Salt Air Destruction of Air-Conditioning Equipment
2019 © Coastal Inspections
 

One of the largest problems with HVAC equipment installed along coastal areas is that air-conditioning condensers and coils will be impacted 24/7 quickly and severely by high levels of salt. The aluminum fins on the coils are exposed to corrosion as salt laden air passes through the coils. Fine grits of sand in the air can sandblast fine coatings to exacerbate corrosion as well. Once corrosion starts to develop, coil capacity and efficiency decreases rapidly. Because the entire HVAC system must function as one unit, each part must work together. Yet, when corrosion settles in, it can create a chain reaction of damage that increases over time, rendering each successive part operationally useless until the unit eventually fails.

In some conditions (i.e. beachfront or within a mile of beachfront or bays), the operating performance of unprotected coils can decrease by almost 50% in less than six months. As coil corrosion increases the outside condenser coil can’t remove the heat it was designed to do, system performance drops significantly and the cost of electricity increases substantially. Interior heat and humidity are not efficiently removed and buildup. Additionally, within the first year of an HVAC installation in such salty areas, HVAC condenser coil fins can become salt coated with start of corrosion to diminish efficiency and mostly along the outer edge of the aluminum coil fin as it eats its way inward. The aluminum fins turn into a powder as the aluminum is eaten away. Condensers along coastal areas may have an estimated life of only a few years which is an economic boom to replacement contractors.

Now that aluminum tubed evaporator coils are replacing copper tubes coils due to formicary corrosion aluminum is very susceptible to salt corrosion. These are recommended to be washed yearly, if not sooner in salt rich environments. Better yet condensers should be coated with a protectant to protect from corrosion. Evaporator coils should also be coasted against mold and bacterial growths associated with aluminum tubed coils. At least they should be washed yearly or more often with water as recommended by the manufacturers. A typical manufacturer may not recommend chemical cleaning. If your contractor wants to chemical clean then have them provide documentation that the the chemical is approved by the manufacturer to avoid damages to the coil and fins.

Cooling is always a large part of annual electricity usage. So an annual and continuous increase in electricity use can be attributed to the exterior condenser coil corrosion and then to the indoor evaporator coil depending on its location. Corrosion is linked to a large percentage of HVAC failures. Corrosion to wire connections, contractors, coil fins, motors, fans and even the screws that hold things together. A unit may appear to be cooling but the cost of electricity to run a system may become somewhat outlandish.

To solve this issue, there are spray and immersion/bake protective coatings available for condensers and evaporator coils as well as their cabinets so they do not get significantly damaged. These specialty coating products are hydrophobic and designed to resist chemicals and corrosion in severe duty locations. NASA, the military, offshore drilling platforms or rigs, ships and chemical plants are common users of these coatings.

As a homeowner what are some of your options and recommendations?

Born on an island, and raised on the coast. As a Coastal Inspector we have answers and great recommendations for properties over 25 miles inland. Historically our inspections are designed to pay for themselves. I don't know anyone else that can say that. We are not a franchise where you buy into a fancy store bought marketing and advertising campaign. You can't buy experience and education.

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