Heat pump sizing calculator
Answer four quick questions about the space you want to heat and we will suggest a capacity in kW, the right type of system, and a realistic cost range, all sized for a cold Queenstown winter. It is a guide to get you started, and the free site visit confirms the exact answer.
What are you heating?
How big is the space?
How old is the home?
Sun and exposure in winter?
Our suggestion for your home
This is a guide based on your answers, not a fixed quote. The real answer is a free site visit, where we measure the rooms, check the insulation and confirm the size and price for your home.
Get your sized quote
Send us your details with your calculator result attached and we will come back with honest options and a fixed price for your home.
Why getting the size right matters
Heat pump sizing is the single biggest reason a system either keeps a home warm or quietly disappoints. Get it right and the unit holds a steady temperature without straining. Get it wrong and you pay for it twice, once up front and again every winter.
An undersized unit runs flat out on the coldest mornings and still falls short, which is exactly when a Queenstown home needs it most. An oversized one costs more to buy, short-cycles on and off, and wears itself out faster. The sweet spot is a unit matched to the room and to how cold and exposed your spot really gets.
That local part matters here more than almost anywhere. Cold air pools on the valley floors around Frankton and Lake Hayes, older timber cottages in Arrowtown leak heat, and exposed new builds catch the wind off the lake. For those homes we step up a size so the heat pump still performs in a hard frost. The calculator builds that thinking in, and our heat pump installation team confirms it on site.
Quick sizing guide
These are the rough capacities behind the calculator. They line up with the ranges on our installation cost guide, so the numbers stay consistent wherever you look.
| Space | Typical capacity | Usual system |
|---|---|---|
| Bedroom or small room (under 20m²) | Around 2.5 kW | Small high-wall |
| Standard living area (20 to 40m²) | Around 5 to 6 kW | Mid high-wall |
| Large or open-plan space (40 to 60m²) | Around 7 to 8 kW | Large high-wall |
| Several rooms | Sized per room | Multi-split system |
| Whole home, even heat | Whole-home, zoned | Ducted system |
| Older or exposed home | Step up one size | As above, sized up |
Once you have a size in mind, compare the formats on our types of heat pump guide, and remember a Warmer Kiwi Homes grant may cover most of the cost for eligible homes.
Sizing questions
What size heat pump do I need?
As a rough guide a bedroom suits a 2.5kW unit, a standard living area needs 5 to 6kW, and a large or open-plan space wants 7 to 8kW. Multiple rooms usually call for a multi-split or ducted system. In Queenstown we size up a step for older or exposed homes, and confirm the exact size on site.
Is a bigger heat pump always better?
No. An oversized unit costs more to buy, short-cycles on and off and runs less efficiently, while an undersized one struggles on the coldest mornings. The aim is the right size for the room and how cold it gets, which is why we confirm the calculator's estimate with a site visit.
Why size up for a Queenstown home?
Cold air pools on the valley floors and older homes lose heat fast, so a unit sized for a milder town can fall short here. For homes built before 1990, or spots that get little winter sun or catch the wind off the lake, we step up a size so the heat pump still performs in a hard frost.
Does the calculator give an exact price?
It gives an honest estimate range, not a fixed quote. The real price depends on your home, the unit you choose and the install itself. The estimate uses the same ranges as our installation cost guide, and we give you a firm, fixed price after a free site visit.
Rather we just sized it for you?
Skip the guesswork. Tell us about your home and we will size it properly and give you a clear, fixed price. No obligation, usually same business day.