HVAC Duct Tools Manual D

Free, offline, no account. Size a run, check total static, or design the whole system and export the schedule as a PDF. Every result shows what it assumed.

HVAC Duct Tools — Manual D duct sizing, whole-system design, and field checks, built for the trade.

Whether you're sizing a duct at the truck, checking static pressure in an attic, or handing a homeowner a full duct schedule, HVAC Duct Tools gives you defensible numbers in seconds — free, offline, no account, no tracking.

FIELD TOOLS • Quick Size — enter CFM and get the duct size, round, rectangular, or flat-oval, with velocity and the governing constraint. The ductulator, in your pocket. Or flip it: enter an existing size and read back its honest capacity range, or scan the all-sizes table. • Duct Check — enter an as-built duct, airflow, and role to read back friction rate and velocity, with a clear undersized / adequate / oversized verdict. • Static Pressure Check — enter supply and return static plus the equipment's rated max to get total external static pressure (TESP), a clear over / within / under verdict, and which side dominates. • No airflow number handy? Estimate CFM from tonnage right where you need it.

DESIGN A WHOLE SYSTEM • Walk Setup → Friction Rate → Runs → Summary and leave with a run-by-run duct schedule. • Static-pressure budget with honest defaults — an overridden default never masquerades as an assumption. • Size every trunk and branch: supply and return, six duct materials, flex with compression, altitude-corrected airflow. • In a hurry? Start from an assumed friction rate and refine when you have real numbers.

SAVE, SHARE, DELIVER • Saved projects with automatic save — walk away mid-job, pick it up tomorrow. • Share any result by text, or export the Summary as a clean PDF or CSV for the homeowner, the inspector, or the office. • Light and dark mode.

BUILT HONEST • Every result shows what it assumes, so you can sharpen it. • Plausibility checks flag implausible inputs as "check your inputs," never a confident wrong answer. • Stocked round sizes and role-based velocity limits reflect real-world practice. • Anything you share or export carries the same caveats you see on screen.

PRIVATE BY DESIGN • Works fully offline. No sign-in, no cloud, no analytics — nothing you enter leaves your phone.

HVAC Duct Tools is a field estimator based on ACCA Manual D methods. It is a professional aid, not a substitute for a stamped Manual D design or measured commissioning.