Heat Pump Sizing for 420 m² (4,521 sq ft) — Nordic / Scandinavia (-20°C Design, SE/NO/FI/DK)
Thermal heat loss calculation, recommended heat pump capacity (kW, BTU/h & HVAC Tons), SCOP efficiency, and annual electricity consumption.
Recommended Heat Pump48.8 kW166,512 BTU/h (13.88 Tons)
Annual Electricity Usage36,874 kWh/yrDelivers 125,372 kWh Heat (SCOP 3.4)
Savings vs Direct Electric88,498 kWh/yrSpecific Load: 114.8 W/m²
Electrical Circuit (230V)110 A BreakerPeak Compressor Input: 18.77 kW
Thermal & Electrical Specification Table (420 m² / 4,521 sq ft)
| Heated Floor Area | 420 m² (4,521 sq ft) |
| Climate Zone & Design Outdoor Temp | Nordic / Scandinavia (-20°C Design, SE/NO/FI/DK) |
| Building Insulation Envelope | Older Uninsulated Building (85 W/m² Base) (114.8 W/m² Peak) |
| Peak Space Heating Load | 48.22 kW Thermal |
| Recommended Heat Pump Output (Incl. DHW) | 48.8 kW (166,512 BTU/h · 13.88 Tons) |
| Seasonal Coefficient of Performance (SCOP) | 3.4 (340%–450% Seasonal Efficiency) |
| Annual Heat Demand vs Electricity Consumed | 125,372 kWh Heat → 36,874 kWh Electricity |
Frequently Asked Questions
What kW size heat pump do I need for a 420 m² (4521 sq ft) house?
For a 420 m² (4521 sq ft) building with Older Uninsulated Building (85 W/m² Base) in Nordic / Scandinavia (-20°C Design, SE/NO/FI/DK), the peak space heating load is 48.22 kW (114.8 W/m²). Including domestic hot water allowance, a 48.8 kW (166,512 BTU/h / 13.88 Ton) heat pump is recommended.
How many kWh of electricity does a 48.8 kW heat pump use per year?
With a Seasonal Coefficient of Performance (SCOP) of 3.4 over 2600 full-load equivalent heating hours, the heat pump consumes approximately 36,874 kWh of electricity per year to deliver 125,372 kWh of heat — saving 88,498 kWh/year compared to direct electric radiators.
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