What is the difference between standard DH and DHW models?

DHW models (e.g. DHW450 and DHW500) feature wider, high-capacity backward-curved impellers and larger motors, delivering higher airflow rates (up to 5,107 CFM) and operating at static pressures up to 3.50 in. wg (875 Pa).

What do the letters and numbers in the model code (e.g., DH355-4E) mean?

In 'DH355-4E': 'DH' designates Downblast centrifugal roof exhaust; '355' indicates the nominal impeller diameter in millimeters; '4' designates a 4-pole motor (~1,400 to 1,750 RPM); and 'E' designates Single-Phase 230V 60Hz power (whereas 'D' designates Three-Phase 230D/380Y/440Y 60Hz power).

What does Pmax mean in the Saudi Fan technical data table?

Pmax represents the Maximum Electrical Motor Input Power in kilowatts (kW) drawn by the external rotor motor at peak catalog load. It is an electrical power rating and should not be confused with pressure.

Why must fans be selected by duty-point CFM rather than maximum catalog CFM?

Maximum catalog CFM represents free-air discharge (0" static pressure). In real installations, duct friction, backdraft dampers, filters, and louvers generate static resistance. Fan selection must be made at the design operating point (CFM at static pressure) along the published fan curve.

What is the AMCA and UL certification status for Saudi Fan DH models?

The Saudi Fan Industries 2018 catalogue (Rev 03) references AMCA Sound and Air Performance ratings based on AMCA Publications 211 and 311. Furthermore, models DH225-2E, DH310-4E, DH355-4E, and DH400-4E carry UL 705 / CSA C22.2 listings (File no. E494511). Cloud Electricals confirms current project-specific license validity upon submittal.

How does 100% speed control work on Saudi Fan direct-drive motors?

Because the external rotor motor is positioned directly inside the moving airstream within the impeller hub, it receives superior cooling. This allows the motor voltage to be reduced from 100% down to 0% using 5-step autotransformers or electronic controllers without overheating.

Are standard Saudi Fan DH downblast fans explosion-proof?

No. Standard DH and DHW models are rated strictly for clean, non-hazardous ambient air up to 60°C (45°C on sizes 450/500). Applications requiring hazardous or explosive vapour exhaust (Zone 1/2, T1–T3) require factory-ordered explosion-proof motors with protection class 'e' (DIN 50019).

Can Saudi Fan DH downblast fans be used for commercial kitchen grease exhaust?

No. Commercial kitchen cooking grease hoods require vertical-discharge Upblast Roof Fans (such as the Saudi Fan DV series or UL 762 compliant Upblast Roof Fans) equipped with grease collection troughs and wash-down drain fittings to prevent grease accumulation on the roof.

What accessories are typically coordinated with Saudi Fan DH downblast fans?

Standard project accessories include prefabricated steel or aluminum roof curbs (sized to curb cap C), gravity or motorized backdraft dampers (sized to rough-in opening RO), 5-step autotransformer speed controllers, and local IP65 lockable disconnect switches.

Saudi Fan DH & DHW Series • 357 to 5,107 CFM (60Hz)

Saudi Fan DH Downblast Roof Fan

Q: What is the difference between Saudi Fan DH and DV roof fans?

DH and DHW are downblast centrifugal roof fans that discharge air downward around the roof curb perimeter with 360-degree weather shielding. DV and DVW are upblast roof fans that discharge air vertically away from the roof surface.

Official Saudi Fan Industries DH & DHW direct-drive centrifugal downblast roof exhaust fans (DH190 to DHW500) featuring external rotor motors, 100% voltage speed control, backward-curved aluminum wheels, and heavy-gauge weatherproof spun aluminum casings.

Request Quote on WhatsApp Call Technical Sales Download Saudi Fan DH/DV Catalogue PDF

In brief

What is the Saudi Fan DH downblast series?

The DH & DHW series is Saudi Fan Industries' direct-drive centrifugal roof exhaust range with downward 360-degree perimeter discharge. Powered by external rotor motors with Class F insulation, these fans offer 100% speed controllability, low starting current, and non-overloading backward-curved impellers for commercial and industrial clean air ventilation.

