Salt air, lightning and a house's electrics

Two things on this coast shorten the life of anything with a hinge or a wire. One is salt, carried inland on the sea breeze every day. The other is lightning, which arrives with the rains. Neither can be stopped, and both can be managed.

What salt does

Salt settles on every surface, holds moisture there and attacks metal. Near the water it is fast: hinges, locks, railings, light fittings, gate motors and the screws holding all of them. Distance from the surf, and whether the house faces the wind, decide how fast.

Not all stainless steel is the same

The common grade of stainless steel, known as 304, resists rust well inland and poorly near the sea. Grade 316 contains molybdenum, which is what resists the pitting that salt causes, and it is the grade to ask for on anything outdoors near the coast. Even 316 develops brown staining if salt is left to sit on it. Stainless steel stays stainless by being washed.

That is the general rule for everything metal: rinse it with fresh water. Rain does this for free in the green season. In the dry months, and on surfaces under a roof that rain never reaches, somebody has to do it.

Air conditioners

The outdoor unit of an air conditioner is a block of thin metal fins with air pulled through it all day, which makes it one of the first things salt destroys. Manufacturers sell versions built for the coast, with coated or all-aluminium coils and protected fasteners, and they are worth considering at replacement time. For the units already installed, a gentle rinse of the outdoor coil with a garden hose, with the power off, slows the damage.

Salt reaches the electrics too. An electrician opening the main panel once a year will see rust on the enclosure, green deposits on copper and discoloured connections long before they become a failure.

Lightning

Costa Rica's electricity institute, ICE, runs a lightning detection network. It has counted more than 600,000 strikes across the country in a single year, most of them in the rainy season.

A direct strike on a house is rare. The usual damage comes from a strike somewhere nearby that sends a surge along the wires. The United States National Institute of Standards and Technology, in its guide to surges in the home, points out that those wires include telephone and cable lines as well as the power line, and that appliances connected to two of them at once, such as a router or a television, are the most exposed.

Its advice is protection in two layers. A surge protector at the main electrical panel diverts large surges before they enter the house, and is installed by an electrician. Plug-in protectors then guard the sensitive equipment, and for anything with a second connection the protector should cover both lines. None of it works without good grounding, which the guide calls fundamental.

Lightning rods are a separate matter. They protect the structure from fire in a direct strike. They do not stop surges in the wiring.

Power cuts and voltage

Storms also bring power cuts and unstable voltage. The compressors in air conditioners and fridges suffer when power drops and returns within seconds. Small voltage protectors that cut the supply when it goes out of range, and wait a few minutes before reconnecting, are inexpensive and widely sold here. After any outage a house should be checked: breakers, the fridge, the pool pump timer and the water pump.

Electrical work, including surge protection and grounding, should be done by a qualified electrician. This article explains what to ask for.