406-522mm LWA Series Axial Fan Blades for HVAC Condenser Units

Customer Requirement

A 482 mm outer diameter with a tolerance of ±3 mm was one of the key requirements provided by our HVAC OEM customer. The customer wants to order four distinct axial fan blades for residential and commercial air conditioning condenser units. They required four sizes of fans: 406 mm, 440 mm, 482 mm, and 522 mm.

The OEM required impellers that could integrate seamlessly with their existing motor platform and housing designs to meet specific performance duty points. Key constraints included precise balancing to minimize vibration and noise.

Before moving into production, the OEM also set several strict technical requirements. For the LWA-φ482X151-3 model, the impeller had to achieve a residual unbalance of no more than 0.25 g at 1100 RPM. The OEM specified glass fiber reinforced ABS (ABS+GF) for its combination of UV resistance in ourdoor environments. They also required industry standards such as UL 507 and while helping the overall HVAC system achieve energy efficiency targets under ASHRAE 90.1. Rather than simply looking for a parts manufacturer, the customer was seeking a long-term supplier capable of delivering production-ready, consistently balanced, and quality-assured fan solution provider.

Engineering Solution

As the client’s fans are used in outdoor condenser units, our engineering team recommended LONGWELL LWA series of axial fan blades. For the 406 mm model, ABS+GF was specified for its excellent mechanical properties and surface finish. This material choice, combined with the blade’s aerodynamic profile from our AcousticFlow™ design family, ensures efficient airflow with minimal noise generation.

To meet the customer’s four product sizes, LONGWELL engineering team recommended four standard models: LWA-φ406×96-4, LWA-φ440×150, LWA-φ482×151, and LWA-φ522×142-3. Each fan blade was supplied with a complete engineering drawing and technical specification, including key quality requirements such as maximum radial and axial runout of 0.8 mm to ensure accurate installation and stable operation. Dynamic balancing was also tightly controlled during production. For example, the 406 mm model is balanced at 1000 ± 50 RPM with a residual unbalance below 0.3 g, helping minimize vibration, reduce noise, and improve the long-term reliability of the customer’s condenser units.

Technical Specifications

The following specifications define the mechanical and quality parameters for the four axial fan impellers delivered for this project. These components form the aerodynamic core of the final fan assembly.

The tight tolerances on dimensions and residual unbalance are critical for ensuring the impellers can be integrated into high-volume OEM production lines, resulting in a final fan product with consistent performance and low vibration.

Technical Documentation

The following documents provide precise specifications for each of the four fan blade models.

LWA-φ406×96-4.pdf: This engineering drawing details the 406 mm 4-blade impeller, specifying ABS+GF material, RoHS compliance, and balancing requirements at 1000 RPM.

LWA-φ440×150-04.pdf: This document provides the mechanical specifications for the 440 mm 3-blade impeller, used by designers for system integration.

LWA-φ482X151-3.pdf: This drawing for the 482 mm impeller includes critical dimensions, runout tolerances (0.8 mm max), and a drop test qualification requirement.

LWA-φ522×142-3.pdf: This specification sheet for the largest 522 mm impeller details the balancing requirement of achieving less than 0.25 g unbalance at 1100 RPM.

Why Longwell for This Application

OEMs in the competitive HVAC market must balance performance, cost, and speed. So, why choose LONGWELL for this application? LONGWELL provides distinct advantages beyond the initial engineering strength.

• Supply Chain Simplification: LONGWELL has the capability to provide all four required impeller models to accommodate the customer’s specific technical and production requirements. Sourcing the complete product range from a single manufacturer simplifies procurement and ensures consistent quality.  It also gives the customer a single point of contact of engineering support, production coordination, and after-sales service throughout the project lifecycle.
• Cost Structure without Compromise: As a high-performance alternative to imported fans, Longwell can deliver significant cost reductions (e.g., 30-35% cost reduction compared to premium brands) while maintaining lead time advantages. This cost advantage was achieved while maintaining stringent quality control, including dynamic balancing to a G2.5 grade or better.
• Fast Custom NPI Cycle: The customer’s requirement was met using Longwell’s existing, validated tooling. This completely avoided the typical 90-day New Product Introduction (NPI) cycle and associated NRE costs, allowing the OEM to move from inquiry to sample testing in a fraction of the standard time.
• Proven Quality & Reliability: The technical drawings specify durability requirements like a 0.6-meter drop test onto concrete without cracking. This, combined with our ISO 9001 certified manufacturing process and 100% in-line balancing, gives OEMs confidence that the impellers will perform reliably in the field, protecting their brand reputation. LONGWELL fans hold a range of international certifications including ISO 9001, CE, UL/ETL, RoHS/REACH, AMCA, and ErP 2026, ensuring compliance with global quality and safety standards for outdoor applications

Explore our full Air Conditioner Fan Blade range.

Frequently Asked Questions

Q: What is the standard lead time for a production order of these axial impellers?

A: For these standard models, production orders up to 500 units per model typically have a lead time of 15-30 days. Larger volume orders are scheduled based on the customers’ specific requirements. We often maintain a safety stock of high-volume models, potentially shortening lead times to under 5 days for urgent, smaller quantity requests.

Q: Can the material or color of the fan blades be customized?

A: Yes. While these standard models use materials like glass-reinforced ABS (ABS+GF) or AS+GF, we can accommodate custom material requests.

Q: What motor specifications are recommended for the LWA-φ482X151-3 impeller?

A: The optimal motor selection depends entirely on the OEM’s target airflow and static pressure point. There is no single recommended motor. For a 482 mm impeller in a typical condenser application, the required shaft power is often in the 150W to 350W range. Our application engineers work with OEM clients, using their system’s impedance curve to recommend a specific Longwell EC or AC motor that will create a fan assembly meeting the desired duty point and efficiency standards like AMCA 210-16.

Project Gallery & Technical Drawings

Project Item: 7026569955-LW406*96-4，LW440*150，LW520*140-3，LW482*151
Project Date: 2026-06-24 01:54:11