Saudi Fan DH direct-drive centrifugal downblast roof exhaust fan with spun aluminum weather cowl

Saudi Fan Downblast Roof Fan

13 verified 60Hz model configurations

Direct-drive external rotor motor (100% speed controllable)

Saudi Fan Industries project supply

Saudi Fan Downblast Roof Fan

Fan Category

Centrifugal Downblast Roof Fan

Product Series

Saudi Fan DH & DHW Series

Airflow Span

357 to 5,107 CFM (60Hz catalogue range)

Max Static Pressure

Up to 3.50 in. wg (875 Pa) on DHW500

Drive Type

Direct Drive External Rotor Motor

Speed Control

100% Voltage Controllable (5-Step Transformer)

Application Check

Is the Saudi Fan DH downblast fan suitable for your ventilation project?

Evaluate system static pressure, electrical supply, ambient temperature limits, and hazardous atmosphere separation.

Good fit

Commercial buildings, department stores, supermarkets, shopping malls, and dining halls
Warehouses, logistics hubs, and industrial manufacturing plants (clean air exhaust)
Enclosed parking garages, service stations, and mechanical equipment plant rooms
Agricultural structures, farm buildings, and commercial utility air relief

Confirm first

Operating duty point: select fan based on required CFM at system static pressure, not free-air maximum
Electrical supply: confirm single-phase (230V 60Hz) vs. three-phase (230D / 380Y / 440Y 60Hz)
Speed controller sizing: match full load amps (FLA) to 5-step autotransformer current rating
AMCA and UL scope: verify current project listing/seal requirements with Cloud Electricals

Use another documented fan

Commercial cooking grease hoods (select UL 762 compliant Upblast Roof Fan with grease drains)
High-temperature emergency fire smoke spill (select Civil Defence approved VDO Smoke Fan)
Hazardous ATEX / explosion-proof environments (requires certified explosion-proof motor option)
Corrosive acid fume extraction (select polypropylene or 316 stainless chemical exhaust fan)

Safety & Application Boundary Notice: CRITICAL ENGINEERING & HAZARDOUS SEPARATION NOTICE: Standard Saudi Fan DH/DHW models feature external rotor motors designed for clean, non-hazardous ambient air up to 60°C (45°C on sizes 450/500). Standard units are NOT explosion-proof. For flammable vapour or hazardous zones (Zone 1/2, T1–T3), specify factory-fitted explosion-proof motors with protection class 'e'. For commercial kitchen grease hoods, select vertical-discharge Upblast Roof Fans.

Airflow & Electrical Performance

Saudi Fan DH & DHW 60Hz Verified Specifications Table

Complete documented performance matrix across all 13 model configurations from the official Saudi Fan Industries catalogue.

Swipe horizontally to view all model specifications and duty points.

