Heat pump installation in Dunedin

Dunedin has some of the oldest housing in New Zealand and a climate that rarely warms up properly in winter. July days average about 10°C and nights about 3°C, so the heating runs through the day as well as the evening. Add steep streets, south-facing hillsides that get little winter sun, and plenty of damp, and it's clear why so many Dunedin households are switching to heat pumps.

A heat pump both heats and dries the air, which helps in homes where condensation and mould are a problem. The catch in Dunedin is that an uninsulated villa loses heat so quickly that even a large unit can struggle. Insulation, draught stopping and correct sizing matter as much as the brand you choose.

This page covers Dunedin-specific sizing, what affects the installed price, and the areas from the city's hill suburbs to Mosgiel and the Peninsula. We're contracting installers region by region, and a contracted installer does the electrical and refrigerant work. Until one is in place in Dunedin, bookings are on a waitlist.

What does Dunedin's climate mean for your heat pump?

Dunedin City is in H1 climate zone 5. The coast and the hills create big local differences. NIWA records show coastal Musselburgh averages only about 8 days a year below 0°C, while Dunedin Airport on the Taieri Plains averages about 66. Homes in Mosgiel and Outram can wake up to hard frosts that the harbour suburbs rarely see.

For heat pumps, cold, damp air means more frequent defrost cycles and lower heating output on the coldest days. Consumer NZ points out that heat pumps find it harder to extract heat as outdoor temperatures drop. On the Taieri in particular, size using each model's low-temperature heating capacity.

Aspect matters too. Many hill suburbs such as Roslyn, Mornington and Belleknowes have homes on south-facing slopes that sit in shade for much of a winter day. These rooms need more heat than a similar-sized north-facing room, and rule-of-thumb sizing numbers, including our calculator's, can undersize them. For a shaded, south-facing room, round up to the next standard unit size.

What sort of houses are we fitting them to?

Much of Dunedin's housing dates from the late 1800s to the mid-1900s, including large villas with high ceilings in suburbs such as Mornington, Roslyn, Caversham and North East Valley. High studs increase the volume of air to heat, and many of these homes still have little or no wall insulation. A single high-wall unit may keep the lounge warm, but a multi-split or ducted system is often needed to take the chill off bedrooms and halls.

Student flats around North Dunedin face the Healthy Homes heating standard, which requires a fixed heater in the main living room that meets a calculated minimum capacity. Newer homes in Mosgiel and East Taieri are better insulated and suit standard high-wall or ducted systems.

What affects the price in Dunedin?

Dunedin prices follow national ranges, but hills and access affect labour. Houses up long flights of steps, outdoor units that must go on high wall brackets, and brick or stone walls that need core drilling all add time. Parking and lifting gear up steep streets can also add cost on some sites.

Because older homes often have dated wiring, the installer's site check should confirm whether the switchboard can take a new circuit. If it needs an upgrade, that cost is itemised separately, and you see it before you accept.

Which parts of Dunedin do we cover?

What do the Dunedin City Council rules say?

A standard heat pump install on a Dunedin house generally doesn't need building consent, but a licensed electrical worker must connect and certify it. Dunedin City Council's district plan sets noise limits, so keep the outdoor unit away from neighbours' bedroom windows where you can, and check that the chosen spot will comply.

Dunedin has many heritage buildings and some character areas. If your home is heritage listed, check with Dunedin City Council before fixing an outdoor unit or pipe covers to a street-facing wall. Landlords installing a heat pump to meet the Healthy Homes heating standard should use the Tenancy Services Heating Assessment Tool to confirm the required capacity.

Local tips

• Check ceiling and underfloor insulation before sizing. In an uninsulated villa it can make more difference than a bigger heat pump.
• Enter the real stud height in the sizing calculator, and round up for a room that faces south.
• In Mosgiel and the Taieri, choose a model with good low-temperature heating output.
• Use the heat pump's dry mode on damp days to help with condensation, and keep filters clean.
• Landlords should run the Heating Assessment Tool before booking, so the heat pump is sized to the required capacity.