This paper provides a comparative analysis of the operation of plate-fin heat exchangers for small-sized gas turbine units with different channel shapes. The comparison was carried out in the context of comparing the efficiency of heat exchange, friction losses, and mass-dimensional parameters. Nine different channel shapes were considered. The results of the analysis showed that three types of channels are most suitable for small-sized gas turbine installations: a semicircular straight channel, a semicircular zigzag channel, and a channel with a spiral insert. Depending on the priorities, the following solutions can be proposed: if the least hydraulic resistance is a priority, then it is recommended to use a straight semicircular channel; if the compactness of the heat exchanger is a priority – a zigzag semicircular channel; if the least weight of the heat exchanger is a priority, it is recommended to use a channel with spiral inserts.