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Industrial Ventilation vs. IAQ. H eating V entilation A ir C onditioning. Industrial Ventilation vs. IAQ. 24. Industrial Ventilation vs. IAQ. Industrial Ventilation vs. IAQ. Routes of Entry. Inhalation Ingestion Absorption Injection. Control Options. Process change Substitution

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Industrial ventilation vs iaq l.jpg
Industrial Ventilation vs. IAQ

Heating

Ventilation

Air

Conditioning





Routes of entry l.jpg
Routes of Entry

  • Inhalation

  • Ingestion

  • Absorption

  • Injection


Control options l.jpg
Control Options

  • Process change

  • Substitution

  • Isolation

  • Ventilation

  • Administrative control

  • Personal protective equipment


Problem characterization l.jpg
Problem Characterization

AIRFLOW

EMISSION SOURCE

BURTON 2-1


Burton ex 2 1 l.jpg
Burton Ex. 2-1

GROUP EXERCISE

Study the figure on page 2-4 and discuss potential control measures that you might use to correct the problem.

BURTON 2-4



The atmosphere l.jpg
The Atmosphere

  • Reaches 50 miles into space.

  • Pressure = 14.7 pounds per square inch.



Pressure measurement l.jpg
Pressure Measurement

Vacuum

Atmospheric Pressure

14.7 psia


Pressure measurement13 l.jpg
Pressure Measurement

14.7 psia =

407in. Water

14.7 psia =

29.92 in. Mercury (Hg.)



Pressure l.jpg
Pressure

  • Differences in air pressure cause movement.


Pressure differential causes movement l.jpg
Pressure Differential Causes Movement

FLOW

LOW

HIGH

FAN

BURTON 3-6





Pressure terms l.jpg
Pressure Terms

  • Static Pressure

  • Velocity Pressure

  • Total Pressure


Static pressure l.jpg
Static Pressure

Flow

SP

Static pressure (SP) is

exerted in all directions.


Velocity pressure l.jpg
Velocity Pressure

Flow

SP

VP

Velocity Pressure (VP) is

kinetic (moving pressure) resulting from air flow.


Total pressure l.jpg
Total Pressure

Flow

SP

VP

TP

Total pressure (TP) is the algebraic sum of the VP and SP.


Pressure upstream and downstream of the fan l.jpg
Pressure Upstream and Downstream of the Fan

TP SP VP

Up-stream - - +

Down-stream + + +

BURTON 3-8


What is use of the term velocity pressure l.jpg
What is use of the term “Velocity Pressure” ?

  • Determine the air flow.

  • To design the system.

  • V = 4005(VP)1/2


What is use of the term static pressure l.jpg
What is use of the term “Static Pressure” ?

  • Accelerate the air.

  • Overcome resistance to friction.


Static pressure and velocity pressure are mutually convertible l.jpg
Static Pressure and Velocity Pressure are Mutually Convertible

When air is accelerated, the static pressure is converted to velocity pressure.

=

When air is decelerated, the velocity pressure can be transformed back into static pressure.


Conservation of mass l.jpg
Conservation of Mass Convertible

  • Mass in = Mass out.

  • Air speeds up when the duct area is smaller.

Q = VA

Q = Cubic Feet Per Minute

V = Velocity

A = Area


Dilution ventilation l.jpg

YES Convertible

non-hazardous

gas, vapor, respirable particle

uniform time emission

emissions not close to people

moderate climate

NO

toxic material

large particulate

emission varies widely over time

large, point source emissions

people in vicinity

severe climate

irritation or complaints

Dilution Ventilation

BURTON 4-1


Volume vapor flow rate l.jpg
Volume Vapor Flow Rate Convertible

BURTON 4-3


Estimating dilution air volume l.jpg
Estimating Dilution Air Volume Convertible

BURTON 4-5


Poor dilution l.jpg
Poor Dilution Convertible


Good dilution l.jpg
Good Dilution Convertible


Example 4 1 l.jpg
Example 4-1 Convertible

What is q, the volume flow rate of vapor formed, if 0.5 gallons of toluene are evaporated uniformly over an 8-hr. shift? What volume flow rate Qd is required for dilution to 10 ppm, if Kmixing = 2 ? (Assume STP; d = 1.0)

What is the average face velocity of air in a room 10ft. * 8ft. * 40ft for these conditions?

