DuctLab Downloads & RevenueDuctLab: HVAC Duct Layout · App Store

DuctLab is an HVAC sheet-metal layout and estimating companion for fabricators, installers, technicians, apprentices, and contractors. Build a job, add fittings, enter real dimensions, and turn them into measurements, diagrams, fabrication steps, material totals, and a shareable PDF.

Private by design
• Offline — calculate layouts, review references, manage projects, estimate material, and create PDFs without an internet connection.
• No Login — start working with no account, email, password, or team workspace.
• Privacy First — customer names, job numbers, notes, dimensions, costs, and fabrication details stay under your control.
• On Device — storage, geometry calculations, diagrams, estimates, and PDF creation run on your iPhone.
• No Cloud Upload — DuctLab has no server or proprietary cloud-sync service and does not upload projects in the background.

Projects are saved locally with iOS file protection. PDFs leave only through a system share action you choose.

Four fabrication layouts
• Rectangular Transition: enter top and bottom openings, length, and horizontal or vertical offsets. Get centerline true length, four panel slopes, centerline angle, sheet area, and development steps.
• Square to Round: enter the rectangular opening, diameter, length, and offsets. Choose 8 to 48 divisions and see circumference, division spacing and angle, corner and side true lengths, area, and triangulated layout steps.
• Duct Offset: use width, height, rise, and run to calculate true travel, offset angle, travel per unit rise, sheet area, and a four-face development method.
• Elbow Layout: develop rectangular or round 45° and 90° elbows with a centerline radius and 1 to 12 segments. Review centerline, throat, and heel arcs, developed perimeter, angle per segment, area, and assembly steps.

Live shop results
The preview, dimensions, area, and key result update while you edit. Saved parts include a drawing, true lengths, slopes or angles, material, quantity totals, and ordered fabrication steps. Add seam allowance area or duplicate a part for a variation.

Material and cost estimating
DuctLab totals parts by quantity, adds waste, compares the result with stock-sheet dimensions, rounds up sheet count, and estimates cost in USD, CAD, AUD, EUR, or GBP. Imperial and Metric are supported; switching systems converts stored dimensions.

Organize projects
Record a customer, job number, and notes; add fittings and quantities; or duplicate a part or project to explore a revision while preserving the original.

On-device PDF export
Generate a multi-page package with job information, material estimates, and individual part pages containing specifications, quantity, seam allowance, diagram, measurements, totals, cautions, and numbered steps. Share, print, or save only when you choose.

Field references
Look up common duct sizes, 30 ga to 20 ga galvanized thicknesses, and typical Pittsburgh, snap-lock, grooved, cleat, and standing-seam allowances. Treat them as starting poi