Dry Cooler Coil Coating
Where it corrodes first
Coil faces behind adiabatic pads or sprays
Water carried from the pre-cooling stage wets the coil and leaves dissolved minerals behind.
Headers and return bends
Large coils have long headers and many return bends that collect deposits.
Fin-to-tube joints
On copper-tube coils the aluminium fin corrodes around every collar once a salt film forms.
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-W | |
| Industrial atmosphere | C4C5 | PG-S1 | PG-C | |
| Adiabatic pre-cooling (wetted coil) | PG-S1 | PG-C | Water quality decides; send the water analysis with the enquiry. | |
| Desert heat, sand and salt | C4C5 | PG-S1 | — |
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.
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.
OEM Contract Coating for Coil Manufacturers
Contract dip and spray coating for coil and unit manufacturers — coating to your specification on partner lines in South China, with batch records.
Why dry coolers need attention
Dry coolers often run continuously, and a data-centre cooler can move air through its coils for most of the year. Their coils are large and expensive to replace, and the heat rejection they provide is usually critical to the site.
Adiabatic systems
Adiabatic dry coolers pre-cool the inlet air with wetted pads or water sprays. When water droplets reach the coil, the coil goes through repeated wet-dry cycles and collects whatever the water carries. Water quality then matters as much as the outdoor atmosphere, so the coating review asks for the water analysis.
Related
- CoatingsWaterborne Polysiloxane (Sol-Gel) Coil Coating
- EquipmentAir-Cooled Chiller Coil Protection
- EnvironmentsCoastal HVAC Corrosion by Distance from the Sea
- GuidesDoes Coil Coating Reduce Heat Transfer?
- CoatingsAir-Dry Two-Component Chemical-Resistant Coating
- EquipmentCopper Tube, Aluminium Fin Coil Protection
Also see
- EnvironmentsIndustrial Atmospheres (SO₂, NOx, Chlorides)
- EnvironmentsDesert Heat, Sand and Salt: Gulf Region HVAC
- EnvironmentsData Center Cooling in Corrosive Locations
Why does adiabatic pre-cooling matter for coating?
Spray or pad water that reaches the coil evaporates and leaves minerals and chlorides on the fins. The coil then sees wet-dry cycling that a dry-only coil does not.
Are dry cooler coils too large to dip?
Some are. Coils that fit the tank are dipped; larger coils are spray coated.
Tell us the equipment, the site and the destination port. We reply within 24 hours.