Stairwell Pressurization Calculator

Design Condition 1: All Doors Closed

Outside Temp (°C)

Building Temp (°C)

No. of Stories

Height/Story (M)

Temperature Factor (Pa/M)

Area Building/Outside (m²)

Note: /2 for two stairwells

Area Stairwell/Building (m²)

Gap Around Stairwell Door

Area Ratio Exterior Walls

Area Ratio Stair Walls

Leakage Area Between Building & outside Per Story (m²)

Leakage Area Between Stairwell & Building Per Story (m²)

Min. Pressure Top Stair (Pa)

Max. Pressure Bottom Stair (Pa)

Q (Total Volume Flow Rate) (L/S)

Volume Flow Rate Per Floor (L/S)

No. of Doors

The exterior doorway was excluded.

No. of Closed Doors

No. of Opened Doors

Pressure Diff. Stair & Outside at the top (Pa)

Pressure Diff. Stair & Outside at the Middle (Pa)

Pressure Diff. Stair & Outside at the Bottom (Pa)

Door Area (m²)

Half the geometric area of the doorway

Effective Flow Area (m²)

Q (Volume Flow Rate) (L/S)

Q (Volume Flow Rate) (L/S)

Total Flow Required for Stairwell (L/S)

Total Flow Required for Stairwell + 10% SAFETY (L/S)