Paint Booths
A paint booth is not a room but a process machine in which airflow is managed. Its job is to do three things at once: draw paint mist away from the operator, prevent dust from settling on the fresh film, and hold a steady air velocity throughout application.
How the process works
Clean air enters the booth through the ceiling filter plenum, descends over the part and is drawn out through the floor grating. This vertical flow removes paint mist from beneath the part rather than around it. Air velocity is a critical balance: too low and the mist is not extracted, increasing operator exposure; too high and atomised paint is carried away from the part, lowering transfer efficiency.
Captured paint is separated in one of three ways, depending on booth type. Water curtain booths wash the air with a film of water; this is the most common solution for high-throughput applications but adds a water treatment load. Venturi systems accelerate the air through a narrowing section; the resulting turbulence binds particles to the water, giving higher separation efficiency. Dry filter booths use staged cardboard and fibre filters; no water infrastructure is needed and they suit low and medium throughput applications.
Criteria that determine the configuration
Choosing the booth type
Where daily paint consumption is high, a water curtain or venturi booth is favoured on operating cost; where it is low, a dry filter booth comes out ahead. With dry filters, the frequency of filter changes and the cost of waste disposal must be taken into account.
Air velocity
General practice works in the 0.25–0.45 m/s range. As quality expectations rise and metallic paints are used, the uniformity of the flow becomes more decisive than its velocity.
Pressure balance
The booth is held at slight positive pressure relative to its surroundings so that dust cannot enter. Supply and exhaust flows are calculated together to maintain this balance.
Electrostatic application
It raises transfer efficiency markedly and lowers paint consumption. The part must, however, be earthable and its geometry must not create a Faraday cage effect.
From the field: when is workmanship considered “good”?
A paint booth conforming to specification is not enough on its own; what really determines coating quality is how the booth is manufactured and installed. In the short video below we explain the criteria by which workmanship is judged in a wet paint plant.
When is workmanship in a paint shop really considered “good”?
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Technical framework
| Air velocity | 0,25–0,45 m/s |
|---|---|
| Filtration | 3-stage |
| Booth types | Water curtain · venturi · dry filter |
| Application | Manual · automatic · electrostatic |
| Pressure regime | Slightly positive relative to surroundings |
| Compliance | EN 12215 · ATEX 2014/34/EU |
The figures are typical operating ranges for the sector. Every line is recalculated according to part geometry, target capacity, paint system and customer specification.
Frequently overlooked points in design
- Where the supply air comes from: As much clean air must enter the building as is extracted from the booth. If this is not planned, doors around the booth become hard to open and winter heating costs rise unexpectedly.
- Access for filter changes: Without safe access to the ceiling filter, changes get postponed and the airflow deteriorates. The access plan is part of the booth design.
- ATEX zone boundary: Lighting, motors and sockets inside the booth must match the zone classification; changing them later is expensive.
Related topics
- Industrial Ovens — drying and curing
- Work Booths — touch-up and final inspection
- Automated Painting Robots
- Ventilation and Air Conditioning
Let’s arrange a preliminary technical discussion for a paint booth. Share your part dimensions, target capacity and paint system, and our process engineer will prepare an outline concept and budget range.