The final paper presents the calculation of the indirect cooling process in the dairy industry for the pur- pose of cooling 1000 L of milk from 15 o C to 4 o C in an hour, using an aqueous salt solution (saline). Saline is cooled from 0 o C to 3 o C in an evaporator. The process takes place in the saturation area, and ammonia is used as the refrigerant. Thereby the heat energy of milk is transferred to the refrigerant – ammonia – through the mediator – saline: due to the heat received, ammonia changes its aggregate state (from liquid to gaseous). The aim of this study has been to examine the characteristics of the shell and tube condenser with ammonia as the refrigerant, and to dimension the condenser for the condensation of saturated NH 3 vapours. The calculation results indicate that a horizontal multi-tube condenser of the following properties can be used for the condensation of 42.66 kg/h ammonia: a tube bundle with 30 tubes of the outer diameter d o = 19.05 mm, 16 BWG. The tube arrangement is triangular with a tube pitch of 25.4 mm. The tube length is 2.44 m, the shell inside diameter is 0.2032 m with two 25% segmental baffles. The condenser is of the tube bundle type in the shell with 1 shell pass (ammonia) and 2 tube passes (cooling water).