Carrier Aero 39MN MW03-110 Series Installation, Start-Up And Service Instructions Manual page 145

a39-4178
ENSURE ADEQUATE
HEIGHT/CLEARANCE
FOR DRAIN TO FLOOR
Fig. 114 — Condensate Drain, Blow-Thru Trapping
(All Sizes)
MIXING
BOX
Return Clean
MXB
Duct Filter
0.4 in. wg
0.5 in. wg 0.2 in. wg
Fig. 115 — Draw-Thru Example
TYPE
FORWARD-CURVED • Double-width, double-inlet (DWDI) construction.
(FC) • Best at low or medium pressure (approximately
SIDE VIEW 0 to 5 in. wg).
• Horsepower increases continuously with
increase in air quantity (overloads) as static
pressure decreases.
• Less expensive than AF fans.
• Runs at relatively low speed, typically 400 to
1200 rpm.
• Blades curve toward direction of rotation.
AIRFOIL • Double-width, double-inlet (DWDI) construction.
(AF) • Best in high capacity and high-pressure
SIDE VIEW
applications (4 to 8 in. wg).
• Horsepower peaks at high capacities.
• Most expensive of centrifugal fans.
• Operates at high speeds, typically 1200 to
2800 rpm. About double the speed of FC fan
for similar air quantity.
• Blades have aerodynamic shape similar to
airplane wing and are curved away from direction
of rotation.
PLENUM, BELT DRIVE
OR DIRECT DRIVE WITH
NEMA MOTORS (PAF)
• Single-width, single-inlet (SWSI) construction.
END VIEW
• Characteristics similar to DWDI airfoil fan.
• Blades have aerodynamic shape similar to
airplane wing and are curved away from direction
of rotation. Fewer blades and wider blade
spacing than AF fans.
• Available as belt drive or as direct drive shaft mounted on a NEMA "T" frame.
PLENUM, DIRECT DRIVE
WITH EC MOTORS
(PFEC) END VIEW
• Single-width, single-inlet (SWSI) construction mounted to rotor of supplier
matched electronically commutated motor.
• Blades curve away from direction of rotation.
• Various combinations of fan sizes and quantities available for fan efficiency opti-
mization.
P + 1/2"
1
1/2"
MINIMUM
H
C
E
O
A
O FAN
T
L
Heating
Cooling
Coil
Coil
0.2
1.2 in. wg
in. wg
Table 35 — Fan Type and Application
CHARACTERISTICS
MIXING
BOX
Trap Against Static Pressure Downstream of Fan - Static Pressure
Between Fan and Drain =
2.3 in. wg - 1.2 in. wg = 1.1 in. wg
Fig. 116 — Blow-Thru Example
145
C
PLENUM
O
FAN
O
L
Static Pressure Between the Fan Static Pressure Between the Fan
and Drain and Drain
(Coil and Plenum Section) (Coil and Plenum Section)
1.2 in. wg 1.2 in. wg
External Static Pressure
Downstream of Fan
2.3 in. wg
APPLICATION
For low to medium pressure
air-handling applications.
For medium to high air capacity and
pressure applications.
Best in applications with limited space
or multiple ducts.
Best in applications with requirements
for limited space, high-efficiency or fan
redundancy.