Air-Cooled Chiller Coil Protection
Where it corrodes first
Coil bank ends and tube sheets
Where coils meet the frame, steel and aluminium are in contact and moisture collects.
Lower rows of V-banks
Rainwater and debris run down the V-shaped coil banks and collect at the base.
Air inlet faces
Large fans pull salt and dust through the whole face area of the coil banks.
Illustrative images of typical corrosion at each location
Recommended system by exposure
Starting point for selection. The final specification also depends on fin density, bake limits and target service life.
| Exposure | ISO 9223 | Recommended | Alternative | Why |
|---|---|---|---|---|
| Coastal | C4C5 | PG-S1 | PG-C | Dip where the coil fits the tank; spray PG-C on larger banks. |
| Desert heat, sand and salt | C4C5 | PG-S1 | PG-C | |
| Industrial atmosphere | C4C5 | PG-C | PG-S1 | |
| Wastewater H₂S | C5 | PG-C | — |
How it is coated
Dip Coating for Finned Heat Exchangers
Full-immersion dip coating for new finned coils — coverage deep in the core and at the fin roots, with film thickness controlled by drain-off.
Spray Coating for HVAC Coils
Spray coating for coils that are too large to dip, already assembled, or need a thicker chemical-resistant film on specific areas.
Full-Unit Corrosion Protection for Outdoor Units
Complete outdoor units disassembled, masked, coated with an air-dry system, reassembled and function-checked before shipment.
Pre-Shipment Coil Coating in China
HVAC coils and outdoor units sourced from China, coated on partner lines before loading — coating selected for site corrosivity, with a batch QC report.
Size decides the method
A chiller coil bank can be several metres long. Coils that fit the dip tank and oven are dipped and baked before the chiller is assembled. Larger coils, and chillers that arrive already assembled, are sprayed from both faces with an air-dry system, and the coverage between the fins is checked.
Finned tube or microchannel
Many air-cooled chillers now use microchannel condensers. Those need a thin film that keeps the louvers open. Copper-tube coils need the fin-to-tube joints isolated. The matrix above applies to both; the fin geometry decides how thick the film can be.
Related
- CoatingsWaterborne Polysiloxane (Sol-Gel) Coil Coating
- EquipmentMicrochannel Coil Corrosion Protection
- EnvironmentsCoastal HVAC Corrosion by Distance from the Sea
- ComparisonsDip Coating vs Spray Coating
- GuidesDoes Coating Increase Air-Side Pressure Drop?
- CoatingsAir-Dry Two-Component Chemical-Resistant Coating
Also see
- EquipmentDry Cooler Coil Coating
- EnvironmentsDesert Heat, Sand and Salt: Gulf Region HVAC
- EnvironmentsIndustrial Atmospheres (SO₂, NOx, Chlorides)
- EnvironmentsData Center Cooling in Corrosive Locations
What is the largest coil that can be dipped?
It depends on the tank and oven size of the partner line. Maximum part sizes are listed in the capacity table and confirmed with each quote.
Can an installed chiller be coated on site?
Only by field spray with an air-dry system. Coating before shipment is easier to control and document.
Tell us the equipment, the site and the destination port. We reply within 24 hours.