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Application Experience and Markets Served

At over $2 trillion, the annual cost of HVAC-R corrosion worldwide represents over 3% of the world’s GDP. In the United States the annual cost of corrosion in direct damage, increased maintenance, and downtime is approximately $1 trillion. Reducing unnecessary equipment failures and reductions in energy efficiency due to corrosion can dramatically affect operating income and profits for virtually every business.

A leader in HVAC corrosion protection, Heresite offers coating products resistant to salt air, salt water, acid rain, hydrogen sulfide, sulfuric acid, ammonia, chlorine, hydrogen chloride, sulfur water, uric acid, and virtually any other acid or alkali.

A long history of protective coating and sealant innovation

Heresite was the first company to apply corrosion resistant coatings to HVAC coils in 1954. It remains a leading coating option for HVAC-R and other heat transfer applications because of its minimal thermal loss, flexible and durable finish, and resistance to thermal shock and temperatures (from well below freezing to 400F). Heresite coatings provide protection in corrosive high salinity marine conditionsindustrial applications such as wastewater treatment, swimming pools, food processing, mining, oil and gas, semi-conductor production, pulp and paper, textile factories and other environments where these systems are exposed to chemical fumes.

Heresite protective coatings are well-known for providing long-lasting, resilient corrosion protection in some of the most challenging environments, including marine environments, wastewater treatment plants, swimming pools, industrial/urban environments with high levels of pollution, agriculture, food processing, transit, and mining.

Selecting the proper coating for your equipment and environment will improve your HVAC-R equipment’s operating efficiency, reduce maintenance costs due to corrosion, and increase energy efficiency.

HVAC-R coating selection FAQs

HVAC-R protective coatings are applied using immersion or spray application techniques. Most Heresite products are applied using the immersion process. Immersion coating provides uniform coverage and protection of every surface, including those that cannot be seen. Test results for our immersion products show extreme durability and superior performance in even the harshest environments. This includes the new ISO 12944-9 Offshore standard, which has combined C5-I (highly corrosive, industrial) and C5-M (highly corrosive, marine) into a new rugged environmental category: CX Extreme.

Heresite also offers spray-applied coatings. Spray application is an ideal solution for situations where components cannot be oven cured or logistics present challenges, and a high-performance coating is needed. Like our immersion coatings, Heresite spray-applied coatings have demonstrated superior effectiveness in the harsh CX environments.

All Heresite coating products for HVAC equipment have been extensively tested for durability using industry-recognized tests. Our testing methods include:
ASTM B117 – tests against 3,500 hours of exposure
ISO 12944-9 – a cyclic 4,200 hour exposure test
ASTM D 4587 – tests against 5,000 hours of UV exposure
ASTM D-2247 – tests against 5,000 hours of water resistance
Cross-hatch adhesion ASTM D-3359
Bend Test ASTM D522
NSF/ANSI 51- tests to ensure coatings meet the requirements for materials and finishes used in commercial food environments

In addition, Heresite products are tested against hundreds of chemicals. A full list can be found by downloading our chemical resistance guide.

Of course, the actual performance of the coating in your specific environment will depend on a variety of factors, but test results should help you determine the estimated performance you can expect from your chosen HVAC coil or unit coating.

The simple answer is yes. Heresite P-413 has been successfully tested against UV exposure using two testing methods. It is the first HVAC-R coil/radiator coating to meet ISO 12944-9 (formerly ISO 20340) standard. ISO 129449 consists of 25 one-week cycles of 72 hours of UV exposure, 72 hours of salt spray, and 24 hours of freezing. In addition, a test conducted in conjunction with Sanuvox Technologies Laboratory demonstrated the effectiveness of P-413 after 1,500 hours of UV-C exposure.

The dry film thickness of Heresite’s newest HVAC- & Radiator protective coatings (ES-600 and P-413) is 1.0 – 1.5 mils. Heresite industrial baked phenolic products (EP-6300) have a dry film thickness of 5.0 – 7.0 mils with a 2 – 3 coat application.

Heresite coatings do not impact heat transfer in any material way. In 2017, we participated in a wind tunnel test for our P-413 baked phenolic epoxy coating which demonstrated no difference between an uncoated coil and a coated coil.

Corrosion resistant coatings are specifically formulated to provide protection in a variety of environments. Your HVAC-R coating should be chosen based upon the environment in which it will be used. Corrosion environments are classified C1 (very low exposure) through C5 (very high exposure). The experts at Heresite are happy to help you choose the right coating for your particular application. Note that a coating capable of providing protection at a high level, such as a C5 environment, will also provide protection at a lower corrosivity category, such as a C4 environment.


No matter the environment, Heresite has you covered.

If you are in the HVAC-R Industry you know that corrosion is one of the largest single expenses resulting in equipment failures and increased charges. Have you considered protecting equipment that services the following environments?

  • Wastewater treatment plants
  • Gas and oil refinery operations
  • Battery manufacturers
  • Sulfur water areas
  • Pulp and paper mills
  • Wineries
  • Chemical Plants
  • Saltwater coastal installations
  • Mining industry
  • Airports
  • Heat recovery
  • Work boats – barges
  • Yacht HVAC
  • Chemical plants
  • Semiconductor manufacturing
  • Pork processing
  • Bakeries
  • Offshore
  • Peanut roasting
  • Swimming pools
  • Lumber drying
  • Defense
  • Confectionary
  • Glass manufacturers
  • Agriculture
  • Pharmaceutical

Protect your investment by relying on Heresite Protective Coatings no matter the Environment.