EC Fan Selection Calculator
Input airflow + static pressure, get a sized LONGWELL EC fan SKU with motor power, wire-to-air efficiency, sound level estimate, and dimensional drop-in cross-reference to ebm-papst K3G and Ziehl-Abegg RH series. Works for EC backward-curved plug fans (Ø133–Ø900) and EC axial fans (Ø250–Ø1250). Updated for 2026 fan platform.
EC Fan Sizing Tool
Returns recommended SKU + power + drop-in replacement in 5 seconds. Calculations based on AMCA 210/211 PQ curves and ISO 5801.
How the Calculator Works
Fan family selection
Total Pa < 400 → axial. Pa = 400–1,800 → backward-curved plug. Pa = 1,800–3,200 → high-pressure plug. Forward-curved for high-CFM low-Pa residential / fan-coil duty.
Diameter sizing
Picks the smallest impeller diameter whose AMCA 210/211 PQ curve crosses your duty point above the 80%-BEP line. Smaller is cheaper, quieter, closer to surge. Larger has headroom, more cost.
Motor power calculation
P (W) = (V × Pa) / (η × 1000) where V in m³/s, Pa total, η wire-to-air efficiency at BEP. Adds 10% safety. Motor nameplate ≥ calculated × 1.1.
Cross-reference lookup
Looks up the dimensional drop-in replacement against ebm-papst K3G250–K3G900 and Ziehl-Abegg RH28C–RH100C mounting tables (May 2026 catalog).
Sound level estimate
Approximates sound power Lw at design load using ISO 13347 reference data + diameter scaling. Actual Lp depends on room geometry and installation. Datasheet provides octave-band breakdown.
Application overlays
The application dropdown adds the right IP rating, certification requirements, and protection options (anti-condensation, ATEX, medical EMC, salt-spray) automatically. Sample SKU code reflects these.
Standard LONGWELL Sizes — Reference Table
| Family | Ø (mm) | Airflow (m³/h) | Static (Pa max) | Power (W max) | η peak | Drop-in for |
|---|---|---|---|---|---|---|
| LWBE3G | 250 | 500–2,400 | 720 | 340 | 82% | ebm-papst K3G250, Ziehl-Abegg RH28C |
| LWBE3G | 280 | 500–2,800 | 900 | 480 | 85% | K3G280, RH28C |
| LWBE3G | 310 | 650–3,500 | 1,050 | 650 | 86% | K3G310, RH31C |
| LWBE3G | 355 | 800–4,500 | 1,200 | 950 | 87% | K3G355, RH35C |
| LWBE3G | 400 | 1,000–5,800 | 1,400 | 1,500 | 88% | K3G400, RH40C |
| LWBE3G | 450 | 1,200–7,200 | 1,550 | 2,200 | 88% | K3G450, RH45C |
| LWBE3G | 500 | 1,200–8,200 | 1,800 | 3,000 | 89% | K3G500, RH50C |
| LWBE3G | 560 | 1,500–10,500 | 1,800 | 4,200 | 89% | K3G560, RH56C |
| LWBE3G | 630 | 1,800–13,000 | 1,800 | 5,500 | 90% | K3G630, RH63C |
| LWBE3G | 710 | 2,200–16,500 | 1,700 | 7,500 | 90% | K3G710, RH71C |
| LWBE3G | 800 | 3,000–20,500 | 1,650 | 11,000 | 90% | K3G800, RH80C |
| LWBE3G | 900 | 3,500–26,000 | 1,600 | 14,000 | 90% | K3G900, RH90C |
| LWHV | 450 | 1,000–5,500 | 3,200 | 3,500 | 85% | ebm-papst K3G high-static |
| LWAE3G | 500 | 3,200–11,000 | 380 | 1,800 | 64% | ebm-papst W3G500, ZA FN050 |
| LWAE3G | 630 | 5,500–18,000 | 420 | 3,200 | 65% | ebm-papst W3G630, ZA FN063 |
| LWAE3G | 800 | 9,000–30,000 | 400 | 6,500 | 64% | ebm-papst W3G800, ZA FN080 |