
What the 4 Inch Classic Centrifugal Fan Delivers
Centrifugal means the impeller throws air outward rather than pushing it straight through. That is why a fan this small still holds pressure against a filter. It moves 123 CFM on 75W and 0.65A at 120V. The blades are backward curved, the casing is powder-coated metal, and the whole thing weighs 6.68 lbs. It is rated IPX4 and built in Germany.
Placing This Inline Duct Fan in the Run
Fit it as the extract on a small tent or as a booster mid-run. Because it is centrifugal rather than axial, it keeps working when a carbon filter starts to load, where a basic axial booster fan just stalls. The honest problem is noise. At 63 dB this belongs in a garage or a basement, not a bedroom closet, unless you put a silencer after it. Mounting brackets are already on the casing, and the cord is 5.5 ft. Hang it on its own strap so the duct carries no weight. Controller choice needs a look before wiring, because Ruck's manual calls this motor voltage controllable and then rules out solid-state speed controls. An autotransformer is the right pairing, not a triac dimmer.
Key Features
- 123 CFM: Centrifugal output that holds up against a loaded carbon filter.
- 75W at 0.65A: Real draw at 120V, so the circuit load is easy to plan.
- 63 dB Maximum: Published sound figure, so you can plan silencing honestly.
- Backward Curved Impeller: The blade form that keeps pressure up on long duct runs.
- Powder-Coated Metal Casing: Metal rather than plastic, and corrosion-resistant in damp air.
- Incorporated Mounting Brackets: Fitted to the casing, so it hangs without extra hardware.
- 5.5 ft Power Cord: Reaches a socket or controller without an extension in most tents.
- Voltage Speed Control Only: Ruck rules out solid-state controllers, so use an autotransformer.
- 3-Year Warranty: German-built, and covered for three years.
Technical Specifications
| Specification | Value |
|---|---|
| Duct Size | 4 in |
| Airflow | 123 CFM |
| Power | 75 W |
| Current | 0.65 A |
| Voltage | 120V, 60 Hz |
| Noise (max) | 63 dB |
| Motor | One-phase AC |
| Impeller | Backward curved |
| Casing | Powder-coated metal |
| Speed Control | Voltage controllable; not for solid-state controls |
| Mounting | Incorporated brackets |
| Cord Length | 5.5 ft |
| Warranty | 3 years |
| Weight | 6.68 lbs |
| Protection Rating | IPX4 |