DWT-Ⅱ Series / Centrifugal Roof Ventilation
DWT-Ⅱ Centrifugal Roof Exhaust Fan
Centrifugal roof exhaust fan for rooftop ventilation systems requiring higher pressure than axial roof fans. Suitable for factories, workshops, equipment buildings and ducted roof exhaust systems with moderate airflow and higher system resistance.
Browse Centrifugal Fans, compare the lower-pressure DWT-Ⅰ Axial Roof Fan, or review the Industrial Workshop Ventilation System.
No. 3–10 878–31,436 m³/h 122–1,072 Pa
AIRFLOW
878–31,436 m³/h
TOTAL PRESSURE
122–1,072 Pa
MOTOR POWER
0.55–7.5 kW
NOISE
≤72 dB(A)
DWT-Ⅱ Series
Technical Index
01 Overview 02 Construction 03 Performance 04 Dimensions 05 Conditions 06 Applications 07 Selection 08 Options 09 Resources 10 FAQ
Quick Facts
Centrifugal Roof Fan
No. 3–10
300–1000 mm
Higher Pressure
Roof Exhaust
No. 3–10
300–1000 mm
Higher Pressure
Roof Exhaust
01 / Engineering Overview
Higher-Pressure Rooftop Exhaust with a Centrifugal Impeller
DWT-Ⅱ uses a centrifugal impeller and is designed for rooftop ventilation systems requiring more pressure than a conventional axial roof fan. The series includes nine fan sizes based on nominal impeller diameters from approximately 300 mm to 1000 mm.
Its operating range makes it suitable for roof exhaust systems with additional resistance from ducts, louvers, dampers and other ventilation components.
DWT-Ⅱ = Centrifugal / Higher Pressure
For larger airflow with lower pressure and more direct roof ventilation, compare the DWT-Ⅰ Axial Roof Fan.
02 / Construction
Centrifugal Roof Fan Assembly
01
Impeller
Centrifugal impeller for higher-pressure rooftop ventilation duty.
02
Motor
Motor selected according to fan size, operating point and electrical requirements.
03
Weather Hood
Fiberglass weather hood protects the roof fan assembly from direct outdoor exposure.
04
Fan Housing
Fan casing, inlet collector and motor-support structure form the main roof assembly.
03 / Performance Data
DWT-Ⅱ Reference Performance
Each fan size provides multiple airflow and pressure operating points. Select the model according to the required duty point rather than fan diameter alone.
SIZE
RPM
AIRFLOW m³/h
PRESSURE Pa
MOTOR
POWER kW
NOISE
WEIGHT kg
No.3
1450
878
220
Y801-4
0.55
≤57
88
925
210
1,059
188
1,130
167
1,253
122
No.3.5
1450
1,395
299
Y802-4
0.75
≤59
95
1,470
285
1,682
256
1,794
227
1,990
166
No.4
1450
1,887
412
Y90S-4
1.1
≤62
115
2,083
391
2,194
372
2,510
334
2,677
298
No.4.5
1450
2,966
495
Y90L-4
1.5
≤63
154
3,124
471
3,574
423
3,812
376
4,514
231
No.5
1450
4,068
615
Y100L1-4
2.2
≤64
195
4,285
582
4,903
522
5,438
485
6,113
378
No.6
960
5,024
385
Y100L-6
1.5
≤65
234
5,512
367
6,120
330
6,782
293
7,338
223
No.7
960
8,015
548
Y132S-6
3.0
≤68
292
8,804
499
9,827
448
10,836
398
11,925
371
No.8
960
12,563
721
Y132M2-6
5.5
≤70
374
13,565
686
14,517
654
15,824
587
16,708
521
No.10
720
22,150
1,072
Y160L-8
7.5
≤72
396
23,298
1,020
26,573
916
28,395
813
31,436
702
Published catalog values are reference operating points. Final selection should be confirmed against actual airflow, system resistance, air condition, roof installation and electrical requirements.
04 / Installation Dimensions
Roof Fan Outline and Installation Dimensions
Compare the outline drawing and dimensional table together when confirming the roof opening, support curb and available installation space.
Drawing reference: D1 = inlet / base reference diameter; D2 = overall fan diameter; H = overall height; H1 = mounting-base height; A = roof foundation opening reference dimension.
SIZE
D1
D2
H
H1
A
No.3
Ø310
Ø690
700
80
430
No.3.5
Ø360
Ø800
720
80
480
No.4
Ø410
Ø920
930
80
520
No.4.5
Ø460
Ø920
940
80
570
No.5
Ø510
Ø1000
980
80
640
No.6
Ø610
Ø1200
1070
80
820
No.7
Ø710
Ø1460
1290
80
910
No.8
Ø810
Ø1610
1370
80
1050
No.10
Ø1010
Ø1840
1560
80
1300
Dimensions in mm. Confirm the selected fan and final installation drawing before constructing the roof curb or cutting the roof opening.
