HVAC Load Calculator
Calculate heating and cooling load requirements based on square footage, insulation, climate zone, and windows.
Understanding HVAC Load Calculations
A proper load calculation (based on ACCA Manual J) ensures your HVAC system is correctly sized. An oversized system short-cycles, wastes energy, and fails to dehumidify. An undersized system runs constantly and cannot maintain comfort.
Key Factors
- Climate Zone: Determines base heating and cooling requirements per square foot.
- Insulation: Poorly insulated homes can need 30-40% more capacity.
- Windows: Large or west-facing windows add significant solar heat gain.
- Occupants: Each person adds approximately 400 BTU of heat to the space.
When to Use This Calculator
This calculator provides a quick estimate for residential HVAC sizing. For commercial buildings, new construction, or complex layouts, a full Manual J calculation by a licensed HVAC contractor is recommended.
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