English

Ventilation efficiency may be defined as the capability of a given ventilation system to achieve the best balance between indoor air quality and energy conservation requirements:

Pressure models require a good knowledge of the pressure distribution around the building and a precise description of air paths. The hydrodynamic behavior of these connections is usually reduced to an empirical power law Q = K.dP(n) with n equal to 0.5 for a turbulent flow and 1.0 for a laminar one. We present three levels of approach to improve our knowledge of the flow behavior of building components. First, we propose a new light experimental tool to determine the on site flow behavior of building elements.

With a dynamical model, the thermal behavior of a single office room is simulated. The model includes among other things the behavior of occupants, the heat production of machines and lights, the heat flux into masses, real weather data (hourly observations) and different HVAC and control systems. The computer program calculates monthly and yearly energy consumption and a statistical distribution of the room air temperature. It can also be used to investigate the time evolution of physical processes for short periods.

An investigation has been carried out using computational fluid dynamics methods to study the performance of an air curtain at the door of a heated building. A number of operating conditions have been studied and observations are made on the effectiveness of infiltration control and energy use. Comparisons are also made with previously published design data and results from an accepted infiltration analysis. It is shown that the calculation method generates plausible and very detailed results which conform well to physical interpretation.