BURTON 4-6


Strategy ex 4 2 l.jpg
Strategy Convertible Ex. 4-2

Step 1: Calculate the volume flow rate of the vapor

emitted q.

q = (387 * lbs. evaporated)/ (MW * t * d)

Note:lbs. Evaporated = gal. * 8.31 * SG

Step 2. Calculate the dilution air volume flow rate

Qd.

Qd = q * 106 * K mixing

Ca (ppm)

Step 3: Calculate the face velocity.

V face = Qd/A

Step 4: Calculate the air changes/ hour.

N = (Qd * 60)/Vr


Purge and buildup l.jpg
Purge and Buildup Convertible

  • Purge and buildup - predict contaminant buildup or purge rate.

  • Steady state -equilibrium maintained.

BURTON 4-9


Example 4 5 l.jpg
Example 4-5 Convertible

An automobile garage was severely contaminated with carbon monoxide.

How long will it take to purge the garage?

BURTON 4-11


Chapter 11 makeup air balance l.jpg
Chapter 11 - Makeup Air Balance Convertible

  • Exhausted air must be replaced.

  • Negative pressure without makeup air.

BURTON 11-1


Make up air l.jpg
Make up Air Convertible

  • Fresh air supplied into the breathing zone of the associate.


Overcoming negative static pressure l.jpg

Changes in static pressure involving radial (squirrel cage) fans cause a small change in the volumetric flow rate.

Changes in static pressure involving axial (propeller) fans cause a large change in the volumetric flow rate.

Overcoming Negative Static Pressure

BURTON 11-2


Good makeup air l.jpg
Good Makeup Air fans cause a small change in the volumetric flow rate.

INDUSTRIAL VENTILATION 2-4


Bad makeup air l.jpg
Bad Makeup Air fans cause a small change in the volumetric flow rate.

INDUSTRIAL VENTILATION 2-4


Reentrainment l.jpg
Reentrainment fans cause a small change in the volumetric flow rate.

BURTON 11-9


Reentrainment44 l.jpg
Reentrainment fans cause a small change in the volumetric flow rate.

BURTON 11-9


Avoiding reentrainment 10 50 3000 rule l.jpg
Avoiding Reentrainment fans cause a small change in the volumetric flow rate.10-50-3000 RULE

BURTON 14-5


Recirculation of exhaust air l.jpg
Recirculation of Exhaust Air fans cause a small change in the volumetric flow rate.

  • Good for non-toxic particulate control.

  • Can recover 40-60% of heat energy.

BURTON 12-1


Types of ventilation systems l.jpg
Types of Ventilation Systems fans cause a small change in the volumetric flow rate.

BURTON 5-1


Why choose local ventilation l.jpg
Why Choose Local Ventilation? fans cause a small change in the volumetric flow rate.

  • No other controls

  • Containment

  • Employee in vicinity

  • Emissions vary with time

  • Sources large and few

  • Fixed source

  • Codes

BURTON 5-2


Exercise 5 3 l.jpg
Exercise 5-3 fans cause a small change in the volumetric flow rate.

Form your group and try exercise 5-3. Compare the operation to the parameters listed below:

  • No other controls available

  • Hazardous contaminant

  • Employee in immediate vicinity

  • Emissions vary with time

  • Emission sources large and few

  • Fixed emission source

  • Codes & standards

BURTON 5-3


Components of a local exhaust system l.jpg
Components of a Local Exhaust System fans cause a small change in the volumetric flow rate.

BURTON 5-4


Static pressure review l.jpg
Static Pressure Review fans cause a small change in the volumetric flow rate.

