⚡ 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 356 m² (3,832 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 Pump29.4 kW100,317 BTU/h (8.36 Tons)
Annual Electricity Usage12,626 kWh/yrDelivers 51,768 kWh Heat (SCOP 4.1)
Savings vs Direct Electric39,142 kWh/yrSpecific Load: 80.8 W/m²
Electrical Circuit (230V)50 A BreakerPeak Compressor Input: 8.91 kW

Thermal & Electrical Specification Table (356 m² / 3,832 sq ft)

Heated Floor Area356 m² (3,832 sq ft)
Climate Zone & Design Outdoor TempUK & Temperate Maritime (-5°C Design, UK/IE/NZ)
Building Insulation EnvelopeOlder Uninsulated Building (85 W/m² Base) (80.8 W/m² Peak)
Peak Space Heating Load28.76 kW Thermal
Recommended Heat Pump Output (Incl. DHW)29.4 kW (100,317 BTU/h · 8.36 Tons)
Seasonal Coefficient of Performance (SCOP)4.1 (340%–450% Seasonal Efficiency)
Annual Heat Demand vs Electricity Consumed51,768 kWh Heat → 12,626 kWh Electricity

Frequently Asked Questions

What kW size heat pump do I need for a 356 m² (3832 sq ft) house?

For a 356 m² (3832 sq ft) building with Older Uninsulated Building (85 W/m² Base) in UK & Temperate Maritime (-5°C Design, UK/IE/NZ), the peak space heating load is 28.76 kW (80.8 W/m²). Including domestic hot water allowance, a 29.4 kW (100,317 BTU/h / 8.36 Ton) heat pump is recommended.

How many kWh of electricity does a 29.4 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 12,626 kWh of electricity per year to deliver 51,768 kWh of heat — saving 39,142 kWh/year compared to direct electric radiators.