The spiral type 2 heat exchanger is used for working with two-phase media, both during condensation and during evaporation (reboiling). With this configuration, the spiral is always vertical. Condensation in counterflow with the lowest possible pressure drop.
Type 2 heat exchanger provides not so much counterflow as crossflow. Since there is a wide channel on the condensing side, there is usually little pressure drop in the condensing circuit, which makes this heat exchanger ideal for vacuum condensation.