Duct Static Loss Calculation

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Marina Bay IR Sand ProjectCalculation for Duct Static Pressure Loss

SamplesOutdoor Air Fan Flow Rate: 325 CMH 2.) 1.) 3.) 4.) 5.) 6.) 7.) 8.) 9.)

Material Duct size (mm) VelocityParameters

(CMH) Round Rectangular (mm) (m/s) (Pa) (m) (Co) Dh (mm) Re f (Pa/m) (Pa)

1 13280 600 600 656 10.9 71.8 0.580 *a CR6-1 0 0.00 0 0.000 0.00 51.6 Q = 3,689 A = 0.36

2 Elbow 90°, Smooth Ra 13280 350 250 323 45.0 1,221.3 0.23 *a CR3-1 0 0.00 0 0.000 0.00 284.6 = 0.71 , r/w = 1.00 K = 1.00

3 Elbow 90°, Smooth Ra 13280 350 250 323 45.0 1,221.3 0.23 *a CR3-1 0 0.00 0 0.000 0.00 284.6 = 0.71 , r/w = 1.00 K = 1.00

4 Elbow 90°, Smooth Ra 13280 350 250 323 45.0 1,221.3 0.23 *a CR3-1 0 0.00 0 0.000 0.00 284.6 = 0.71 , r/w = 1.00 K = 1.001 ~5 Duct Galvanized 13280 350 250 323 45.0 1,221.3 22.5 292 0.09 872320 0.016 68.67 1545.2

5 Transition, Rectangula 13280 350 250 323 45.0 1,221.3 0.14 *a ER4-1 0 0.00 0 0.000 0.00 169.8 = 0.71 , q = 30°5~6 Duct Galvanized 13280 350 350 383 32.0 617.8 0.5 350 0.09 744500 0.016 28.95 14.5

6 Flexible connection 13280 350 350 383 32.0 617.8 *f 0 0.00 0 0.000 0.00 5.07 Fresh air Fan 13280 0.00 0.0

Sub Total 2639.8 PaTotal c/w Markup Factor x 1.1 2910 Pa

*a ASHRAE Hand Book, Fundamentals 2001*f Based on Manufacturer Data

. 1.) Velocity (V) = 0.001Q/A Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:11 9.) For Ducting,

But, Total Pressure = Duct Pressure Loss per m x Length

A =Where, For Fittings,

- Circular Equivalent of Rectangular duct for equal length

Q - Air flow rate (l/s) Total Pressure = Velocity Pressure x Loss Coefficients

2.) = Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:25

Where,

- Circular Equivalent of Rectangular duct for equal length

a - Length one side of duct,mm

b - Length adjacent side of duct,mm

3.) Pv = Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:09

Where,

Rv - Velocity Pressure

V - Fluid mean Velocity, m/s

` = 2xaxb (Only For Square Duct) Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:24 (a+b)

Where,

- Hydraulic Diameter, mm

5.) For Absolute Roughness Factor Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Table No: 01

6.) Re = Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:23

But,

Re - Reynolds number

- Hydraulic Diameter, mm

V - Velocity, m/s

7.) f' = Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:21

Where,

Re - Reynolds number

- Hydraulic Diameter, mm

ε - Material absolute roughness factor, mm

8) If,f' >= 0.018

= Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:19

But,

ρ = for Air

- Hydraulic Diameter, mm

V - Velocity, m/s

If,f' < 0.018

= Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:19

But,

ρ = for Air

- Hydraulic Diameter, mm

V - Velocity, m/s

Fitting Number

Duct Element

Airflow Rate

Equivalent Dia.

Velocity Pressure

Duct Length

Loss coefficient

s ASHRAE Fitting

Number

Hydraulic Diameter

Absolute Roughness

Renold Number

Friction Factor

Duct Pressure

loss

Total Pressure

Loss

Duct Opening c/w Wire Mesh

H/W0

H/W0

H/W0

A0/A1

(3.14 x De2 )/4

De

De 1.3(ab)0.625

(a+b)0.25

De

.602x V2

Dh

Dh

66.4 Dh x V

Dh

0.11( ε/ De + 68/Re ) 0.25

Dh

∆Pf 1000x f' xρ x V2

(Dh x 2)

1.204 kg/m2

Dh

∆Pf 1000x (0.85f' +0.0028)xρ x V 2

(Dh x 2)