BURTON 5-5


Energy conservation l.jpg
Energy Conservation fans cause a small change in the volumetric flow rate.

BURTON 5-6


Basic air flow equations l.jpg
Basic Air Flow Equations fans cause a small change in the volumetric flow rate.

  • Q = V * A

  • TP = SP + VP

  • V = 4005(VP/d)0.5

BURTON 5-7


Static pressure loss l.jpg
Static Pressure Loss fans cause a small change in the volumetric flow rate.

  • Static Pressure Loss = Kloss * VP * d

BURTON 5-8


Elbow loss l.jpg
Elbow Loss fans cause a small change in the volumetric flow rate.

Air moving through elbows spends static pressure because of:

  • directional change

  • friction

  • shock losses

  • turbulent mixing

  • air bunching up

  • SP(loss) = K(elbow )* VP * d

BURTON 5-9


Elbow loss ex 5 8 l.jpg
Elbow Loss Ex. 5-8 fans cause a small change in the volumetric flow rate.

What is the elbow loss factor K(elbow) where the elbow radius of curvature is R/D = 2.0 in a smooth transition elbow.

BURTON 5-9


Elbow loss exercise 5 9 l.jpg
Elbow Loss Exercise 5-9 fans cause a small change in the volumetric flow rate.

What is the actual loss in inches of water of air flowing through a 60-degree, 3-piece elbow at V = 3440 fpm? R/D = 1.5, STP, d=1.

BURTON 5-10


Elbow loss exercise 5 958 l.jpg
Elbow Loss Exercise 5-9 fans cause a small change in the volumetric flow rate.

  • SPloss = K * VP * d

  • Use Chart 13, Appendix pg. 25 for information on a 90-degree 3- piece elbow with R/D = 1.5

  • Let K = (angle/90) * K 90

  • VP = (V/4005)2


Friction loss as a function of duct length l.jpg

Friction Loss = K * VP * L * R * d fans cause a small change in the volumetric flow rate.

K is a value taken from Chart #5,

appendix page 9

VP is duct velocity pressure, in w.g.

L is the length of the duct in feet

d is the density correction factor

R is roughness correction factor

Friction Loss as a Function of Duct Length

BURTON 5-11


Exercise 5 10 l.jpg
Exercise 5-10 fans cause a small change in the volumetric flow rate.

What is the friction loss for a length of galvanized duct with the following parameters? D = 8in., Q = 1000scfm, L = 43 ft. R = 1.


Tee losses l.jpg
Tee Losses fans cause a small change in the volumetric flow rate.

BURTON 5-11


Tee losses ex 5 12 l.jpg
Tee Losses Ex. 5-12 fans cause a small change in the volumetric flow rate.

What is the estimated static pressure loss in inches of water for a branch entry of 30 degrees where the branch entry velocity is 4500 fpm?

BURTON 5-12


Converting static pressure to velocity pressure l.jpg
Converting Static Pressure To Velocity Pressure fans cause a small change in the volumetric flow rate.

At the hood, all of the available static pressure is converted to velocity pressure and hood entry loss.

SPh = VP + he

BURTON 6-2


Measuring hood static pressure l.jpg
Measuring Hood Static Pressure fans cause a small change in the volumetric flow rate.

Measure hood static pressure 4-6 duct diameters downstream from the hood.

4-6 D

BURTON 6-2


Hood entry losses l.jpg
Hood Entry Losses fans cause a small change in the volumetric flow rate.

The hood entry loss is the sum total of all losses from the hood face to the point of measurement in the duct.

SP(loss) = K * VP * d

he = K * VP * d

BURTON 6-2


Example 6 1 l.jpg
Example 6-1 fans cause a small change in the volumetric flow rate.

What is the hood static pressure when the duct velocity pressure is VP = 1.10 in. w.g. and the hood entry loss is

he = 1.00 in w.g.

SPh = VP + he

SPh = 1.10+ 1.00

= -2.10 in w.g.

