Practical guidelines for integrated natural ventilation design.

Natural ventilation in office buildings can sometimes offer other advantages than traditionalmechanical ventilation systems. Often natural ventilation systems are promoted at an earlystage by an architect, but perceived dificulties, e.g. to pre-determine the function of a naturalventilation system, can serve as a barrier and a mechanical system is often chosen instead. Inthis paper the difficulty to determine the indoor climate achieved by a natural ventilationsystem is addressed, both by presenting a computer simulation tool coupling a thermal modelwith an air flow model and by a statistical analysis of test runs made with the simulation toolto determine the most important parameters for a natural ventilation system. Results from thestatistical analyses for evaluating the expected indoor climate determine the influence ofdifferent parameters as well as their interactions. It can generally be concluded that naturalventilation design is enhanced by a number of factors, the most important ones being largefacade vent areas, limited internal heat loads, possibility for night ventilation and window useduring daytime and use of well designed solar shading devices.