General Assist Technical Reference
BLUE FIN Anti-Corrosion Coating
Outdoor heat-exchanger fin protection, limitations and maintenance guidance
Applicable to RAC, PAC and VRF outdoor coils where BLUE FIN is specified
BLUE FIN is a factory-applied anti-corrosion coating for aluminium outdoor heat-exchanger fins. It uses a three-layer protective system to improve corrosion resistance while maintaining hydrophilic properties for effective water runoff.
1. What BLUE FIN is
BLUE FIN is aluminium finstock coated with a multi-layer protective system designed to resist corrosion while retaining hydrophilic properties. The hydrophilic surface helps water drain from the heat exchanger efficiently, supporting stable heat-transfer performance.
2. Three-layer protective structure
| Layer | Function |
|---|---|
| 1. Hydrophilic resin layer | Maintains long-lasting hydrophilicity to promote clean water runoff and stable heat exchange. |
| 2. Blue corrosion-resistant resin layer | Primary corrosion barrier. The blue tint identifies this protective resin layer. |
| 3. Chromate conversion layer | Surface treatment of the aluminium substrate that further suppresses corrosion initiation. |
3. Expected corrosion performance
- Provides significantly higher corrosion resistance than bare aluminium fins.
- Offers improved durability compared with single-layer or inorganic-coated fins.
- Helps maintain heat-exchange performance by supporting water runoff from the fin surface.
Important: Salt-spray and laboratory test results are indicative only. Actual service life depends on the installation environment, exposure level, siting and maintenance.
4. Scope and limitations
- The BLUE FIN specification applies only to the aluminium fin material.
- Cabinets, fasteners, PCBs, brackets and other outdoor-unit components are not protected by the BLUE FIN fin coating.
- BLUE FIN does not make the complete outdoor unit corrosion-proof.
- Correct siting and ongoing maintenance remain important, particularly in coastal or aggressive environments.
Coastal installations: BLUE FIN improves fin corrosion resistance but does not eliminate the effects of direct salt spray or aggressive airborne contaminants on the rest of the outdoor unit.
5. Deployment and maintenance guidance
| Area | Recommended practice |
|---|---|
| Siting | Avoid direct salt spray where practical. Consider wind breaks, shielding or additional setback from shorelines. |
| Routine maintenance | Rinse the coil periodically with fresh water at low pressure to remove salt, dust and contaminants. |
| Cleaning chemicals | Avoid harsh alkaline or acidic cleaners that may attack the coating. |
| Pressure cleaning | Do not use high-pressure jets that can bend fins or erode protective coatings. |
| Fin damage | Straighten bent fins carefully. Where the coating is damaged, use approved repair or touch-up methods where applicable. |
6. Key takeaways
- BLUE FIN is a three-layer protective system focused specifically on the outdoor coil fins.
- It improves corrosion resistance and helps maintain effective water runoff from the heat exchanger.
- It does not protect every outdoor-unit component from corrosion.
- Proper installation location and regular cleaning remain essential for long-term performance.