⚡ Cu ρ (75°C): 0.0214 Ω·mm²/m 🔌 NEC / IEC Standards: NFPA 70 & IEC 60364 🇺🇸 US Grid Avg: $0.175/kWh 🇩🇪 DE Grid Avg: €0.345/kWh 🇸🇪 SE Elpris: 1.54 SEK/kWh 🇳🇴 NO Strøm: 1.17 NOK/kWh 🔩 Copper Ref: $9,650/t (2026-10-25)
❄️ Heat Pump & HVAC Thermal Load · EN 12831 & ACCA Manual J Reference

Heat Pump Sizing for 66 m² (710 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: 47.2 W/m²
Electrical Circuit (230V)10 A BreakerPeak Compressor Input: 1.42 kW

Thermal & Electrical Specification Table (66 m² / 710 sq ft)

Heated Floor Area66 m² (710 sq ft)
Climate Zone & Design Outdoor TempNordic / Scandinavia (-20°C Design, SE/NO/FI/DK)
Building Insulation EnvelopeModern / New Build Insulation (35 W/m² Base) (47.2 W/m² Peak)
Peak Space Heating Load3.12 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 Consumed8,112 kWh Heat → 2,386 kWh Electricity

Frequently Asked Questions

What kW size heat pump do I need for a 66 m² (710 sq ft) house?

For a 66 m² (710 sq ft) building with Modern / New Build Insulation (35 W/m² Base) in Nordic / Scandinavia (-20°C Design, SE/NO/FI/DK), the peak space heating load is 3.12 kW (47.2 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.