Small heat pumps in NZ: the smallest models, what they heat and what they cost

Bedrooms are where oversizing happens most. A unit sized for a lounge will heat a bedroom in minutes, then cycle on and off all night, which is noisier, less comfortable and less efficient. The smallest units on the market are made for exactly this job.

What is the smallest heat pump in NZ?

Each of the big four brands sells a high-wall split rated at 2.0 kW cooling. On heating, which is the figure that matters in a New Zealand winter, they deliver 2.5 to 2.8 kW. Mitsubishi Electric's AP20 Mini is physically the smallest indoor unit, at 760 mm wide, and is quoted from 21 dB(A) on its lowest fan speed. The others are standard-width units at the bottom of their range. Every figure below was read on the maker's own New Zealand page on 30 October 2026.

A smaller indoor unit doesn't mean a smaller bill for the install. Labour, pipework and the electrical connection are about the same as for a mid-size unit, so the saving over a 3.5 kW model is usually a few hundred dollars. Choose the smallest model when the room is small or the wall space is tight, such as above a door or between a window and a wardrobe, not to save money.

What size heat pump do I need for a bedroom?

For a typical 10 to 15 m² bedroom with a standard 2.4 m stud and reasonable ceiling insulation, the smallest high-wall size is usually enough anywhere north of Christchurch. A larger master bedroom with an ensuite, a high villa stud, or a cold Canterbury, Otago or Southland bedroom with single glazing may need the next standard size. Our sizing calculator works it out from the room's size, stud height, insulation and region, and shows the working.

How much does a small heat pump cost to install?

About $2,500 to $3,500 installed for a small-room high-wall split, according to current New Zealand price guides. The unit itself is the cheaper part of a small install; labour, pipework and the electrical connection are much the same as for a bigger unit, which is why a bedroom heat pump doesn't cost half what a lounge one does. The cheapest jobs are back-to-back, with the outdoor unit directly behind the indoor one on an outside wall. Bedrooms on the second storey, or with no outside wall, cost more. Full ranges are in our heat pump cost guide.

How quiet should a bedroom heat pump be?

Look for the indoor unit's sound level at its lowest fan speed, listed in dB(A) on the spec sheet. The smallest premium units have a quiet or night mode that drops the fan right down; compare that figure between models, not the high-speed one. Then think about the outdoor unit: if it's under your own bedroom window or a neighbour's, its sound rating matters as much, and council noise rules apply at night.

Where should a heat pump go in a bedroom?

• High on a wall where the air blows along the room, not straight at the bed. Waking up with a draught across your face is the commonest bedroom complaint.
• On or near an outside wall, so the pipe run to the outdoor unit is short.
• Clear of curtains and wardrobe doors, which block the airflow and the sensor.
• Not directly above the bed head, where the condensate drain or a drip during defrost would land.

Should every bedroom have its own heat pump?

Not necessarily. If you're heating three or more bedrooms, a multi-split system runs several small indoor units from one outdoor unit, and a ducted system heats the whole house through ceiling or floor vents. In a well-insulated house, one unit in the hallway with the bedroom doors open sometimes takes the chill off well enough. For a single cold bedroom, a small high-wall unit is the simplest answer.