Model Code	Voltage / Phase (60Hz)	Pmax (kW)	Imax (A)	Max CFM (0" SP)	CFM @ 0.50" SP	CFM @ 1.00" SP	Roof Opening	Damper Size	IP / Class	Max Air Temp	Weight
DH190-2E	230V / 1-Ph	0.075 kW	0.34 A	357 CFM	228 CFM	108 CFM	220x220 mm	215x215 mm	IP44 / Cl. F	60°C	5.5 kg
DH225-2E	230V / 1-Ph	0.210 kW	0.95 A	758 CFM	562 CFM	390 CFM	220x220 mm	215x215 mm	IP44 / Cl. F	60°C	5.5 kg
DH310-4E	230V / 1-Ph	0.175 kW	0.76 A	1,110 CFM	735 CFM	320 CFM	291x291 mm	286x286 mm	IP44 / Cl. F	60°C	11.0 kg
DH310-4D	230D/380Y / 3-Ph	0.240 kW	0.65 A	1,148 CFM	810 CFM	410 CFM	291x291 mm	286x286 mm	IP54 / Cl. F	60°C	11.0 kg
DH355-4E	230V / 1-Ph	0.430 kW	1.95 A	1,577 CFM	1,140 CFM	720 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	60°C	21.0 kg
DH355-4D	380V / 3-Ph	0.320 kW	0.85 A	1,537 CFM	1,160 CFM	690 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	60°C	21.0 kg
DH400-4E	230V / 1-Ph	0.740 kW	3.30 A	2,137 CFM	1,780 CFM	1,380 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	60°C	23.0 kg
DH400-4D	230D/380Y / 3-Ph	0.660 kW	1.60 A	2,319 CFM	1,880 CFM	1,410 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	60°C	23.0 kg
DH450-4E	230V / 1-Ph	1.500 kW	6.70 A	3,395 CFM	3,080 CFM	2,520 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	45°C	32.0 kg
DH450-4D	230D/380Y / 3-Ph	1.200 kW	2.70 A	3,395 CFM	3,000 CFM	2,460 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	60°C	32.0 kg
DHW450-4E	230V / 1-Ph	1.650 kW	7.20 A	3,833 CFM	3,420 CFM	2,900 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	45°C	32.0 kg
DHW450-4D	230D/380Y / 3-Ph	1.500 kW	3.40 A	4,349 CFM	3,920 CFM	3,420 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	50°C	32.0 kg
DHW500-4D	230D/380Y/440Y	2.500 kW	5.60 A	5,107 CFM	4,820 CFM	4,450 CFM	443x443 mm	438x438 mm	IP54 / Cl. F	45°C	43.0 kg

Model Code & Power Clarifications: (1) Pmax (kW) represents the Maximum Electrical Motor Input Power drawn at peak load, not static pressure. (2) Suffix 'E' = Single-Phase 230V 60Hz; Suffix 'D' = Three-Phase 230D / 380Y / 440Y 60Hz. (3) AMCA & UL Scope: Performance ratings based on AMCA Publication 211 & 311 procedures (2018 catalogue). Models DH225-2E to DH400-4E listed under UL 705 (File E494511).

Dimensions & Opening Schedule

Saudi Fan DH Architectural Dimensions & Opening Schedule

Dimensions in millimeters for roof curb rough-in, curb cap landing, and gravity damper sizing.

Swipe horizontally to view all dimensional values.

Model Series	Base Plate A (mm)	Curb Cap C (mm)	Cowl Dia. B (mm)	Height H (mm)	Roof Opening (RO)	Damper Size	Weight (kg)
DH 190 / DH 225	355 x 355 mm	332 x 332 mm	484 mm (Dia)	200 mm	220 x 220 mm	215 x 215 mm	5.5 kg
DH 310	450 x 450 mm	434 x 434 mm	598 mm (Dia)	280 mm	291 x 291 mm	286 x 286 mm	11.0 kg
DH 355 / DH 400	630 x 630 mm	598 x 598 mm	800 mm (Dia)	380 mm	443 x 443 mm	438 x 438 mm	21.0 - 23.0 kg
DH 450 / DHW 450	630 x 630 mm	663 x 663 mm	865 mm (Dia)	475 mm	443 x 443 mm	438 x 438 mm	32.0 kg
DHW 500	630 x 630 mm	663 x 663 mm	865 mm (Dia)	475 mm	443 x 443 mm	438 x 438 mm	43.0 kg

1. Roof Curb Construction

Build concrete or prefabricated curb minimum 300 mm above finished roof level matching curb cap C (332 to 663 mm).

2. Damper Coordination

Coordinate square gravity or motorized backdraft dampers: 215x215 mm (DH190/225), 286x286 mm (DH310), or 438x438 mm (DH355-DHW500).

3. Perimeter Weather Gasket

Apply continuous closed-cell EPDM gasket tape along the curb top landing before bolting the aluminum curb cap.

4. 5-Step Speed Controller

Install matching 5-step autotransformer speed controller and local IP65 lockable disconnect switch.

Engineering Architecture

Saudi Fan External Rotor Technology & Weather Protection

Engineered for high aerodynamic efficiency, compact dimensions, zero belt maintenance, and 100% voltage speed control.

