pressure drop calculation combined steel and mesonery duct

Calculation sheet

ProjectProject ConsultantClient xxContractor xxSubject Staircase pressurization fansLocation xxxFan TypeDesign By xx

ItemNo. Identification

HydrolicDia - Dh

(mm)

Length(m)

AirFlowRate(L/S)

DuctVelocity

(m/s)

RenoldsNumber

Absoluteroughness -

ɛ (mm)f'

Darcyfriction

coefficient(f)

TotalPressure

Drop(Pa) Remarks

1.00 Staircase pressurization shaft

1.01 c-d 1550 800 1055.32 5 18632 15.03 1052906 1.3 0.02087 0.02087 13.40Refer eq.21, ASHRAEFundamentals HB 1997

1.02 d-e 1550 800 1055.32 4.9 16562 13.36 932850 1.3 0.02091 0.02091 10.39Refer eq.21, ASHRAEFundamentals HB 1997

1.03 e-f 1550 800 1055.32 4.9 14492 11.69 816255 1.3 0.02095 0.02095 7.97Refer eq.21, ASHRAEFundamentals HB 1997

1.04 f-g 1550 800 1055.32 4.9 12422 10.02 699661 1.3 0.02100 0.02100 5.87Refer eq.21, ASHRAEFundamentals HB 1997

1.05 g-h 1550 800 1055.32 4.9 10352 8.35 583073 1.3 0.02108 0.02108 4.09Refer eq.21, ASHRAEFundamentals HB 1997

1.06 h-i 1550 800 1055.32 4.9 8282 6.68 466478 1.3 0.02119 0.02119 2.63Refer eq.21, ASHRAEFundamentals HB 1997

1.07 i-j 1550 800 1055.32 4.9 6212 5.01 349890 1.3 0.02138 0.02138 1.49Refer eq.21, ASHRAEFundamentals HB 1997

1.08 j-k 1550 800 1055.32 5.95 4142 3.34 233295 1.3 0.02173 0.02173 0.82Refer eq.21, ASHRAEFundamentals HB 1997

1.09 k-l 1550 800 1055.32 4.55 2072 1.67 116707 1.3 0.02270 0.02270 0.16Refer eq.21, ASHRAEFundamentals HB 1997

xxxxx

Duct Size(mm)

Calculation sheet

ItemNo. Identification

Length(m)

No ofFittings

&Accesso

ries

AirFlowRate(L/S)

DuctVelocity

(m/s)

VelocityPressure

(Pa)

LossCoefficientsfor Fittings

EquivalentDia (mm)

PressureDrop

(Pa/m)

TotalPressure

Drop(Pa) Remarks

2.00 Straight Duct Section2.01 a-b 1350 1300 5.84 18632 10.62 67.85 1448.1 0.74 4.342.02 b-c 1350 1300 5.98 18632 10.62 67.85 1448.1 0.74 4.44

Duct Fittings3.00 Bends & Elbows

3.01b-90 degreebend 1350 1300 1 18632 10.62 67.85 0.21 1448.1 - 14.25

Refer Table 14-10-F, SMACNA1990, R/W=1

3.02c-90 degreebend 1000 800 1 18632 23.29 326.54 0.23 976.2 - 73.80

Refer Table 14-10-F, SMACNA1990, R/W=1

4.00 Tees

4.01 d-main 1550 800 1 18632 15.03 135.92 0.01 1201.1 - 1.51Refer Table 14-14-Q SMACNA1990

4.02 e-main 1550 800 1 16562 13.36 107.39 0.01 1201.1 - 1.34Refer Table 14-14-Q SMACNA1990

4.03 f-main 1550 800 1 14492 11.69 82.23 0.01 1201.1 - 1.18Refer Table 14-14-Q SMACNA1990

4.04 g-main 1550 800 1 12422 10.02 60.41 0.02 1201.1 - 1.03Refer Table 14-14-Q SMACNA1990

4.05 h-main 1550 800 1 10352 8.35 41.96 0.02 1201.1 - 0.84Refer Table 14-14-Q SMACNA1990

4.06 i-main 1550 800 1 8282 6.68 26.85 0.03 1201.1 - 0.81Refer Table 14-14-Q SMACNA1990

4.07 j-main 1550 800 1 6212 5.01 15.11 0.05 1201.1 - 0.69Refer Table 14-14-Q SMACNA1990

4.08 k-main 1550 800 1 4142 3.34 6.72 0.09 1201.1 - 0.60Refer Table 14-14-Q SMACNA1990

2062

Duct Size

Calculation sheet

5.00 Transition

5.01

a - Transition(1250x1250-Ø1250) 1250 1 18632 15.18 138.77 0.06 1250.0 - 7.82

Refer Table 14-12-A SMACNA1990

5.02

a - Transition(Ø1250-1350x1300) 1250 1 18632 15.18 138.77 0.21 1250.0 - 29.56

Refer Table 14-11-B SMACNA1990

5.03

c - Transition(1350x1300-1000x800) 1000 800 1 18632 23.29 326.54 0.06 976.2 - 19.90

Refer Table 14-12-A SMACNA1990

5.04

c - Transition(1000x800 -1550x800) 1000 800 1 18632 23.29 326.54 0.23 976.2 - 74.86

Refer Table 14-11-B SMACNA1990

6.00 VCD/ damper

6.01 l-Airfoil blade 800 500 1 2072 5.18 16.15 0.52 686.7 - 8.40Refer Table 14-18-E SMACNA1990

6.02 a-Airfoil blade 1250 1250 1 18632 11.92 85.60 0.52 1366.5 - 44.51Refer Table 14-18-E SMACNA1990

External Static Pressure of Staircase pressurization fan(Pa) 336.72Add 20% safety factor 67.34Total External Static Pressure of Staircase pressurization fan (External static pressure+20%SF+50) (Pa) 455.00

Notes - Vertical duct section (from "c" to "l") - concreate construction - Duct section in the roof - Sheet metal (GI) - Absolute roughness (ɛ) of concrete 1.3 mm ( pg. 32.7, ASHRAE Fundamentals HB 1997 ) - The size of virtical duct section (shaft) should be equal to the slab opening size (1550x800 mm) and finished using side walls. 9 numbers of wall openings (600x900 mm ) should be provided for the air terminals. - Total External Static Pressure of Staircase pressurization fan = External static pressure + 20%SF + 50 (pa)