4223 m³/h EC Axial Fan for Commercial Condensers: 450mm Square Panel Case Study

The brief

4,223 cubic meters per hour at a maximum static pressure of 80 Pa was the primary airflow target when the OEM submitted their thermal cooling brief for a new commercial condenser line. The initial documentation requested a 450mm axial fan configuration mounted on a standard square panel. Space constraints dictated a maximum outer panel dimension of 575mm by 575mm to fit the existing chassis rails without requiring modifications to the sheet metal housing. The electrical architecture required operation on a 220 VAC bus. Factoring in grid instability, we needed to ensure full functionality across a voltage tolerance between 200 and 277 VAC at either 50 or 60 Hz.

The engineering team mandated strict environmental endurance for the copper windings. Specifically, the motor required Class F insulation to handle elevated internal ambient temperatures up to 60°C during peak summer cooling loads. The initial specification asked for an IP55 protection rating to guard against dust and moisture ingress in outdoor rooftop installations. Noise was another critical factor for this urban deployment. The acoustic limit pushed against a 66 dB(A) ceiling to comply with strict municipal zoning ordinances. Finally, the client needed precise variable speed capabilities via 0-10V or PWM to sync the fan RPM with the compressor load.

Selecting the fan: choosing the ec axial fan

Designing the exact air mover for this thermal application required balancing the high airflow target against motor efficiency and thermal limits. We initially reviewed a standard AC motor variant for the 450mm frame. The AC option was rejected. Achieving the variable speed requirement would have forced the client to install a separate external inverter. This adds both unacceptable component cost and a secondary point of failure to the condenser control board.

Instead, we specified our internally commutated EC motor architecture. Integrating the electronics directly into the motor hub allowed us to accept the client’s 0-10VDC/PWM control signal natively. This SmartEC™ implementation gives the client granular control from the maximum 1,080 RPM down to standby mode when the VSP voltage drops below 1.2VDC.

Material selection heavily influenced the acoustic and durability outcomes. We molded the 450mm five-blade impeller from PA6 thermoplastic reinforced with 30% glass fiber. This composite yields a lighter rotational mass than traditional stamped aluminum. Lower mass drops the input power requirement to just 100W while maintaining structural rigidity at 60°C continuous operation. The motor stator was wound with Class F insulation. This directly addresses the thermal soak requirements requested in the original brief.

During the design review, we negotiated a slight modification to the environmental sealing. The client initially requested IP55. Based on the enclosure design and airflow path, our engineers determined that IP54 protection using maintenance-free deep groove ball bearings would fully satisfy the weatherproofing needs. This adjustment prevents trapped heat buildup inside the motor casing. It reduced the per-unit cost without sacrificing field reliability. The final approved model, designated LWAE3G450SS-5PKW-11-11, delivers the necessary 2,484 CFM volume.

What was supplied

The combination of a 100W input power and a 4,223 m³/h airflow output indicates a highly optimized aerodynamic profile, keeping operational energy costs low for the end user. The Class F insulation and wide 200-277 VAC tolerance ensure the motor survives in harsh, poorly regulated electrical environments.

Every figure above comes from our own test chamber, measured using AMCA 210/211 and ISO 5801 methods. The published procedures behind those numbers are available from AMCA. As always, confirm the duty point against the finished unit before release, since installation conditions move it.

Datasheet and drawings

longwell-lwae3g450ss-5pew-10-technical-doc-01.pdf
The finalized technical specification sheet containing the P-Q performance curve, wiring diagram, and mechanical dimensions for the design engineering team.

longwell-lwae3g450ss-5pew-10-project-image-02.docx
The raw project source document outlining initial dimensional constraints and component requirements provided by the client.

The original catalog reference image showing the Class F insulation requirement update and the expected EC motor physical configuration.

Why Longwell took this on

• Accelerated Prototyping: While European manufacturers typically require 12 to 18 months for custom panel fan modifications, our Ningbo facility completed the mechanical redesign and Class F insulation verification in under 90 days.
• Cost Efficiency: By using our in-house EC motor production lines and standardizing the PA6+30%GF impeller, we held unit cost steady without dropping the airflow below the 4,223 m³/h threshold.
• Independent Validation: Aerodynamic performance was strictly measured against ISO 5801 and GB/T2888 standards. This ensures the 80 Pa static pressure claim holds up during independent laboratory verification by the OEM.
• Certification Readiness: Holding CE certification and testing against EN 60335-1 means the client avoids compliance bottlenecks when exporting the final condenser units to the European market.
• Broad Voltage Tolerance: Condenser units installed in remote or industrial locations frequently encounter unstable electrical grids. The customized EC control board guarantees stable 1,080 RPM operation across a wide voltage input range from 200 VAC up to 277 VAC, preventing sudden thermal shutdowns.

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Follow-up questions

Q: Can this 450mm EC axial fan be controlled via a centralized building management system?

A: Yes, the integrated SmartEC controller accepts standard 0-10VDC or PWM signals (frequency 1K–10KHz, amplitude 10V). This allows direct connection to standard BMS hardware. The fan motor will automatically switch to standby mode when the control voltage drops below 1.2VDC.

Q: What are the exact dimensions of the square mounting panel?

A: The external dimension of the square panel is 575 mm by 575 mm, with a thickness profile of 100 mm. The mounting holes are spaced at 520 mm by 520 mm, using 10 mm diameter clearance holes for standard metric hardware.

Q: Does the motor require an external VFD for speed control?

A: No external Variable Frequency Drive is needed. The internal electronics handle the AC to DC conversion and commutation directly from the 220 VAC (200-277 VAC range) input power. This reduces installation complexity and keeps the total power input down to 100W at the maximum 1,080 RPM.