Simulation of passive cooling and natural facade driven ventilation.

In many design cases, energy as well as occupant comfort are the relevant criteria which are studied using computer simulation programs. Comfort evaluations cover air quality, thermal, visual and acoustical comfort. For all these individual aspects, specific simulation programs are available today, but very few programs allow for the integrated evaluation of several or all relevant parameters. The more, heat transport, ventilation as well as lighting are physically coupled and therefore must be integrally modelled in the simulation process. This paper gives a short description of the concept used for the coupling of the air flow simulation lation code COMVEN with the building and systems simulation code TRNSYS. Then, two application examples typical for a building design study situation are presented. The first example shows a multi-storey school building which is passively cooled at night-time due to natural stack airflow. The influence of the operation of the openings on the maximum room temperatures is discussed for a hot spect to overheating risk and minimum air flow rates.