The two labels you will see
Heat pumps sold in New Zealand carry an energy rating label under the rules shared with Australia. Since 1 July 2021, new heat pumps must carry the zoned energy rating label.
You may still see the older star label on older units. It shows separate star ratings for heating and cooling. The zoned label adds a climate zone map and shows how the unit performs in each zone.
Reading the star rating
Red stars are for heating and blue stars are for cooling. More stars means the unit delivers more heat or cooling for each unit of electricity. On the zoned label, stars run from 0 to 10.
In New Zealand the heating stars matter most for most homes. Compare heating stars between models of the same size, because larger units often rate lower than small ones.
Reading the zoned label
The zoned label has three climate zones: hot, average and cold. Each zone has its own star rating and an estimate of yearly energy use for heating and cooling.
The hot and average zones cover parts of Australia. All of New Zealand is in the cold zone, so read the cold zone figures, not the best-looking ones on the label. A unit that scores well in a milder zone can rate lower in the cold zone.
The label also shows heating capacity at 7 °C and at 2 °C outdoors. Check that the 2 °C figure is not much lower than the 7 °C one, because that is closer to a New Zealand winter morning.
Heating output in cold weather
This is the number most people miss. A heat pump's rated heating capacity is measured at a mild outdoor temperature. As it gets colder outside, the output drops.
Manufacturer spec sheets usually list heating capacity at low outdoor temperatures, often at minus 7 °C or similar. If you live somewhere with regular frosts, compare that figure, not just the headline kW. Two units with the same rated size can be very different on a July morning.
Noise levels
Noise is listed in decibels, usually as dB(A). Showing noise on the energy label is optional in New Zealand, and where it appears it is measured at full capacity, so the spec sheet is the better place to look. Indoor units are quoted at each fan speed, and the lowest figure matters for bedrooms.
Decibels are not linear. An increase of about 10 dB sounds roughly twice as loud, so a few dB between two outdoor units is a real difference if the unit sits under a window.
Refrigerant
Most new residential heat pumps use R32 refrigerant, which has a much lower global warming impact than the R410A used in many older units. If you are replacing an old heat pump, whether the existing pipework can be reused depends on the new unit's installation instructions and the pipe size and condition. Some manufacturers require new pipe.
What to compare between quotes
| Check | Where to find it | Why it matters |
|---|---|---|
| Heating stars | Energy label | Efficiency in day-to-day heating |
| Cold zone rating | Zoned label | Realistic performance in New Zealand |
| Heating capacity at 2 °C | Zoned label | Whether output holds up as it gets colder |
| Heating capacity at low temperatures | Spec sheet | Whether it keeps up on frosty mornings |
| Indoor noise on low fan | Spec sheet | Comfort in bedrooms and quiet rooms |
| Outdoor noise | Spec sheet | Neighbours and bedroom windows |
| Warranty terms | Installer and brand | Parts and labour cover, and any servicing conditions |
Questions to ask the installer
- What is the heating output of this unit at low outdoor temperatures?
- How many heating stars does it have in the cold zone?
- How loud is the outdoor unit, and where will it go?
- Does the warranty require regular servicing to stay valid?
- Is there a more efficient model in the same size, and is it worth it for how I use the room?