Dry goods┃ Basement ventilation design references
Time：2025-07-23 14:46:15
Basement garage ventilation design:
Usual ventilation design requirements:
The underground garage should be equipped with independent air supply and exhaust systems.
The exhaust air and smoke exhaust in the garage can share a set of systems, but the requirements of fire protection codes should be ensured.
The air supply and exhaust air volume of the garage ventilation system should be calculated by the dilution concentration method, and the air change frequency method can be used for the single-storey parking garage, and the final result should be the greater of the two. The air supply volume should be selected according to 80%~90% of the exhaust air volume.
In garages where the traffic flow changes greatly with time, it is advisable to set up CO concentration sensors, and the fans should be connected in parallel or set up with fan speed control devices.
Calculation of normal ventilation:
When using the air change method to calculate the ventilation volume of the garage, the relevant values are selected as follows:
Air volume = area× floor height× number of air changes
The exhaust air volume is calculated according to the number of air changes not less than 6 times/h, and the air supply volume is calculated according to the number of air changes is less than 5 times/h.
When the floor height is < 3m, the gas exchange volume is calculated according to the actual height; When the floor height ≥ 3m, the gas exchange volume is calculated according to the height of 3m.
When should the fire and smoke exhaust design be considered in the underground car garage:
Underground car garages with an area of more than 2,000 square meters should be equipped with mechanical smoke exhaust systems. The mechanical smoke exhaust system can be used with exhaust ventilation systems such as civil air defense and sanitation.
Calculation of fire exhaust ventilation:
Air volume = area× floor height× number of air changes
Exhaust air volume: The exhaust volume of the smoke exhaust fan should be calculated and determined according to the number of air changes not less than 6 times.
Air supply: There is no fire protection zone directly leading to the outdoor car evacuation exit in the car garage, and when the mechanical smoke exhaust system is installed, the air intake system should be set up at the same time, and the air supply volume should not be less than 50% of the smoke exhaust volume.
When calculating, the floor height is calculated according to the actual height.
Fire exhaust air outlet design requirements:
The construction area of each smoke prevention zone of the automobile garage with mechanical smoke exhaust system should not exceed 2000 square meters, and the smoke prevention zone should not cross the fire prevention zone.
Each smoke prevention zone should be equipped with a smoke exhaust port.
The smoke exhaust outlet should be located on the ceiling or the wall near the roof.
The horizontal distance between the smoke exhaust outlet and the farthest point in the smoke prevention zone should not exceed 30m.
Steel air outlets are adopted. Steel damper is used.
Fire exhaust duct design requirements:
The wind speed of the mechanical smoke exhaust pipe should not be greater than 20 meters when using metal pipes. The air duct with smooth inner surface should not be larger than 15 meters.
The wind speed at the smoke exhaust port should not exceed 7 meters.
Selection of garage ventilators:
Axial flow fans, cabinet centrifugal fans can be selected, and cabinet centrifugal fans are usually selected.
The cabinet centrifugal fan used in the smoke exhaust system should adopt the external motor type.
Selection of garage ventilators:
The smoke exhaust fan can be a centrifugal fan or an axial flow fan, and a smoke exhaust fire valve that can automatically close when the flue gas temperature exceeds 280 °C should be provided on the smoke exhaust branch pipe, and the smoke exhaust fan should ensure that it can work continuously for 30 minutes at 280 °C.
Sound dampening design principles:
The muffler can be ZP type plate muffler and ZW type muffler pipe.
The muffler can be an impedance composite muffler.
The muffler should be installed at the outlet of the ventilation room and close to the wall of the machine room. Avoid noise passing through the air duct to the outside of the computer room.
Ventilation design of equipment rooms:
Ventilation purpose: There is a large amount of residual heat and humidity in the building