BURTON 6-3


Vena contracta l.jpg
Vena Contracta fans cause a small change in the volumetric flow rate.

The greatest loss normally occurs at the entrance to the duct, due to the vena contracta formed in the throat of the duct.

BURTON 6-3


Hood efficiency l.jpg
Hood Efficiency fans cause a small change in the volumetric flow rate.

A hood’s efficiency can be described by the ratio of actual to ideal flow. This ratio is called the Coefficient of Entry, Ce.

Ce = Q(actual)/Q(ideal)

BURTON 6-4


Hood static pressure and entry losses example 6 5 l.jpg
Hood Static Pressure and Entry Losses Example 6-5 fans cause a small change in the volumetric flow rate.

The average velocity in a duct serving a hood is V = 2000 fpm. The loss factor for the hood has been obtained from the manufacturer as Khood = 2.2. What are the he and SPh? (Assume STP, d = 1)

BURTON 6-5


Hand grinding table example 6 6 l.jpg
Hand Grinding Table fans cause a small change in the volumetric flow rate.Example 6-6

Assume that a special hand grinding table hood has been built and the following data have been measured:

SPh = -2.50 in w.g., V = 4000fpm, and the duct diameter is 18 in. (Assume STP, d=1)

BURTON 6-6


Types of hoods l.jpg
Types of Hoods fans cause a small change in the volumetric flow rate.

  • Receiving

  • Capturing

  • Enclosing

BURTON 6-10


Hood types l.jpg
Hood Types fans cause a small change in the volumetric flow rate.

  • SLOTTED HOOD


Hood types73 l.jpg
Hood Types fans cause a small change in the volumetric flow rate.

  • ENCLOSED HOOD


Hood types74 l.jpg
Hood Types fans cause a small change in the volumetric flow rate.

  • ENCLOSING HOOD


Hood types75 l.jpg
Hood Types fans cause a small change in the volumetric flow rate.

  • CAPTURING HOOD


Grinding wheel hood example example 6 9 l.jpg
Grinding Wheel Hood Example Example 6-9 fans cause a small change in the volumetric flow rate.

Determine the volume flow rate, transport velocity, duct diameter, loss factor K, Ce, he, and SPh, for a grinding wheel hood, wheel diameter = 13in. (low surface speed), straight take off [sto], STP)

BURTON 6-12


Exercise 6 10 useful formulas l.jpg
EXERCISE 6-10 fans cause a small change in the volumetric flow rate.USEFUL FORMULAS

Q = V * A

V = 4005(VP)1/2

VP = (V/4005)2

he = K * VP

SPh = VP + he

BURTON 6-12 AND 6-13


Exercise 6 10a l.jpg
Exercise 6-10a fans cause a small change in the volumetric flow rate.

Where appropriate, determine the volume flow rate, transport velocity, duct diameter, loss factor K, Ce, he, and SPh for a grinding wheel hood with a wheel diameter of 14 in. (low surface speed, tapered takeoff [tto]. Note: the picture in the book is for a buffing hood.

BURTON 6-12


Exercise 6 10a strategy l.jpg
Exercise 6-10a Strategy fans cause a small change in the volumetric flow rate.

1. Use Chart 11C, appendix pg. 18 to find Q, Vtrans., K, and Ce.

2. Use Chart 5A in appendix pg. 9 to find the diameter of the pipe needed and it’s area.

3. Calculate Vactual = Q/A

4. VP = (Vactual/4005)2

5.he = K * VP

6. SPh = VP + he


Exercise 6 10b l.jpg
Exercise 6-10b fans cause a small change in the volumetric flow rate.

Where appropriate, determine the volume flow rate, transport velocity, duct diameter, loss factor K, Ce, he, and SPh for a hand grinding table 10 feet long by 2 feet wide.

BURTON 6-13


Exercise 6 10b strategy l.jpg
Exercise 6-10b Strategy fans cause a small change in the volumetric flow rate.

