Heat Pump Sizing for 420 m² (4,521 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 Pump30.6 kW104,411 BTU/h (8.7 Tons)
Annual Electricity Usage20,592 kWh/yrDelivers 72,072 kWh Heat (SCOP 3.5)
Savings vs Direct Electric51,480 kWh/yrSpecific Load: 71.5 W/m²
Electrical Circuit (230V)63 A BreakerPeak Compressor Input: 11.33 kW
Thermal & Electrical Specification Table (420 m² / 4,521 sq ft)
| Heated Floor Area | 420 m² (4,521 sq ft) |
| Climate Zone & Design Outdoor Temp | US North & Canada Cold (-18°C Design, NY/IL/MI/ON) |
| Building Insulation Envelope | Standard Double-Glazed Insulation (55 W/m² Base) (71.5 W/m² Peak) |
| Peak Space Heating Load | 30.03 kW Thermal |
| Recommended Heat Pump Output (Incl. DHW) | 30.6 kW (104,411 BTU/h · 8.7 Tons) |
| Seasonal Coefficient of Performance (SCOP) | 3.5 (340%–450% Seasonal Efficiency) |
| Annual Heat Demand vs Electricity Consumed | 72,072 kWh Heat → 20,592 kWh Electricity |
Frequently Asked Questions
What kW size heat pump do I need for a 420 m² (4521 sq ft) house?
For a 420 m² (4521 sq ft) building with Standard Double-Glazed Insulation (55 W/m² Base) in US North & Canada Cold (-18°C Design, NY/IL/MI/ON), the peak space heating load is 30.03 kW (71.5 W/m²). Including domestic hot water allowance, a 30.6 kW (104,411 BTU/h / 8.7 Ton) heat pump is recommended.
How many kWh of electricity does a 30.6 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 20,592 kWh of electricity per year to deliver 72,072 kWh of heat — saving 51,480 kWh/year compared to direct electric radiators.
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