High-wall heat pumps for Auckland homes

A high-wall is the slim indoor head on the wall and an outdoor unit on the other side of it, and nothing heats a single room for less. Three things decide whether it suits your place: whether there's a wall it can go on, whether one will cover the space you're heating, and whether it needs to be built for coastal air.

How much does a high-wall heat pump cost in Auckland?

Supplied and fitted, a bedroom unit runs about $2,500 to $3,500. A main living area is $3,200 to $4,800, and a large open-plan space $4,500 to $6,500. In capacity that's roughly 2.5kW, 5 to 6kW and 7 to 8kW.

Those are finished-job prices, not the box on its own: the indoor and outdoor units, brackets, pipework, cabling, the electrical connection and the tidy-up. A price online that looks a lot cheaper is usually supply only, with the install still to come.

The price mostly comes down to the install, not the heat pump itself. In a two-storey house, the indoor unit's often upstairs but the outdoor unit sits at ground level, so the pipework has to run further and higher than in a single-storey place, more materials, more labour. Then if the spot for the outdoor unit is tight or hard to get at, that's extra hours on top again.

If you want a rough price without anyone having to come out, just add your details to the sizing calculator, takes a minute, gives you a capacity and a price. And what actually moves that price up or down is worth knowing too.

Where a high-wall heat pump can go in your room

A high-wall wants a clear stretch of wall up high with the room opening out in front of it, because it only blows one way and the air has to get somewhere. Point it into a doorway or across the back of the sofa and it warms the air right around itself, reads that as the room being up to temperature, and backs off long before it is.

In the weatherboard villas through Ponsonby, Grey Lynn and Mount Eden, finding that stretch is the hard part. Between sash windows, a chimney breast, picture rails and a door in the wrong place there's often only one wall that works, and it's rarely the one you'd have picked. Take it anyway. A slightly awkward position that heats the whole room beats a tidy one that leaves half of it cold.

Apartments and terraces are a different problem, and there it's usually the outdoor unit that settles it rather than the indoor one. The body corporate generally has a say in what can hang off an outside wall, and on a lot of buildings there's only one place the pipework can reach anyway. If your room has no usable high wall at all, a floor console sits low like an old gas heater and heats it just as well from down there.

Will one high-wall heat pump heat an open-plan room?

A high-wall blows warm air out in one direction, and that's about as far as it gets. With the internal doors open it'll carry a compact house further than you'd think, but it can't blow round a corner, and it won't push heat down a hallway into the bedrooms.

The open-plan builds around Botany and Flat Bush are where that catches people out. Put one unit at the end of a long living, dining and kitchen run and the far end stays cool however hard it works, and turning it up doesn't help either, because the unit reads the temperature right where it's mounted, decides the job's done and backs off while the other end is still cold.

Two ways round it. The cheap one is a bigger unit, sized for the whole space and aimed down the length of the room rather than across it, and that's often all it takes. Otherwise a multi-split runs several heads off one outdoor unit, so the lounge and a couple of bedrooms get sorted without lining the house with ductwork. In a villa that's usually the practical answer, because running ducts through an old cottage means lifting floors or dropping ceilings. In a new build with room above the ceiling, price ducted as well.

High-wall heat pumps near the coast

The outdoor unit is a copper coil threaded through hundreds of thin aluminium fins, and those fins are how it dumps heat outside. Salt settles on them and works its way in, and once they've gone chalky and started crumbling there's less metal left to shed heat through, so the unit works harder for less. No brand is immune to that.

It reaches further inland than people expect, too, because Auckland gets salt air off two harbours rather than one. Anywhere on the Shore between Devonport and Albany sits in it, and so does the estuary end of the east, around Half Moon Bay.

Some coated coils and casings stand up to it far better than others, and the extra is small next to replacing a unit years early. Where you put it matters as much as what you buy. Out of the direct spray, with air round it so it can breathe, up off the ground so it isn't sitting in a puddle, and somewhere a technician can actually get at it for the yearly service without hauling a ladder over the fence.

Does a high-wall heat pump cool as well as heat?

It does. A high-wall is reverse-cycle, which just means it can run the refrigerant the other way and move heat out of the house instead of into it, so the unit that warms the lounge in July cools it in February. Nothing extra to buy, nothing else on the wall.

It pulls moisture out while it cools, as well, which is what makes a muggy Auckland evening bearable rather than just cooler. The same dry mode earns its keep in winter, when getting the damp out of a room does as much for how it feels as the temperature does.

If cooling is the main reason you're buying, the air conditioning page covers the same gear from that angle.

Still weighing it up? The types of heat pump page sets a high-wall against a floor console, a ceiling cassette, a multi-split and a ducted system, and heat pump installation covers how the day runs. When you want a number, get a free quote.