1. Use Chart 11C, appendix pg. 18 to find Q, Vtrans., K, and Ce.

2. Use Chart 5A in appendix pg. 9 to find the diameter of the pipe needed and it’s area.

3. Calculate Vactual = Q/A

4. VP = (Vactual/4005)2

5.he = K * VP

6. SPh = VP + he


Exercise 6 10c l.jpg
Exercise 6-10c fans cause a small change in the volumetric flow rate.

Where appropriate, determine the volume flow rate, transport velocity, duct diameter, loss factor K, Ce, he, and SPh for a band saw used to cut wood that has a blade width of 1 inch.

BURTON 6-13


Exercise 6 10c strategy l.jpg
Exercise 6-10c Strategy fans cause a small change in the volumetric flow rate.

1. Use Chart 11E, appendix pg. 20 to find Q, Vtrans., K, and Ce.

2. Use Chart 5A in appendix pg. 9 to find the diameter of the pipe needed and it’s area.

3. Calculate Vactual = Q/A

4. VP = (Vactual/4005)2

5.he = K * VP

6. SPh = VP + he


Exercise 6 10d l.jpg
Exercise 6-10d fans cause a small change in the volumetric flow rate.

Where appropriate, determine the volume flow rate, transport velocity, duct diameter, loss factor K, Ce, he, and SPh for a bell-mouthed hood used for welding. X=10 in., Vc = 100 fpm, Vtrans = 3000 fpm.

BURTON 6-13


Exercise 6 10d strategy l.jpg
Exercise 6-10d Strategy fans cause a small change in the volumetric flow rate.

1. Use Chart 11A, appendix pg. 16 to find Q, K, and Ce.

2. Use Chart 5A in appendix pg. 9 to find the diameter of the pipe needed and it’s area.

3. Calculate Vactual = Q/A

4. VP = (Vactual/4005)2

5.he = K * VP

6. SPh = VP + he


Exercise 6 10e l.jpg
Exercise 6-10e fans cause a small change in the volumetric flow rate.

Where appropriate, determine the volume flow rate, transport velocity, duct diameter, loss factor K, Ce, he, and SPh for a canopy hood used for a hot-liquid open surfaced tank. P = 16 ft., X = 3 ft., Vcontrol = 125 fpm, Vtrans = 2000fpm.

BURTON 6-13


Exercise 6 10e strategy l.jpg
Exercise 6-10e Strategy fans cause a small change in the volumetric flow rate.

1. Use Chart 11B, appendix pg. 17 to find Q, K, and Ce.

2. Use Chart 5A in appendix pg. 9 to find the diameter of the pipe needed and it’s area.

3. Calculate Vactual = Q/A

4. VP = (Vactual/4005)2

5.he = K * VP

6. SPh = VP + he


Factors influencing hood performance l.jpg
Factors Influencing Hood Performance fans cause a small change in the volumetric flow rate.

  • Competition

  • Mixing

  • Work practices

BURTON 6-17


Canopy hoods l.jpg
Canopy Hoods fans cause a small change in the volumetric flow rate.

  • Use only for hot processes with rising air.

  • Estimate initial and terminal velocities of rising air stream.

  • The volume of air exhausted from the hood must exceed the volume of air arriving at the hood face.

  • Warm rising air expands as it rises. Make the cross-sectional area of the hood face 125% larger than the plume of hot air.

  • Avoid canopy hoods if an employee must work over the source.

BURTON 6-19


Chapter 7 selection and design of ductwork l.jpg
Chapter 7 fans cause a small change in the volumetric flow rate.Selection and Design of Ductwork

BURTON 7-1


Exercise 7 2 l.jpg
Exercise 7-2 fans cause a small change in the volumetric flow rate.

Standard air (d=1) moves through an 8 in. galvanized duct system at 4000 fpm. Estimate VP, find the loss factors K from the Charts, and then estimate static pressure loss for each component in each branch. (Note: treat the branch entry as two 45-degree entries and use the ACGIH value for K on Chart 14.)

