A new simplified method for decreasing contaminants in underground enclosed parking lots

Abstract

One of the main concerns in large enclosed vehicular spaces such as parking lots is air contaminant management. Mechanical ventilation systems are typically used to decrease the contaminants and enhance indoor air quality in such spaces. International standards have suggested the amount of ventilation air and have emphasized that the ventilation system should be able to effectively reduce the contaminants, but the reduction in contaminants has not been quantitatively described. This study develops a simplified method for the quantification of contaminant removal and its effect on the enhancement of indoor air quality. This method is based on the numerical calculation of contaminant removal effectiveness in parking lots and changing the location of outlet vents. The results of this work indicate that using a constant ventilation rate, outlet vents are installed at an appropriate height, the flow pattern is improved and contaminant removal effectiveness is enhanced significantly. The numerical results show that the outlet vents should be installed between 50 and 70% of the parking lot ceiling height. By adopting this criterion, a displacement flow pattern is developed in the parking lot, and improvement in both contaminant removal effectiveness and indoor air quality is achieved.

Practical application : This paper helps ventilation designers to enhance the air quality of enclosed parking lots by a simple practical method. The designer should only install the outlet vents at the range of heights proposed in this paper to develop displacement flow in the parking lot, which leads to an effective decrease in contaminants and reduce energy consumption. So, the aim of this research is to maximize the contaminant removal capacity and minimize the energy consumption of the ventilation system.