⚡ 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 84 m² (904 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 Pump3.4 kW11,601 BTU/h (0.97 Tons)
Annual Electricity Usage1,225 kWh/yrDelivers 5,022 kWh Heat (SCOP 4.1)
Savings vs Direct Electric3,797 kWh/yrSpecific Load: 33.2 W/m²
Electrical Circuit (230V)6 A BreakerPeak Compressor Input: 1.03 kW

Thermal & Electrical Specification Table (84 m² / 904 sq ft)

Heated Floor Area84 m² (904 sq ft)
Climate Zone & Design Outdoor TempUK & Temperate Maritime (-5°C Design, UK/IE/NZ)
Building Insulation EnvelopeModern / New Build Insulation (35 W/m² Base) (33.2 W/m² Peak)
Peak Space Heating Load2.79 kW Thermal
Recommended Heat Pump Output (Incl. DHW)3.4 kW (11,601 BTU/h · 0.97 Tons)
Seasonal Coefficient of Performance (SCOP)4.1 (340%–450% Seasonal Efficiency)
Annual Heat Demand vs Electricity Consumed5,022 kWh Heat → 1,225 kWh Electricity

Frequently Asked Questions

What kW size heat pump do I need for a 84 m² (904 sq ft) house?

For a 84 m² (904 sq ft) building with Modern / New Build Insulation (35 W/m² Base) in UK & Temperate Maritime (-5°C Design, UK/IE/NZ), the peak space heating load is 2.79 kW (33.2 W/m²). Including domestic hot water allowance, a 3.4 kW (11,601 BTU/h / 0.97 Ton) heat pump is recommended.

How many kWh of electricity does a 3.4 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 1,225 kWh of electricity per year to deliver 5,022 kWh of heat — saving 3,797 kWh/year compared to direct electric radiators.