Heat Pump Sizing for 396 m² (4,263 sq ft) — Australia & Mild APAC (Sydney/Melbourne/Tokyo)
Thermal heat loss calculation, recommended heat pump capacity (kW, BTU/h & HVAC Tons), SCOP efficiency, and annual electricity consumption.
Recommended Heat Pump18.0 kW61,419 BTU/h (5.12 Tons)
Annual Electricity Usage5,420 kWh/yrDelivers 24,388 kWh Heat (SCOP 4.5)
Savings vs Direct Electric18,968 kWh/yrSpecific Load: 44.0 W/m²
Electrical Circuit (230V)30 A BreakerPeak Compressor Input: 4.86 kW
Thermal & Electrical Specification Table (396 m² / 4,263 sq ft)
| Heated Floor Area | 396 m² (4,263 sq ft) |
| Climate Zone & Design Outdoor Temp | Australia & Mild APAC (Sydney/Melbourne/Tokyo) |
| Building Insulation Envelope | Standard Double-Glazed Insulation (55 W/m² Base) (44.0 W/m² Peak) |
| Peak Space Heating Load | 17.42 kW Thermal |
| Recommended Heat Pump Output (Incl. DHW) | 18.0 kW (61,419 BTU/h · 5.12 Tons) |
| Seasonal Coefficient of Performance (SCOP) | 4.5 (340%–450% Seasonal Efficiency) |
| Annual Heat Demand vs Electricity Consumed | 24,388 kWh Heat → 5,420 kWh Electricity |
Frequently Asked Questions
What kW size heat pump do I need for a 396 m² (4263 sq ft) house?
For a 396 m² (4263 sq ft) building with Standard Double-Glazed Insulation (55 W/m² Base) in Australia & Mild APAC (Sydney/Melbourne/Tokyo), the peak space heating load is 17.42 kW (44.0 W/m²). Including domestic hot water allowance, a 18.0 kW (61,419 BTU/h / 5.12 Ton) heat pump is recommended.
How many kWh of electricity does a 18.0 kW heat pump use per year?
With a Seasonal Coefficient of Performance (SCOP) of 4.5 over 1400 full-load equivalent heating hours, the heat pump consumes approximately 5,420 kWh of electricity per year to deliver 24,388 kWh of heat — saving 18,968 kWh/year compared to direct electric radiators.
Compare Other Home Sizes & Climate Zones
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