VentScan vs clash detection
Clash detection finds where geometry collides in a federated 3D model — a duct running through a beam, a damper inside a wall. VentScan does not check geometry. It reconciles HVAC sources across revisions, recalculates the engineering consequences of each change, and seals the result in a Proof Pack. They answer different questions, so most teams use both.
| Dimension | Clash detection | VentScan |
|---|---|---|
| Question answered | Do two elements occupy the same space? | Do the sources agree, and what changed when a revision landed? |
| Primary input | Federated 3D geometry across disciplines. | HVAC sources (IFC, schedules) across revisions. |
| Output | A list of geometric collisions to resolve. | Reconciled entities, recalculated consequences, a Proof Pack. |
| Engineering numbers | Not calculated — geometry only. | Cooling load and capacity margin, recalculated deterministically. |
| Change over time | Re-run per model version; no decision trail. | Reconciles revisions and records who decided what, and why. |
| Evidence | Viewpoint screenshots of the clash. | Source, consequence and evidence linked in an append-only pack. |
01What clash detection does
Clash detection coordinates geometry. It loads models from several disciplines into one federated view and reports where elements intersect or sit too close. The job is spatial coordination: a soft clash near a clearance zone, a hard clash through structure. It is essential for making a building physically buildable.
It works on shapes, not on the engineering behind them. A duct that fits perfectly can still be undersized for its load; clash detection has no opinion on that, because capacity is not a geometric property.
02What VentScan does
VentScan reconciles the HVAC sources that describe the same project — the IFC model, equipment schedules, room data — and flags where they disagree. When a new revision arrives, it matches entities across versions and recalculates the consequences that depend on them, such as cooling load and capacity margin, from written specifications.
Every result carries its units and maturity, and every decision is sealed into a Proof Pack: the source values, the recalculation, and the engineer's approval, append-only. The current cooling-load calculation is an estimate pending engineer review, and it is labelled as such.
03Why teams use both
The two tools sit at different stages of the same workflow. Clash detection keeps the model physically coordinated; VentScan keeps the HVAC numbers consistent with the sources and proves the decisions behind them. Resolving a clash often moves equipment or changes a duct route — and that change is exactly the kind of thing VentScan recalculates the consequences of.
When to use clash detection
If your problem is spatial — geometry passing through geometry, clearances, constructability across disciplines — clash detection is the right tool, and VentScan does not replace it.
Reach for VentScan when the question is whether the HVAC sources agree, what a revision changed, and whether the capacity still holds — and when you need that decision recorded so it stands up later.