Project overview
A restaurant kitchen's ovens throw off hot air, steam and fumes all through service, and the extraction has to pull it away cleanly so the kitchen stays comfortable and safe to work in. Whether it does depends heavily on where the extractors sit, and that is hard to judge from a drawing.
In this project we used computational fluid dynamics (CFD) in SolidWorks Flow Simulation to model the kitchen, its ovens and the air moving through it, then ran two extraction layouts: extractors along a wall, and extractors in the roof. The kitchen and the ovens are identical in both cases, so the only thing that changes is where the air is taken out. Animated flow trajectories make the air path visible from the ovens to the extractors.
Objectives
CFD setup
| Setting | Value | Notes |
|---|---|---|
| Tool | SolidWorks Flow Simulation | Airflow and air temperature through the kitchen |
| Domain | The kitchen space | The room with its ovens, openings and extractors |
| Case 1 | Wall extractors | A row of extractors along one wall |
| Case 2 | Roof extractors | Extractors overhead, in the roof |
| Results | Flow trajectories | Animated, coloured by air speed (wall case) and air temperature (roof case) |
Keeping the kitchen and the ovens identical in both runs makes the comparison fair: any difference in how the air moves comes from the extraction layout alone.
Results: wall extractors
With the extractors on the wall, the air has to be pulled sideways across the kitchen to reach them. The animation follows it from one side of the room, past the ovens, to the extractors on the far wall.
Results: roof extractors
With the extractors overhead, they sit above the ovens, in the path of the hot air rising off them. This run is coloured by air temperature, so it shows where the warm air goes as well as how the air moves.
The air turns over in broad loops through the whole kitchen, and most of it stays near the cool end of the temperature scale, with the warmer air close to the ovens. Because hot air rises on its own, an overhead extractor collects it where it is already heading, working with buoyancy rather than against it.
Comparing the two layouts
| Layout | Position | Path of the air |
|---|---|---|
| Wall extractors | Along one wall | Pulled sideways across the kitchen, past the ovens, to the far wall |
| Roof extractors | Overhead, in the roof | Drawn upward, with the hot air rising off the ovens |
Set side by side, the two animations show what decides the choice for this kitchen: which layout clears the air off the ovens more directly, how much of it moves through the room before it is caught, and where it circles or stalls. That is the evidence needed to choose between wall and roof extraction, and to place and size the extractors with confidence.
Conclusion
The CFD turns a ventilation question into something you can see. By modelling the kitchen and its ovens and animating the airflow for both a wall and a roof layout, the study shows how the air actually moves and how each layout handles it, before anything is installed or changed on site. For a busy commercial kitchen, that means a cleaner, safer and more comfortable space, with extraction chosen on evidence. We have applied the same approach to an office container and to the natural ventilation of a warehouse.
Frequently asked questions
Why use CFD to design kitchen extraction?
Because airflow cannot be seen. CFD shows where the hot air from the ovens goes, whether the extractors capture it and where it circles or stalls, so the layout can be fixed on screen instead of on site.
Is a roof extractor or a wall extractor better for a kitchen?
It depends on the kitchen. Hot air rises, so extraction overhead works with buoyancy and collects the air where it is already heading, but the positions of the ovens, the openings and the supply air all change the picture. That is why we model both layouts in the actual kitchen and compare them.
What do the flow trajectories show?
The paths the air takes through the kitchen, coloured by air speed or temperature. Animated, they show the direction of the air from the ovens to the extractors, and where it loops or slows down.
Which software was used?
SolidWorks Flow Simulation, for the airflow and air temperature in the kitchen, with the same room and ovens in both the wall and the roof extraction cases.
