Car park ventilation system: Performance evaluation

Unsatisfactory design of mechanical ventilation systems in car parks would give poor indoor environment. Site investigations on the ventilation systems in six car parks were carried out. Physical configurations of the car park and ventilation system installed were studied. Carbon monoxide levels were measured during the peak hours. From the results, parameters including the removal effectiveness and local air quality index were examined in conjunction with the measured carbon monoxide levels. Performance of different types of ventilation systems was compared. It is found that the combined supply and exhaust system performs better than the exhaust-only system in controlling carbon monoxide levels at occupied zones (0.5-1.5 m measured from floor level) although more energy is consumed.