⚡ 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 126 m² (1,356 sq ft) — US Sunbelt & Mediterranean (TX/FL/CA/ES/IT)

Thermal heat loss calculation, recommended heat pump capacity (kW, BTU/h & HVAC Tons), SCOP efficiency, and annual electricity consumption.

Recommended Heat Pump9.7 kW33,098 BTU/h (2.76 Tons)
Annual Electricity Usage3,102 kWh/yrDelivers 13,650 kWh Heat (SCOP 4.4)
Savings vs Direct Electric10,548 kWh/yrSpecific Load: 72.2 W/m²
Electrical Circuit (230V)15 A BreakerPeak Compressor Input: 2.69 kW

Thermal & Electrical Specification Table (126 m² / 1,356 sq ft)

Heated Floor Area126 m² (1,356 sq ft)
Climate Zone & Design Outdoor TempUS Sunbelt & Mediterranean (TX/FL/CA/ES/IT)
Building Insulation EnvelopeOlder Uninsulated Building (85 W/m² Base) (72.2 W/m² Peak)
Peak Space Heating Load9.1 kW Thermal
Recommended Heat Pump Output (Incl. DHW)9.7 kW (33,098 BTU/h · 2.76 Tons)
Seasonal Coefficient of Performance (SCOP)4.4 (340%–450% Seasonal Efficiency)
Annual Heat Demand vs Electricity Consumed13,650 kWh Heat → 3,102 kWh Electricity

Frequently Asked Questions

What kW size heat pump do I need for a 126 m² (1356 sq ft) house?

For a 126 m² (1356 sq ft) building with Older Uninsulated Building (85 W/m² Base) in US Sunbelt & Mediterranean (TX/FL/CA/ES/IT), the peak space heating load is 9.1 kW (72.2 W/m²). Including domestic hot water allowance, a 9.7 kW (33,098 BTU/h / 2.76 Ton) heat pump is recommended.

How many kWh of electricity does a 9.7 kW heat pump use per year?

With a Seasonal Coefficient of Performance (SCOP) of 4.4 over 1500 full-load equivalent heating hours, the heat pump consumes approximately 3,102 kWh of electricity per year to deliver 13,650 kWh of heat — saving 10,548 kWh/year compared to direct electric radiators.