The 12 Inch S-Prime EVO EC: 1,389 CFM on 262W
This one draws less than the 10 inch and moves more air, which is not a rounding error. 1,389 CFM on 262W sits against 1,271 CFM on 298W, and the reason is impeller speed: 2,960 RPM here against 3,900 on the smaller fan. A bigger blade turning slower is the more efficient machine, and this size shows it best. Maximum current is 3.1A, the motor is rated IP30, and the unit weighs 25.8 lbs.
Living With a Quiet 12 Inch EC Fan Day to Day
This size suits a room that ventilates continuously with someone working next door. An EC motor holds a level rather than cycling, so humidity swings less. The sound stays constant instead of starting and stopping through the day. The practical constraint is footprint: at 27 by 15.75 by 15.75 inches it needs real space and a hanger to match. The motor rating asks for the same dry mounting position as the 10 inch. Ruck builds it in Germany and covers it for three years.
Key Features
- 1,389 CFM: Mixed flow output for a 12 inch duct.
- Sound Insulated Casing: Galvanized steel lined to damp noise off the fan body.
- EC Motor: Draw falls with speed on a 0-10V input.
- Stepless 0-10V Control: Works with the MTP 21 and most climate controllers.
- Motor in the Hub: Kept out of the airstream, so airflow is not disrupted.
- Made in Germany: Built and tested at the Ruck factory.
- 3-Year Warranty: Covered for three years, German built.
Technical Specifications
| Specification | Value |
|---|---|
| Duct Size | 12 in |
| Airflow | 1,389 CFM |
| Power | 262 W |
| Max Current | 3.1 A |
| Impeller Speed | 2,960 RPM (max) |
| Motor Protection Rating | IP30 |
| Terminal Box Rating | IP44 |
| Complete Unit Rating | IPX4 |
| Weight | 25.8 lbs |
| Dimensions | 27.17 x 15.75 x 15.75 in |
| Operating Temperature | -22 to 104 °F |
| Voltage | 120V, 60 Hz |
| Motor | EC, one-phase |
| Speed Control | Stepless 0-10V (MTP 21 compatible) |
| Thermal Protection | TEC cut-out |
| Insulation Class | F |
| Casing | Sound insulated galvanized sheet steel |
| Impeller | Mixed flow, motor in the hub |
| Warranty | 3 years |
| Origin | Made in Germany |