October brings the nor'easters, and the dune that used to catch the salt isn't there anymore
Matthew and Nicole took the dune down. The salt that the dune used to stop now lands on the fins. Here is how to keep up with it, and where to stop.
The season nobody plans for
Hurricane season gets the attention, but the beachside’s slow damage comes from October through the winter, when nor’easters park offshore and push onshore wind for days at a time. Spray lifts off the surf, carries over the dune line and settles on everything downwind. Before 2016 the dune did a fair job of catching it. Matthew took a bite of the dune that year, Nicole in 2022 took more and forced 49 buildings along this stretch of coast to evacuate, and the county has been rebuilding sand and sea walls ever since. On a lot where the dune is low or gone, the condenser is now in the spray.
This guide is the routine for living with that. It separates what a beachside owner can do with a garden hose from what needs a technician with the right chemicals and the right judgment.
What salt does to an outdoor unit
Salt is hygroscopic: it holds moisture against metal. On the aluminum fins it causes pitting that eventually turns the fin edges to powder, so the coil moves less heat and the compressor runs hotter. At the fin-to-tube joints it sets up galvanic corrosion between aluminum and copper that ends in refrigerant leaks. On the cabinet it rusts the base and seizes the fasteners. Inside the control compartment it greens the contactor and the capacitor terminals. None of it is fast. All of it is steady.
The monthly routine, October through March
This is yours to do, and it takes ten minutes.
- Turn the power off at the disconnect by the unit.
- Rinse the coil with a garden hose at low pressure, from the top down and, if the top grille lifts off easily, from the inside out. Fresh water dissolves salt; pressure bends fins. Never use a pressure washer.
- Rinse the cabinet and the base, where salt collects in the drain holes.
- Clear the base of sand blown in by the wind. A unit sitting in a dune of its own holds moisture against the bottom rails.
- Look at the fins in good light. Note where pitting is starting so you can watch it.
- Turn the power back on and let the unit run before you walk away.
In the calm months, April through September, once a month is still worthwhile. In a week of sustained onshore wind, rinse twice.
The seasonal routine, twice a year
Also yours, with a little more effort.
- Spring: rinse out the oak catkins and pollen that pack the fins in February and March, trim shrubs back a few feet from the unit, and check that the pad or stand is level after a winter of blowing sand.
- Fall, before the nor’easters: check that the disconnect box closes tight and its gasket is sound, that the line-set insulation is intact where it leaves the wall, and that nothing has been stacked against the unit over the summer.
What belongs to a technician
There is a line, and on the beachside it is worth respecting.
Coil cleaning with a proper cleaner. Hose water removes loose salt. A technician’s coil cleaner, applied and rinsed correctly, removes the crust that the hose cannot and does so without eating the aluminum, which the wrong product will. Once a year on the beachside, twice on an oceanfront lot.
Electrical inspection under load. The contactor, capacitor and terminals in the control compartment are where salt does its quietest work. A technician measures them under running load and replaces what is drifting before June. Opening that compartment is not an owner job.
Fin repair and protective coating. Fins that have been bent can be combed; fins that have pitted can sometimes be coated after cleaning to slow the rest. Whether a given coil is worth coating is a judgment call made with the fins in hand.
Hardware replacement. Seized panel screws drilled out and replaced with stainless, rusted base rails addressed, a corroded disconnect swapped.
The replacement decision. When the coil leaks at the joints or the fins crumble, the honest advice is a new unit built for the coast: factory-coated coils, sealed electrical compartment, stainless hardware, a stand that lifts it above blown sand, and a louvered screen set well back if the lot allows. High-efficiency models qualify for FPL’s instant rebate through a participating contractor, and they last longest here when the monthly routine above starts on day one.
A short glossary, for the record
- Fin: the thin aluminum plate that moves heat from the copper tube to the air. Thousands per coil; the first thing salt attacks.
- Galvanic corrosion: what happens where two different metals meet in salt water; here, aluminum fins on copper tubes.
- Contactor: the heavy-duty switch that starts the compressor. Salt greens its contacts.
- Coated coil: a coil treated at the factory to resist salt. The beachside default.
- Onshore wind: wind from sea to land. The nor’easter’s gift to your condenser.
Beachside maintenance questions
Is there a spray or coating I can put on the coil myself?
Consumer coil coatings exist, but a coating applied over salt and grime seals the damage in. Factory-coated coils on a new unit are the real answer; on an existing unit, a professional cleaning followed by a proper coating is a technician job, and we’ll tell you whether the coil is worth coating.
Should I cover the outdoor unit in winter like people do up north?
No. A heat pump runs in winter here, and a covered unit traps moisture and salt against the metal while it sits. Shelter from direct spray with a louvered screen set well back from the unit is fine; a cover is not.
Does the dune restoration the county is doing help my equipment?
Some. Every foot of dune rebuilt between the surf and your yard knocks down spray, and the sand fences help too. But the dunes have been rebuilt and lost before, so plan the maintenance as if the dune were not there.
How do I know when the condenser is too corroded to save?
When the fins crumble at the touch of a fin comb, when the coil has refrigerant leaks at the fin-to-tube joints, or when the cabinet base has rusted through so the unit sits crooked. Any one of those and the next service visit becomes a replacement quote with coastal-grade equipment.
The salt doesn't take the winter off
Call Cook's for a beachside coil cleaning and corrosion check.