DWT-Ⅰ Series / Axial Roof Ventilation
DWT-Ⅰ Low-Noise Axial Roof Exhaust Fan
Large-airflow, low-pressure axial roof fan for factory, warehouse, workshop and industrial building ventilation. Multiple fan sizes and speeds allow project-based selection according to airflow, pressure, noise and roof installation requirements.
No. 3–24 1,450–220,800 m³/h 62–330 Pa
AIRFLOW
1,450–220,800 m³/h
TOTAL PRESSURE
62–330 Pa
MOTOR POWER
0.06–18.5 kW
FAN SIZE
No. 3–24
DWT-Ⅰ Series
Technical Index
01 Overview 02 Construction 03 Performance 04 Noise & Duty 05 Roof Installation 06 Applications 07 Selection 08 Resources 09 FAQ
Quick Facts
Axial Roof Fan
No. 3–24
Large Airflow
Low Pressure
Low-Noise Series
No. 3–24
Large Airflow
Low Pressure
Low-Noise Series
01 / Engineering Overview
Large-Volume Rooftop Ventilation at Low System Pressure
DWT-Ⅰ is the axial-flow version of the DWT roof fan family. It is intended for ventilation systems requiring high air volume with relatively low pressure directly through a roof opening.
The series is particularly suited to factories, warehouses, workshops and large building spaces where heat, stale air or general process ventilation must be discharged vertically through the roof.
DWT-Ⅰ = Axial / Large Airflow / Lower Pressure
For higher-resistance rooftop systems requiring more pressure, the DWT-Ⅱ centrifugal roof fan is the more suitable branch of the DWT family.
02 / Construction
Roof-Mounted Axial Ventilation Assembly
01
Axial Impeller
Axial-flow impeller designed for large-volume, low-pressure air movement.
02
Fan Cylinder
Supports the fan assembly and forms the main airflow passage through the roof.
03
Weather Hood
Roof-mounted hood helps protect the fan opening from rain and direct weather exposure.
04
Gravity Damper
Optional shut-off arrangement can reduce reverse airflow when the fan stops.
05
Safety Protection
Bird screen and safety mesh can be incorporated according to the installation arrangement.
03 / Performance Data
DWT-Ⅰ Reference Performance
Multiple speeds are available across the series. Use airflow and pressure together when identifying the required size; fan diameter alone is not a selection point.
SIZE
RPM
AIRFLOW m³/h
PRESSURE Pa
POWER kW
NOISE dB(A)
No.3
2850
2,600–3,300
181–232
0.37
66
1450
1,450–1,650
62–72
0.06
56
No.4
2850
5,300–7,450
193–250
0.75
69
1450
4,580–5,700
176–190
0.55
67
960
1,880–3,820
80–92
0.25
60
No.5
1450
5,600–8,000
135–191
0.55
68
960
6,400–7,000
113–131
0.37
63
720
4,100–6,000
88–96
0.25
58
No.6
1450
13,000–15,000
232–267
1.5
73
960
9,100–11,000
168–193
1.1
67
720
7,600–8,500
111–136
0.55
62
No.7
960
12,500–17,500
165–212
1.5
69
720
9,200–12,000
141–177
0.75
63
560
7,200–9,300
83–102
0.55
59
No.8
960
23,000–27,000
175–228
2.2
72
720
16,000–20,000
129–167
1.5
66
560
12,250–15,750
78–121
0.75
63
No.9
960
24,000–34,500
202–256
3.0
76
720
24,000–32,000
126–177
2.2
73
560
18,600–24,000
102–126
1.1
67
No.10
960
39,000–50,000
251–317
5.5
81
720
35,000–46,000
141–183
3.0
76
560
20,000–28,000
111–133
1.5
69
No.11.2
960
40,400–56,900
253–322
5.5
82
720
40,000–52,500
138–183
3.0
77
560
25,000–32,000
111–142
1.5
71
No.12
720
44,000–57,000
196–209
5.5
73
560
33,000–42,000
126–148
3.0
67
No.14
720
57,500–76,700
250–268
7.5
77
480
51,500–69,000
159–175
4.0
69
No.15
720
70,000–88,500
195–208
7.5
78
480
55,800–74,750
149–165
4.0
70
No.16
720
81,500–107,500
235–256
11
79
320
42,600–61,000
131–167
4.0
70
No.18
720
96,450–129,300
261–287
15
80
480
74,300–96,250
122–143
5.5
71
320
62,500–79,150
115–148
4.0
66
No.20
480
131,000–168,700
215–247
15
78
320
95,200–125,500
118–132
5.5
68
No.22
480
165,000–201,600
193–210
15
79
320
119,500–155,000
135–155
7.5
71
No.24
480
176,500–220,800
212–246
18.5
84
320
135,000–175,000
148–188
11
77
220
85,000–140,000
150–171
7.5
70
Published catalog values are reference performance data. Final selection should be confirmed against the actual roof opening, airflow requirement, system resistance, noise requirement and electrical supply.
