Free tools for better HVAC work
Free calculators and practical tools for HVAC professionals and designers.
HVAC Calculators
Start with the Duct Calculator to compare duct sizes. Choose Air Distribution for airflow, velocity and pressure-budget questions, or Air Properties to work with temperature and moisture together.
Size round and rectangular ductwork using airflow, friction rate, and velocity.
Airflow, velocity, air changes, friction rate, pressure relationships, and practical air-distribution calculations.
Moist-air and psychrometric tools for humidity, temperature, enthalpy, and HVAC analysis.
Resources
Design Reference #01
A two-page HVAC duct design reference covering airflow, velocity, duct area, friction rate, pressure relationships, rectangular duct fundamentals, conversions, and design checks.
