Most ducted heat pump quotes look roughly the same on paper. A brand, a capacity, a number of outlets, a price. What separates a system you’re happy with in ten years from one you resent by the second winter is almost entirely in the detail underneath that.

So here’s how to choose a ducted heat pump if you’re in Auckland — the things worth checking, in the order they actually matter, from people who install these for a living.

1. Start with the heat load, not the brand

Sizing is the single biggest determinant of whether you’ll be happy, and it’s the thing most often done badly. A proper heat load calculation accounts for floor area, ceiling height, insulation, glazing area and orientation, room by room. A rule-of-thumb figure per square metre does not.

Oversizing is the more common error and the more damaging one. An oversized system reaches temperature fast, shuts down, and cycles — which is noisy, dehumidifies poorly, and wears the compressor. Undersizing leaves you disappointed on the coldest fortnight of the year.

Ask any installer quoting you: what heat load did you calculate, and room by room or whole-house? If the answer is vague, that tells you something.

2. Duct design is the part nobody checks

The equipment gets all the attention and the ductwork does most of the work. Three things to look for on a quote:

  • Duct sizing and static pressure. Undersized ducts force the fan to work harder, which means more noise and less air where you want it. This should be designed, not guessed.
  • Insulation rating. Ducts run through an Auckland roof void, which is cold in winter and brutally hot in summer. Poorly insulated ducts leak your money into the roof space.
  • Return air sizing. The forgotten one. If the return path is too small, the whole system is choked no matter how good the unit is.

You’ll rarely see this detail volunteered. Asking for it is a reasonable way to sort the careful installers from the quick ones.

3. Zoning: ask what it actually controls

Zoning lets you heat bedrooms overnight and living areas during the day rather than conditioning the whole house continuously. Worth having. But “zoned” covers a wide range.

The questions that matter: does each zone have its own temperature sensor, or does one master thermostat govern everything? Do the dampers modulate by percentage or just open and shut? And does the fan speed adjust as zones close, or does closing zones simply push more pressure through the remaining outlets?

We use AirTouch controllers, which handle all three and work across brands. Whatever system you’re quoted, those are the three questions.

4. The efficiency label that actually applies in New Zealand

You’ll see advice to look for an “Energy Star” rating. That’s a North American programme and it isn’t the New Zealand scheme. What applies here is the Zoned Energy Rating Label (ZERL), which replaced the old single star rating.

Two things about it are worth knowing before you rely on it:

  • Labels on ducted systems are voluntary, so not every ducted product carries one. Absence of a label doesn’t mean the unit is inefficient — it means you need the manufacturer’s published performance data instead.
  • New Zealand sits entirely in the ZERL’s “cold” climate zone, so read the bottom row and ignore the two above it. Because that zone covers everywhere from Kaitaia to Bluff, the annual kWh figure will tend to overstate consumption for an Auckland home. Treat it as a comparison tool between models rather than a bill forecast.

The ratings are derived from testing at 7°C and 2°C for heating and 35°C for cooling, which is a reasonable proxy for relative efficiency even if the absolute numbers won’t match your house.

5. Filtration: what’s realistic and what isn’t

You’ll read that you should look for HEPA filtration in a ducted system. In residential ducted equipment that’s largely a myth. A true HEPA filter creates far more resistance than a standard residential fan coil is designed to push against — fit one and you choke the airflow.

What a ducted system realistically gives you is decent coarse filtration that captures dust and pollen, which is a genuine benefit if someone in the house has hay fever. Some manufacturers offer treated filter media as well.

The part that matters more than the specification: filters only work when they’re clean. A blocked filter costs you airflow, efficiency and eventually the compressor. If air quality rather than temperature is your main concern, a dedicated ventilation system addresses it more directly.

6. The outdoor unit and Auckland’s salt air

This one is specific to where you live and rarely gets mentioned. Auckland is a coastal city, and a lot of its housing sits within a few kilometres of salt water. Salt-laden air corrodes outdoor coils and casings, and a unit that would last fifteen years inland can degrade noticeably faster in Devonport, Mission Bay, Milford or out west.

If you’re near the coast, ask about corrosion protection on the outdoor unit — treated coils and coated cabinets are available across most ranges — and factor in more frequent outdoor cleaning. It’s a small specification decision at quote stage and an expensive one to retrofit.

7. Noise and your boundary

Under the Auckland Unitary Plan, noise at a neighbouring residential boundary is limited to 40 dB LAeq at night. Ducted outdoor units are larger than a high wall’s and correspondingly harder to place on a tight section.

Helpfully, the ZERL includes a noise figure — for ducted systems that’s the outdoor unit reading, which is exactly the number relevant to your boundary. It’s optional for suppliers to display it in New Zealand, so ask if it isn’t shown. If the unit produces a tonal hum, NZS 6802 adds a penalty on top of the measured level, which tightens the margin further.

8. Warranty: read the servicing conditions

Five to six years is standard on residential ducted equipment, and most reputable brands will meet that. The clause people miss is that warranty cover almost always depends on the system being installed by an accredited installer and serviced at the required interval.

Skip two years of servicing to save a few hundred dollars and you can find the warranty unenforceable on a repair costing several thousand. Ask what the servicing requirement is before you sign, not after. We handle ducted servicing and repairs across Auckland.

Questions worth asking before you sign

  • What heat load did you calculate, and was it room by room?
  • What duct sizes and insulation rating are you specifying?
  • How is the return air sized?
  • Does each zone get its own sensor, and do the dampers modulate?
  • What’s the outdoor unit’s noise figure, and where will it sit relative to the boundary?
  • Is corrosion protection specified, given the distance to the coast?
  • What servicing does the warranty require?
  • Who actually does the install — your team, or a subcontractor?

Frequently asked questions

How much does a ducted heat pump cost in Auckland?

Ducted systems start from around $7,500 supplied and installed. The final figure depends on capacity, zone count, duct runs and roof access, which is why ducted is quoted after a site visit rather than over the phone.

Does my house need to suit ducted?

Roof space is the constraint. You need enough height and access to site the indoor unit and run ducts to every room. Villas and low-pitch 1960s–70s roofs are the ones that need assessing before anything is promised — sometimes a multi-split is the better answer.

Is a ducted system cheaper to run than a high wall?

Not for the same room — ducts lose some heat on the way. Ducted heats the whole house evenly, which costs more in total but gives you a warmer, drier home.

Which brand should I choose?

Sizing and duct design matter more than the badge. We’re accredited across Daikin, Mitsubishi and Panasonic and specify whichever suits the job — there’s more detail in our piece on Daikin ducted systems.

How long does installation take?

A typical residential retrofit runs two to three days on site, depending on zone count and roof access.

Get a quote

If you’re comparing ducted quotes and they all look the same, we’re happy to go through yours and explain what the differences actually mean — including if the honest answer is that someone else’s specification is better.

Request a free quote or call 0800 224 123. More on our ducted heat pump installations.