04 / Noise & Operating Conditions
Lower Speed Can Reduce Noise - But It Also Changes Fan Duty
DWT-Ⅰ offers multiple speed options across the size range. A lower-speed version can provide lower sound levels, but airflow and available pressure are also reduced. Select by the required operating point rather than choosing the lowest-noise motor speed alone.
Medium
General ventilation air. Gas composition should be confirmed for special applications.
Temperature
Standard catalog reference: medium temperature not exceeding 60°C.
Dust Content
Standard reference condition: less than 100 mg/m³ and without excessive sticky material.
Corrosive / Humid Air
Material configuration should be reviewed separately for corrosive or humid service.
05 / Roof Installation
Roof Opening and Installation Matter as Much as Fan Size
01
Roof Opening
Confirm the available roof opening and mounting dimensions before final fan selection.
02
Roof Base
The supporting curb or base should match the fan footprint and roof structure.
03
Water Protection
Roof sealing, flashing and drainage around the fan base are part of the site installation.
04
Air Path
Check whether the fan exhausts directly through the roof or works with additional duct resistance.
Long ductwork or high system resistance?
DWT-Ⅰ is primarily a large-airflow, low-pressure roof fan. Higher-resistance systems should be reviewed before confirming this series.
06 / Application Fit
Typical DWT-Ⅰ Roof Ventilation Applications
Factories
Large-volume exhaust or general roof-level ventilation.
Warehouses
Roof exhaust for large storage spaces with low system resistance.
Equipment Buildings
Heat removal and air exchange from machinery and utility spaces.
Large Buildings
General supply or exhaust duties where rooftop axial ventilation is suitable.
07 / Before Selection
Information Required for DWT-Ⅰ Selection
01
Required Airflow
Required roof ventilation volume in m³/h or CFM.
02
System Pressure
Roof opening, louvers, dampers and duct resistance.
03
Roof Opening
Available opening size and mounting-base dimensions.
04
Noise Target
Project noise limit or nearby occupied-space requirement.
05
Air Condition
Temperature, humidity, dust and corrosive components.
06
Electrical
Voltage, frequency, phase and motor requirements.
Airflow known but pressure unknown?
Send the roof opening, ventilation area, louvers, duct arrangement and project drawings. Read the engineering guide →
08 / 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
Is DWT-Ⅰ the Right Roof Fan?
DWT-Ⅰ
Axial roof fan - larger airflow, lower pressure, general roof ventilation.
DWT-Ⅱ
Centrifugal roof fan - better suited to lower airflow with higher pressure requirements.
Axial Flow Fans
Browse other axial ventilation fan configurations.
09 / FAQ
DWT-Ⅰ Roof Fan Questions
What is a DWT-Ⅰ roof fan used for?
DWT-Ⅰ is used for large-volume rooftop supply or exhaust ventilation in factories, warehouses, workshops and other large buildings.
What is the difference between DWT-Ⅰ and DWT-Ⅱ?
DWT-Ⅰ is an axial-flow roof fan intended for high airflow and relatively low pressure. DWT-Ⅱ uses a centrifugal configuration for applications requiring more pressure.
What is the DWT-Ⅰ airflow range?
Published series data covers approximately 1,450 to 220,800 m³/h, depending on fan size and rotational speed.
Is DWT-Ⅰ suitable for high-pressure duct systems?
DWT-Ⅰ is primarily intended for large-airflow, low-pressure ventilation. Systems with significant duct or equipment resistance should be reviewed separately.
What information is needed to select a roof fan?
Provide required airflow, pressure or roof system information, roof opening dimensions, noise requirement, air condition, voltage, frequency and quantity.
Can the motor be supplied for different voltages and frequencies?
Yes. Motor selection can be reviewed according to voltage, frequency, phase and destination-market project requirements.
DWT-Ⅰ Roof Fan Selection
Send the Roof Ventilation Requirement. We Review the Fan.
Airflow · Pressure · Roof Opening · Noise Target · Air Condition · Voltage · Frequency · Quantity
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