Methodology, sources and calculations for New Zealand

Source data

New Zealand regulates appliance energy labelling and minimum energy performance standards through the E3 programme, run by the Energy Efficiency and Conservation Authority (EECA) jointly with Australia. Products are registered once, on the shared trans-Tasman register, and the registrant declares the countries the model is sold in. New Zealand-specific registrations carry a Z-prefixed registration number.

Our New Zealand data is every registration on that shared register (published by the Australian Department of Climate Change, Energy, the Environment and Water on data.gov.au under CC BY 3.0 AU as the Energy Rating Data for household appliances) whose registrant lists New Zealand as a market. Current New Zealand database: 9,271 registrations, 17,816 model numbers, 271 brands; source file dated 2 October 2026, imported 3 October 2026.

Coverage by category: heat pumps (full), fridges (full), freezers (full), dishwashers (partial), clothes dryers (full), tvs (full), pool pumps (none), washing machines (full), washer dryers (full). Pool pumps are not regulated under E3 in New Zealand and are not shown. Water efficiency (WELS) is an Australian scheme and is not shown for New Zealand.

Products that drop out of the government file are kept and marked as no longer listed rather than deleted. When a value changes between files, the previous value is retained with its dates.

Climate zones and annual kWh for heat pumps

Since the 2019 determination, heat pumps carry a Zoned Energy Rating Label with separate star ratings and annual energy figures for three climate zones: cold (based on Canberra), mixed (Richmond, NSW) and hot (Rockhampton, QLD). All of New Zealand is the cold zone, so New Zealand pages show cold-zone figures. Annual kWh = the label’s cooling-season electricity (tcec) plus heating-season electricity (thec) for a residential usage profile. Cooling-only units have no heating figure.

Fridges and freezers

The label carries one national annual energy figure (comparative energy consumption, kWh per year) and one star rating, tested to AS/NZS IEC 62552.3. We keep the government classification exactly as published: designation, group, product class and configuration. The consumer type shown in headings is derived by a fixed rule from those fields and the door count, for example “French door” = group 5B (frost-free, bottom-mounted freezer) with three or more doors, and “bar fridge” = a refrigerator-designated unit under 200 L; every product page states the rule used.

We do not rank fridges by kWh per litre: two fridges of equal volume with different freezer shares have different adjusted volumes, and the star rating already normalises for that. Each model is compared in raw kWh against its cohort (same consumer type and 100 L size band) and against its MEPS level as published in the registration.

Dishwashers, clothes dryers, TVs

Label figures use fixed usage assumptions: dishwashers 7 cycles a week (365 a year), dryers one full load a week (52 a year), TVs 10 hours on and 14 hours in standby a day. Product pages show the label figure first, then let you change the usage; the “How we calculate this” panel on each page shows the government inputs, your assumptions and the arithmetic.

Running cost

Estimated cost = annual kWh × electricity price, in NZD. The default 33c/kWh is an example; change it to the usage rate on your bill and the site remembers it in your browser for New Zealand. Five- and ten-year figures multiply the annual figure with no inflation, tariff change or degradation assumed.

Comparable models and percentiles

A product’s cohort is every currently registered model sold in New Zealand of the same kind and size group (for heat pumps: same configuration, air distribution, type and capacity band). Model numbers that share a registration share test results, so a cohort counts each registration once. “Uses less than 82% of comparable models” means 82% of registrations in the cohort have a higher annual kWh in the cold zone. No percentile is shown for cohorts under five registrations. Cohorts, percentiles, similar models and comparison pages are computed separately for each market.

Heat pumps capacity bands are centred on marketed sizes: 2 kW (0 to 2.25 kW), 2.5 kW (2.25 to 3 kW), 3.5 kW (3 to 4.25 kW), 5 kW (4.25 to 5.5 kW), 6 kW (5.5 to 6.5 kW), 7 kW (6.5 to 7.5 kW), 8 kW (7.5 to 9 kW), 10 kW (9 to 11.25 kW), 12.5 kW (11.25 to 13.25 kW), 14 kW (13.25 to 15 kW), 16 kW (15 to 17 kW), 18 kW (17 to 19 kW), 20 kW (19 to 22.5 kW), 25 kW (22.5 to 30 kW), 35 kW (30 to 37.5 kW), 40 kW (37.5 to 45 kW), 50 kW (45 to 57.5 kW), 65 kW (57.5 to 72.5 kW), 80 kW and above (72.5 to ∞ kW).

Similar models and alternatives

Similar models share type and have a size within a fixed tolerance of the product’s (12% of cooling capacity for heat pumps, one size band otherwise). “Comparable models that use less electricity” are similar models with at least 3% lower annual kWh. Comparison pages are generated for close matches from different brands; any two models of the same kind can also be compared through the compare tool.

What we do not do

We do not test appliances, rate them subjectively, write reviews, or estimate figures the government has not published. Where a field is missing in the source, it is shown as missing. Retail prices are not shown.

Corrections

Registration data is supplied to the regulator by the registrant. If you believe a figure is wrong, check the Energy Rating registration database or EECA; we import what is published there.