On every booth project for a truck workshop the same question arrives after the design is signed off: did you mean the tractor alone, or the tractor with its trailer? It arrives late because the figure was sent once at the start and never questioned.
Chamber length with trailer is settled by one rule: if you refinish the truck with the trailer attached, the figure that matters is the overall length, not the tractor length.
Why the error happens at all
Tractor length is a known number printed in the vehicle’s papers. Full combination length is not — it changes with the trailer, and a workshop may take several trailer lengths behind the same tractor unit.
So the available figure gets sent rather than the governing one. The result is a chamber that takes the tractor and leaves the trailer past the door, which is the exact problem the booth was bought to solve.
| What is measured | What it sets | Cost of omitting it |
|---|---|---|
| Tractor alone | Nothing in the chamber design | The trailer stays outside |
| Overall length with trailer | Internal length and door length together | Redesign after sign-off |
| Longest combination taken in | The final approved size | One vehicle stays out of service |
Length governs two figures, not one
Internal length is the first, and the delivered range in this family runs from 3,000 to 24,000 mm. The second is the door: a long chamber with a short door keeps the vehicle outside exactly as a short chamber does.
Both are therefore fixed from the same number, and the published main door range reaches 14,200 × 5,000 mm with powered actuation on large builds.
What if the trailers differ
The size is fixed on the longest combination that actually comes in, not on the average. An average gives a chamber that serves most of the work and leaves the highest-value job outside it — the worst thing a number in a specification can do.
- Send the longest combination — tractor plus the longest trailer the workshop receives
- Say whether uncoupling is possible — some workshops refinish trailers separately, which changes the calculation entirely
- Add the approach path — internal length is no use if the route to the chamber will not allow the manoeuvre
Frequently asked questions
Should I refinish the trailer separately to reduce the size?
You can, and it genuinely reduces the length required. But it adds an uncouple-and-recouple step to every vehicle and doubles the cycle count. The decision is purely operational: uncoupling time against the cost of a longer chamber.
What is the longest you deliver?
The delivered range in this family reaches 24,000 mm long, and the final size is set by your vehicle rather than by the top of the range.
Does length affect air capacity?
Yes, because capacity is calculated on chamber volume rather than vehicle type. The published range reaches 190,000 m³/h and 600,000 kcal/h on large builds.
Related reading
- Refrigerated trailer refinishing
- Paint booth door sizing
- Powered booth door
- Tender specification writing
- Air capacity for wood coating
What to do next
Send the overall length of the longest tractor-and-trailer combination you take in, and we will return a chamber and door length built on it. talk to a specialist. Sector detail is on the Trucks & RV sector page.