Rack-mount fans: size by heat load, then check duct resistance
Start from the heat a cabinet generates and convert it to required airflow at the allowed temperature rise; dense racks with high flow resistance take rack-mount centrifugal blowers, open cabinet tops take axial fans.
The common mistake in cabinet cooling is sizing the fan by device count instead of by heat. The right sequence: total the heat inside the cabinet (kW) → set the allowed temperature rise (usually 10 K) → convert to airflow (m³/h) → then choose a rack-mount blower or an axial fan based on free space and flow resistance. Rack blowers use a wide, flat scroll to push air through densely packed equipment in 19-inch cabinets; axial fans are short and move large volumes, ideal for roof or door exhaust openings.
Selection points
- Airflow estimate: 1 kW of heat dissipation at a 10 K temperature rise needs roughly 300 m³/h; double the heat, double the airflow.
- Flow resistance: dust filters and densely packed equipment raise it sharply — step up to a higher-static-pressure rack blower.
- Mounting: do not short-circuit inlet and outlet; front-to-rear rack blowers need free space at both cabinet faces.
- Control and monitoring: EC models take 0-10V/PWM and alarm outputs, so fan speed can follow cabinet temperature and cut noise at night.
Model comparison
| Model | Airflow | Max static pressure | Power | Noise | Voltage |
|---|---|---|---|---|---|
| CF160-2000CFM-01 | 3400 m³/h | 720 Pa | 360W | 66dB(A) | 110-254 VAC |
| CF315A-E092E3-01 | 1750 m³/h | 1001 Pa | 220 W | 66 dB(A) | 230 VAC |
| CF250A-E092D1-01 | 1205 m³/h | 1010 Pa | 160 W | 64dB(A) | 120 VAC |
| CF146-650CFM-01 | 1100 m³/h | 680 Pa | 180 W | 56dB(A) | 110-254 VAC |
| CF200A-E092D3-01 | 1080 m³/h | 905 Pa | 160 W | 63 dB(A) | 230 VAC |
| CF160A-E072D1-01 | 820 m³/h | 710 Pa | 115 W | 61dB(A) | 120 VAC |
| CF150A-E072B3-01 | 720 m³/h | 905 Pa | 115 W | 60 dB(A) | 230 VAC |
| CF125A-E072A1-01 | 380 m³/h | 810 Pa | 85 W | 60dB(A) | 120 VAC |
Specs are taken from each model's product page — full curves, dimension drawings and certificates live on the model pages. Models not listed can be browsed by series in the product catalogue.
Frequently asked questions
Should a 19-inch cabinet use a 1U or 2U fan?
Start from available height and heat load: 1U units fit telecom cabinets with moderate heat; high heat or high flow resistance calls for a 2U or dual-fan build with more airflow and static-pressure headroom.
How do I estimate the airflow a cabinet needs?
Use Q ≈ 3.1 × P / ΔT (Q in m³/h, P in W, ΔT in K). A 2 kW load at a 10 K rise needs about 620 m³/h — then add 20–30% margin for filter loading.
The cabinet fan is too loud — what now?
Slow it down first (EC models accept a direct 0-10V setback), then improve inlet/outlet clearance and opening ratio; swapping in a smaller fan usually gets louder because it has to spin faster.