Heat Pump Sizing Guide for NZ Homes
Getting the right sized heat pump matters — undersized units run constantly, oversized units short-cycle and waste energy.
Rule of Thumb
For a standard NZ home: approximately 75W per m² of floor area for an average insulated, moderate climate home. Adjust for climate zone and insulation quality.
Typical NZ Heat Pump Costs (Installed)
| Size | Typical unit | Supply + install |
|---|---|---|
| 2.5 kW | Small bedroom | $2,000–$2,800 |
| 3.5 kW | Medium bedroom / small lounge | $2,500–$3,500 |
| 5.0 kW | Large lounge / open plan | $3,200–$4,500 |
| 7.0 kW | Large open-plan living | $4,500–$6,500 |
| Multi-split | Whole home | $8,000–$18,000+ |
Top NZ Brands
- Mitsubishi Electric — most popular in NZ, excellent cold-climate performance
- Fujitsu — reliable, good warranty support
- Panasonic — strong inverter tech
- Daikin — premium build quality
- LG — Art Cool designer range
All heat pump installers must be REW-registered electricians and ideally HVAC-certified.