Direct-Drive External Rotor Motor

Compact motor integrated directly within the backward-curved impeller hub, ensuring exceptional cooling, zero belt losses, and low starting currents.

Backward-Curved Aluminum Impeller

Aerodynamically balanced aluminum backward-curved centrifugal impeller delivers high static pressure efficiency with non-overloading power characteristics.

Spun Aluminum Weatherproof Casing

Heavy-gauge corrosion-resistant spun aluminum cowl, curb cap, and wind band with built-in bird screen designed for harsh outdoor desert environments.

100% Variable Voltage Speed Control

External rotor design enables smooth, 100% stepless or 5-step voltage speed control using matching autotransformer or electronic thyristor controllers.

Key Features

Saudi Fan DH Downblast Engineering Highlights

Precision manufacturing by Saudi Fan Industries under EN ISO 9001:2015 quality assurance management.

Direct-drive external rotor motor architecture eliminates belt slippage, alignment, and wear

Complete 60Hz model range (DH190 to DHW500) covering 357 to 5,107 CFM at up to 3.50 in. wg SP

100% speed controllable across operating range using optional 5-step autotransformer controller

Heavy-gauge corrosion-resistant aluminum housing with integral bird screen and wind band

Built-in thermal overload protection contacts wired directly in series with motor windings

Permanently lubricated, over-dimensioned sealed ball bearings on both sides for long service life

Ingress protection IP44 (sizes 190–310 single-phase) and IP54 (three-phase and larger models)

AMCA Sound and Air Performance certification & optional UL 705 listed models referenced in catalogue

Specifications

Category Technical Specifications

Comprehensive engineering specifications for Saudi Fan DH and DHW downblast centrifugal roof exhaust fans.

Swipe horizontally to compare all specifications.

Specification	Engineering Details
Product Category	Roof Fan
Product Type	Direct Drive Downblast Centrifugal Roof Exhaust Fan
Brand / Series	Saudi Fan Industries DH & DHW Series
Installation Mounting	Rooftop curb mounting with perimeter flashing flange
Air Discharge Type	Downblast (360-degree downward perimeter discharge)
Airflow Range (0" SP)	357 to 5,107 CFM across 13 model configurations
Static Pressure Capability	Tested from 0" up to 3.50" in. wg (0 to 875 Pa) on DHW500
Motor Technology	External rotor direct-drive motor with Class F insulation
Speed Control Method	100% voltage controllable via 5-step autotransformer or electronic regulator
Electrical Supply Options	Single-phase 230V / 60Hz ('E') or Three-phase 230D / 380Y / 440Y 60Hz ('D')
Motor Ingress Protection	IP44 (sizes 190–310 1-Ph) / IP54 (three-phase and sizes 355–500)
Maximum Air Temperature	60°C continuous (45°C on DH450-4E, DHW450-4E, DHW500-4D; 50°C on DHW450-4D)
Casing Construction	Heavy-gauge spun aluminum shroud, curb cap, and wind band with bird screen
Compliance Documentation	Catalogue PDF, AMCA/UL reference, SASO COC, CR, and VAT certificates

Inclusions & Options

Standard Inclusions vs. Optional Accessories

Clear distinction between factory-included standard equipment and optional project mounting accessories.

Standard Inclusions (Base Package)

Included with every Saudi Fan DH/DHW unit from the factory

Spun Aluminum Downblast Cowl & Shroud
Heavy-Gauge Aluminum Curb Mounting Cap
Backward-Curved Centrifugal Aluminum Impeller
Direct-Drive External Rotor Motor (IP44 / IP54, Class F)
Galvanized Protective Wire Bird Screen
IP55 Weatherproof Electrical Terminal Enclosure

Optional Accessories (Project Coordinated)

Specify during quotation review according to site mounting requirements

Prefabricated Steel / Aluminum Roof Curb (Matching Curb Cap C)
Gravity Backdraft Damper (Square Rough-In Sizing)
Motorized Actuated Backdraft Damper (230V / 24V)
5-Step Autotransformer Speed Controller (1-Phase / 3-Phase)
Local Lockable IP65 Electrical Disconnect Switch
Sound-Absorbing Curb Upstand Liner

Applications

Where Saudi Fan DH Downblast Fans Are Installed

Weather-protected rooftop centrifugal exhaust across commercial buildings, logistics warehouses, and industrial production plants.

