Free residential HVAC load & duct sizing tool. Run a simplified ACCA Manual J / Manual S heating and cooling load calculation room by room, then size equipment, airflow, and ventilation per ASHRAE.
Educational & Preliminary Use Only
This tool provides preliminary estimates for educational purposes. Results must be reviewed and stamped by a licensed Mechanical Engineer (PE) before use in construction documents or permit applications. Equipment selection must comply with ACCA Manual J (8th Ed.), Manual S, Manual D, local energy codes, and manufacturer specifications. Always consult the Authority Having Jurisdiction (AHJ) for local code adoption. Improper HVAC design can result in equipment failure, poor indoor air quality, moisture damage, and safety hazards — engage a licensed professional for all permitted work. EngineersUniverse assumes no liability for errors, omissions, or misuse of results.
Winter: 10°F · Summer: 90°F DB / 75°F WB