Coastal Corrosion AC Repair in Charleston, SC

Coastal corrosion AC repair in Charleston starts with one question: how much sound metal is left? Salt air eats condenser coils, cabinets and electrical contacts on homes near the harbor, the marsh and the barrier islands, and the right fix depends on how far the damage has gone.

Aero Air Techs inspects the unit, tells you what can be saved and quotes before any work begins.

Some coastal units need a cleaning and a few new parts. Others are past that point, and spending on them would be a waste. You will hear which one you have.

What does salt air AC damage look like?

Corrosion shows up outside first, then in the numbers. Walk around your unit and look for these signs.

On the unit	Likely cause	Why it matters
White powder or crust on the fins	Aluminum is corroding	The coil sheds less heat
Fins that crumble when brushed	Advanced fin loss	Cleaning will not bring them back
Rust at the base pan or cabinet screws	Steel parts are failing	Panels loosen and hardware seizes
Green or white crust on wire lugs	Corroded connections	Heat builds and contacts fail
Longer run times and warmer air on hot days	The coil cannot shed heat	Compressor runs hotter and works harder
Refrigerant low again after a recharge	A leak, often at weakened tubing	The problem repeats until it is found

Coastal corrosion AC repair in Charleston begins with the chemistry

Three different processes wear on equipment here, and only two of them involve salt. Telling them apart decides the fix.

Salt on aluminum fins

Sea spray leaves a film of salt on every surface. Salt pulls moisture from humid air, so the film stays damp through our long, sticky nights. The chloride in that film breaks through the thin oxide layer that normally protects aluminum, and the metal starts to pit. A coil has a huge fin surface, which gives salt plenty to work on.

Galvanic corrosion

Two different metals in contact with a salty, wet film behave like a weak battery. The more active metal gives itself up to protect the other. In most coils, that means aluminum fins corrode where they touch copper tubes. The fins can look fine while the bond to the tube fails, and once that bond goes, heat stops moving from the tube into the fin. The same thing happens where steel screws meet aluminum or copper lugs meet steel.

Formicary corrosion

This one happens indoors and has nothing to do with salt. Formicary corrosion needs copper, moisture, oxygen and organic acids, which can come from household chemicals, adhesives and building materials. It bores microscopic tunnels through the copper tube wall, usually on the indoor evaporator coil. You will not see crust. What you get is a repeat refrigerant leak with no obvious source. An all-aluminum coil avoids it, though aluminum is still exposed to salt outdoors.

What we check on a coastal unit

A corrosion inspection looks at the whole system, not only the part that failed.

• Coil fins. Condition, thickness and how firmly they grip the tubes
• Copper tubes and joints. Oil stains, weak spots and leaks
• Cabinet and base pan. Rust, seized screws and drainage
• Electrical panel. Contactor, capacitor, lugs and wire insulation
• Fan motor. Bearings, shaft and blade
• Mounting. Stand, platform and any tie-down hardware
• Pressures and temperatures. How well the system is shedding heat
• Indoor coil. A leak search if refrigerant keeps dropping

Clean, coat, repair or replace?

Each option fits a different stage of damage, and each has a catch.

Option	Helps when	The trade-off
Coil cleaning and rinse	Salt film and light surface corrosion	Slows the damage but restores no lost metal
Coil coating	Clean coil with sound fins	Needs careful prep and a touch-up routine
Part replacement	Corroded contactor, capacitor, lugs or motor	Simple fix, unless the coil is failing too
New condenser coil	Coil is gone but the rest is sound	Parts can be hard to find on older models
Full AC replacement	Coil, cabinet and compressor are all worn	Highest cost, and the longest fix

Coatings deserve a closer look. Trade sources describe coastal air as the most documented case for coil coatings, but quality varies, and the common benchmark is a salt-fog test under ASTM B117. Ask for test data. Surface prep is everything, because a coating over trapped salt seals the problem in. Factory-coated coils are usually applied more evenly than anything done in the field, so raise them when you buy a new coastal AC unit.

