Stairwell pressurization is a critical part of fire safety design in high-rise buildings. It ensures smoke does not enter escape routes during a fire, allowing safe evacuation.
If you’re looking for a quick and accurate way to design a stairwell pressurization system, you can use our free Excel sheet below.
👉 Free Stairwell Pressurization Excel Sheet (Instant Download)
✔ Calculates airflow automatically
✔ Based on NBC & international guidelines
✔ Easy for engineers & site use
🧠 WHAT IS STAIRWELL PRESSURIZATION?
Stairwell pressurization is a mechanical ventilation system that maintains positive pressure inside staircases to prevent smoke ingress.
🔥 WHY IT IS REQUIRED
- Prevent smoke entry
- Maintain visibility
- Ensure safe evacuation
- Required for buildings above 15m
📐 DESIGN PRINCIPLE
The system works by maintaining a pressure difference between:
- Staircase
- Adjacent areas
🔢 BASIC FORMULA
Q=A×V
Where:
- Q = Airflow (m³/s)
- A = Leakage area (m²)
- V = Air velocity (m/s)
🧮 STEP-BY-STEP CALCULATION
1. Calculate Leakage Area
- Doors
- Gaps
- Shafts
2. Select Velocity
Typical values:
- 0.75 – 2 m/s
3. Calculate Airflow
👉 Use formula:
Flow = Area × Velocity
4. Add Safety Factor
- Add 10–20% extra airflow
5. Select Fan Capacity
Final airflow → fan selection
📊 EXAMPLE CALCULATION
- Leakage area = 2 m²
- Velocity = 1 m/s
👉 Flow = 2 × 1 = 2 m³/s
👉 Add 20% = 2.4 m³/s
📥 USE OUR EXCEL SHEET
Instead of manual calculation:
👉 Use our Excel tool to calculate instantly
👉 [Download Stairwell Pressurization Excel Sheet]
🏗 DESIGN REQUIREMENTS (NBC)
- Minimum pressure: 50 Pa
- Door opening force < 100 N
- Continuous airflow
⚙ COMPONENTS REQUIRED
- Supply fan
- Pressure sensor
- Duct system
- Control panel
❌ COMMON MISTAKES
- Incorrect leakage estimation
- Oversized fans
- No pressure control
- Ignoring door force
🏭 BRANDS
❓ FAQ SECTION
What is stairwell pressurization?
It is a system that maintains positive pressure to prevent smoke entry.
What pressure is required?
Typically 50 Pa as per standards.
Why is it important?
It ensures safe evacuation during fire.
What is airflow formula?
Airflow = Area × Velocity
📢 Why Download from MEPWORK?
- Free DWG files
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- Designed for engineers
- Updated as per industry standards
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