1.204 kg/m2

Dh

Calculation for Plenum Box loss coefficient

AHU / PAU / PEU NO Vin / Vout H / L W / H k REMARKS

sampel Plenum box near Louver 2400 x 2200 1000 5.28 28,512 7.92 1.50 1.50 1.50 1.00 2.20 1.09 1 0.4 0.15 0.1 -0.4 0 1.25 0.5 1.875 Selected Flow way - 1 to 2

PLENUM BOX SIZE(mm x mm)

W x H

CHAMBER

LENGTH(mm)

L

CHAMBER VOLUME

(m3)

AIR FLOW(CMH)

AIR FLOW(m3 / S)

AIR CHANGE

S PER SECOND

Vin

(m/s)Vout

(m/s)CO C1 C2 C3 C4 C5 CT

SELECTED LOSS

COEFFICIENT

(CT x 1.5)

HVAC SYSTEM

Calculation for Duct Static Pressure LossAHUReturn Air Flow Rate:10,431.36 CMH

Duct ElementDuct size (mm) Velocity

Parameters

(CMH) Round Rectangular (mm) (m/s) (Pa) (m) (Co) Dh (mm) Re f (Pa/m) (Pa)

1 Free Return Throw Shaft 10431.36 0 0.0 *f 0 0.00 0 0.000 0.00 50.0 V = 2,898 l/s 0.002 Air Handling Unit 10431.36 0.00 0.0

Sub Total 50 PaTotal c/w Markup Factor x 1.1 55 Pa

AHUSupply Conditioned Air Flow Rate: 10,431.36 CMH

Duct ElementDuct size (mm) Velocity

Parameters

(CMH) Round Rectangular (mm) (m/s) (Pa) (m) (Co) Dh (mm) Re f (Pa/m) (Pa)

2 Air Handling Unit3 Flexible connection 10431.4 800 300 521 13.6 111.3 *f 0 0.00 0 0.000 0.00 5.03a Transition, Rectangular 10431.4 600 600 656 8.6 44.3 0.480 *a SR4-1 0 0.00 0 0.000 0.00 21.3 = 1.50 , q = 30°4 Elbow 90°, Smooth Radius, Without Vanes 10431.4 800 300 521 13.6 111.3 0.260 *a CR3-1 0 0.00 0 0.000 0.00 28.9 = 0.38 , r / W = 1.00 K = 1.005 Fire Damper, Curtain type, Type B 10431.4 800 300 521 13.6 111.3 0.19 *a CR9-6 0 0.00 0 0.000 0.00 21.2 n = 2.0

3a~6 Duct 10368.0 800 300 521 13.5 110.0 4.0 436 0.90 391620 0.024 6.05 24.2 Internal Insulated

6 Silencer 10368.0 800 300 521 13.5 110.0 *f 0 0.00 0 0.000 0.00 60.06~7 Duct 10368.0 800 300 521 13.5 110.0 3.0 436 0.09 391620 0.016 4.13 12.4

7 Wye,Symmetrical, Doverging 10368.0 800 300 521 13.5 110.0 0.650 *a SR5-14 0 0.00 0 0.000 0.00 71.5 Qs/Qc = 0.347 , As/Ac = 0.757~8 Duct 6955.0 450 400 464 11.4 78.7 4.0 424 0.09 321472 0.016 3.05 12.2

8 Tee, Diverging 6955.0 450 400 464 11.5 78.9 1.070 *a SR5-5 0 0.00 0 0.000 0.00 84.5 Qb/ QC = 0.86 Ab/Ac = 0.898~9 Duct 5962.8 400 400 437 11.0 73.3 4.0 400 0.09 293101 0.017 3.16 12.6

9 Tee, Diverging 5962.8 400 400 437 11.0 73.3 0.170 *a SR5-5 0 0.00 0 0.000 0.00 12.5 Qs/ QC = 0.609~10 Duct 3602.5 400 400 437 6.7 26.8 1.0 400 0.09 177078 0.018 1.20 1.2

10 Transition, Rectangular 3602.5 400 400 438 6.6 26.6 0.400 *a SR4-1 0 0.00 0 0.000 0.00 10.6 = 1.33 , q = 30°10~11 Duct 3602.5 400 300 378 8.9 47.9 3.5 343 0.09 203108 0.018 2.52 8.8

