Describe the route before the parts
Start with a dimensioned sketch showing the cupboard connection, fan and final discharge. Mark walls, ceilings and other services that constrain the route. Identify which dimensions have been checked on site and which remain provisional.
The chemical-resistant ducting guide covers material and application questions. For fittings, add enough detail to show how each connection meets the next component.
Create a fitting schedule
| Part | Details to show |
|---|---|
| Bend | Diameter, direction, angle and available space. |
| Transition | Both end sizes, shape, length and alignment. |
| Branch | Main and branch dimensions, orientation and connected duty. |
| Equipment connection | Manufacturer’s connection dimensions and joint arrangement. |
| Fabricated item | Drawing, material requirement and access constraints. |
Use one reference number for each part on the drawing and schedule. This makes revisions easier to follow during quotation and installation.
Keep airflow in the conversation
A fitting occupies space and contributes to system resistance. Changes made to avoid a beam or pipe can therefore affect more than the parts list. Have the responsible designer review the final route and the conditions near the fan.
Our pressure-drop guide explains how the components fit into the resistance schedule. Use it alongside the fan selection guide when equipment and ducting are being specified together.
Confirm the practical details
- Identify the substances and operating conditions the duct will encounter.
- Show supports, access and the installation sequence on the project drawings.
- Confirm joint details and interfaces with equipment suppliers.
- Record site measurements before releasing fabricated dimensions.
- Keep changes traceable to an approved drawing revision.
For replacement components, a photograph helps explain the arrangement, but include measured dimensions and the existing equipment identification as well.
Where the specification is still being developed, compare rigid routes and flexible connections or review PVC and polypropylene against the application. If moisture has appeared on an existing route, collect the observations in our duct condensation guide before requesting replacement parts.