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TRG-TRC013-EN manual period two, Centrifugal Fan, Air Conditioning Fans, g FN, g FO
Models:
TRG-TRC013-EN
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Constant-VolumeSystem
Input Power
Page 34
Image 34
g
Air Conditioning Fans
period two
g FN
cwt
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rt”
Centrifugal Fan
g FO
S” p
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Page 33
Page 35
Page 34
Image 34
Page 33
Page 35
Contents
Page
THE TRANE COMPANY Attn Applications Engineering
BUSINESS REPLY MAIL
BUSINESS REPLY MAIL
3600 Pammel Creek Road La Crosse WI
Air Conditioning Fans
Comment Card
Response Card
One of the Equipment Series
p e The Trane Company
Worldwide Applied Systems Group
Air Conditioning Fans
A Trane Air Conditioning Clinic
99999999999999999999999999999
caQ3caM6793O
Air Conditioning Fans
axial centrifugal
Air Conditioning Fans
period one
Measuring Pressure
atmospheric ductpressure pressure
R-2 x”rwt
Positive Duct Pressure
fwt” p 2 p ”tvp rp S” r“- 4 jK 7683-- r-“4lcwt
are “water gage” wg and “water column” wc
pressure
Inclined Manometer
duct
reservoir
Total Pressure
Velocity Pressure vs. Static Pressure
g DC
Velocity Pressure vs. Static Pressure
Velocity Pressure vs. Static Pressure
damper fully open
g DD
Measuring Static Pressure
Velocity Pressure vs. Static Pressure
g DE
Measuring Total Pressure
Fan Performance Test
g DG
Velocity V = Constant ⋅ √ Pρ
Determining Fan Airflow
Velocity Pressure Pv = Pt - P s
Airflow = Velocity ⋅ Fan Outlet Area
static pressure
Plotting Fan Performance Points
Plotting Fan Performance Points
2.0 in. H2O
airflow
Fan Performance Curve
static pressure
airflow
Fan Speed
Input Power
Fan Surge
Fan Surge Line
Percent of Wide-OpenAirflow
Pp” -p”
Tabular Performance Data
fan’s speed and input power requirement
g EG
System Resistance
System Resistance
Airflow
System Resistance Curve
Static Pressure
Static Pressure
System Resistance Curve
Fan - System Interaction
Fan - System Interaction
Higher System Resistance
Lower System Resistance
Static Efficiency
Power Out Static Efficiency SE = Power In
SE = Constant ⋅ Input Power
Airflow ⋅ Static Pressure
1.65 m3/s ⋅ 491 Pa
3,500 cfm ⋅ 2.0 in. H2O
= 55%
⋅ 1.5 kW
resistance curve
Constant-VolumeSystem
design system
pressure
g FH
Variable-PitchVaneaxial Fan
variable-pitch blades
85% 80% 70%
total pressure
surge region
airflow
g FM
total pressure
surge region
angl
Air Conditioning Fans
period two
Centrifugal Fan
g FN
cwt ux r2 - PM2 up” PM up” r-” -t
Forward Curved Fan
Forward Curved Fan
cwt r
50 to 65%
Forward Curved Fan
static efficiency
application
Backward Inclined Fan
backward inclined
FC vs. BI Fans
forward curved
Backward Inclined Fan
Backward Inclined Fan
cwt p“xrp
backward inclined
Backward Curved Fan
Airfoil Fan
backward curved
static efficiency
Plug or Plenum Fan
Airfoil Fan
80 to 86%
straightening vanes fan wheel or impeller
Vaneaxial Fan
g HF
application
Vaneaxial Fan
Variable-PitchVaneaxial Fan
static efficiency
airflow
surge region
pressure
g HI
Backward inclined BI or airfoil AF
Fan Selection
Forward curved FC
Vaneaxial
Air Conditioning Fans
period three
VAV System
K 9e“5
VAV System
Riding the Fan Curve
“Riding the Fan Curve”
S” p eKe
Forward Curved Centrifugal Fan
Fan Control Loop
VAV System Modulation Curve
Discharge dampers Inlet vanes Fan-speedcontrol
Methods of Fan Capacity Control
Discharge Dampers
Variable-pitchblade control
Discharge Dampers
upward. The fan begins to “ride up” its constant-speedperformance curve toward f, from the design operating point e, trying to balance with this new system resistance curve. As a result, the fan delivers a lower airflow at a higher static pressure
Inlet Vanes
Inlet Vanes
Inlet Vanes
upward. The fan begins to “ride up” its current vane position curve toward f, from the design operating point e, trying to balance with this new system resistance curve. As a result, the fan delivers a lower airflow at a higher static pressure
Fan-SpeedControl
Fan-SpeedControl
g MF
Variable-PitchBlade Control
p“-”vKe
variable-pitch blades
cwt t
e eK/ up”
discharge
Fan Control Comparison
power
design airflow
Air Conditioning Fans
period four
g MI
sensor
System Static-PressureControl
controller
VAV supplyterminal units fan
Optimized Static-PressureControl
System Effect
System Effect
Acoustics
Avoid rectangular sound traps, if possible
Acoustical Guidelines
Minimize system effects
Use adequate vibration isolation
1 Air Density Ratio =
Effect of Actual Conditions
5 Poweractual = Air Density Ratio ⋅ Powerstandard
Densityactual
Equipment Certification Standards
Purpose
Review-PeriodOne
period five
Air Conditioning Fans
axial centrifugal
Review-PeriodTwo
Review-PeriodThree
“Riding the fan curve” Discharge dampers
g NO
Review-PeriodFour
Application considerations
System static-pressurecontrol System effect
cp”t Kx
Page
NLt -”trp” wp”s“t wxvwt PO up”4
DDList two possible causes of system effect
E F 64 x”4 R8 j78 pl e F 82A98 u- j7
bndb Kx
cbt L
“riding the fan curve” K -tsx
9bw5
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