Manufacturers of air-conditioning equipment have designed units, particularly coils, to meet higher Seasonal Energy Efficiency Ratio (SEER) ratings. Equipment today is much more efficient than that of just 3-5 years ago. This is gratifying to the owner and power companies as the initial operating demand for energy is reduced. However, the new design of most fin tube heat exchangers (coils) while more efficient is less resistant to corrosion from atmospheric conditions.
In developing higher efficiency equipment, manufacturers include typical changes such as increasing the fins per inch, increasing the face area of the coil and adding configured or enhanced fins to increase air flow and create a greater vortex of air passing through the coil for improved heat transfer. The higher fin count and the raised enhancements require thinner gauge aluminum to be employed in manufacturing the fin.
Further consider that most modern aluminum is recycled and may contain impurities from the re-manufacturing process. These impurities create anodic cells and intensify the rate of corrosion. Recycled aluminum is not as pure as aluminum derived from bauxite. Coating your coils can eliminate these hot spots of corrosion.
These design features make the modern coil even more susceptible to corrosion and entrapment of airborne particles, thus reducing operating efficiency over time. Dirt and other airborne particulates impede air flow through the coil. In corrosive environments, thinner, enhanced fins are more likely to deteriorate from abrasion and corrosion than a coil of older design (14 fpi wavy or plate fin coil made of heavier gauge aluminum).
Regularly scheduled coil cleaning removes corrosion and accumulated airborne pollutants such as dirt, soils, insect residue from the coil surface. Proper coil cleaning at regular intervals makes a significant contribution to extending equipment life and is an excellent source of energy conservation for your new coil. Yes, replacing your coils can save you money on your energy bill, but to maximize your savings, you need to protect those coils and keep them clean over the life of the coil.