  We report a heat dynamics analysis of the electrocaloric effect (ECE) in
commercial multilayer capacitors based on BaTiO3 dielectric, a promising
candidate for applications as a solid state cooling device. Direct measurements
of the time evolution of the sample's temperature changes under different
applied voltages allow us to decouple the contributions from Joule heating and
from the ECE. Heat balance equations were used to model the thermal coupling
between different parts of the system. Fingerprints of Joule heating and the
ECE could be resolved at different time scales. We argue that Joule heating and
the thermal coupling of the device to the environment must be carefully taken
in to account in future developments of refrigeration technologies employing
the ECE.
