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

Heat Pump Sizing for 596 m² (6,415 sq ft) — US North & Canada Cold (-18°C Design, NY/IL/MI/ON)

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

Recommended Heat Pump66.5 kW226,907 BTU/h (18.91 Tons)
Annual Electricity Usage45,161 kWh/yrDelivers 158,064 kWh Heat (SCOP 3.5)
Savings vs Direct Electric112,903 kWh/yrSpecific Load: 110.5 W/m²
Electrical Circuit (230V)150 A BreakerPeak Compressor Input: 24.63 kW

Thermal & Electrical Specification Table (596 m² / 6,415 sq ft)

Heated Floor Area596 m² (6,415 sq ft)
Climate Zone & Design Outdoor TempUS North & Canada Cold (-18°C Design, NY/IL/MI/ON)
Building Insulation EnvelopeOlder Uninsulated Building (85 W/m² Base) (110.5 W/m² Peak)
Peak Space Heating Load65.86 kW Thermal
Recommended Heat Pump Output (Incl. DHW)66.5 kW (226,907 BTU/h · 18.91 Tons)
Seasonal Coefficient of Performance (SCOP)3.5 (340%–450% Seasonal Efficiency)
Annual Heat Demand vs Electricity Consumed158,064 kWh Heat → 45,161 kWh Electricity

Frequently Asked Questions

What kW size heat pump do I need for a 596 m² (6415 sq ft) house?

For a 596 m² (6415 sq ft) building with Older Uninsulated Building (85 W/m² Base) in US North & Canada Cold (-18°C Design, NY/IL/MI/ON), the peak space heating load is 65.86 kW (110.5 W/m²). Including domestic hot water allowance, a 66.5 kW (226,907 BTU/h / 18.91 Ton) heat pump is recommended.

How many kWh of electricity does a 66.5 kW heat pump use per year?

With a Seasonal Coefficient of Performance (SCOP) of 3.5 over 2400 full-load equivalent heating hours, the heat pump consumes approximately 45,161 kWh of electricity per year to deliver 158,064 kWh of heat — saving 112,903 kWh/year compared to direct electric radiators.