The 4-68 centrifugal ventilation fan is a general-purpose series for factory and large-building ventilation. The original catalogue covers No.2.8A through No.20B with A, C, D and B drive arrangements.
Standard catalogue duty is for air or other non-self-igniting, non-explosive, non-volatile and non-corrosive gas without sticky material. Dust and hard-particle content should not exceed 150 mg/m³, and gas temperature should not exceed 80°C.
Final model, speed, motor, rotation, discharge position and installation dimensions should be confirmed from the actual duty point and selected drive arrangement.
Large-Airflow General Ventilation Across Multiple Fan Sizes
The 4-68 series is positioned for factory ventilation, large-building ventilation, workshop air exchange, warehouse circulation, equipment-room exhaust and other general air-handling duties where a broad size and drive range is useful.
The original catalogue covers small direct-drive A-type fans, medium and large C-type belt-drive and D-type coupling-drive fans, and large B-type belt-drive units. This lets one series cover different installation layouts and airflow levels.
For workshop and building ventilation planning, review the Industrial Workshop Ventilation System. Final selection should then be confirmed from airflow, pressure, medium, temperature, drive arrangement, motor and installation space.
4-68 Series Technical Parameters
A, C, D and B Drive Arrangements by Fan Size
The original catalogue separates the series by fan size and transmission form. The arrangement below should be used as the first screening step before speed, motor, foundation and service-space review.
No.2.8 / 3.15 / 3.55 / 4 / 4.5 / 5
Direct-drive arrangement for the small-size group.
No.6.3 / 8 / 10 / 12.5
Belt-drive arrangement with separate shaft, pulley and motor transmission.
No.6.3 / 8 / 10 / 12.5
Coupling-drive arrangement with separate shaft and bearing support.
No.16 / 20
Large-size belt-drive arrangement with V-belt and pulley selection.
When 4-68 Fits - and When Another Fan Series Should Be Reviewed
Suitable for Ordinary Ventilation Conditions
Air or other non-self-igniting, non-explosive, non-volatile, non-corrosive gas; no sticky material; dust and hard particles ≤150 mg/m³; gas temperature ≤80°C.
Review Another Material or Fan Family
Corrosive gas, gas above 80°C, sticky material, dust / hard particles above 150 mg/m³, explosive or volatile gas, or process conditions outside the standard catalogue boundary.
4-68 Performance Range and Model Coverage
The original catalogue contains model-specific performance tables across the 4-68 range. The values below describe the overall documented envelope and drive-family coverage rather than one operating point.
Reference condition: air temperature 20°C, density 1.2 kg/m³ and atmospheric pressure 101325 Pa. Final selection must match airflow and pressure from the same model and speed row.
| Item | Catalogue Range | Selection Meaning |
|---|---|---|
| Model Range | No.2.8A–No.20B | Small through very large general ventilation duties. |
| Airflow | 565–239,654 m³/h | Match airflow with the pressure from the same catalogue duty row. |
| Total Pressure | 166–3,863 Pa | Do not select by airflow alone. |
| Speed | 250–2900 r/min | Varies by fan size and drive arrangement. |
| Motor Power | 0.55–220 kW | Varies with model, speed and operating point. |
| Group | Catalogue Sizes | Drive Arrangement | Selection Note |
|---|---|---|---|
| A Type | 2.8 / 3.15 / 3.55 / 4 / 4.5 / 5 | Direct drive | Small-size group. |
| C Type | 6.3 / 8 / 10 / 12.5 | Belt drive | Check pulley, belt, motor position and service space. |
| D Type | 6.3 / 8 / 10 / 12.5 | Coupling drive | Check coupling, shaft arrangement, base and alignment. |
| B Type | 16 / 20 | Large-size belt drive | Check foundation, belt transmission and motor capacity. |
4-68 Outline and Installation Dimensions
Use the drawing together with the selected fan model and drive arrangement before foundation, duct, motor-base or support fabrication. Final dimensions should be confirmed from the approved project drawing.
No.2.8-5
Direct-drive outline and foundation data are covered by the catalogue.
No.6.3-12.5
Belt-drive and coupling-drive groups have corresponding installation drawings.
Multiple Angles
Catalogue drawings for No.8 / 10 / 12.5 include discharge-position installation references.
No.16 / 20
Large-size tables include inlet / outlet dimensions, outline data, foundation information and weight excluding motor.
For guidance on checking installation interfaces, see the Industrial Fan GA Drawing Guide.
Select From Airflow + Pressure + Working Condition
Airflow
Required m³/h, m³/s or CFM.
Pressure
Static or total pressure at the required airflow.
Medium
Confirm gas condition, dust / particles, corrosion and whether sticky material is present.
Temperature
Normal and maximum gas temperature; standard 4-68 catalogue duty is ≤80°C.
Drive & Motor
A / C / D / B arrangement plus voltage, frequency, phase and motor protection.
Installation
Rotation, discharge position, duct interface, foundation and available service space.
If system pressure is not yet confirmed, use the Static Pressure Unknown Guide and send duct length, duct size, elbows, filters and other resistance information.
Factory Ventilation, Building Air Exchange and General Industrial Air Handling
Factory Ventilation
General supply or exhaust ventilation for production buildings and large workshops.
Large Building Ventilation
Large-volume air exchange for industrial or utility buildings.
Warehouse Air Circulation
General circulation and exhaust where the conveyed medium remains within standard catalogue limits.
Equipment Room Exhaust
Heat-removal or general exhaust for machinery and utility spaces.
Drying / Process Air Circulation
Large-volume, lower-pressure circulation can be reviewed when actual inlet-gas conditions remain within the confirmed 4-68 limits. View Drying Oven Application →
Replacement Projects
Old fan nameplate, motor data, photos, dimensions, rotation and outlet position can be used to review a replacement.
4-68 Centrifugal Ventilation Fan FAQ
What is the 4-68 centrifugal ventilation fan used for?
It is used for factory ventilation, workshop air exchange, warehouse circulation, large-building ventilation and general industrial air supply or exhaust.
What model range is covered by the original catalogue?
The documented series extends from No.2.8A through No.20B, with A, C, D and B drive arrangements.
Can 4-68 be used for dusty or corrosive gas?
Standard catalogue duty allows dust / hard particles up to 150 mg/m³ with no sticky material and no corrosive, explosive or volatile gas. Conditions outside this boundary require another configuration or fan-series review.
What is the standard gas-temperature limit?
The original catalogue states that gas temperature should not exceed 80°C for the standard 4-68 duty.
What reference condition is used for catalogue performance?
The catalogue states 20°C air temperature, air density 1.2 kg/m³ and atmospheric pressure 101325 Pa.
What information should I send before quotation?
Send airflow, pressure, medium, temperature, drive preference, rotation, discharge position, voltage, frequency, quantity and any drawing or replacement information available.
Send the Required Airflow and Pressure
Send airflow, total or static pressure, medium, temperature, voltage, frequency, drive requirement, rotation, discharge position, quantity and destination. For replacement projects, attach the old fan nameplate, photos and available dimensions.
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