Using Surface Coatings to extend life and improve performance in industrial air conditioners.

Air conditioners are commonly used to keep electronics cool in various areas, such as industrial automation, telecommunication equipment, security and defense systems as well as other indoor and outdoor electronics applications. The electronics may be housed in protective enclosures, where air conditioners deliver cooled air to keep the entire enclosure at desired temperatures for optimum electronics operation.

The operating environment of these air conditioners can be aggressive and may present harsh elements, such as chloride and sulfur compounds in coastal areas, sulfur oxides and nitrogen oxides in industrial polluted areas, as well as airborne particles, cutting oils and solvents on factory floors. Air conditioners are typically packaged units, with air-to-refrigerant condensers and evaporators. These heat exchangers are often constructed with copper coils and aluminum fins, allowing refrigerant to flow within the tubes while air flows through the fins. Heat exchangers are susceptible to hostile environments and, over time, contaminants can corrode the heat exchangers or particles can accumulate within them. This causes the heat exchanger performance to degrade, leading to capacity loss, high head pressure and, eventually, compressor failure.

To minimize heat exchanger corrosion and dust accumulation, coatings can be used

to protect metal parts from harsh industrial environments. This white paper will discuss the different types of corrosions present, common coils used in air conditioners and salt spray and dust loading testing results, which indicate the effect of coatings on air conditioner performance and efficiency.

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CONTENTS OF WHITEPAPER

• Introduction
• Type of Corrosions
• Galvanic Corrosion
• General Corrosion
• Formicary Corrosion
• Type of Coils
• Uncoated Coils
• All-Aluminum Coils
• Pre-Coated Aluminum Fin Coils E-Coated Coils
• Salt Spray Test Results 
• Dust Accumulation
• Dust Loading Test Results
• Effect of Fin Density
• Effect of Coating
• Effect of Oil/Lubricant Residual
• Effect of Fin Pattern
• Conclusions and Recommendations

--- Featured Image by Charlie Medinger, Drives and Motor Consultant for CED Nebraska