RAFAVENT CENTRIFUGAL FAN SUBFAMILY
Double-Inlet Forward-Curved Centrifugal Fans
Double-inlet, double-width forward-curved centrifugal fans for high-volume low-to-medium-pressure ventilation duties.
DIDW · DOUBLE INLET · DOUBLE WIDTHPreliminary engineering data
CONSTRUCTION AND APPLICATION
Forward-curved double-inlet arrangement
Balanced air entry from both sides into one double-width multi-blade forward-curved wheel.
External shaft and bearings; belt-drive selection requires separate fan and motor speeds, pulley pitch diameters and transmission review.
AHUs, cabinet ventilation, clean-air supply and extract systems requiring higher volume at low-to-medium pressure.
Wheel balancing, shaft and bearing verification, belt-load review, vibration acceptance and confirmed discharge orientation.
Calculated scenario summary
| Study ID | Wheel Ø mm | Fan rpm | Sample Q m³/h | Pt Pa | Ps Pa | Max assumed shaft kW | Motor budget kW |
|---|---|---|---|---|---|---|---|
| SC-FWD-DI-310 | 310 | 1129.0 | 8,611–11,301 | 474–522 | 234–383 | 3.31 | 5.5 |
| SC-FWD-DI-350 | 350 | 1000.0 | 10,976–14,406 | 474–522 | 234–383 | 4.22 | 5.5 |
| SC-FWD-DI-400 | 400 | 875.0 | 14,336–18,816 | 474–522 | 234–383 | 5.51 | 7.5 |
| SC-FWD-DI-450 | 450 | 777.8 | 18,144–23,814 | 474–522 | 234–383 | 6.97 | 11 |
| SC-FWD-DI-500 | 500 | 700.0 | 22,400–29,400 | 474–522 | 234–383 | 8.61 | 11 |
| SC-FWD-DI-560 | 560 | 625.0 | 28,099–36,879 | 474–522 | 234–383 | 10.80 | 15 |
| SC-FWD-DI-630 | 630 | 555.6 | 35,562–46,675 | 474–522 | 234–383 | 13.66 | 18.5 |
| SC-FWD-DI-710 | 710 | 493.0 | 45,167–59,282 | 474–522 | 234–383 | 17.35 | 22 |
Study IDs are engineering scenarios, not released sales model codes. Similar pressure ranges result from the constant tip-speed assumption and do not represent eight independent tests.
Six-point calculated data
SC-FWD-DI-310 — six-point calculated Q–pressure–power data
| Point | Q m³/h | Pt Pa | Ps Pa | Assumed shaft kW |
|---|---|---|---|---|
| 1 | 8,611 | 522 | 383 | 2.77 |
| 2 | 9,149 | 517 | 360 | 2.92 |
| 3 | 9,687 | 509 | 333 | 3.05 |
| 4 | 10,225 | 500 | 304 | 3.16 |
| 5 | 10,763 | 489 | 272 | 3.25 |
| 6 | 11,301 | 474 | 234 | 3.31 |
Sampled interval only; no extrapolation. Assumed efficiency 45%. Motor budget covers these six study points only, is not a purchase specification, and is not guaranteed conservative.
SC-FWD-DI-350 — six-point calculated Q–pressure–power data
| Point | Q m³/h | Pt Pa | Ps Pa | Assumed shaft kW |
|---|---|---|---|---|
| 1 | 10,976 | 522 | 383 | 3.54 |
| 2 | 11,662 | 517 | 360 | 3.72 |
| 3 | 12,348 | 509 | 333 | 3.88 |
| 4 | 13,034 | 500 | 304 | 4.03 |
| 5 | 13,720 | 489 | 272 | 4.14 |
| 6 | 14,406 | 474 | 234 | 4.22 |
Sampled interval only; no extrapolation. Assumed efficiency 45%. Motor budget covers these six study points only, is not a purchase specification, and is not guaranteed conservative.
SC-FWD-DI-400 — six-point calculated Q–pressure–power data
| Point | Q m³/h | Pt Pa | Ps Pa | Assumed shaft kW |
|---|---|---|---|---|
| 1 | 14,336 | 522 | 383 | 4.62 |
| 2 | 15,232 | 517 | 360 | 4.86 |
| 3 | 16,128 | 509 | 333 | 5.07 |
| 4 | 17,024 | 500 | 304 | 5.26 |
| 5 | 17,920 | 489 | 272 | 5.41 |
| 6 | 18,816 | 474 | 234 | 5.51 |
Sampled interval only; no extrapolation. Assumed efficiency 45%. Motor budget covers these six study points only, is not a purchase specification, and is not guaranteed conservative.
