Centrifugal fan DDM 12/12 E6G3702 1F 6P in BOX

Nicotra Gebhardt DDM 12/12 E6G3702 1F 6P double-width double-inlet centrifugal fan delivered as a complete assembly — DWDI fan with ERM motor pre-mounted and aligned inside an acoustic plenum BOX enclosure. It is the 6-pole motor variant of the DDM 12/12 range — and this pole count difference completely defines the product's application profile.

Why 6-pole instead of 4-pole — the essential difference

The number of poles in an asynchronous motor determines the synchronous speed at 50Hz:

The E6G3702 6-pole motor operates at approximately 900 rpm — around 35% slower than the equivalent 4-pole variant. The direct impact on the installation:

Significantly reduced noise. Aerodynamic fan noise varies approximately with the fifth power of impeller tip speed. Reducing speed by 35% produces an 8–12 dB(A) reduction compared to the 4-pole variant — a substantial difference clearly perceptible to the human ear, equivalent to a fan perceived as 2–3 times quieter.

Lower energy consumption. Fan power consumption varies with the cube of speed — at 900 rpm versus 1,400 rpm, consumption falls to approximately 27% of the 4-pole variant at the same airflow point. A major advantage for installations running 24/7.

Reduced mechanical wear. ERM bearings running at 900 rpm instead of 1,400 rpm have a significantly longer service life — centrifugal forces and friction are lower, the motor runs cooler.

The trade-off: maximum airflow and static pressure are lower than the 4-pole variant. The DDM 12/12 6-pole is the correct choice for installations with low hydraulic resistance (short ducts, few bends, low-resistance grilles) where the required airflow falls within the operating curve at 900 rpm.

ERM motor E6G3702 — construction and advantages

The external rotor motor of the DDM series has the rotor surrounding the fixed stator — the fan impeller is mounted directly on the rotor, without a separate transmission shaft. Compared to conventional internal rotor motors: zero mechanical transmission losses, compact axial footprint, permanently lubricated pre-loaded ball bearings, single-phase 230V / 50Hz, IP54, Class F insulation (155°C winding resistance), integrated automatic-reset thermal protection.

Acoustic BOX enclosure — acoustic isolation for sensitive spaces

The fan is supplied pre-mounted in the acoustic BOX. This solves the noise transmission problem — especially relevant for a model chosen specifically for its quiet operation. Aluminium profile load-bearing frame, galvanised steel panels with polyurethane insulating core, all panels screwed for rapid disassembly, removable side panel for direct access to motor, terminal box and impeller, configurable air connections in multiple orientations.

The combination of 6-pole motor at ~900 rpm + acoustic BOX enclosure produces the lowest noise level available in the DWDI 12/12 category in the ventilation.ro catalogue.

DDM 12/12 range comparison:

FAQ — EN

How much quieter is it than the DDM 12/12 4-pole variant? The 6-pole motor (~900 rpm) produces 8–12 dB(A) less aerodynamic noise than the 4-pole motor (~1,400 rpm) at equivalent size. Adding the acoustic BOX enclosure, the difference compared to a bare-mounted DDM 12/12 4-pole can exceed 15–20 dB(A) in the installation space — equivalent to a fan perceived as 4–6 times quieter.

Does it have lower airflow than the 4-pole variant? Yes — at the lower speed of ~900 rpm, maximum airflow and static pressure are lower than the 4-pole variant. This is the correct solution for installations with low hydraulic resistance. Contact us with your installation layout and required airflow to confirm the DDM 12/12 6P fits your project operating point.

Can it be connected to a speed controller? Yes — the single-phase ERM 6-pole motor can be connected to linear speed controllers compatible with single-phase capacitor motors. Contact us for a specific controller recommendation.

Is the fan included or must it be ordered separately from the BOX? Product /4399 is supplied as a complete assembly — the DDM 12/12 fan pre-mounted and aligned inside the acoustic BOX enclosure. No separate ordering required.

👉 DDM 12/12 E6G3501 1F 4P — single-phase 4-pole variant for maximum airflow 👉 Centrifugal fans BOX type — complete range 👉 Airflow calculator 📞 +40 722 667 239 — free consultancy for selection and installation sizing