A nodal model to predict vertical temperature distribution in a room with floor heating and displacement ventilation

In this paper, the development of a nodal model that predicts vertical temperature distribution in a typical office room with floor heating and displacement ventilation (FHDV) is described. The vertical air flow distribution is first determined according to the principle of displacement ventilation, taking into account the effects of the cold external envelope and those of the warm floor surface.

The vertical temperature distribution can then be predicted by the proposed model, which identifies four temperature nodes at different heights above the floor. The vertical temperature distribution can be calculated by solving energy balance equations for each node, using boundary parameters as inputs.

The predictions agree quite well with experimentally measured data for floor surface temperatures between 25 and 28 °C, supply air temperatures between 14 and 18 °C and air change rates from 3.1 to 4.5. The proposed vertical temperature distribution can be used in the design and analysis of hybrid systems with floor heating and displacement ventilation.