BURTON 7-4


Exercise 7 2a flanged hood l.jpg
Exercise 7-2a, Flanged Hood fans cause a small change in the volumetric flow rate.

BURTON 7-4


Exercise 7 2b plain duct hood l.jpg
Exercise 7-2b, Plain Duct Hood fans cause a small change in the volumetric flow rate.

BURTON 7-4


Exercise 7 2c elbow 3 piece l.jpg
Exercise 7-2c, Elbow, 3-piece fans cause a small change in the volumetric flow rate.

BURTON 7-4


Exercise 7 2d elbow 5 piece l.jpg
Exercise 7-2d, Elbow, 5-piece fans cause a small change in the volumetric flow rate.

BURTON 7-4


Exercise7 2e elbow 4 piece l.jpg
Exercise7-2e, Elbow, 4-piece fans cause a small change in the volumetric flow rate.

BURTON 7-4


Exercise 7 2f branch entry l.jpg
Exercise 7-2f, Branch Entry fans cause a small change in the volumetric flow rate.

BURTON 7-4


Exercise 7 2g 50 ft of duct l.jpg
Exercise 7-2g, 50 ft. of Duct fans cause a small change in the volumetric flow rate.

BURTON 7-4


Roughness example 7 1 l.jpg
Roughness fans cause a small change in the volumetric flow rate.Example 7-1

Standard air is flowing in 40 feet of a 24 in. concrete pipe at the 4000 fpm. What is the correction factor, R? The loss factor K?

BURTON 7-5


Duct shapes l.jpg
Duct Shapes fans cause a small change in the volumetric flow rate.

Use round duct whenever possible, it resists collapsing, provides better aerosol transport conditions, and may be less expensive.

BURTON 7-6


Pressure diagrams l.jpg
Pressure Diagrams fans cause a small change in the volumetric flow rate.

BURTON 7-11


Chapter 8 fan selection and operation l.jpg

AXIAL FANS fans cause a small change in the volumetric flow rate.

propeller fans

CENTRIFUGAL FANS

radial fans

forward inclined

backward inclined

Chapter 8 Fan Selection and Operation

BURTON 8-2


Fan total pressure l.jpg
Fan Total Pressure fans cause a small change in the volumetric flow rate.

The fan total pressure (FTP) represents all energy requirements for moving air through the ventilation system.

The fan total pressure is often referred to as the fan total static pressure drop.

FTP = TP outlet - TP inlet

FTP = SPout - VP out - SPin - VP in

FTP = SPout - SPin

BURTON 8-3


Exercise 8 1 l.jpg
Exercise 8-1 fans cause a small change in the volumetric flow rate.

Find the Fan Total Pressure given that the SPin = -5.0 in w.g, SPout = +0.40 in w.g.

VPin = VPout = 1.0 in. w.g.

FTP = SPout - SPin =

0.40 - (-5.0) = 5.4 in w.g.

BURTON 8-3


Exercise 8 2 fan static pressure l.jpg
Exercise 8-2 fans cause a small change in the volumetric flow rate.Fan Static Pressure

The fan static pressure out of the fan is defined as the fan total pressure minus the average velocity pressure out of the fan.

FSP = Fan TP - VPout

BURTON 8-4


Sop and fan curves l.jpg
SOP and Fan Curves fans cause a small change in the volumetric flow rate.

To develop a system curve, the fan should be turned at different rpms and the flow and the absolute values of the static pressures at the fan are plotted.

BURTON 8-5


Developing fan curves l.jpg
Developing Fan Curves fans cause a small change in the volumetric flow rate.

BURTON 8-6


Sop on steep part of curve l.jpg
SOP on Steep Part of Curve fans cause a small change in the volumetric flow rate.

BURTON 8-7


Example 8 1 l.jpg
Example 8-1 fans cause a small change in the volumetric flow rate.

Choose an appropriate fan for a system operating point of Q = 10,000 scfm and FTP = 1.5 in. w.g.

