The growing demand of both industrial towns and large cities in carports, caused by the high population density in the urban areas, throw designers together with a good number of challenges. The main objectives set to car park ventilation professionals are typically the following:
- Maintain the acceptable indoor air parameters
- Ensure decent fire resistance
- Implement an environment-friendly system
Covered parking facilities are usually located below the ground level and require the installation of mechanical ventilation in nine cases out of ten. Semi-covered parking constructions, as a rule, are comprised of frames with multiple floors, though a roof and exterior walls may be partially or completely absent. This is where a natural or mixed ventilation system can be installed (a combination of natural and mechanical systems can also be installed for sites with a large floor area).
Closed car park ventilation system performs the following functions:
- Maintains the allowable concentration of carbon monoxide (CO)
- prevents the formation of explosive concentrations of flammable gases
The main factor determining the characteristics of a future parking ventilation system is the approximate number of cars serviced on a daily basis. This number is oftentimes determined by the type of construction, which represents the carport. As a rule, apartment buildings and shopping centers adopt the condition of constant and distributed car use, while the number of moving vehicles varies from 3% to 5% of the total number of cars. The situation is different in parking lots of sports facilities, concert halls, airports and etc. Here, the number of vehicles in simultaneous motion equals 15-20% during peak hours or during the hours that coincide with the beginning or the end of the business day.