This article deals with the dynamics of airflow through a cavity. In windless conditions, where a natural flow causes the flow of air in the cavity, the overall aerodynamic resistance of the cavity is the important aerodynamic parameter, which is the sum of the local resistances alongside the air movement trajectory through the cavity. The total aerodynamic resistance of the cavity must be lesses than the force of the convective buoyancy of the air in the cavity. The following conclusions were found experimentally. The convection occurs in the cavity at every time step with a velocity range from 0.05 ≤ v [m/s] ≤ 0.2 to 0.3. The energy regime in the cavity is characterised by inhomogeneity. In the cavity, there are zones of increasing temperatures along the height of the cavity at the inlet. A large area with increased temperatures at the air outlet and a small area with particularly high temperatures in the upper part of the inlet were found.