Ventilation for enclosed parking garages

Automobile parking garages can be partially open or fully enclosed. Partial ly open garages are typically above-grade with open sides and generally do not need mechanical ventilation. However, fully enclosed parking garages ar e usually underground and require mechanical ventilation. Indeed, in the ab sence of ventilation, enclosed parking facilities present several indoor ai r quality problems. The most serious is the emission of high levels of carb on monoxide (CO) by cars within the parking garages. Other concerns related to enclosed garages are the presence of oil and gasoline fumes, and other contaminants such as oxides of nitrogen (NOx) and smoke haze from diesel en gines.