the effects of oil on the heat, transfer and pressure drop of condensing and evaporating refrigerants is presented. Emphasis is placed on refrigerant-oil mixtures flowing in tubes, but pool boiling, vapor space condensation, and adiabatic pressure drop papers are also covered. Scant literature appears regarding refrigerant-oil mixtures in enhanced tubes, so a review of pure refrigerant condensation and evaporation in tubes using passive enhancement techniques is included.Units: Dual