BURTON 8-8


Exercise 8 3 l.jpg
Exercise 8-3 fans cause a small change in the volumetric flow rate.

Find a fan and appropriate rpm for a fan exhausting 15,000 cfm at a fan TP = 2.0 in. w.g.

BURTON 8-8


Exercise8 4 l.jpg
Exercise8-4 fans cause a small change in the volumetric flow rate.

Find a suitable fan and the appropriate rpm for a ventilation system exhausting 480 cfm at a fan TP = 13.8 in. w.g.

BURTON 8-8


Commercial fan curves l.jpg
Commercial Fan Curves fans cause a small change in the volumetric flow rate.

BURTON 8-9


Commercial fan curves113 l.jpg
Commercial Fan Curves fans cause a small change in the volumetric flow rate.

BURTON 8-10


Commercial fan curves114 l.jpg
Commercial Fan Curves fans cause a small change in the volumetric flow rate.

BURTON 8-11


System effect losses l.jpg
System Effect Losses fans cause a small change in the volumetric flow rate.

BURTON 8-12


Six and three rule l.jpg
Six-and-Three Rule fans cause a small change in the volumetric flow rate.

BURTON 8-13


Air horsepower l.jpg
Air Horsepower fans cause a small change in the volumetric flow rate.

Air horsepower refers to the minimum amount of power to move a volume of air against the fan total pressure. It represents the power to get the air through the duct system.

ahp = ( FTP * Q * d)/6356

BURTON 8-14


Brake horsepower l.jpg
Brake Horsepower fans cause a small change in the volumetric flow rate.

Brake horsepower refers to the actual power required to operate the fan so that it fulfills the job of moving the specified cfm against the FTP. It takes into account fan inefficiencies, i.e. losses in the fan.

bhp = ahp/ME

BURTON 8-15


Shaft horsepower l.jpg
Shaft Horsepower fans cause a small change in the volumetric flow rate.

Shaft horsepower is bhp plus any power required for drive losses, bearing losses, and pulley losses between the fan and the shaft of the motor.

shp = bhp * Kdl

BURTON 8-15


Rated horsepower l.jpg
Rated Horsepower fans cause a small change in the volumetric flow rate.

  • Rated horsepower is the nameplate horsepower on the motor.

BURTON 8-15


Example 8 4 l.jpg
Example 8-4 fans cause a small change in the volumetric flow rate.

What is the required power for the system and what rated power motor would you use?

FTP = 5.0 in. w.g. ,

Q = 12000 scfm

ME = 0.60, Kdl = 1.10, d = 1,

f = 6356

BURTON 8-16


Exercise 8 7 l.jpg
Exercise 8-7 fans cause a small change in the volumetric flow rate.

Estimate the ahp, bhp, shp, and the rated power motor you would choose for the following system.

Fan TP = 10.0 in. w.g.,

Q = 5000 scfm

Kdl = 1.15, STP(d=1),

f = 6356, ME = 0.65

BURTON 8-17


Fan laws l.jpg
Fan Laws fans cause a small change in the volumetric flow rate.

BURTON 8-19


Local exhaust ventilation design l.jpg
Local Exhaust Ventilation Design fans cause a small change in the volumetric flow rate.

BURTON 9-1


Plenum design l.jpg
Plenum Design fans cause a small change in the volumetric flow rate.

BURTON 9-3


Balancing l.jpg
BALANCING fans cause a small change in the volumetric flow rate.

Balancing during the design phase means adjusting losses in duct runs leading to a junction that the predicted loss in each run is essentially equal.

BURTON 9-4


Example 9 2 l.jpg
Example 9-2 fans cause a small change in the volumetric flow rate.

Design an local exhaust system based on the criteria listed in the example.

BURTON 9-5


Example 9 3 l.jpg
Example 9-3 fans cause a small change in the volumetric flow rate.

Design a local exhaust system based upon the criteria listed on this page.

BURTON 9-11


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