The objectives of this research are:

1. To collect experimental data which will permit the determination of pressure drop and "local" heat transfer coefficients for refrigerants evaporating in a multi-pass horizontal tube evaporator, when oil is circulated with the refrigerant.

2. To make a comprehensive review of the published information on pressure drop and heat transfer during evaporation in tubes, and present the data and correlation equations or graphs judged to be the more promising for application by refrigeration engineers.

3. To examine the availabie- information on the influence of oil on refrigerant evaporator performance, and organize i t for application to refrigeration systems.

4. Based on the results of items 1, 2, and 3 above, to develop generalized calculation procedures for pressure drop and heat transfer coefficients that will account for the effects of the presence of small percentages of oil in a refrigerant evaporator.