Vent-Design
VENTILATION DESIGN WORK SHEET
Organization: Elevation:
Location: Temperature:
Shop: Factor:
Velocity Pressure Calculation Method
1 Duct Segment Identification Unit
1a Type of Duct (GALV=Galvinzied) (BLK=Black Iron or Al or SS)
2 Volumetric Flowrate: (See Design Criteria) inches
3 Minimium Transport Velocity (See Design Criteria) fpm
4 Duct Diameter (Round Duct) inches
5 Duct Area Sq. Ft.
6 Actual Duct Velocity fpm
7 Duct Velocity Pressure (Vd/4005)^2 = VP "wg
8 H Slot Area Sq. Ft.
9 O S Slot Velocity fpm
10 O L Slot Velocity Pressure "wg
11 D O Slot Loss Factor (ACGIH Vent Manual Chapter 10)
12 T Acceleration Factor 0 or 1
13 S S Plenum Loss per VP
14 U Plenum SP
15 C Duct Entry Loss Factor (See Design Specifications)
16 T Acceleration Factor (if Vd>Vs; 1) 1 or 0
17 I Duct Entry Loss per VP
18 O Duct Entry Loss "wg
19 N Other Loss "wg
20 Hood Static Pressure (SPh) "wg
21 Straight Duct Length feet
22 Friction Factor (Hf)
23 Friction Loss per VP
24 No. of 90 Degree Elbows
25 Elbow Loss per VP (See Table Below or ACGIH, Fig 5-13)
26 Number of Entries
27 Entry Loss per VP (See Table Below or ACGIH, Fig 5-14)
28 Special Fittings Loss Factors
29 Duct Loss per VP
30 Duct Loss "wg
31 Duct SP Loss "wg
32 Cumulative Static Pressure "wg
33 Governing Static Pressure "wg
34 Corrected Volumetric Flowrate (Balanced) cfm
35 Resultant Velocity Pressure "wg
36 Corrected Velocity (Based on the Governing SP) fpm
PERTINENT EQUATIONS:
R/D
Q corr. = Q Design (SP gov./ SP duct)^1/2 Stamped
5- Piece
VP r = ((Q1 + Q2)/(4005(A1 + A2)))^2 or 4- Piece
= (Q1/Q3)*VP1 + (Q2/Q3)*VP2 3- Piece
60 elbow = 2/3 loss
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Vent-Design
Hf = 0.0307(V^0.533)/(Q^0.612) = GALV in Line 1a 45 elbow = 1/2 loss
30 elbow = 1/3 loss
= 0.0425(V^0.465)/(Q^0.602) = BLK in Line 1a
Branch Entry
FSP = SP outlet - SP inlet - VP inlet Loss Factors
=〖 Coefficient of Entry =( 〖 VP+S 〗 _Ph) 〗 ^(1/2) or
Angle
1 (for perfect hood - No losses) 30
Ce 15
SPh = Velocity Pressure = SPh - he 45
60
VP = Hood Static Pressure = (V/4005)^2 90
"Type equation here."
he = Entry Loss = Fh x VP
TP = Total Pressure = SP + VP
SP; VP = Static Pressure; Velocity Pressure
Vd = Duct Velocity
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Vent-Design
SIGN WORK SHEET
0 Feet Date: 3-Nov-24
70 °F Drawing No.
Designer:
Calculation Method
A-1 B-1 1 ---- 3 C-2 D-2 2----3 3-W
BLK BLK BLK BLK BLK BLK BLK BLK
5000 3030 8030
3500 3500 3500
16.0 12.0 22.0
1.396 .785 2.640
3581 3858 3042
.799 .928 .577
.250 .250
1 1
1.250 1.250
.999 1.160
0 0
1.00 1.16
200 100 500
.011 .016 .008
2.266 1.586 3.948
5 3 6
0.39 0.39 0.39
0 1 0
0 0.18 0
0 0 0
2.656 2.156 4.338
2.123 2.000 2.503
3.123 3.160 2.503
3.409 6.486
.000 .000
90 Degree Round Elbow Loss Factors
0.5 0.75 1 1.5 2 2.5
0.71 0.33 0.22 0.15 0.13 0.12
0.46 0.33 0.24 0.19 0.17
0.5 0.37 0.27 0.24 0.23
0.9 0.54 0.42 0.34 0.33 0.33
60 elbow = 2/3 loss
Page 3
Vent-Design
45 elbow = 1/2 loss
30 elbow = 1/3 loss FSP = Fan Static Pressure #VALUE!
Branch Entry TP = FSP + VP out = #VALUE!
Loss Factors
Factor ME = Mechanical efficiency
0.09 (Usually .5 - .65)
0.18
0.28 ME = 1 Q = 0
0.44
1 BHP = Q x TP = #VALUE!
6356 x ME
"Type equation here."
Delta in SP: #VALUE!
Delta in SP(1): 1.18%
Fan Specifications Existing Required
Blade Type: Tubeaxial
Size:
RPM:
HP: ###
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Vent-Design
BLK
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