IHWAP Diagnostics vs PT Ductulator

Illinois Home Weatherization Assistance Program (IHWAP) Diagnostics application for the University of Illinois. This app is the product of a collaboration between the Indoor Climate Research & Training Center’s Senior Weatherization Trainer, Nate Price, and me. The Zone Pressure Diagnostics (ZPD) function will quantify the connection between the house and a zone and between that zone and the outdoors. It will also estimate the total leakage reduction potential in the zone, which should assist with prioritizing air sealing measures. The Total External Static Pressure (TESP) function will calculate total pressure and the pressure caused by the various components of a duct system and compare them to Illinois Home Weatherization Assistance Program (IHWAP) standards for recommended replacement options. The American Society of Heating and Air-Conditioning Engineers (ASHRAE) function will calculate home ventilation requirements ensuring proper pollutant control and ENERGY STAR compliance.

This is the easiest duct sizing calculator you’ll ever use. PT Ductulator is a simple, modern duct sizing tool for HVAC technicians, designers, and students. No spinning wheels, no cluttered screens—just clean inputs and instant, easy-to-read results. Whether you’re on a rooftop, in an attic, or at the design desk, Ductulator helps you make fast, confident decisions about duct size, airflow, and comfort. Why it feels so easy - Straightforward layout – Type in what you know, see what you need. No hunting through menus. - Big, readable numbers – Designed for real job sites, not just a desk. - Instant feedback – Adjust a value and see airflow, friction, and velocity update right away. What you can do with it - Size round and rectangular ducts -Enter airflow and your target friction or velocity and get recommended duct sizes in seconds. - Compare duct options - See how changing size affects velocity and friction so you can avoid noise, hot spots, and high static. - Get equivalent round sizes - Convert rectangular duct dimensions to an equivalent round size to compare and explain choices. - Work anywhere All calculations run offline on your device. Perfect for basements, rooftops, and new construction sites. Built for HVAC pros Use Ductulator to: - Double-check proposed duct sizes before installation - Verify existing systems during service calls - Teach apprentices how size, airflow, and friction relate - Have clearer conversations with homeowners, builders, and inspectors If you work with ductwork, this is the ductulator you’ll actually want to use—fast, simple, and always in your pocket.