Calculation for Stair case pressurization System . ST-1 & 2CLASS A SYSTEM

Double Door area ( only at Ground floor)Height-H/(m) = 2.2 mWidth-D/(m) = 2.2 mTotal No of Door = 1 Nos

Total Area = 4.84Leakage factor for Double Door is , K 0.03Air Flow rate Q , as per BS 5588

Q=0.83x(1X0.03)x50^0.5

Q1 0.18Single Door Area (all the floor apart from Ground Floor )

Height-H/(m) = 2.2 mWidth-D/(m) = 1.1 mTotal No of Door = 29 Nos

Total Area = 70.18Leakage factor for single Door is , K 0.01Air Flow rate Q , as per BS 5588

Q=0.83x(29X0.01)x50^0.5

Q2 1.70Total Air Flow rate for ST-01

Q3 = Q1+Q2

Q3 = 0.18+1.7

1.88 3,980.66 cfm

Increase by 50% 2.82

Q3 = 5,970.99 cfm

Single Door AreaHeight-H/(m) = 2.2 mWidth-D/(m) = 1.1 m

Total area A = 2.42 sqmFrom the BS5588 ,velocity is to be 0.75m/s

V = 0.75Q4= AV

Q4= 2.42X0.75

Q4= 1.815 3,846.97 cfm

Total of case 1 & Case 2Q= Q3+Q4

Q= 2.82+1.815

Q= 4.63 9,818 cfm

Case-1 ; Considering only leakage through the Door at the ST-1 area

m2

Q=0.83xAxP^0.5

m3/s

m2

Q=0.83xAxP^0.5

m3/s

m3/s

m3/s

m3/s

Case-2 ; Considering one single door is opened (Class A system)

m/s

m3/s

m3/s

m3/s

m3/s

Total Volume Flow Rate 9,817.96 cfm

Add Duct leakages @ 15% 0.69 1,472.69 cfm

Total Volume Flow Rate of the Fan should be 5.33 11,290.65 cfm

According to the BS 5588 Staircase pressurization fan is to be single speed 1hr fire rating @300C

a) To calculate pressure required in stairwell to exhaust 1.815 m3/s to atmosphere via fire floorArea of single leaf door=2.2X1.1=2.42 sq.mArea of exhaust vent = 1.815/2.5 =0.726 sq.mA.E = (1/A1^2+1/A2^2)^-0.5

= (1/2.42^2+1/0.726^2)^-0.5= 0.70 sq.m

P1=(Q/(0.83XA.E))^2= (1.815/(0.83X0.7))^2= 9.75890283533939 Pa

This is more than covered by 50 Pa

b) To calculate area of pressure reliefQuantity of air to be wasted = 5.33 - 2.82

= 2.51Area of pressure relief = Q/(0.83XP^0.5)

= 2.51 / (0.83X50^0.5)= 0.428 sq.m

Let Height of Pressure relief damper = 0.7 mthen Width will be = 0.428 / 0.7 = 0.62 m, say 0.65m

FAN SELECTED IS 11,300 CFM @ 240 PA

m3/s

m3/s

m3/s

Static Pressure CalculationsNote:-1) The Equivalent Diameter Formula is: De = 1.3(ab)^0.625 / (a+b)^0.252) The friction loss and the velocity can be obtained from the charts knowing the flow and the eq. diameter3) The equivalent length for an elbow can be obtained from the formula: Le = W exp [-2.13(H/W)^0.126 ln(0.33R/W)]

ST-01 & 02 - Presurization unit (11310cfm)@237Pa

Straight Ducts

Width/(mm) Height/(mm) Length(m)1600 500 11,310.00 10 0.9391550 500 10,933.00 4 0.9261500 500 10,556.00 4 0.9131450 500 10,179.00 4 0.9001400 500 9,802.00 4 0.8861350 500 9,425.00 4 0.8721300 500 9,048.00 4 0.8571250 500 8,671.00 4 0.8431200 500 8,294.00 4 0.8271150 500 7,917.00 4 0.8121100 500 7,540.00 4 0.7951050 500 7,163.00 4 0.7791000 500 6,786.00 4 0.762950 500 6,409.00 4 0.744900 500 6,032.00 4 0.726850 500 5,655.00 4 0.706800 500 5,278.00 4 0.687750 500 4,901.00 4 0.666700 500 4,524.00 4 0.644650 500 4,147.00 4 0.622600 500 3,770.00 4 0.598550 500 3,393.00 4 0.573500 500 3,016.00 4 0.547450 500 2,639.00 4 0.518400 500 2,262.00 4 0.488350 500 1,885.00 4 0.455300 500 1,508.00 4 0.420250 500 1,131.00 4 0.381500 200 754.00 10 0.337350 200 377.00 8 0.286

54Fittings

Size Qty Eq. length (m) Friction Loss (Pa)Elbow 1600x500 2 3 4.0

Volume flow Rate/(cfm)

Eq. Diameter(De)

m

Reducer 29 1.0 19.1

SAT(sound attonuator) 0 70VAV 0 0Flexible duct 0 0.3inch/100ft 0.00

sub total 89.14

Fire Damper Size Pressure Drop (Pa)0

VCD Size Qty Avg Pressure Drop/(Pa)Various 2 20

grilles Qty Avg Pressure Drop/(Pa)Various 1 10

Preassure Drop (Pa) 197.20 PaAdditional 20% 39.44 Pa

237 paTotal pressure Drop accros the exhaust air side of FAHU-1 unite

3) The equivalent length for an elbow can be obtained from the formula: Le = W exp [-2.13(H/W)^0.126 ln(0.33R/W)]

