Close this search box.

Choosing the right Heresite coating

Choosing the best HVAC-R protective coating for your particular environment and application is an important decision. At Heresite, our HVAC-R coating products are continually evolving to provide you with the best possible solution for your environment. Be sure you select the most appropriate solution when specifying a coating for a particular application by consulting with our experts. We will work with you to ensure your equipment is protected with a coating that is well-matched to your environment.

Our experts will help you evaluate your needs by considering:

  • The corrosivity of your environment. Learn more about corrosivity categories by reading What you need to know about ISO Corrosivity Categories.
  • The chemical elements your equipment must withstand. Download a copy of our Chemical Resistance Guide to learn about the service conditions we have tested against.
  • Application environment. Can the product be transported to our facility or another authorized applicator? Our facility can coat units or coils up to our largest oven size – 55 feet long by 11 ½ feet tall and 10 ½ feet wide. Plus, we have overhead cranes that can lift up to 60,000 pounds. However, we also offer products that do not require oven curing and can be applied at your location.
  • The testing method specified. Whether you need a coating that has been tested against ASTM B-117 or prefer the more realistic cyclic offshore ISO 12944-9 test, we can help you find a product that meets your specifications.

The following table compares test results and uses for our four most popular products, including:

HereShield (WB-506) Air-Dry Water-Based Coating

A single-component air-dry coating offering faster drying, better corrosion resistance, extremely low VOC, and can be used for spraying or dipping.

P-413 Modified Baked Phenolics

A thin film, high performance coating used principally for coil and radiator heat exchangers as well as other air and fume handling equipment fabricated of light gauge metals. It is the first HVAC-R coil and radiator coating to meet the ISO 12944-9 (formerly ISO 20340) Standard for severe offshore marine environments.

ES-606 Epoxy-Silane

A two-component direct-to-metal coating for excellent adhesion and high resistance to UV and corrosive environments. The highest-performing non-baked HVAC coating on the market.

Hydrophilic HL-300

A topcoat that reduces the contact angle of water exposed to the surface. This robust coating provides superior hydrophilic protection in high salt spray or immersion environments, reducing water carryover downstream from a wet coil or coil covered with condensate.

P-413 ES-600 VR Next Generation VR-514
Chemistry Phenolic Epoxy Epoxy Silane Proprietary Phenolic
Cure Mechanism Oven Cured Chemical Cure; Air-Dried Air-Dried Air-Dried
Method of Application Immersion, flow or spray Spray Immersion, flow or spray Spray
Cyclic offshore (ISO 12944-9) (aluminum + copper) Pass 25 weeks (4,200 hrs) Pass 25 weeks (4,200 hrs) Pass 25 weeks(4,200 hrs) NT
Static Salt Spray (ASTM B-117) (hours) 6,000+ (test panel up to 18,000) 3,500+ 5,000+ 2,000
Humidity (ASTM D-2247) (hours) 5,000+ 5,000+ 1,000+ 250
QUV (ASTM D-4587) (hours) 3,000+ (with UC-5500) 5,000+ 500+
QUV-C Sterilizer (hours)


ASTM G-85 3,000+ NT NT NT
Solvent Resistance (ASTM D5402) (MEK) 100+ 100+ <10 <10
Adhesion (ASTM B-3359) 5B 4B/5B 5B 5B
Flexibility (ASTM D-522) >1/4” >1/4” >1/4” >1/4”
Hardness (ASTM D-3363) 5-6H 2H-4H 4H 4H
Temperature Limitation 400F (250C) 200F (93C) 200F (93C) 200F (93C)
DFT (mils)

1.0 – 1.5

1.0 – 1.5 1.0 – 1.5 1.5 – 2.5
Chemical Resistance Immersion and fume Fumes Fumes Fumes
NSF Yes Approvable Approvable Approvable
VOC lbs/gallon (as-applied)


1.1 <1.0 2.8

NT = Not Evaluated Yet

With the broadest product portfolio in the industry, we can match your needs to our products and find a coating solution that truly protects in even the harshest environments. Contact us for assistance selecting the coating that is right for you.