Corrosion Resistant Coil Coatings Extend the life of your HVAC system with one of our coating options Technicoat 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.ductless ac units dual zone 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. portable air conditioning units san diegoE-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. home ac repair lakeland flUsing 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. 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. The 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.

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.Coil corrosion is an expensive problem in the HVAC industry, leading to coil replacement or entire system replacement. Corrosion results in failure, and is responsible for about 40% of equipment failures in industrial applications, according to CED Engineering.In 2015, subscribers who read this article also: Purchased CoilShine Coil Cleaning SolutionPurchased CoilShine Mold & Mildew InhibitorDownloaded HVAC “Spring Cleaning” ChecklistsAs the authors of an article in Reliable Plant explain, coil corrosion comes in the form of either pitting or formicary deterioration. Corrosion may occur as quickly as a few weeks after an installation or it may take up to four years to present itself.Pitting corrosion is most often caused by exposure to fluoride or chloride. Fluoride is present in municipal water supplies, while chloride is found in a variety of products including snow melt, detergents, cleaners, carpeting and fabrics.

Pitting occurs when chloride or fluoride ions are transported to the metal via condensate. The ions attack the metal, forming pits that form pinholes, causing the coils to leak refrigerant.Formicary corrosion is typically caused by exposure to acetic or formic acids. These acids are present in a host of household products including cleaning solvents, insulation, adhesives, paints, plywood and many other materials. This type of corrosion is not always immediately visible and sometimes presents itself as black or blue-gray deposits. Formicary corrosion creates tunnels within the tubing that result in pinholes forming in the coils, again often leading to a refrigerant leak.Facilities located in more corrosive environments including near saltwater or in industrial sites are particularly prone to experiencing coil corrosion. Other environments that may contribute to a higher amount of corrosive materials being expelled include areas around pools, laundry facilities, water treatment plants, sewers and high traffic areas.

In such highly corrosive areas, coils have been known to fail in less than one year, according to CED Engineering.A potential cause of coil corrosion is Chinese drywall, also known as odorous wallboard. Chinese drywall is also hazardous to your health. According to an article in G3 Environmental & Industrial Hygiene, an environmental and industrial hygiene service company, the drywall was imported from China from 2004 to 2007 and installed in both residential and commercial buildings. The drywall emits sulfur compounds, which corrode metal, including air conditioning coils.The Centers for Disease Control and Prevention confirms that exposure to Chinese drywall can cause certain health problems such as irritated eyes and skin, respiratory problems and headaches. Exposure to this type of drywall can also exacerbate asthma symptoms.You can identify the drywall by looking at the back. It should contain a label with the words: “Made in China,” “China,” or “Knauf.” Some Chinese drywall is not marked.

In that case, metal corrosion including in plumbing, electrical, and natural gas lines, combined with a rotten egg odor may signify a Chinese drywall installationTo combat the problem of coil corrosion, coil manufacturers are applying coatings prior to production. In addition, there are companies offering aftermarket coatings. In a brochure, Aeris Technologies Ltd., a manufacturer of aftermarket coil-protection coatings, explains that the consequences of coil corrosion can include reduced efficiency, unattractive surface deterioration and equipment failure.Additionally, reduced heat rejection may occur, resulting in an increasing compressor temperature and lower cooling capacity, which in turn increases the power usage. Lower cooling capacity means the compressor doesn’t cycle as intended, which means increased power consumption. As systems work harder they become more stressed, experience more breakdowns and have higher maintenance costs. A lower cooling capacity may also mean occupants aren’t very comfortable, resulting in loss of business or productivity.

Preventing coil corrosion is much more effective and cheaper than replacing coils or the entire system.There are basically four types of coil coating materials: polyurethanes, epoxies, fluoropolymers and silanes, according to Reliable Plant. Choose carefully as the wrong coating, especially with aftermarket products, can reduce heat transfer and result in more expensive operating costs. An aftermarket application may affect the manufacturer’s specifications.Thinner coatings have better heat transfer while thicker coatings restrict heat transfer. Hydrophobicity, or how effectively water drains from the coil, can affect heat transfer. Water buildup may also cause mold or mildew growth. The advantages of the four types of coatings differ as to how they resist scratching and corrosion; and heat transfer abilities.Polyurethane is inexpensive, flexible and thin, but it’s not as long-lasting as other coating options. Epoxy is cheap, but it’s usually a thicker coating and can’t be applied in the field;

the coils must usually be shipped to a factory for professional application. Fluoropolymers are highly resistant to acids and solvents, and are inexpensive, but the sprays generally adhere poorly and their effectiveness wanes quickly.Silanes form a thin coating that affects heat transfer very little and they typically last longer than other coatings. But they’re more expensive and proper application is best done by a professional and usually off-site. Each coating type has varying toxicity levels. Technicians applying the coating should wear equipment as specified by OSHA and an appropriate breathing apparatus.Whether coated or not, continuing maintenance of coils is the primary way to combat the effects of corrosion. Twice annual cleaning with an alkaline coil cleaner or ph balanced coil cleaner will clear away any accumulated deposits, keeping coils safe from corrosion but also positively impacting the efficiency of your system.Have you experienced coil corrosion? How did you combat the problem?