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RAFAVENT CENTRIFUGAL FAN SUBFAMILY

Backward-Curved Double-Inlet Centrifugal Fans

Double-inlet centrifugal arrangement for duties requiring balanced two-sided air entry.

RAFAVENT backward-curved double-inlet centrifugal fan with belt drive
Representative belt-driven configuration. Belt and pulley guards must be fitted before operation.

RAFAVENT RF-CF-BCD SERIES

Backward-Curved Double-Inlet Centrifugal Fans — Technical Selection Data

Double-width, double-inlet backward-curved centrifugal fans for AHUs, base-mounted ventilation assemblies and large-volume MEP air systems.

RAFAVENT Engineering Calculation — Preliminary Selection — Non-Certified. Values are calculated at 20 °C and standard air density 1.20 kg/m³ using fan-law scaling and engineering assumptions. They are not laboratory-certified ratings. Airflow, pressure, power and sound values are not simultaneous guarantees. Final selection requires a confirmed duty point, inlet arrangement, drive side and approved production drawing.

Construction and application

  • Double-width scroll casing with two unobstructed inlets and a backward-curved steel impeller.
  • Shaft carried by bearings on both casing sides; bearing selection, service access and lubrication arrangement are confirmed by order.
  • Belt-drive preliminary basis with motor on base frame. State drive side when viewed from the inlet and confirm rotation/discharge orientation.
  • Three-phase IEC motor basis, IP55 and Class F specification subject to the approved motor datasheet.
  • Clean or lightly dust-laden non-corrosive air, preliminary ambient duty −20 to +50 °C. No ATEX, smoke or high-temperature certification is claimed.
  • Standard model series Ø200–Ø800. Larger construction up to Ø1600 is custom capability only after engineering review and is not a standard catalogued model.

Model selection table

ModelWheel Ø mmrpmRecommended Q m³/hRecommended Ps PaCalculated max QCalculated peak PsEst. shaft kWPreliminary motor selection kWSupplyEst. LpA @3m dB(A)Drive basis
RF-CF-BCD-2002001450194–35440–854321000.010.12230/400 V 3Ph52 ±6Belt drive; drive side by order
RF-CF-BCD-2502501450379–69162–1328431560.030.12230/400 V 3Ph52 ±6Belt drive; drive side by order
RF-CF-BCD-3153151450759–1,38299–2101,6862470.080.12230/400 V 3Ph53 ±6Belt drive; drive side by order
RF-CF-BCD-35535514501,086–1,979126–2672,4133140.150.18230/400 V 3Ph55 ±6Belt drive; drive side by order
RF-CF-BCD-40040014501,553–2,831159–3393,4523980.280.37230/400 V 3Ph57 ±6Belt drive; drive side by order
RF-CF-BCD-45045014502,212–4,031202–4294,9155040.50.75230/400 V 3Ph59 ±6Belt drive; drive side by order
RF-CF-BCD-50050014503,034–5,529249–5296,7426230.851.1230/400 V 3Ph62 ±6Belt drive; drive side by order
RF-CF-BCD-56056014504,263–7,768312–6649,4737811.52.2230/400 V 3Ph64 ±6Belt drive; drive side by order
RF-CF-BCD-63063014506,069–11,060395–84013,4889882.74400/690 V 3Ph66 ±6Belt drive; drive side by order
RF-CF-BCD-7107109605,752–10,481220–46812,7825501.422.2230/400 V 3Ph62 ±6Belt drive; drive side by order
RF-CF-BCD-8008009608,228–14,993279–59418,2856992.583230/400 V 3Ph64 ±6Belt drive; drive side by order

Recommended flow and pressure ranges define an intended preliminary selection envelope; they are not opposite corners of a guaranteed duty point. Estimated free-field A-weighted sound pressure at 3 m has ±6 dB(A) uncertainty before casing, duct, reflection, inlet, outlet, belt guard, silencer and system effects.

Calculated model curves

Open a model to view its six-point preliminary Q–Ps curve.

RF-CF-BCD-200 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
1072
28692
3173100
425986
534552
64320
RF-CF-BCD-250 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10112
2169143
3337156
4506134
567481
68430
RF-CF-BCD-315 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10178
2337227
3674247
41,012212
51,349128
61,6860
RF-CF-BCD-355 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10226
2483289
3965314
41,448270
51,931163
62,4130
RF-CF-BCD-400 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10287
2690367
31,381398
42,071343
52,762207
63,4520
RF-CF-BCD-450 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10363
2983464
31,966504
42,949434
53,932262
64,9150
RF-CF-BCD-500 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10448
21,348573
32,697623
44,046535
55,394324
66,7420
RF-CF-BCD-560 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10562
21,895718
33,789781
45,684672
57,578406
69,4730
RF-CF-BCD-630 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10712
22,698909
35,395988
48,093850
510,790514
613,4880
RF-CF-BCD-710 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10396
22,556506
35,113550
47,669473
510,225286
612,7820
RF-CF-BCD-800 — calculated Q–Ps curve
Airflow Q (m³/h)Static pressure Ps (Pa)
PointQ (m³/h)Ps (Pa)
10503
23,657643
37,314699
410,971601
514,628363
618,2850

Selection requirements

Confirm airflow, static pressure, air density, temperature, conveyed-air composition, both inlet conditions, base/AHU arrangement, drive side, rotation and discharge position, pulley ratio, motor voltage, control method, corrosion class, permissible sound level, access space and accessories before order.

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