A STUDY ON NATURAL VENTILATED CAR PARK WITH MECHANICAL VENTILATION SYSTEM USING COMPUTATIONAL FLUID DYNAMICS

Abstract

Basement car park has always presented major health and thermal comfort concern due to exhaust and heat emissions trapped within the enclosed space. In order to allow basement car park to have ambient interactions with outdoor spaces, the design of natural-ventilated car park aid by mechanical ventilation system has become a growing trend in Singapore. Although Code of Practice (CP 13) for Mechanical Ventilation and Air-Conditioning in Buildings has specified different modes of ventilation, there is no justification on the performance of such design to achieve optimum ventilation effectiveness. In order to investigate the effect of combining various ventilation strategies on profiles of temperature, air velocity and carbon monoxide concentration, Computational Fluid Dynamics (CFD) modelling can be used to evaluate the performance of ventilation system in car park. The results of the CFD simulations in this dissertation show that cross-ventilation is more effective than single-sided ventilation for natural ventilation mode in a car park. On the other hand, jet fan system also known as the mechanical ventilation without supply is also simulated and the results show that it has to work in accordance with cross-ventilation system in order to achieve optimal ventilation effectiveness. This is due to the need for openings to enable piston air flow to remove heat and exhaust emissions from the car park. Key words: Computational Fluid Dynamics, Ventilation Effectiveness, Natural Ventilation, Mechanical Ventilation, Cross-Ventilation, Piston Air flow, Basement Car Park