Corrosion means replacement when the fins crumble, the coil leaks in more than one spot, the base pan has rusted through or the compressor has been running hot for a long time. Stopping there beats paying for a coil that goes into a rotten cabinet.

How a corrosion visit runs

1. Tell us what you see. Photos of the fins and panel help us plan.
2. Inspect and test. We work through the list above, with the power off where needed.
3. Show you the damage. You see it for yourself and hear what it means.
4. Quote the options. You get a clear, upfront quote, often with more than one path.
5. Do the approved work. Refrigerant handling follows EPA Section 608, which bars venting and requires technicians to be certified.
6. Confirm cooling. We run the system and check the temperature drop.

How long it takes

Cleaning and electrical repairs can often finish on the first visit if the parts are on hand. Coils usually take longer, because many are ordered by model, and coatings need a clean, dry surface. We will give you the likely sequence when we quote.

What drives the price

Cost depends on the damage. The main factors are how much of the coil is affected, whether parts are still available, the refrigerant involved, the climb to a raised stand and whether the work goes on a rental between guests. If you hear a compressor or coil price, weigh it against the age of the equipment before you approve it.

A rinse schedule for coastal units

Fresh water is cheap protection. No agency publishes a rinse schedule, so use this as a starting point and adjust to what you see on the fins.

Location	Suggested rinse
Oceanfront or first row on the islands	Monthly in cooling season
Harbor or marsh-front homes	Every two or three months
A mile or more inland	At spring and fall tune-ups

To rinse, turn the power off at the disconnect, then use a garden hose on a gentle setting. Work across the fins and let the unit dry before you restore power. Never use a pressure washer, and do not use a cleaner the manufacturer has not approved. Add a rinse after any onshore storm. Atlantic hurricane season runs June 1 to November 30, according to NOAA, and our hurricane prep guide covers the rest. Pair the rinses with a yearly AC tune-up, and read how long units last on the coast.

Rules start when a repair turns into new equipment. City of Charleston guidance says machinery in the Special Flood Hazard Area must sit at the Design Flood Elevation, and Charleston County publishes its own height rule for replacement units. A coil coating needs no permit that we know of, but a condenser change-out is listed on the City's Form 5.1. Ask your local office before a salt-worn unit gets swapped.

Why call Aero Air Techs about salt damage?

• Rated 4.9 on Google, with 16 reviews as of October 2026.
• A quote before the work, so you can weigh every option first.
• Plain talk. One customer described the technician as "knowledgeable about our unit."
• Around the clock. Google lists us as open 24 hours, 7 days a week.

We are based in Charleston and serve the coast and surrounding areas, including Folly Beach, Sullivan's Island, Isle of Palms and Awendaw. Give us your address and we will talk through timing for your stretch of coast. For faults that have nothing to do with salt, see AC repair.

Salt exposure is not the same at every address.

• Folly Beach: ocean on one side and river marsh on the other, so wind brings spray or damp air either way.

• Sullivan's Island: treat coil protection as the first decision, then Town design review.

• Isle of Palms: rental units need rinses scheduled around changeovers.

• Awendaw: Bulls Bay homes get salt, while forest-edge lots get pine straw instead.

• Kiawah Island: condensers on stands need a plan that fits the regime's approvals.

• Seabrook Island: closed villas can go a season with no one noticing crust.

• James Island: marsh air works on contacts more slowly than ocean spray, but it never stops.

• Mount Pleasant: homes near the harbor end can have salt on both condensers.

• Georgetown County: Waccamaw Neck homes sit between the river and the ocean, so plan a long trip around a full inspection.

• Beaufort: river damp joins the salt, and old frames add humidity, so bring photos before we plan the drive.

• Hilton Head Island: planned work only at this distance, so book coil checks well ahead of the rental season.

• Myrtle Beach: condo condensers often share a roof, which suits one planned visit for several units.