AI Server / Data Center Cooling: High-Density EC Axial
AI training rack heat load has jumped from the traditional 2-5kW to 10-30kW per rack, changing the cooling logic entirely: you can no longer rely on a single AC axial fan. You need an EC fan array + automatic PWM speed control + N+1 redundancy. Choose wrong and you either get GPU thermal throttling, or both electricity cost and noise go through the roof. More products: EC axial fans, AC axial fans.
Typical Configurations
| Rack Type | Heat Load | Recommended Fan | Configuration |
|---|---|---|---|
| General server rack | 3-5 kW | AC 12038 ×4 | Top-bottom push-pull |
| GPU inference rack | 8-12 kW | EC 17251 ×6 | 6+2 redundancy |
| AI training rack (8×H100) | 20-30 kW | EC 17251 ×8 | 8+2 redundancy, PWM control |
| Storage / network rack | 2-4 kW | AC 12038 ×2 | Top exhaust |
Typical Case Study
Case: 8-GPU Training Rack (25kW heat load)
Requirements: inlet 35°C, outlet ≤45°C, noise ≤75dB(A), 24/7 operation
Solution: eight EC 17251 fans (6+2 redundancy), PWM auto-speed by inlet temperature. At normal load, speed is 60% (~5500 RPM); at full load, 100% (~7500 RPM).
Result: ~35% annual electricity savings vs AC, no downtime when one fan fails, nighttime noise drops to 62dB.
Send us your rack dimensions, per-rack heat load, and target noise level, and we will deliver an EC fan array configuration proposal within 1 working day, or contact us for selection support.
Frequently Asked Questions
How much heat does an AI server rack generate?
Traditional server racks generate 2-5kW, while AI training racks (8 GPUs) reach 10-30kW per rack. Airflow demand is 3-5x higher, requiring EC fan arrays instead of a single axial fan.
Why must I use EC instead of AC?
AI racks run 24/7. AC fans have only 25%-35% overall efficiency, with self-heating accounting for 15%+ of the cooling budget. EC fans achieve 50%-65% efficiency and support PWM speed control by load, reducing PUE by 0.1-0.2.
What does N+1 redundancy mean?
Install N fans for required airflow plus 1 spare. If any fan fails, the remaining N fans still maintain minimum cooling, preventing GPU thermal throttling. AI racks typically use 6+2 or 8+2 configurations.
How do I keep noise under 75dB?
Don't run at full speed. EC fans support 0-100% PWM speed control, automatically slowing down based on inlet temperature (typically set at 35°C). At night or under low load, speed drops to 50% and noise falls from 75dB to 60dB.
Can JIEFENGFAN supply AI rack fans?
JIEFENGFAN EC axial fans cover 12038-17251 sizes, support PWM/FG/RD signals and 0-10V speed control, and can be configured in arrays to meet rack airflow requirements. Samples ship same day; bulk MOQ is 50 units.