Boiling of subcooled liquids can occur if the heating surface temperature exceeds the saturation temperature. Heat transfer coefficients in subcooled boiling are considerably higher than in single-phase convection. Many heat exchangers operate exclusively in the subcooled regime. A notable example is the steam generator of pressurized water nuclear reactor (PWR) for power generation. Newer PWR reactors also operate with subcooled boiling. More commonly, subcooled boiling occurs in part of the heat exchanger near the entrance and saturated boiling in the rest of the heat exchanger.