What it does
Duct Pressure reads a duct system from your model — ducts, flex ducts, fittings and accessories — and calculates the pressure loss of each element using industry-standard fitting data. It then finds the critical path through the system and lists those elements in order with a running total, so you can see at a glance where the losses are and what the fan needs to overcome.
It's built for mechanical and services designers who want a quick, repeatable pressure check as the design develops, using the flows and sizes already in the Revit model rather than a separate hand calculation.
Highlights
- Calculates pressure loss straight from the modelled ducts, flows and sizes.
- Finds the critical path automatically and shows the cumulative loss along it.
- Covers straight duct, flexible duct, fittings and accessories in one pass.
- Recognises your fitting families automatically, with easy correction where needed.
- Fitting assignments are remembered, so the next run is faster.
- Flags anything that needs a second look, so nothing slips through unnoticed.
- Select the elements behind any result straight from the list.
- Export the results to Excel for design reports and records.
- Write results back to parameters on the elements for schedules and tags.
- Always reports in metric — mm, m, L/s and Pa — whatever the project units.
Before you start
- Revit 2024, 2025, 2026 or 2027.
- An active AECOtools seat or trial — Duct Pressure is included with a seat.
- Open the model with the duct system you want to check.
- Ducts and fittings should belong to a Revit duct system and be properly connected.
- Air terminals need their flows set, so the system carries airflow.
Quick start
- Optionally select a duct, fitting or air terminal in the system you want to check.
- Go to MEP Tools ▸ MEP+ and click Duct Pressure.
- If nothing was selected, pick a system from the list and click Open.
- Review the results. Where a fitting has been recognised as the wrong type, highlight it and click Map/Remap Selected — the results update straight away.
- Click Export Excel and/or Push Parameters to keep the results, then Close.
Tips
Results are a design aid only. They depend on the flows, sizes and fittings in the model, and must be checked by the responsible mechanical engineer.
The first time you run it on a project, take a minute to check how each fitting family has been recognised. Once they're right, every later run benefits.
Tidy up open ends and unconnected fittings before you run it — a well-connected system gives the clearest critical path.
Need more detail?
The complete Duct Pressure guide — every option, the results, and troubleshooting — is built into AECOtools. Open the tool and click the ? button in its window.
- Stuck? In Revit, use AECOtools ▸ Support ▸ Report Issue to send us the details.
- Not using AECOtools yet? Start a 30-day free trial.
- Questions: get in touch.