To stop corrosion even in the worst conditions

One of the aspects that should be always taken into consideration in HVAC industry is prevention of damages and deterioration of components, even in the worst conditions. In particular, corrosion often affects heat exchangers and can lead to performance loss and failure. It is therefore very important to provide adequate protection in order to avoid or delay corrosion and its effects. Geoclima can provide different coating solutions, according to the type and the site of installation. In fact, not every application is under high risk of corrosion and in those cases there is no need for special coatings. Instead, some environmental conditions or some types of application present high risk of corrosion that should be prevented or reduced. In such scenario consideration of environment and of application is essential to provide the more resistant solution.


Environments that put equipment under high risk of corrosion are: coastal and seaside areas, rural areas, polluted urban centres, industrial zones, desert zones.

From an installation point of view, types of application with high risk of corrosion are: power stations, chemical, fuel and gas industry, waste disposal and sewage treatment industry.

Some examples of coils uncoated or coated with inadequate protection:

Sprayed coating


Other corrosion resistant coatings


For all applications and environmental conditions where standard coatings are inadequate, we at Geoclima can offer a special coating treatment that provides the highest and best protection from corrosion.

This special coating is ELECTROFIN, a factory-applied electro-deposition coating process that guarantees complete heat exchanger coverage. The coil is immersed in a bath. Here the coil acts as a magnet and attracts the coating to every surface. The result is a thin, flexible, durable, corrosion-resistant coating.


Main feature of this special coating is that, whereas other coating processes fail in covering the entire surface, especially in particular structures such as microchannel or round tube plate coils, ELECTROFIN coating penetrates deep into the 100% of coil surfaces, covering all edges and filling all cracks.
In addition to this, the final stage of the ELECTROFIN coating process provides an extra UV-Resistant Topcoat: a layer is applied by spray to protect the ELECTROFIN coat from UV and ensure durability and long life to coils and microchannel.

How ordinary coatings and ELECTROFIN coating look like:

Standard cathodic immersion
Cu/Al coil

Standard cathodic immersion
Cu/Cu coil

Cu/Al coil

Cu/Al coil


Salt spray corrosion test has been carried out on two heat exchangers to test the corrosion resistance of ELECTROFIN applied on standard Cu/Al heat exchanger compared to an uncoated standard Cu/Cu solution.

These are the results after inspection:

Cu/Cu heat exchanger without coating – Inspection after 1000 hours: the fin surface and the tubes appear completely oxidized

Cu/Al heat exchanger with ELECTROFIN coating – Inspection after 3500 hours: no attack is visible


  • 100% coverage of coil surface
  • Maximum uniformity of coating
  • No obstructions
  • No loss of operational efficiency
  • Reduction of maintenance, replacement and operating costs
  • Extension of heat exchanger’s life

Technical Performance Specifications

ASTM B117-97(Salt Spray)ISO 9227Certified @ 6.048 hrs
ASTM G85 (Swaat test – Modified Salt Spray) ISO 9227Tested 4.000 hrs with no failures
ASTM D3359-97 (Cross Hatch Adhesion)ISO 24095B Rating/0 European
AHRI 410 (Heat Transfer Reduction) below 1%
ASTM D7091 (Dry Film Thickness) ISO 198400.6-1.2 mils / 15-30 µm
ASTM D870-02 (Water Immersion) ISO 2812-2above 1,000 hrs
ASTM D2794-93 (Impact Resistance) ISO 6272-1160 in/lbs direct
GM 9540P-97 (Accelerated Corrosion Test) 120 cycles
MIL-STD-810F Method 509.4 (Sand and Dust)
TEMPERATURE LIMITS -71 F to 325 F / -57°C to 163°C (dry load)
pH RANGE 3 – 12
C5 Mar.& C5 Ind.– High Durability (>15years) ISO 12944(for E-coat+UV)

Chemical resistance guide (at ambient temperature)

AcetoneChlorine GasHydrofluoric Acid (*)Methyl Isobutyl KetoneSodium Bisulfite
Acetic Acid Chromic Acid (*) Hydrogen Peroxide 5%Mustard Gas Sodium Chloride
Acetates (ALL) Citric Acid Hydrogen Sulfide NaptholSodium Hypochlorite below 5%
Amines (ALL)Creosol Hydrazine Nitric Acid (*)Sodium Hydroxide below 10%
Ammonia Diesel Fuel Hydroxylamine Oleic AcidSodium Hydrox. above 10% (*)
Ammonium Hydroxide Diethanolamine Iodine Oxalic AcidSodium Sulfate
Amino Acids Ethyl Acetate Isobutyl Alcohol Ozone Stearic Acid
Benzene Ethyl Alcohol Isopropyl Alcohol Perchloric Acid Sucrose
Borax Ethyl Ether Kerosene Phenol 85% Sulfuric Acid 25-28%
Boric AcidFatty Acid Lactic Acid Phosgene Sulfates (ALL)
Butyl Alcohol Fluorine Gas Lactose Phenolphthalein Sulfides (ALL)
Butyl Cellosolve Formaldehyde 27% Lauryl Acid Phosphoric Acid Sulfites (ALL)
Butyric Acid Fructose Magnesium Potassium Chloride Starch
Calcium Chloride Gasoline Maleic Acid Potassium Hydroxide Toluene
Calcium Hypochlorite Glucose Menthol Propyl Alcohol Triethanolamine
Carbon Tetrachloride Glycol Methanol Propylene Glycol Urea
Cetyl Alcohol Glycol Ether Methylene Chloride Salicylic Acid Vinegar
Chlorides (ALL)Hydrochloric Acid below 10% Methyl Ethyl Ketone Salt Water Xylene

(*)ElectroFin is NOT suitable for high concentrations of: Nitric Acid, Sodium Hypochlorite, Formic Acid, Hydrofluoric Acid, Sulfuric Acid, Sodium Hydroxide and others.

General description – subject to change or deviations
Kindly consider that the “mix effect” is not considered

Specific environment

Installation sitePropertiesAggressive substancesElectroFin protection
Power plantsCombustion productsSulfur oxides (SOx), Nitrogen oxides (NOx), Chlorides, Fluorides, CO, Volatile organic compoundsEXCELLENT
Chemical industryProcess emissionsAmmonia, Chlorides, NOx, SOxEXCELLENT
Bio fuel plantsProcess emissionsAmmonia, SOx, NOx, HC, Volatile organic compoundsEXCELLENT
Petro industryOils, fuel, process emissionsAmmonia, Chlorides, NOx, SOx, CO, Volatile organic compoundsEXCELLENT
AirportsCombustion productsNOx, SOx, ChloridesEXCELLENT
AgriculturalFertilizer, organic compoundsAmmonia, SOx, NOxEXCELLENT
Sea air, ships, offshoreSalt water sprayChlorides, SulphurEXCELLENT
Heavy industryCarbon dustSulphur, SOx, NOxEXCELLENT
Food IndustryFat, air humidity, cleaning agentsChlorine, acid, SOx, NOxEXCELLENT
Waste disposal industryOrganic airborne particlesAmmonia, Fly ashes, ChloridesEXCELLENT
Sewage treatment plantsOrganic airborne particlesSulphur, AmmoniaEXCELLENT
DesertsLow air humiditySandEXCELLENT

ELECTROFIN coating is certified for high durability (> 15 years) in C5-Marine and C5-Industrial environments, which is the highest possible corrosion class according to ISO-12944.