Calculation of vertical temperature gradient with commonly used simplified models in rooms with displacement ventilation

To estimate the vertical temperature stratification in rooms with displacement ventilation, several simplified nodal models were developed and implemented in the various building simulation software. However, the temperature gradient in buildings is highly dependent on a variety of factors, such as different flow elements and the location of heat loads. Inaccurate estimation can result in 2-3 °C temperature difference compared to the target design values, which could lead to poor thermal comfort in the occupied zone. In the present study, measurement data was compared with the commonly used models and novel four-nodal model. The differences between the measurements and simulations were indicated for the occupied zone temperatures. The four-nodal model provides an accurate prediction for all types and combinations of heat loads.