SC-FWD-DI-450 — six-point calculated Q–pressure–power data
| Point | Q m³/h | Pt Pa | Ps Pa | Assumed shaft kW |
|---|---|---|---|---|
| 1 | 18,144 | 522 | 383 | 5.84 |
| 2 | 19,278 | 517 | 360 | 6.15 |
| 3 | 20,412 | 509 | 333 | 6.42 |
| 4 | 21,546 | 500 | 304 | 6.66 |
| 5 | 22,680 | 489 | 272 | 6.85 |
| 6 | 23,814 | 474 | 234 | 6.97 |
Sampled interval only; no extrapolation. Assumed efficiency 45%. Motor budget covers these six study points only, is not a purchase specification, and is not guaranteed conservative.
SC-FWD-DI-500 — six-point calculated Q–pressure–power data
| Point | Q m³/h | Pt Pa | Ps Pa | Assumed shaft kW |
|---|---|---|---|---|
| 1 | 22,400 | 522 | 383 | 7.22 |
| 2 | 23,800 | 517 | 360 | 7.60 |
| 3 | 25,200 | 509 | 333 | 7.92 |
| 4 | 26,600 | 500 | 304 | 8.22 |
| 5 | 28,000 | 489 | 272 | 8.45 |
| 6 | 29,400 | 474 | 234 | 8.61 |
Sampled interval only; no extrapolation. Assumed efficiency 45%. Motor budget covers these six study points only, is not a purchase specification, and is not guaranteed conservative.
SC-FWD-DI-560 — six-point calculated Q–pressure–power data
| Point | Q m³/h | Pt Pa | Ps Pa | Assumed shaft kW |
|---|---|---|---|---|
| 1 | 28,099 | 522 | 383 | 9.05 |
| 2 | 29,855 | 517 | 360 | 9.53 |
| 3 | 31,611 | 509 | 333 | 9.94 |
| 4 | 33,367 | 500 | 304 | 10.31 |
| 5 | 35,123 | 489 | 272 | 10.60 |
| 6 | 36,879 | 474 | 234 | 10.80 |
Sampled interval only; no extrapolation. Assumed efficiency 45%. Motor budget covers these six study points only, is not a purchase specification, and is not guaranteed conservative.
SC-FWD-DI-630 — six-point calculated Q–pressure–power data
| Point | Q m³/h | Pt Pa | Ps Pa | Assumed shaft kW |
|---|---|---|---|---|
| 1 | 35,562 | 522 | 383 | 11.46 |
| 2 | 37,785 | 517 | 360 | 12.06 |
| 3 | 40,008 | 509 | 333 | 12.58 |
| 4 | 42,230 | 500 | 304 | 13.04 |
| 5 | 44,453 | 489 | 272 | 13.42 |
| 6 | 46,675 | 474 | 234 | 13.66 |
Sampled interval only; no extrapolation. Assumed efficiency 45%. Motor budget covers these six study points only, is not a purchase specification, and is not guaranteed conservative.
SC-FWD-DI-710 — six-point calculated Q–pressure–power data
| Point | Q m³/h | Pt Pa | Ps Pa | Assumed shaft kW |
|---|---|---|---|---|
| 1 | 45,167 | 522 | 383 | 14.55 |
| 2 | 47,990 | 517 | 360 | 15.32 |
| 3 | 50,813 | 509 | 333 | 15.98 |
| 4 | 53,636 | 500 | 304 | 16.57 |
| 5 | 56,459 | 489 | 272 | 17.05 |
| 6 | 59,282 | 474 | 234 | 17.35 |
Sampled interval only; no extrapolation. Assumed efficiency 45%. Motor budget covers these six study points only, is not a purchase specification, and is not guaranteed conservative.
Calculation basis and limitations
- Reference basis: Kruger FDA 500 curve readings at 900 rpm; reference manufacturer remains identified and is not presented as RAFAVENT test data.
- Density 1.20 kg/m³; geometrically similar scaling; constant diameter × speed; assumed total efficiency 45%, transmission efficiency 95% and 15% motor margin.
- Static pressure equals total pressure minus calculated outlet velocity pressure using an assumed scaled discharge area.
- Motor output is not shaft power. Final absorbed-power review across the operating range is mandatory.
- No LpA at 3 m is stated because available reference sound data must not be converted into a RAFAVENT product claim without defined installation and test conditions.
- Double-inlet is not the same as a twin-fan assembly.
Technical documents, dimensions and service
Technical documents and dimensions
Final dimensions, connection details, materials, motor data and project drawings are issued for the selected configuration after engineering review.
Installation and maintenance
Provide level support, flexible connections, guarded drive components, alignment checks and safe maintenance access. Follow the approved project-specific O&M document.
Selection tables and calculated curves on this page are preliminary engineering guidance, not certified RAFAVENT test ratings. Confirm the operating point and controlled documents before order.
Information required before selection
- Required airflow and static pressure
- Operating temperature and conveyed-air composition
- Installation orientation, space and connection details
- Electrical supply, control method and duty pattern
- Sound, material and environmental constraints
Request an engineering selection
Send the duty point, installation arrangement, operating conditions and available drawings for a project-specific selection.
Send project requirements