Car Park Ventilation is intended to:
 1. Eliminates air pollutants such as carbon monoxide (CO), nitrogen dioxide (NO₂).
 2. Temperature control and
 3. Vent out smoke in the event of a fire.

Calculation of the ventilation system for the car park is divided into 2 main cases:

1. Normal ventilation system (Normal Ventilation)

Purpose: Remove CO from vehicle exhaust.

Popular methods:
 • Use Air Changes per Hour (ACH).
 • Or use a ventilation rate of CFM/m² or L/s/m².

 How 1: Calculated from ACH

Type Recommended ACH Value
Open parking (Open/Semi-Enclosed) 3 - 6 ACH
Fully Enclosed Parking 6 - 10 ACH

Formula for calculating the required air volume (Q):
Q = ACH \times Volume
where
 • Q = Air volume (m³/h)
 • Volume = Building volume (width × length × height)

Method 2: Calculated from the rate per square meter.

Standard rate
4.24 – 6.8 L/s/m²
/ 10 – 12 liter/second/car or ~6 L/s/m²

Formula:
Q = rate \times area

2. Emergency ventilation system (Smoke Extraction / Fire Mode)

- Used in the event of a fire. To suck smoke out so people can escape the fire

- Standard (such as , )

Type Rate used
Smoke Extraction ≥ 10 ACH
or 10 – 12 cubic meter/second per zone 
or ≥ 5.5 m³/s/vent zone 

✅ Additional information that should be used in design
 • Number of cars that can be parked.
 • Application type (open/closed / underground / hot air)
 • Parking area height
 • Legal smoke pressure (Smoke Layer Height).
 • CO detection and automatic fan control system.

✅ Example of basic calculations

Parking space size: Width 40 m. × Length 50 m. × Height 3 m.
Need ventilation at 6 ACH
 1. Calculate volume:
V = 40 × 50 × 3 = 6,000 m³
 2. Calculate the air volume:
Q = 6 × 6,000 = 36,000 m³/h
 3. Convert to CFM (if desired):
36,000 \div 1.699 = \approx 21,187 CFM