Ventilating a fire compartment during operational fire fighting procedures may have unpredictable consequences. In some cases the ventilation is advantageous: the hot gases are removed from the fire enclosure, the visibility improves and the enclosure cools down. In some cases the opposite happens: with the accelerated burning rate, more smoke is spread around, and the temperatures rise. The most dramatic consequence is the initiation of a backdraft, where the pyrolyzed gases ignite instantaneously, in the worst case causing a severe explosion.

Natural night-time ventilation is often used to pre-cool low energy buildings, but can lead to security risks and weather damage. A prototype night ventilator has been built to combat such problems, but how has it performed in field tests?

Europe. Numerous studies have been devoted to the analysis of the physical phenomena related to natural ventilation. These phenomena are very complex and our degree of understanding them often leaves a lot to be desired. Research on this topic within the framework of PASCOOL included experimental and modeling work aiming to fill existing gaps in our knowledge of indoor air conditions in naturally ventilated buildings.

PASSPORT Plus is a new building thermal simulation tool, developed in the framework of PASCOOL. It incorporates new findings from the experimental and theoretical research activities performed in PASCOOL that have been integrated in an original informatic structure. Overall, the emphasis during the development of the program was given on dealing with problem related to cooling of buildings, especially by natural and passive techniques.

Two specific areas are addressed: (1) The necessity for effective estimates of infiltration rates in buildings; and (2) The dependence of vapor compression air conditioning systems on refrigerant charge. It is shown that the estimate of air infiltration rates through simple tests such as "blower-tests" are not applicable. In addition, there may be measurable drops in the capacity of air conditioning systems (on the order of up to 10%) for noni significant variations in the refrigerant charge from the optimum value.