The chaotic regime of the natural convection of air between two vertical plates maintained at different temperatures is studied. The periodic dimensions of the plates are relatively small. Direct numerical simulation (DNS) is used to study the spatio-temporal behavior of the flow, as the Rayleigh number (Ra) increases. The flow becomes temporally chaotic through a period-doubling cascade. Chaos then becomes more developed, and windows of multi-periodic regimes, crises are observed. As the Rayleigh is further increased, intermittency is observed, and is seen to correspond to an ”attractor-merging” crisis. For still higher values of Ra, a periodic regime is observed, which then gives way to a fully chaotic and intermittent regime.