11 Elbow 90° 3602.5 300 400 378 8.9 47.9 1.120 *a SR3-1 0 0.00 0 0.000 0.00 53.7 = 1.33 , W0/W1 = 1.00 K = 1.0012 Fire Damper 3602.5 300 400 378 8.9 47.9 0.19 *a 0 0.00 0 0.000 0.00 9.1 n = 2.0

11~13 Duct 3602.5 300 400 378 8.9 47.9 3.5 343 0.09 203108 0.018 2.52 8.813 Wye,Symmetrical, Doverging 3602.5 300 400 378 8.9 47.9 0.480 *a SR5-14 0 0.00 0 0.000 0.00 23.0 Qs/Qc = 0.345 , As/Ac = 0.6314 Elbow 90°, Smooth Radius, Without Vanes 2023.2 300 250 300 8.0 38.1 0.220 *a CR3-1 0 0.00 0 0.000 0.00 8.4 = 0.83 , r / W = 1.00 K = 1.00

13~15 Duct 2023.2 300 250 300 8.0 38.1 6.5 273 0.09 144052 0.019 2.65 17.215 Tee, Diverging 2023.2 300 250 299 8.0 38.6 0.030 *a SR5-5 0 0.00 0 0.000 0.00 1.2 Qs/ QC = 0.81

15~16 Duct 1646.7 300 250 299 6.5 25.5 1.0 273 0.09 117977 0.020 1.87 1.916 Transition, Rectangular 1646.7 300 250 300 6.5 25.2 0.394 *a SR4-1 0 0.00 0 0.000 0.00 9.9 = 1.25 , q = 30°

16~17 Duct 1646.7 300 200 267 8.2 40.2 2.5 240 0.09 130253 0.020 3.35 8.417 Tee, Diverging 1646.7 300 200 266 8.2 40.6 0.100 *a SR5-5 0 0.00 0 0.000 0.00 4.1 Qs/ QC = 0.7518 Elbow 90°, Smooth Radius, Without Vanes 1242.4 300 200 267 6.2 22.9 0.240 *a CR3-1 0 0.00 0 0.000 0.00 5.5 = 0.67 , r / W = 1.00 K = 1.00

17~19 Duct 1242.4 300 200 267 6.2 22.9 3.0 240 0.09 98276 0.020 1.91 5.719 Tee, Diverging 1242.4 300 200 266 6.2 23.1 0.030 *a SR5-5 0 0.00 0 0.000 0.00 0.7 Qs/ QC = 0.84

19~20 Duct 1037.9 300 200 266 5.2 16.1 2.0 240 0.09 82464 0.021 1.41 2.820 Tee, Diverging 1037.9 300 200 266 5.2 16.1 0.030 *a SR5-5 0 0.00 0 0.000 0.00 0.5 Qs/ QC = 0.80

20~21 Duct 833.3 300 200 266 4.2 10.4 2.5 240 0.09 66213 0.022 0.95 2.421 Tee, Diverging 833.3 300 200 266 4.2 10.4 0.050 *a SR5-5 0 0.00 0 0.000 0.00 0.5 Qs/ QC = 0.75

21~22 Duct 622.3 300 200 266 3.1 5.8 1.5 240 0.09 49444 0.023 0.56 0.822 Transition, Rectangular 622.3 300 200 267 3.1 5.7 0.240 *a SR4-1 0 0.00 0 0.000 0.00 1.4 = 2.00 , q = 30°23 Elbow 90°, Smooth Radius, Without Vanes 622.3 200 150 189 6.2 22.9 0.230 *a CR3-1 0 0.00 0 0.000 0.00 5.3 = 0.75 , r / W = 1.00 K = 1.0024 Volume Control Damper 622.3 200 150 189 6.2 22.9 0.19 *a 0 0.00 0 0.000 0.00 4.3 n = 1.0

22~25 Duct 622.3 200 150 189 6.2 22.9 3.5 171 0.09 70170 0.022 2.94 10.325 Tee, Diverging 622.3 200 150 189 6.2 22.9 0.400 *a SR5-5 0 0.00 0 0.000 0.00 9.2 Qs/ QC = 0.55

