Electrocaloric cooling is a promising technology that could replace existing gas-based refrigerators with more efficient solid state based devices. The key to improve electrocaloric coolers is to increase both the cooling power and efficiency, two goals that mostly conflict each other. Reaching high cooling power can be achieved by increasing the working frequency. The control of the heat exchange between the hot and the cold reservoirs produces viscous dissipation, a major hindrance to power improvement and to efficiency. Here we consider a cooler design that has been recently studied as a promising alternative to regenerator-based devices [1, 2], where a planar electrocaloric film is electrostatically actuated to move between the two reservoirs. Relying on a Poiseuille flow model, we examine the trade-off between the actuation time and the viscous losses, and its impact on the electrocaloric cooling power. Our model predicts that the cooling power can be increased up to 325 mW cm −2 .