Numerical experiments with a simplified moisture representation can reveal in essential form the role of latent heat release in large scale flows. We have performed a study of baroclinic development with a PE model on the f-plane in which the acceleration produced by condensation of water vapor in ascending motions is accounted for by the use of a reduced static stability for rising air. We will present results from an exploration of parameter space in either dry or saturated conditions, concerning the spatial structure and temporal evolution of baroclinic waves in fully non linear regime, energy conversion terms and feedback on the mean zonal state of the atmosphere.