25~26 Duct 342.9 200 150 189 3.4 7.0 2.0 171 0.09 38722 0.025 1.02 2.026 Transition, Rectangular 342.9 200 150 189 3.4 6.9 0.400 *a SR4-1 0 0.00 0 0.000 0.00 2.8 = 1.33 , q = 30°27 Elbow 90°, Smooth Radius, Without Vanes 342.9 150 150 164 4.5 12.2 0.210 *a CR3-1 0 0.00 0 0.000 0.00 2.6 = 1.00 , r / W = 1.00 K = 1.00

26~28 Duct 342.9 150 150 164 4.5 12.2 3.0 150 0.09 44930 0.024 1.96 5.928 Transition, Rectangular to round 342.9 150 150 164 4.5 12.2 0.040 *a SR4-1 0 0.00 0 0.000 0.00 0.5 = 0.36 , q = 30°

28~29 Flexible Duct 342.9 200 200 3.0 5.5 2.0 200 3.00 40281 0.040 1.02 2.029 Volume Control Damper 342.9 200 200 3.0 5.5 1.00 *a 200 0.00 0 0.000 0.00 5.5 D/D0 = 1.0 , q = 10° n = 0.030 Round diffucer 342.9 200 200 3.0 5.5 *f 0 0.00 0 0.000 0.00 40.0 V = 95 l/s 0.00

0Sub Total 643.2 PaTotal c/w Markup Factor x 1.1 708 Pa

*a ASHRAE Hand Book, Fundamentals 2001*f Based on Manufacturer Data

Required External Static Pressure for AHU 763 Pa Design : 763 Pa 10431 CMH

Mfg :

Fitting Number

Airflow Rate

Equivelant Dia.

Velocity Pressure

Duct Length

Loss coefficients ASHRAE

Fitting Number

Hudraulic Diameter

Absolute Roughness

Renold Number

Friction Factor

Duct Pressure

loss

Total Pressure

Loss

Fitting Number

Airflow Rate

Equivelant Dia.

Velocity Pressure

Duct Length

Loss coefficients ASHRAE

Fitting Number

Hudraulic Diameter

Absolute Roughness

Renold Number

Friction Factor

Duct Pressure

loss

Total Pressure

Loss

A0/A1

H/W0

A0/A1

H/W0

H/W0

A0/A1

H/W0

A0/A1

H/W0

A0/A1

H/W0

A0/A1

1.) Velocity (V) = 0.001Q/A Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:11

But,

A =Where,

- Circular Equivalent of Rectangular duct for equal lengthQ - Air flow rate (l/s)

2.) = Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:25

Where,

- Circular Equivalent of Rectangular duct for equal length

a - Length one side of duct,mm

b - Length adjacent side of duct,mm

3.) Pv = Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:09

Where,

Pv - Velocity Pressure

V - Fluid mean Velocity, m/s

4) = 2xaxb (Only For Square Duct) Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:24 (a+b)

Where,

- Hydraulic Diameter, mm

5.) For Absolute Roughness Factor Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Table No: 01

6.) Re = Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:23

But,

Re - Reynolds number

- Hydraulic Diameter, mm

V - Velocity, m/s

7.) f' = Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:21

Where,

Re - Reynolds number

- Hydraulic Diameter, mm

ε - Material absolute roughness factor, mm

8) If,

(3.14 x De2 )/4

De

De 1.3(ab)0.625

(a+b)0.25

De

.602x V2

Dh

Dh

66.4 Dh x V

Dh

0.11( ε/ De + 68/Re ) 0.25

Dh

f' >= 0.018

= Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:19

But,

ρ = for Air

- Hydraulic Diameter, mm

V - Velocity, m/s

If,f' < 0.018

= Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:19

But,

ρ = for Air

- Hydraulic Diameter, mm

V - Velocity, m/s

∆Pf 1000x f' xρ x V2

(Dh x 2)

1.204 kg/m2

Dh

∆Pf 1000x (0.85f' +0.0028)xρ x V 2

(Dh x 2)

1.204 kg/m2

Dh

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:11 9.) For Ducting,

For Fittings,

Circular Equivalent of Rectangular duct for equal length

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:25

Circular Equivalent of Rectangular duct for equal length

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:09

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:24

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Table No: 01

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:23

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:21

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:19

Ref: 2001 ASHRAE Fundamentals Handbook (SI), Chapter 34, Equation No:19