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❄️ Heat Pump & HVAC Thermal Load · EN 12831 & ACCA Manual J Reference

Heat Pump Sizing for 154 m² (1,658 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 Pump11.1 kW37,875 BTU/h (3.16 Tons)
Annual Electricity Usage3,257 kWh/yrDelivers 14,658 kWh Heat (SCOP 4.5)
Savings vs Direct Electric11,401 kWh/yrSpecific Load: 68.0 W/m²
Electrical Circuit (230V)20 A BreakerPeak Compressor Input: 3.0 kW

Thermal & Electrical Specification Table (154 m² / 1,658 sq ft)

Heated Floor Area154 m² (1,658 sq ft)
Climate Zone & Design Outdoor TempAustralia & Mild APAC (Sydney/Melbourne/Tokyo)
Building Insulation EnvelopeOlder Uninsulated Building (85 W/m² Base) (68.0 W/m² Peak)
Peak Space Heating Load10.47 kW Thermal
Recommended Heat Pump Output (Incl. DHW)11.1 kW (37,875 BTU/h · 3.16 Tons)
Seasonal Coefficient of Performance (SCOP)4.5 (340%–450% Seasonal Efficiency)
Annual Heat Demand vs Electricity Consumed14,658 kWh Heat → 3,257 kWh Electricity

Frequently Asked Questions

What kW size heat pump do I need for a 154 m² (1658 sq ft) house?

For a 154 m² (1658 sq ft) building with Older Uninsulated Building (85 W/m² Base) in Australia & Mild APAC (Sydney/Melbourne/Tokyo), the peak space heating load is 10.47 kW (68.0 W/m²). Including domestic hot water allowance, a 11.1 kW (37,875 BTU/h / 3.16 Ton) heat pump is recommended.

How many kWh of electricity does a 11.1 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 3,257 kWh of electricity per year to deliver 14,658 kWh of heat — saving 11,401 kWh/year compared to direct electric radiators.