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    BTU Heating Calculator — Furnace & Boiler Sizing

    How many BTU do I need to heat a 2000 sq ft house?

    For a well-insulated 2,000 sq ft home in IECC zone 5, design heating load is roughly 50,000–70,000 BTU/hr. Cold climates (zone 6–7) and older construction push that to 80,000–100,000 BTU/hr. Use a full Manual J calculation before purchasing equipment.

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    Use the BTU Heating Calculator — Furnace & Boiler Sizing to get an exact answer for your inputs.

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    Estimates and general guidance only. Verify against your local code and AHJ before any installation. Gas, electrical, and refrigerant work is hazardous to untrained users.

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