EOLIOS used CFD simulation to model an industrial process for treating Volatile Organic Compounds (VOCs) : scalar-variable dispersion, capture and scrubbing efficiency, in order to improve treatment performance and reduce emissions.
The Jean Chéreau plant manufactures refrigerated vehicles and is located in Ducey-Les-Chéris, Normandy. Opened in 1981, it is fitted with a ventilation system improved over time but still based on an old design. At various points along the production line, several potentially harmful pollutants (gelcoat, resin) are released into the air in excessive quantities. The main objective : improve the efficiency of the existing ventilation system while respecting the plant's constraints.
EOLIOS brought its expertise in understanding and modelling airflow movements, in order to analyse the issues identified and propose suitable solutions to correct them.
The significant pollutant emissions occur during gelcoat and resin spraying, as well as during the manufacture of the truck skins — operations located in halls 2 and 3, which were selected for the study.
The system has distinct supply and extract zones for each hall. In hall 2, fresh air is delivered by two nozzle ducts (also active during gelcoat curing); extraction is via vents and intake grilles beneath the workstations and on the mezzanine, supplemented by mobile hoods. Hall 3 has two supply points, one of them adjustable above the spraying stations, plus extract ducts beneath the mezzanine (with some efficiency limitations), wall grilles and mobile hoods.
During the airflow audit of the site, the engineers carried out detailed measurements, a 3D model of the plant and smoke tests for a complete assessment, also recording the outdoor weather conditions to ensure accurate simulations.
The results show that the overall air movement is mainly driven by the supply jets. In hall 2, the air converges towards the spraying stations, creating disturbances and a rise of air under the roof that hampers extraction. In hall 3, a looping circulation was identified, with the flow splitting into two parts; extraction is good near the stations but limited by obstructions. The closed-doors simulation — run with theoretical flow rates and on-site measurements — shows a strong match with the readings: air flows from the rear of the halls (East) towards the West, with high VOC concentrations in the West of hall 2 and the East of hall 3, due to inadequate ventilation.
VOCs are organic molecules that evaporate easily at room temperature. Present in paints, glues, cleaning products and materials, they are a source of indoor pollution with potentially harmful consequences for health and the environment. EOLIOS uses CFD to model their dispersion, analyse air movements and predict concentrations in each zone, ensuring optimised ventilation and extraction.
Prolonged exposure can cause irritation, headaches, allergic reactions, and even damage to the liver, kidneys and nervous system; some VOCs are classified as carcinogenic. The key to minimising exposure lies in effective extraction and good ventilation, keeping concentrations below dangerous thresholds.
EOLIOS places compliance with standards at the heart of its approach. For this study, particular attention was paid to ventilation best-practice guides — ED 839 and ED 906 — as well as the French Labour Code, ensuring solutions that compromise neither the safety of people nor that of the equipment. This rigour minimises risk and optimises the working environment to the highest standards.
Two designs were proposed. The first introduces partitioning around the emission zones, uniform low-velocity supply via textile ducts and adjustments to the extract points, to keep VOCs below 25% of the OEL (with PPE in the confined zones). The OEL (Occupational Exposure Limit) sets the maximum concentration of a substance to which a worker may be exposed. Flow rates were tuned to control circulation and reduce the concentration at operator face level.
The second configuration introduces extract ducts beneath the resin and gelcoat tables, removing the cumbersome side extractions and making extraction more efficient. The supply ducts are repositioned for a downward vertical sweep, eliminating unwanted upward movements, homogenising velocities and reducing VOC dispersion at breathing height — preventing build-up between tables and partitions.
Listening, compromise and dialogue between engineers and workers were central to the approach. Regular visits at each stage made it possible to integrate every perspective, and to bring out solutions that were not only aerodynamically optimal but also practical for the workers — a participatory approach resulting in a solution that is safe, efficient and aligned with stakeholders' needs.
Expertise: smoke-test audit, VOCs & industrial air qualityThe study aims to improve air quality at the Jean Chéreau plant by optimising its ventilation system. Measurements and simulations identified the zones with high pollutant concentrations and led to two configurations for better air distribution and lower VOC levels. The collaborative approach integrated the workers' needs while respecting safety standards — for efficient, compliant pollutant extraction.
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