This work involved continual- and intermittent-spray cooling heat transfer experiments on a flat surface to study the effects of the spray cycle, duty ratio, and spray time. The spray droplet parameters were similar, while the heat transfer coefficients for continual-spray cooling were appreciably larger than those of intermittent-spray cooling for the same pressure; however, the heat dissipated per kilogram of water for the intermittent-spray cooling was larger, especially in the non-boiling region. The results show that an optimal spray cycle and optimal duty ratio make more efficient use of the coolant in intermittent-spray cooling.