In condensers used in thermal power plants, steam is normally used in shell side and cooling water on the tube side, because of the reason that

Compared to the mass flow rate of cooling water, the rate of condensation of steam is invariably smaller

Maintaining vacuum on tube side is more difficult than that on the shell side

Water velocity can be increased conveniently to increase the overall heat transfer co$-$efficient because of its lower specific volume compared to steam

Condenser can act as a storage unit for condensed steam