Heat Pump Sizing for 420 m² (4,521 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 Pump30.9 kW105,435 BTU/h (8.79 Tons)
Annual Electricity Usage10,336 kWh/yrDelivers 45,480 kWh Heat (SCOP 4.4)
Savings vs Direct Electric35,144 kWh/yrSpecific Load: 72.2 W/m²
Electrical Circuit (230V)50 A BreakerPeak Compressor Input: 8.58 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 Sunbelt & Mediterranean (TX/FL/CA/ES/IT) |
| Building Insulation Envelope | Older Uninsulated Building (85 W/m² Base) (72.2 W/m² Peak) |
| Peak Space Heating Load | 30.32 kW Thermal |
| Recommended Heat Pump Output (Incl. DHW) | 30.9 kW (105,435 BTU/h · 8.79 Tons) |
| Seasonal Coefficient of Performance (SCOP) | 4.4 (340%–450% Seasonal Efficiency) |
| Annual Heat Demand vs Electricity Consumed | 45,480 kWh Heat → 10,336 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 Older Uninsulated Building (85 W/m² Base) in US Sunbelt & Mediterranean (TX/FL/CA/ES/IT), the peak space heating load is 30.32 kW (72.2 W/m²). Including domestic hot water allowance, a 30.9 kW (105,435 BTU/h / 8.79 Ton) heat pump is recommended.
How many kWh of electricity does a 30.9 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 10,336 kWh of electricity per year to deliver 45,480 kWh of heat — saving 35,144 kWh/year compared to direct electric radiators.
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