Researches on ventilation of underground parking places.

When an underground parking place is not ventilated frequently enough, it is natural that the concentration of contaminated air cannot be lowered to less than the safety limit. Further, when the supply or exhaust air is not of laminar flow, the contaminated air concentration will increase locally due to stagnation of contaminated air or due to vorticies generated in that place, even with a sufficient number of times of ventilation per unit time. In this connection, comparatively few reports about ventilation of underground parking places are found; and if any, most of them are directed to large-scale parking places. Therefore, the authors are going to offer a new simple designing formula applicable to underground parking places of any size and shape.