Heat Pump Sizing for 42 m² (452 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 Pump3.7 kW12,625 BTU/h (1.05 Tons)
Annual Electricity Usage2,386 kWh/yrDelivers 8,112 kWh Heat (SCOP 3.4)
Savings vs Direct Electric5,726 kWh/yrSpecific Load: 74.2 W/m²
Electrical Circuit (230V)10 A BreakerPeak Compressor Input: 1.42 kW
Thermal & Electrical Specification Table (42 m² / 452 sq ft)
| Heated Floor Area | 42 m² (452 sq ft) |
| Climate Zone & Design Outdoor Temp | Nordic / Scandinavia (-20°C Design, SE/NO/FI/DK) |
| Building Insulation Envelope | Standard Double-Glazed Insulation (55 W/m² Base) (74.2 W/m² Peak) |
| Peak Space Heating Load | 3.12 kW Thermal |
| Recommended Heat Pump Output (Incl. DHW) | 3.7 kW (12,625 BTU/h · 1.05 Tons) |
| Seasonal Coefficient of Performance (SCOP) | 3.4 (340%–450% Seasonal Efficiency) |
| Annual Heat Demand vs Electricity Consumed | 8,112 kWh Heat → 2,386 kWh Electricity |
Frequently Asked Questions
What kW size heat pump do I need for a 42 m² (452 sq ft) house?
For a 42 m² (452 sq ft) building with Standard Double-Glazed Insulation (55 W/m² Base) in Nordic / Scandinavia (-20°C Design, SE/NO/FI/DK), the peak space heating load is 3.12 kW (74.2 W/m²). Including domestic hot water allowance, a 3.7 kW (12,625 BTU/h / 1.05 Ton) heat pump is recommended.
How many kWh of electricity does a 3.7 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 2,386 kWh of electricity per year to deliver 8,112 kWh of heat — saving 5,726 kWh/year compared to direct electric radiators.
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