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❄️ Heat Pump & HVAC Thermal Load · EN 12831 & ACCA Manual J Reference

Heat Pump Sizing for 70 m² (753 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 Pump3.9 kW13,307 BTU/h (1.11 Tons)
Annual Electricity Usage1,118 kWh/yrDelivers 4,920 kWh Heat (SCOP 4.4)
Savings vs Direct Electric3,802 kWh/yrSpecific Load: 46.8 W/m²
Electrical Circuit (230V)6 A BreakerPeak Compressor Input: 1.08 kW

Thermal & Electrical Specification Table (70 m² / 753 sq ft)

Heated Floor Area70 m² (753 sq ft)
Climate Zone & Design Outdoor TempUS Sunbelt & Mediterranean (TX/FL/CA/ES/IT)
Building Insulation EnvelopeStandard Double-Glazed Insulation (55 W/m² Base) (46.8 W/m² Peak)
Peak Space Heating Load3.28 kW Thermal
Recommended Heat Pump Output (Incl. DHW)3.9 kW (13,307 BTU/h · 1.11 Tons)
Seasonal Coefficient of Performance (SCOP)4.4 (340%–450% Seasonal Efficiency)
Annual Heat Demand vs Electricity Consumed4,920 kWh Heat → 1,118 kWh Electricity

Frequently Asked Questions

What kW size heat pump do I need for a 70 m² (753 sq ft) house?

For a 70 m² (753 sq ft) building with Standard Double-Glazed Insulation (55 W/m² Base) in US Sunbelt & Mediterranean (TX/FL/CA/ES/IT), the peak space heating load is 3.28 kW (46.8 W/m²). Including domestic hot water allowance, a 3.9 kW (13,307 BTU/h / 1.11 Ton) heat pump is recommended.

How many kWh of electricity does a 3.9 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 1,118 kWh of electricity per year to deliver 4,920 kWh of heat — saving 3,802 kWh/year compared to direct electric radiators.