About DuctPro Max
Practical commercial duct decisions, with the method shown
DuctPro Max is built by the DuctPro Max team to make preliminary duct sizing, pressure-loss checks and design comparisons faster to perform and easier to explain.
Who the tools are for
The calculators and guides serve engineers, HVAC technicians, estimators, contractors and facility managers evaluating commercial supply, return and exhaust duct systems. They are designed for early decisions, field checks, option comparisons and clearer contractor conversations.
What DuctPro Max covers
The suite covers duct sizing from airflow and friction rate, velocity, straight-run and fitting pressure loss, round-to-rectangular conversion, material and weight comparisons, reference sizes, preliminary project planning and worked educational examples.
How the calculations are presented
DuctPro Max publishes the equations or methods, material and air assumptions, unit conventions, rounding logic and source basis alongside its tools where applicable. Results include interpretation and neighboring-size comparisons so users can see how changing a design variable affects velocity and friction—not only retrieve a number.
Editorial and review process
Every guide is written and reviewed by the DuctPro Max editorial team. Methods are drafted from the ASHRAE Handbook—Fundamentals (2021) and SMACNA HVAC duct construction and design standards, and each published equation is checked against the implementation in the matching calculator so the guidance and the tools never disagree. When a coefficient, method or assumption changes, the change is recorded on the update log with its date and reason, and the affected pages are revised in the same release.
Reader feedback shapes the roadmap: correction reports and tool requests arrive through the contact page and the per-page feedback votes, and are triaged into the update log.
Where the tools stop
DuctPro Max produces preliminary estimates and educational guidance. It does not provide stamped engineering, approve code compliance, perform load calculations, select final equipment, inspect field conditions or replace testing, adjusting and balancing. A qualified professional must confirm actual fitting geometry, fan and equipment data, leakage class, acoustics, fire and smoke requirements, local code adoption and constructability before a design is issued.