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Corrosion resistant coated evaporator coils

Fins on evaporator and condenser coils are made using aluminum, which is relatively corrosion resistant even without any type of coating. However, the harsh conditions under which Specific Systems® units are placed often requires additional protection. In order to meet these needs, Specific Systems® makes available numerous coil coating options, each with unique and energy saving traits. Further, any of our systems can be ordered with copper fins in addition to the copper tubes, providing greater resistance to corrosive contaminants.

For an added stage of protection in severe environments such as offshore, we offer a coated condenser section.

Corrosion Resistant Coil Coatings

Extend the life of your HVAC system with one of our coating options


Technicoat coated coilTechnicoat is an air-dried resin-based thermoplastic on top of a baked phenolic coating designed specifically for use in salt-water environments. TechniCoat has been and is currently being successfully used in water treatment plants, paper mills, food processing plants, oil & gas related plants, off-shore drilling rigs, hatcheries, hospitals, laboratories & research facilities, and hotels. Technicoat requires minimal maintenance, with only a recommended quarterly washdown with a fan-nozzled pressurewasher and very mild detergent. Technicoat averages 2–3 mils thick, including the top coat and received excellent ratings with the ASME B117 salt fog test, holding up to an additional 1500 hours of testing.


Heresite (P413) is an oven-cured, modified phenolic coating that is generally dark brown in color. Heresite is extremely flexible for a coating of this type. Heresite has been used to protect HVAC/R equipment in corrosive industrial environments, including marine/offshore applications for over 50 years making it the one of the most widely-used coatings worldwide. This coating is very abrasion and chemical resistant, yet is extremely flexible for a coating of this type. Because of its ease of application, the coating maintains a uniform 1–2 mil thickness across and throughout the coil, minimizing the effects on heat transfer.


E-Coat (or electrocoating), as applied by Electrofin, is an environmentally friendly wet- paint process used on many products, including as a primer on many new vehicles. E-coat resists chipping and will extend the life of coils, E-Coat is also the thinnest coating, with applications computer-controlled to between 0.8 and 1.2 mils. Using a proprietary complete immersion process, Electrofin ensures complete coverage without any fin- bridging (up to 30 fpi/16 rows).


Thermoguard Fin Guard Blue epoxy uses a heat-conductive spray coating technique produced to achieve long-lasting corrosion protection. Thermoguard has passed the 80-cycle Kesternich sulfuric environment, Industrial ASTM G85, and Marine ASTM B117 tests. Because its smooth surface resists adhesion from dust and dirt, Thermoguard allows energy consumption to remain at nominal input levels with minimal routine maintenance, and can be applied as thin as 1.2 mils.


Esgard 910 KotesAll wax/alkyd is the base coating applied by Specific Systems® if a coating is requested. For general purpose use, Esgard 910 extends the life of coils, and is the choice if the environment is not super-corrosive and regular maintenance on the coils can be maintained.

Condenser Protection

Our last word in corrosion protection

Because the condenser sections of HVAC units remain outside and are therefore constantly exposed to the environment, systems designed for a corrosive atmosphere should include multiple types of protection. As the final stage in corrosion protection, Specific Systems® makes available Carboline protection for the condenser sections of any unit. Applications such as refineries and processing facilities, especially offshore, will benefit greatly from the additional protection Carboline provides to otherwise unprotected equipment.

What is Carboline?

Carboline-coated anti-corrosion condenser sectionThe Carboline used by Specific Systems® is a single coat modified epoxy, applied to a depth of approximately 5 mils. The epoxy is filled with aluminum flakes that greatly increase the distance water must travel in order to reach the underlying components. Combined with their reflective properties, the aluminum flakes help to prevent the harmful effects of ultraviolet rays, thereby protecting the system in all weather conditions.

Carboline is used in many industries to coat structural steel, fire escapes, water towers, bridges, and oil tanks. Carboline has outperformed competing products in multiple standard tests, including the Weather-Ometer, salt-fog, and coastal site evaluation.

Final Stage

Carboline is applied in the final stage prior to shipping, after the unit has been assembled and all the coils have their requested coatings. The entire condenser section of the unit, including cabinet, fans, motor, and piping, is sprayed with the coating. Component labels are masked off to allow for service and technical information access. The coils themselves do not get coated with Carboline, because they generally have corrosion protection such as Esgard, Technicoat or E-Coat baked on before assembly, and additional coating would be unnecessary and interfere with airflow.

Copper Fin/Copper Tube (CuCu) Coils

For ultimate protection, particularly in salt-water atmospheres

While more expensive than standard aluminum fin coils, copper fin coils provide some unique advantages:

  • Copper is generally stronger and more durable than aluminum, which can help prevent damage to fins
  • Copper provides better heat transfer than aluminum (92% vs 49% according to some estimates)
  • Copper is inherently more corrosion resistant than aluminum, since it does not react with water. Instead, it creates copper oxide which can help protect the copper from additional corrosion.

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