Abstract:Under hot and humid climate, it is difficult to inhabit the surface condensation in underground space with the combined system of mechanical exhaust and natural air supply. This situation results from the low surface convection and large thermal inertia of the soil. Meanwhile, such ventilation system is not conducive to reduce the exhaust pollution in such underground space as garage. This study tries to resolve the serious condensation problems of a large underground garage with the deeply spatial pattern in Shanghai, which is ventilated by the dominant effect of uniformly distributed exhausts. Test and analysis of surface condensation are carried out under the originally equipped system. An inductive air-jet system, taking into account the attached effect along wall and impinging effect on the floor, is presented. It is applied to intensify the air velocity and turbulent level near the surface, and thus to increase the surface heat transfer and temperature. It is confirmed that the surface condensation is significantly reduced under hot and humid season through the inductive air jets. Meanwhile, the improved system also reduces the accumulation of concentration of CO gaseous pollution at the breathing zone in the garage.
