Data Center Cooling Fans: An Import-Dominated Segment

China's data center cooling fan demand is estimated at ¥3–8 billion per year. A large share of that spend is imported. In the CRAC (computer room air conditioning) segment, the reference product is the EBM-Papst RadiPac class of backward-curved centrifugal fans, typically costing around ¥30,000–50,000 per fan. For anyone building or servicing precision cooling units, that single component is one of the largest line items in the fan section of the bill of materials.

Two forces are opening this segment to domestic supply. First, CRAC builders and data center operators are looking for cost reduction on a component whose price is set by a small number of overseas manufacturers. Second, the shift from AC motors with throttling to electronically commutated (EC) motors changes the retrofit and replacement logic entirely, because the energy saving alone can justify a fan change on an existing unit.

Why EC Retrofit Is the Entry Point

Most installed CRAC units and cooling towers still use AC motors. Speed control on these is usually achieved by throttling — dampers, inlet vanes, or similar mechanical means — which reduces flow but not proportionally the power drawn. EC motors control speed electronically instead. At part-load, which is where data center cooling equipment spends most of its operating hours, EC motors cut power by 30–50% compared with AC motors with throttling.

That figure is what makes retrofit discussions practical rather than theoretical. A retrofit project does not require replacing the CRAC unit, the coil, or the controls architecture. It requires matching the fan's aerodynamic curve to the existing unit, fitting an EC motor and its integrated controller, and connecting speed command and feedback to the existing BMS or unit controller.

  • Airflow and static pressure must be matched to the original fan curve, not simply to its motor rating.
  • Impeller diameter, rotation direction, and outlet geometry determine whether a drop-in replacement is possible.
  • Control interface (0–10 V, Modbus, or unit-specific signalling) has to match the existing controller.
  • Part-load power and sound level should be verified on the actual unit, since system resistance differs from bench conditions.

OEM Supply Requirements

Data center cooling fans are sold into a conservative procurement environment. Buyers in this segment generally evaluate suppliers on four things before discussing price:

  • Curve-matched performance. The replacement fan has to meet the airflow and pressure point of the unit it goes into, with documented data.
  • EC motor and controller integration. Motor, electronics, and impeller must be engineered as one assembly rather than sourced separately.
  • Supply consistency. CRAC and cooling tower production lines cannot absorb unpredictable lead times or specification drift between batches.
  • Documentation. Drawings, performance data, and control interface details are needed for the OEM's own engineering approval and for end-user acceptance.

SINDFAN's EC Fan Roadmap

SINDFAN, based in Tianjin, China, is developing EC fan platforms for the two main cooling duties in a data center:

  • EC axial fans, models SM-EC710 and SM-EC910 — intended for cooling towers and dry coolers.
  • Backward-curved EC centrifugal fans, models SD-EC450, SD-EC560 and SD-EC630 — intended for CRAC units, addressing the RadiPac-class application.

The stated cost target for these platforms is no more than one third of the imported bill of materials they replace. That target is the reason the program is worth examining for OEMs and retrofit contractors: it is a BOM-level objective, not a marginal discount on a comparable imported fan.

What a data center fan OEM has to hand over with the impeller

When the impeller leaves us and goes into someone else's CRAC or CRAH unit, the unit builder carries the warranty on the finished machine. That only works if the impeller arrives with more than a drawing and a flow figure.

  • The curve at the motor speed actually used — not a nominal curve at a nominal speed. The fan wall is selected against a real 0-10V or Modbus speed range, so the part load points have to be on the same sheet as the design point.
  • Mass and centre of gravity per impeller — the OEM's fan tray, isolators and lifting points are designed from these two numbers, not from the diameter.
  • Balance grade and the residual unbalance figure — ISO 1940 G6.3 is a grade, but the installer needs the residual value to set his own vibration alarm threshold.
  • Interface drawing with the shaft fit, key and locking arrangement — a replacement impeller that does not match the existing shaft means the whole unit comes back.
  • Material and temperature statement — cast aluminium impellers are usable to the temperature the maker states, and the OEM's compliance file has to quote that figure, not a rounded one.

For a retrofit, add the existing motor's frame size and the space available inside the housing. Those two decide whether the impeller can go in at all, before any aerodynamic question is asked.

How to Evaluate This for Your Project

The practical starting point is your duty point, not a model number. To determine whether an EC axial or backward-curved EC centrifugal fan fits a given CRAC unit, cooling tower, or dry cooler, the useful inputs are airflow, static pressure, available installation space, supply voltage, and the control signal available at the unit. Where a retrofit is intended, the existing fan curve and the unit's part-load operating profile matter as much as the design point.

Send your duty parameters to SINDFAN on WhatsApp at +852 9524 8434 or by email at info@sind-tech.com. Include the required airflow and static pressure, the duty (CRAC, cooling tower, or dry cooler), and the control interface you need, and we will respond with the applicable EC fan platform and the information required for your engineering review.