Commercial department stores

Removes: High-volume air exchange, solar heat buildup, and indoor humidity

Warehouses & logistics

Removes: Stagnant heat and general ventilation air through downward roof discharge

Industrial manufacturing plants

Removes: Clean process heat, equipment exhaust, and factory ambient air

Supermarkets & retail malls

Removes: General roof air relief with weather-shielded downblast airflow

Enclosed parking garages

Removes: Warm air, light vehicular exhaust, and general ventilation air

Mechanical plant rooms

Removes: Compressor heat, chiller room ambient air, and electrical substation warmth

Agricultural & farm facilities

Removes: Humid air and thermal load in livestock and storage utility barns

MEP project ventilation

Removes: Supplied with exact DH/DHW model, duty point, and Saudi compliance docs

Airstream & discharge boundary: Saudi Fan DH fans are engineered exclusively for downward discharge of clean ambient air (≤ 60°C). For commercial cooking grease hoods requiring vertical discharge and grease collection, select a Saudi Fan DV Upblast Roof Fan. For high-capacity industrial belt-drive downblast duty, select an RCD Downblast Roof Fan. For low-cost un-ducted mechanical room exhaust, select an RMD Axial Roof Fan.

Selection support

What to Send for Correct Saudi Fan DH Selection

Provide design airflow (CFM) at system static pressure, preferred DH/DHW model, electrical voltage & phase, roof curb dimensions, speed controller requirements, and project city in Saudi Arabia.

Required exhaust airflow (CFM) at system static pressure (in. wg / Pa)

Exact model code preference (e.g. DH355-4E vs. DH355-4D vs. DHW450-4D)

Electrical supply: single-phase 230V 60Hz ('E') vs. three-phase 380V 60Hz ('D')

Roof opening and curb cap outside dimension (C dimension: 332 to 663 mm)

Matching gravity or motorized backdraft damper size (215 to 438 mm square)

Speed controller requirement (5-step autotransformer matching motor FLA)

Airstream temperature check: clean ambient air <= 60°C (45°C on 450/500 models)

Quantity of fans required per roof zone

Project city and delivery schedule in Saudi Arabia

Submittal compliance requirements (Datasheet, AMCA/UL scope, CR, VAT, COC)

Downloads

Documents & Procurement Files

Download the official Saudi Fan DH/DV catalogue PDF and request technical submittal packages for engineering approvals.

Saudi Fan DH/DV Roof Fan Catalogue — Rev 03 (2018) PDFDownload PDF

Saudi Fan DH Technical Submittal & Performance CurvesRequest Submittal

Cloud Electricals Company ProfileRequest Profile

Saudi Commercial Compliance (CR/VAT/COC)Request Compliance Docs

Saudi Fan AMCA & UL 705 Verification ScheduleRequest Certification Schedule

Related Commercial & Industrial Fans

Explore other rooftop and wall-mounted exhaust fan categories for complete project ventilation schedules.

Saudi Fan DV Upblast Roof Fan

Downblast Roof Fan

Centrifugal Roof Fan

RMD Direct Drive Axial Roof Fan

FAQ

Saudi Fan DH Downblast Questions

Answers for HVAC consultants, MEP contractors, and building procurement engineers reviewing Saudi Fan DH & DHW downblast roof exhaust fans in Saudi Arabia.

DH and DHW are downblast centrifugal roof fans that discharge air downward around the roof curb perimeter with 360-degree weather shielding. DV and DVW are upblast roof fans that discharge air vertically away from the roof surface.

Quotation Request

Request Saudi Fan DH Downblast Roof Fan Quotation

Send your required Saudi Fan DH/DHW model (DH190 to DHW500), design airflow (CFM), static pressure (in. wg / Pa), voltage/phase (230V 1-Ph vs. 380V 3-Ph), and project city in Saudi Arabia.

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