05 / Operating Conditions
Confirm the Air Condition Before Selection
Temperature
Catalog reference operating range: -20°C to +40°C.
Relative Humidity
Less than 90% under catalog reference conditions.
Standard Version
For non-corrosive, non-flammable and non-explosive gases with dust content not exceeding 100 mg/m³.
Explosion-Proof Version
Explosion-proof configuration can be reviewed for suitable non-corrosive environments containing flammable or explosive gases.
Corrosion-Resistant Version
Material configuration can be reviewed for corrosive gas environments.
Reference Electrical Supply
Three-phase 380 V / 50 Hz catalog configuration. Export-project voltage and frequency can be reviewed separately.
06 / Application Fit
Where DWT-Ⅱ Fits Better Than an Axial Roof Fan
Factory Workshops
Rooftop exhaust where duct, damper or louver resistance requires additional pressure.
Industrial Buildings
Mechanical roof ventilation for production and utility buildings.
Power Facilities
Roof exhaust applications requiring moderate airflow and higher pressure capability.
Ducted Roof Exhaust
Systems where resistance is too high for a low-pressure axial roof fan.
07 / Before Selection
Information Required for DWT-Ⅱ Selection
01
Airflow
Required exhaust or supply volume.
02
Pressure
Required total pressure or known roof-system resistance.
03
Roof Opening
Existing opening and available curb dimensions.
04
Air Condition
Temperature, humidity, dust and corrosive or hazardous components.
05
Noise Requirement
Project sound limit or nearby occupied-space requirement.
06
Electrical
Voltage, frequency, phase and control requirements.
Pressure not available?
Send the roof opening, duct route, louvers, dampers and available building drawings. Read the engineering guide →
08 / Control & Configuration Options
Match the Roof Fan to the Operating Requirement
Two-Speed Motor
Can be considered where two fixed operating speeds are required.
Variable Frequency
Variable-frequency operation can be configured for suitable motors. Catalog guidance recommends a frequency adjustment range of 25–50 Hz.
Airflow Regulation
Manual or electric regulating devices can be considered according to project requirements.
Roof Louvers
Roof exhaust louver arrangements can be reviewed according to installation requirements.
09 / Technical References
Related Engineering Guides
AIRFLOW & PRESSURE
Industrial Fan Airflow and Pressure Explained → STATIC PRESSURE
What to Send When Static Pressure Is Unknown → FAN SELECTION
Industrial Fan Selection Center → Product Path
Choose by Roof Resistance and Installation Duty
DWT-Ⅰ Low-Noise Axial Roof Exhaust Fan
Large airflow and lower pressure for more direct roof ventilation with relatively low system resistance.
DWT-Ⅱ
Centrifugal roof fan for higher-pressure rooftop exhaust where ducts, louvers, dampers or other components create more resistance.
T40 Axial Flow Fan
General wall, free-air and duct ventilation. Use when a dedicated rooftop weather hood and curb-mounted roof-fan structure are not required.
T35-11 / BT35-11 Axial Flow Fan
General low-resistance workshop, wall-opening and short-duct ventilation, including project-based explosion-proof configuration.
Industrial Workshop Ventilation System
Use the system page when fan duty depends on building volume, heat load, roof openings, ducts, louvers and overall air-change requirements.
Centrifugal Fans
Browse other centrifugal industrial fan configurations for higher-resistance ventilation and process-air duties.
10 / FAQ
DWT-Ⅱ Centrifugal Roof Fan Questions
What is the DWT-Ⅱ roof fan used for?
DWT-Ⅱ is designed for rooftop ventilation systems requiring moderate airflow and more pressure than a low-pressure axial roof fan.
What is the difference between DWT-Ⅰ and DWT-Ⅱ?
DWT-Ⅰ uses an axial-flow arrangement for large airflow and relatively low pressure. DWT-Ⅱ uses a centrifugal impeller for higher-pressure roof ventilation.
What is the DWT-Ⅱ airflow range?
The detailed catalog performance table covers approximately 878 to 31,436 m³/h.
What pressure can DWT-Ⅱ provide?
Published operating points cover approximately 122 to 1,072 Pa, depending on fan size and airflow.
Can DWT-Ⅱ use variable-frequency control?
Variable-frequency operation can be configured for suitable motors. The catalog recommends a frequency adjustment range of 25–50 Hz.
What installation information is required?
Provide the roof opening, curb dimensions, available installation space, airflow, pressure and building or duct drawings where available.
Can the motor be supplied for other voltages and frequencies?
The catalog uses three-phase 380 V / 50 Hz as the standard reference. Alternative voltage and frequency requirements can be reviewed for export projects.
DWT-Ⅱ Roof Fan Selection
Send the Roof Exhaust Requirement. We Review the Fan.
Airflow · Pressure · Roof Opening · Air Condition · Noise Target · Voltage · Frequency · Quantity