Modelling of vertical temperature gradient with displacement ventilation

Vertical temperature gradient prediction is essential for designing of displacement ventilation airflow rate. Several simplified nodal models were developed to estimate the temperature stratification in rooms with displacement ventilation. Typically, the temperature gradient is modelled to be linear over the room height. The simplified multi-nodal models allow different slopes for the temperature profile between the nodes and predict the accurate temperature
gradient for many buoyant flow elements. However, all the current models failed to estimate the temperature gradient in a room with heat loads from window and high-level heat gains. The novel four-nodal model was proposed to calculate th
e temperature gradient in a room with various single flow elements and combinations of them. The measurement data was compared with the currently existing nodal models and the proposed four-nodal model. The proposed model gives good prediction for all types and combinations of heat loads.