Heat Pump Sizing for 300 m² (3,229 sq ft) — UK & Temperate Maritime (-5°C Design, UK/IE/NZ)
Thermal heat loss calculation, recommended heat pump capacity (kW, BTU/h & HVAC Tons), SCOP efficiency, and annual electricity consumption.
Recommended Heat Pump16.3 kW55,618 BTU/h (4.63 Tons)
Annual Electricity Usage6,875 kWh/yrDelivers 28,188 kWh Heat (SCOP 4.1)
Savings vs Direct Electric21,313 kWh/yrSpecific Load: 52.2 W/m²
Electrical Circuit (230V)30 A BreakerPeak Compressor Input: 4.94 kW
Thermal & Electrical Specification Table (300 m² / 3,229 sq ft)
| Heated Floor Area | 300 m² (3,229 sq ft) |
| Climate Zone & Design Outdoor Temp | UK & Temperate Maritime (-5°C Design, UK/IE/NZ) |
| Building Insulation Envelope | Standard Double-Glazed Insulation (55 W/m² Base) (52.2 W/m² Peak) |
| Peak Space Heating Load | 15.66 kW Thermal |
| Recommended Heat Pump Output (Incl. DHW) | 16.3 kW (55,618 BTU/h · 4.63 Tons) |
| Seasonal Coefficient of Performance (SCOP) | 4.1 (340%–450% Seasonal Efficiency) |
| Annual Heat Demand vs Electricity Consumed | 28,188 kWh Heat → 6,875 kWh Electricity |
Frequently Asked Questions
What kW size heat pump do I need for a 300 m² (3229 sq ft) house?
For a 300 m² (3229 sq ft) building with Standard Double-Glazed Insulation (55 W/m² Base) in UK & Temperate Maritime (-5°C Design, UK/IE/NZ), the peak space heating load is 15.66 kW (52.2 W/m²). Including domestic hot water allowance, a 16.3 kW (55,618 BTU/h / 4.63 Ton) heat pump is recommended.
How many kWh of electricity does a 16.3 kW heat pump use per year?
With a Seasonal Coefficient of Performance (SCOP) of 4.1 over 1800 full-load equivalent heating hours, the heat pump consumes approximately 6,875 kWh of electricity per year to deliver 28,188 kWh of heat — saving 21,313 kWh/year compared to direct electric radiators.
Compare Other Home Sizes & Climate Zones
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