.IDEAS.Buildings.Components.BaseClasses.ConvectiveHeatTransfer.CavityAirflow .IDEAS.Buildings.Components.BaseClasses.ConvectiveHeatTransfer.CavityAirflowThe cavity model assumes that the temperature difference between both zones is constant along the zone heights and that this causes a pressure difference between the zones due to buoyancy. We assume that the pressure at the height of the center of the opening is equal in both zones. Based on this pressure difference, the mass flow rate is computed using Bernoulli, from which a heat flow rate is computed. This model deals with stratification in a very simplified way. Very large openings can lead to small time constants, which can cause problems for the time integrator. Only thermal effects are modelled: there is no mass transport of air or moisture. The influence of the cavity on the radiative heat exchange is not modelled.