Heat pumps for the peninsula, harbour and beaches

From St Clair around the harbour to Macandrew Bay and Portobello, and north to Waikouaiti and Karitane, these homes sit on salt water and take the southerly full on. It is a harsher environment for a heat pump than anywhere else around Dunedin, and the choice of unit and its position matter more than the brand on the front.

What salt does, and how fast

An outdoor unit is a copper coil threaded through hundreds of thin aluminium fins. Salt settles on those fins, holds moisture against the metal and corrodes it. The fins go chalky, then powdery, then break away from the tube.

By then the unit cannot shed heat properly, so it works harder for less output and the power bill climbs. From the outside it looks fine right until it stops. On an exposed St Clair or Brighton frontage, an ordinary unit meant for an inland suburb can show real fin damage within a few years.

Every major brand sells a coastal or anti-corrosion version with a treated fin stack and a better cabinet finish. Out here that is the default, not an upgrade, and it is worth checking what the warranty says about coastal installs before you sign.

The southerly and where the unit goes

St Clair, Brighton and Waldronville face the open ocean and take the southerly swell and the wind that comes with it. Mounting the outdoor unit on that elevation is the shortest route to a short life, however tidy it looks.

The landward or lee side is almost always available, and the extra pipework costs far less than replacing the unit early. Under the eaves beats out in the open, because rain rinses salt off while wind-driven spray only adds more. Up off the ground on a stand keeps it clear of splash and lets air move underneath.

Around the harbour at Macandrew Bay, Portobello, Port Chalmers and Ravensbourne the wind is different: funnelled along the water rather than straight off the ocean, and often stronger than it looks from the road. The sheltered spot is usually behind the house rather than beside it.

Older baches and newer builds side by side

The housing out here is mixed in a way the city suburbs are not. Portobello, Karitane and Brighton still have plenty of small older places built as baches and later lived in year round, with minimal insulation and single glazing.

Those benefit enormously from one well-sized unit in the main living space, and they are the homes where a heat pump makes the biggest difference to how the place feels. Port Chalmers and Sawyers Bay add older workers' cottages on steep sections, where access for the install is the practical constraint.

Newer coastal builds at Waldronville and parts of St Clair are the opposite: well insulated, big glazing to the sea, and prone to overheating on the rare still summer day. They usually need less capacity than owners expect, and the money is better spent on the right model for the salt.

Making it last

The single most useful thing you can do on the coast is rinse the outdoor coil with fresh water every few months. A gentle hose from the side, never a water blaster, which folds the fins flat and does more harm than the salt.

Beyond that, keep the filters clean, keep plants back from the outdoor unit and have it checked properly every year or two. Regular heat pump servicing catches fin corrosion while it is still cosmetic. If you want the detail on how the install itself is done, the heat pump installation page covers it, and installation cost has the ranges.

Suburbs covered in Otago Peninsula and the beaches

• St Clair
• Andersons Bay
• Macandrew Bay
• Portobello
• Port Chalmers
• Sawyers Bay
• Ravensbourne
• Brighton
• Waldronville
• Waikouaiti
• Karitane

Somewhere else around the district? Your local installer also covers Central Dunedin and the hill suburbs, South Dunedin and the flat and Mosgiel, Outram and the Taieri. The full list is on the areas we serve page, or get a free quote for your place.