VENTTOOLS
Professional HVAC tools
V5 Beta
Built on site experience

Professional HVAC
Installation Tools

Fast, practical calculators for duct fitters, installers and workshop teams.

Site tools

Choose a calculator

Mobile-first • Free to use
🔥LIVE

Fire Damper Openings

BSB and Actionair builder’s opening calculators with official installation references.

📐LIVE

Offset Calculator

Straight and rolled offsets using practical manufacturer bend take-offs.

⭕LIVE

Rect to Round Ductulator

Convert rectangular duct area to an equivalent round spiral diameter.

🌀IN DEVELOPMENT

Ductwrap Calculator

Round segmented bend wrap measurements and marking guides.

🛠️CONCEPT

VentTools Workshop

Site measures, drawings, parts lists and future fabrication exports.

⚡

Latest updates

Actionair CSS calculatorAdded
DWFX-F / DWFX-3F methodsAdded
HEVAC / HVCA frame calculatorAdded
Official manual buttonsImproved
🏭

Supported manufacturers

BSBFSD-TD • FSD-CActive
Actionair by SwegonCSS • DWFX-F • HEVACActive
More manufacturersAdded carefully from current IOMsPlanned
Why VentTools?

Built by a duct fitter, for duct fitters.

The tools are designed around the measurements, decisions and problems that actually come up on site.

REAL SITE EXPERIENCE
Vent ToolsOffset Calculator
V5 Beta

Offset Calculator

Diagram → inputs → cut size

Schematic centreline diagram — rolled offsets are 3D, so check orientation on site.
Fitting style: —
Warns when opposing bend spigots/swages may meet inside the straight.
Known manufacturer bend take-offs are used for supported diameters at 15°, 30°, 45°, 60° and 90°. Other sizes or angles use rm × tan(θ/2) as an estimate.
Cut straight L
—
Roll angle
—
Vent ToolsRect to Round
V5 Beta

Rect to Round Ductulator

Same-area conversion for quick spiral size check

Same-area equivalent, not full equal-friction duct design.
Equivalent round
—
Nearest spiral
—
Rectangular area
—
Standard sizes used: 80, 100, 125, 150, 160, 180, 200, 224, 250, 280, 300, 315, 355, 400, 450, 500, 560, 600, 630, 710, 800, 900, 1000, 1120, 1250 mm.
Vent ToolsFire Damper Openings
Beta

Fire Damper Hole Calculator

Choose the manufacturer, exact product and tested installation method.

Builder's Opening
—
Selected method
—
Damper: —
Rule: —
Reference: —
Guide: —
View official manufacturer manual
Use the result only for the selected manufacturer, product and installation method. Confirm the damper label, supporting construction, permitted aperture range and latest official installation manual before forming the opening.
VentTools V5 Beta • Designed and developed in Northern Ireland
© 2026 VentTools. All rights reserved.
V5 Beta • Built for ductwork installers