Friction loss

pa/m inch/100ft

0.57 0.07 5.7400.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 2.2960.57 0.07 5.7400.57 0.07 4.592

TOTAL 78.064

Total Friction

Loss(Pa)

Calculation for Stair case pressurization System . ST-3 to 7CLASS A SYSTEM

Double Door area ( only at Ground floor)Height-H/(m) = 2.2 mWidth-D/(m) = 2.2 mTotal No of Door = 1 Nos

Total Area = 4.84Leakage factor for Double Door is , K 0.03Air Flow rate Q , as per BS 5588

Q1 =0.83X(1X0.03)X50^0.5

Q1 0.18Single Door Area (all the floor apart from Ground Floor )

Height-H/(m) = 2.2 mWidth-D/(m) = 1.1 mTotal No of Door = 6 Nos

Total Area = 14.52Leakage factor for single Door is , K 0.01Air Flow rate Q , as per BS 5588

Q2=0.83X(4X0.01)X50^0.5

Q2= 0.35Total Air Flow rate for ST-01

Q 3 = Q1+Q2

Q 3 = 0.18+0.35

0.53 1,119.56 cfm

Increase by 50% 0.79 1,679.34 cfm

Single Door AreaHeight-H/(m) = 2.2 mWidth-D/(m) = 1.1 m

Total area A = 2.42 sqmFrom the BS5588 ,velocity is to be 0.75m/s

V = 0.75Q4= AV

Q4= 2.42X0.75

Q4= 1.8153846.97 cfm

Total of case 1 & Case 2Q= Q3+Q4

Q= 0.62+1.815

Q= 2.607 Q= 5,526 cfm

Total Volume Flow Rate of the Fan should be 5,526.31 cfm

Case-1 ; Considering only leakage through the single Door at the ST-3 area

m2

Q=0.83xAxP^0.5

m3/s

m2

Q=0.83xAxP^0.5

m3/s

m3/s

m3/s

m3/s

Case-2 ; Considering one single door is opened (Class A system)

m/s

m3/s

m3/s

m3/s

m3/s

Add duct losses @ 15% 0.39 828.95 cfm

Total Volume Flow Rate of the Fan should be 3.00 6,355.26 cfm

According to the BS 5588 Staircase pressurization fan is to be single speed 1hr fire rating @300C

a) To calculate pressure required in stairwell to exhaust 1.815 m3/s to atmosphere via fire floorArea of single leaf door=2.2X1.1=2.42 sq.mArea of exhaust vent = 1.815/2.5 =0.726 sq.mA.E = (1/A1^2+1/A2^2)^-0.5

= (1/2.42^2+1/0.726^2)^-0.5= 0.70 sq.m

P1=(Q/(0.83XA.E))^2= (1.815/(0.83X0.7))^2= 9.75890283533939 Pa

This is more than covered by 50 Pa

b) To calculate area of pressure reliefQuantity of air to be wasted = 2.80 - 0.62

= 2.18Area of pressure relief = Q/(0.83XP^0.5)

= 2.18 / (0.83X50^0.5)= 0.371 sq.m

Let Height of Pressure relief damper = 0.5 mthen Width will be = 0.371 / 0.5 = 0.742 m, say 0.75m

FAN SELECTED IS 6400 CFM @ 150 PA

m3/s

m3/s

m3/s

Static Pressure CalculationsNote:-1) The Equivalent Diameter Formula is: De = 1.3(ab)^0.625 / (a+b)^0.252) The friction loss and the velocity can be obtained from the charts knowing the flow and the eq. diameter3) The equivalent length for an elbow can be obtained from the formula: Le = W exp [-2.13(H/W)^0.126 ln(0.33R/W)]

ST-3 TO 7 - Presurization unit (6356cfm)@148Pa

Straight Ducts

Width/(mm) Height/(mm) Length(m)

Friction loss

pa/m inch/100ft

750 650 6,356.00 10 0.763 0.57 0.07 5.740650 650 5,448.00 4 0.711 0.57 0.07 2.296650 550 4,540.00 4 0.653 0.57 0.07 2.296550 550 3,632.00 4 0.601 0.57 0.07 2.296450 550 2,724.00 4 0.543 0.57 0.07 2.296350 550 1,816.00 4 0.477 0.57 0.07 2.296350 350 908.00 4 0.383 0.57 0.07 2.296

34 TOTAL 19.516Fittings

Size Qty Eq. length (m) Friction Loss (Pa)Elbow 2100x1100 2 3 4.0Reducer 6 1.0 4.0

SAT(sound attonuator) 0 70VAV 0 0Flexible duct 0 0.3inch/100ft 0.00

sub total 73.96

Fire Damper Size Pressure Drop (Pa)0 0

VCD Size Qty Avg Pressure Drop/(Pa)Various 2 20

grilles Qty Avg Pressure Drop/(Pa)Various 1 10

Preassure Drop (Pa) 123.48 PaAdditional 20% 24.70 Pa

148 pa

Volume flow Rate/(cfm)

Eq. Diameter(De)

m

Total Friction

Loss(Pa)

Total pressure Drop accros the exhaust air side of FAN-ST-1 unite