Design calculation for Staircase Pressurization
Project no: Date: Sheet no.: 1 of 1 Computed by: Sulaiman
Subject: Stairwell Pressurisation Checked by: Marrar
Approved by:
This sheet calculates the staircase pressurization required to maintain a +ve pressure in the stairewell in case of fire emergency.
The calculations in this sheet follow the ASHRAE Standard.
Condition 1 : Analysis with Closed Doors
Design Conditions
Outside Design Temprature 46 C°
Building Design Temprature 24 C°
No. of Story 10
Height Per Story 4 M
Temprature Factor -0.80 Pa/M
Area Between Building & outside Per Story 600 M2
Area Between Stairwell & Building Per Story 16 M2
Area of the Gap Around each Stairwell Door 1
Area Ratio For Exterior Walls 1
Area Ratio For Stair Well Walls 1
Leakage Area Between Building & outside Per Story (Abo) 0.03 M2
Leakage Area Between Stairwell & Building Per Story (Asb) 0.024224 M2
Minimum pressure diffrence at the top of the stair (dPsbt) 13 Pa
Maximum pressure diffrence at the bottom of the stair (dPsbb) 32 Pa
Q(Total Volume Flow Rate) 961 L/S
Volume Flow Rate Per Floor 96 L/S
Condition 2 : Analysis with Opened Doors
No. of Doors 9
No. of Closed Doors 6
No. of Opened Doors 3
Pressure Diffrence Between Stair & Outside at the top (dPsot) 21 Pa
Pressure Diffrence Between Stair & Outside at the Middle (dPsom) 38 Pa
Pressure Diffrence Between Stair & Outside at the Bottom (dPsob) 54 Pa
Door Area 1 M2
Effective Flow Area (Abo) 0.030 M2
Q(Volume Flow Rate) 509 L/S
Condition 3 : Analysis with Exterior Door Opened
Q(Volume Flow Rate) 6143 L/s
Total Flow Required for Stairwell 7228 L/s
Total Flow Required for Stairwell+10% SAFETY 7951 L/s
