Paint Booth Lighting: Key Requirements
Paint booth lighting affects coating quality, visual inspection, workplace safety and operating costs. Lighting design should take into account illuminance, uniformity, colour rendering, ATEX requirements, temperature conditions and maintenance needs.
Illuminance and uniformity
Lighting calculations should be based on the working surfaces, booth geometry and the dimensions of the parts being coated. Vertical illuminance requires particular attention. Lighting should be uniform over the full height of the workpiece and minimise shadows cast by equipment. The required illuminance depends on the process and the requirements for visual inspection.
Colour rendering
The required colour rendering depends on the process. For many industrial painting applications, Ra ≥ 80 is sufficient. Where accurate colour assessment, surface inspection or defect detection is important, luminaires with Ra ≥ 90 are recommended. Colour temperature also affects visual assessment, particularly when checking colour and coating uniformity.
ATEX requirements
Spraying flammable paints, lacquers and solvents can create an explosive atmosphere inside a paint booth.
When liquid coating materials are used, the area may be classified as Zone 1 or Zone 2. In powder coating applications involving combustible powders, the area may be classified as Zone 21 or Zone 22.
Gas and vapour hazardous areas are classified in accordance with EVS-EN IEC 60079-10-1. Areas with explosive dust atmospheres are classified in accordance with EVS-EN 60079-10-2. Luminaires installed in classified areas must comply with the requirements of ATEX Directive 2014/34/EU. IECEx certification may also be required for international projects.
Ventilation directly affects the concentration of solvent vapours, overspray and airborne powder. When assessing Ex zones, the ventilation rate, airflow direction and ventilation operating mode must be taken into account.
The requirements for a luminaire depend on its actual installation location. If the luminaire is installed behind a sealed transparent panel that forms the boundary of the classified area, the Ex classification at the luminaire location may differ from the classification inside the booth.
Operating temperature
Temperatures inside paint booths can rise significantly. Luminaires should therefore be selected according to the maximum actual temperature at the installation point, taking all booth operating modes into account. If this exceeds the permitted Ta rating of a standard industrial luminaire, a high-temperature luminaire is required.
Contamination and maintenance
Overspray and powder build up on luminaire protective surfaces over time, reducing illuminance.
Lighting calculations should include an appropriate maintenance factor based on contamination levels and cleaning intervals. Smooth housings and protective glass make cleaning easier.
When refurbishing an existing booth, the dimensions and mounting openings of the existing luminaires should also be checked. A replacement luminaire with matching dimensions can reduce installation work and avoid modifications to the booth structure.
Safety and operating costs
Operating costs are affected by:
- luminous efficacy;
- installed power;
- service life;
- cleaning and maintenance requirements;
- access to the luminaires;
- luminaire replacement frequency;
- compatibility with the existing booth structure.
In continuous or multi-shift production, switching to LED lighting can significantly reduce energy consumption and maintenance costs.
A common mistake when upgrading paint booth lighting is selecting replacement luminaires without checking their Ex classification, permitted operating temperature, photometric performance and installation dimensions. This can result in insufficient illuminance or luminaires that are unsuitable for the actual operating conditions.
Vitalight provides complete lighting solutions for paint booths and paint lines. We carry out lighting calculations, verify Ex requirements and select industrial and ATEX luminaires suited to the actual operating conditions.