Ventilation & HVAC

Ventilation and ductwork, sized as you draw.

Lay ductwork out in plan, connect terminals and plant, and let the solver size the runs and report the index run. The network you drew is the network that gets calculated — there is no second model and no spreadsheet to keep in step.

What you draw

Ductwork, terminals and plant as real objects.

Every element is typed and parameterised, so it can be sized, scheduled and counted rather than simply drawn.

Ductwork in plan

Rectangular and circular runs drawn with object snaps, dynamic input and AutoCAD-style coordinate entry, carrying size, system and elevation.

Terminals and plant

Diffusers, grilles, fans and air-handling units placed as typed objects with their own parameters and connection points.

Fire dampers

Fire partitions create dampers automatically where services cross them.

Flexible connections

Duct connectors are reconciled automatically against the run that owns them, so a boot never drifts from its terminal.

How it is sized

Automatic sizing against a pressure gradient.

Sizing runs on the connected network, using first-principles hydraulics.

  • Automatic duct sizing — the solver iterates duct size along a run until the pressure gradient meets the target you set.
  • Darcy–Weisbach — pressure drop with Colebrook–White friction factors, across both laminar and turbulent flow.
  • Fitting losses — tee, bend and terminal losses are accounted for in the run.
  • Index run — the critical route reported end to end, with pressure drop accumulated along it.
  • System pressure analysis — total system resistance, so fan selection is based on the model.
  • Heat map — colour paths and terminals by pressure drop to see at a glance where a system is struggling.
Darcy–WeisbachColebrook–White

What comes out

Plant-down calculation, then the paperwork.

Ventilation Manager

A plant-down calculation across a whole system, seeded from any path, including merged multi-seed networks.

Schedules

Duct and ventilation schedules generated from the model, plus a wizard for schedules of your own design.

Quantities

Duct lengths by size and terminal counts by type, aggregated per level and per system.

Drawings

Paper-space layouts and title blocks, exported to PDF, DXF or DWG in batches by view state.

See it on your own project.

engiCAD is in active development and we are onboarding a small number of practices. Tell us what you work on and we will arrange a walkthrough against a drawing you recognise.